WO2025058733A1

WO2025058733A1 - Joint uu and sidelink reference signal time difference (rstd) measurement for joint uu and sidelink positioning

Info

Publication number: WO2025058733A1
Application number: PCT/US2024/040283
Authority: WO
Inventors: Alexandros MANOLAKOS; Mukesh Kumar
Original assignee: Qualcomm Incorporated
Priority date: 2023-09-14
Filing date: 2024-07-31
Publication date: 2025-03-20
Also published as: WO2025058733A4; TW202512784A

Abstract

Disclosed are techniques for wireless communication. In an aspect, a user equipment (UE) obtains at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both, and determines the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

Description

JOINT UU AND SIDELINK REFERENCE SIGNAL TIME DIFFERENCE (RSTD) MEASUREMENT FOR JOINT UU AND SIDELINK POSITIONING

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

[0001] Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

[0002] Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks), a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). There are presently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular analog advanced mobile phone system (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), the Global System for Mobile communications (GSM), etc.

[0003] A fifth generation (5G) wireless standard, referred to as New Radio (NR), enables higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The 5G standard, according to the Next Generation Mobile Networks Alliance, is designed to provide higher data rates as compared to previous standards, more accurate positioning (e.g., based on reference signals for positioning (RS-P), such as downlink, uplink, or sidelink positioning reference signals (PRS)) and other technical enhancements.

[0004] Leveraging the increased data rates and decreased latency of 5G, among other things, vehicle-to-everything (V2X) communication technologies are being implemented to support autonomous driving applications, such as wireless communications between vehicles, between vehicles and the roadside infrastructure, between vehicles and pedestrians, etc. SUMMARY

[0005] The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.

[0006] In an aspect, a method of wireless communication performed by a user equipment (UE) includes obtaining at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determining the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0007] In an aspect, a method of wireless communication performed by a user equipment (UE) includes obtaining a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determining the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determining the one or more SL- RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL- PRS) resources transmitted by one or more first sidelink anchor UEs.

[0008] In an aspect, a user equipment (UE) includes one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: obtain at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determine the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs. [0009] In an aspect, a user equipment (UE) includes one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: obtain a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determine the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determine the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs. [0010] In an aspect, a user equipment (UE) includes means for obtaining at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and means for determining the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs. [0011] In an aspect, a user equipment (UE) includes means for obtaining a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; means for determining the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmissionreception points (TRPs); and means for determining the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0012] In an aspect, a non-transitory computer-readable medium stores computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: obtain at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determine the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0013] In an aspect, a non-transitory computer-readable medium stores computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: obtain a single reference node for one or more downlink reference signal time difference (DL- RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determine the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determine the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs. [0014] Other obj ects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are presented to aid in the description of various aspects of the disclosure and are provided solely for illustration of the aspects and not limitation thereof.

[0016] FIG. 1 illustrates an example wireless communications system, according to aspects of the disclosure.

[0017] FIGS. 2A, 2B, and 2C illustrate example wireless network structures, according to aspects of the disclosure.

[0018] FIGS. 3A, 3B, and 3C are simplified block diagrams of several sample aspects of components that may be employed in a user equipment (UE), a base station, and a network entity, respectively, and configured to support communications as taught herein.

[0019] FIG. 4 illustrates examples of various positioning methods supported in New Radio (NR), according to aspects of the disclosure.

[0020] FIGS. 5 A and 5B illustrate various scenarios of interest for sidelink-only or joint Uu and sidelink positioning, according to aspects of the disclosure.

[0021] FIG. 6 is a diagram illustrating an example downlink positioning reference signal (DL- PRS) configuration for two transmission-reception points (TRPs) operating in the same positioning frequency layer, according to aspects of the disclosure.

[0022] FIG. 7 illustrates an example Long-Term Evolution (LTE) positioning protocol (LPP) capability transfer procedure, assistance data transfer procedure, and location information transfer procedure between a target device and a location server, according to aspects of the disclosure.

[0023] FIG. 8 is a diagram illustrating an example joint time difference of arrival (TDOA) positioning method, according to aspects of the disclosure.

[0024] FIG. 9 illustrates an example method of wireless communication, according to aspects of the disclosure.

[0025] FIG. 10 illustrates different example priority rules for measuring sidelink positioning reference signal (SL-PRS) resources, according to aspects of the disclosure. [0026] FIGS. 11 and 12 illustrate example methods of wireless communication, according to aspects of the disclosure.

DETAILED DESCRIPTION

[0027] Aspects of the disclosure are provided in the following description and related drawings directed to various examples provided for illustration purposes. Alternate aspects may be devised without departing from the scope of the disclosure. Additionally, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.

[0028] Various aspects relate generally to wireless positioning. Some aspects more specifically relate to obtaining joint downlink and sidelink positioning measurements. In some examples, a location server may select a common reference cell for a sidelink user equipment (UE) and a transmission-reception point (TRP), may select independent reference cells for the sidelink UE and TRP, or may select both. In some examples, if a target UE is aware of sidelink anchor UEs, it may select a reference sidelink anchor UE. The selection may be based on timing error group, synchronization priority, or both. The reference sidelink anchor UE may be selected at each or every N occasions, every T msec, or both. The location server and/or a base station may help the target UE with selecting a reference for the remainder of a positioning session.

[0029] In some examples, the location server and a UE may exchange signaling for measurements between sidelink anchor UE and TRP positioning reference signals (PRS). The location server may provide assistance data for sidelink anchor and downlink PRS resources and may indicate pairs of resources with an identifier. A UE may report measurements with the identifier provided in the assistance data. In some examples, the location server may indicate a minimum number of measurements to be reported by a UE across sidelink and uplink measurements, and the UE may select sidelink and uplink resources. In some examples, the location server may indicate different priority rules for Uu and sidelink, common priority rules for Uu and sidelink, or a combination of both. For example, a UE may measure all TRP PRS resources first then sidelink UE resources. In another example, a UE may measure the highest priority TRP PRS resources then the highest priority SL UE resources. [0030] In some examples, a UE may receive or report at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both. The UE may then obtain the one or more joint downlink and sidelink RSTD measurements of one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first TRPs or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0031] In some examples, a UE may determine a single reference node for one or more DL- RSTD measurements and one or more SL-RSTD measurements. The UE may then obtain the one or more DL-RSTD measurements of one or more reference signal resources transmitted by the single reference node and one or more first DL-PRS resources transmitted by one or more first TRPs. The UE may also obtain the one or more SL- RSTD measurements of the one or more reference signal resources transmitted by the single reference node and one or more first SL-PRS resources transmitted by one or more first sidelink anchor UEs.

[0032] Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some examples, by determining the at least one reference node for one or more joint downlink and sidelink RSTD measurements, the described techniques can be used to enable the UE to select an appropriate reference node for the joint RSTD measurements.

[0033] The words “exemplary” and/or “example” are used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” and/or “example” is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term “aspects of the disclosure” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.

[0034] Those of skill in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description below may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, in part on the desired design, in part on the corresponding technology, etc.

[0035] Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequence(s) of actions described herein can be considered to be embodied entirely within any form of non- transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, upon execution, would cause or instruct an associated processor of a device to perform the functionality described herein. Thus, the various aspects of the disclosure may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspects may be described herein as, for example, “logic configured to” perform the described action.

[0036] As used herein, the terms “user equipment” (UE), “vehicle UE” (V-UE), “pedestrian UE” (P-UE), and “base station” are not intended to be specific or otherwise limited to any particular radio access technology (RAT), unless otherwise noted. In general, a UE may be any wireless communication device (e.g., vehicle on-board computer, vehicle navigation device, mobile phone, router, tablet computer, laptop computer, asset locating device, wearable (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (loT) device, etc.) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN). As used herein, the term “UE” may be referred to interchangeably as a “mobile device,” an “access terminal” or “AT,” a “client device,” a “wireless device,” a “subscriber device,” a “subscriber terminal,” a “subscriber station,” a “user terminal” or UT, a “mobile terminal,” a “mobile station,” or variations thereof.

[0037] A V-UE is a type of UE and may be any in-vehicle wireless communication device, such as a navigation system, a warning system, a heads-up display (HUD), an on-board computer, an in-vehicle infotainment system, an automated driving system (ADS), an advanced driver assistance system (ADAS), etc. Alternatively, a V-UE may be a portable wireless communication device (e.g., a cell phone, tablet computer, etc.) that is carried by the driver of the vehicle or a passenger in the vehicle. The term “V-UE” may refer to the in-vehicle wireless communication device or the vehicle itself, depending on the context. A P-UE is a type of UE and may be a portable wireless communication device that is carried by a pedestrian (i.e., a user that is not driving or riding in a vehicle). Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc.) and so on.

[0038] A base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and may be alternatively referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), a New Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A base station may be used primarily to support wireless access by UEs including supporting data, voice and/or signaling connections for the supported UEs. In some systems a base station may provide purely edge node signaling functions while in other systems it may provide additional control and/or network management functions. A communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which the base station can send signals to UEs is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein the term traffic channel (TCH) can refer to either an UL / reverse or DL / forward traffic channel.

[0039] The term “base station” may refer to a single physical transmission-reception point (TRP) or to multiple physical TRPs that may or may not be co-located. For example, where the term “base station” refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to a cell (or several cell sectors) of the base station. Where the term “base station” refers to multiple co-located physical TRPs, the physical TRPs may be an array of antennas (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming) of the base station. Where the term “base station” refers to multiple non-co-located physical TRPs, the physical TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical TRPs may be the serving base station receiving the measurement report from the UE and a neighbor base station whose reference radio frequency (RF) signals the UE is measuring. Because a TRP is the point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station are to be understood as referring to a particular TRP of the base station.

[0040] In some implementations that support positioning of UEs, a base station may not support wireless access by UEs (e.g., may not support data, voice, and/or signaling connections for UEs), but may instead transmit reference RF signals to UEs to be measured by the UEs and/or may receive and measure signals transmitted by the UEs. Such base stations may be referred to as positioning beacons (e.g., when transmitting RF signals to UEs) and/or as location measurement units (e.g., when receiving and measuring RF signals from UEs).

[0041] An “RF signal” comprises an electromagnetic wave of a given frequency that transports information through the space between a transmitter and a receiver. As used herein, a transmitter may transmit a single “RF signal” or multiple “RF signals” to a receiver. However, the receiver may receive multiple “RF signals” corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multipath channels. The same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a “multipath” RF signal. As used herein, an RF signal may also be referred to as a “wireless signal” or simply a “signal” where it is clear from the context that the term “signal” refers to a wireless signal or an RF signal.

[0042] FIG. 1 illustrates an example wireless communications system 100, according to aspects of the disclosure. The wireless communications system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labelled “BS”) and various UEs 104. The base stations 102 may include macro cell base stations (high power cellular base stations) and/or small cell base stations (low power cellular base stations). In an aspect, the macro cell base stations 102 may include eNBs and/or ng-eNBs where the wireless communications system 100 corresponds to an LTE network, or gNBs where the wireless communications system 100 corresponds to a NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

[0043] The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or 5G core (5GC)) through backhaul links 122, and through the core network 170 to one or more location servers 172 (e.g., a location management function (LMF) or a secure user plane location (SUPL) location platform (SLP)). The location server(s) 172 may be part of core network 170 or may be external to core network 170. A location server 172 may be integrated with a base station 102. A UE 104 may communicate with a location server 172 directly or indirectly. For example, a UE 104 may communicate with a location server 172 via the base station 102 that is currently serving that UE 104. A UE 104 may also communicate with a location server 172 through another path, such as via an application server (not shown), via another network, such as via a wireless local area network (WLAN) access point (AP) (e.g., AP 150 described below), and so on. For signaling purposes, communication between a UE 104 and a location server 172 may be represented as an indirect connection (e.g., through the core network 170, etc.) or a direct connection (e.g., as shown via direct connection 128), with the intervening nodes (if any) omitted from a signaling diagram for clarity.

[0044] In addition to other functions, the base stations 102 may perform functions that relate to one or more of transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC / 5GC) over backhaul links 134, which may be wired or wireless.

[0045] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported by a base station 102 in each geographic coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, or the like), and may be associated with an identifier (e.g., a physical cell identifier (PCI), an enhanced cell identifier (ECI), a virtual cell identifier (VCI), a cell global identifier (CGI), etc.) for distinguishing cells operating via the same or a different carrier frequency. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband loT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. Because a cell is supported by a specific base station, the term “cell” may refer to either or both the logical communication entity and the base station that supports it, depending on the context. In some cases, the term “cell” may also refer to a geographic coverage area of a base station (e.g., a sector), insofar as a carrier frequency can be detected and used for communication within some portion of geographic coverage areas 110.

[0046] While neighboring macro cell base station 102 geographic coverage areas 110 may partially overlap (e.g., in a handover region), some of the geographic coverage areas 110 may be substantially overlapped by a larger geographic coverage area 110. For example, a small cell base station 102' (labelled “SC” for “small cell”) may have a geographic coverage area 110' that substantially overlaps with the geographic coverage area 110 of one or more macro cell base stations 102. A network that includes both small cell and macro cell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG).

[0047] The communication links 120 between the base stations 102 and the UEs 104 may include uplink (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links 120 may be through one or more carrier frequencies. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or less carriers may be allocated for downlink than for uplink). [0048] The wireless communications system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available.

[0049] The small cell base station 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102' may employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. The small cell base station 102', employing LTE / 5G in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. NR in unlicensed spectrum may be referred to as NR-U. LTE in an unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA), or MULTEFIRE®.

[0050] The wireless communications system 100 may further include a mmW base station 180 that may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with a UE 182. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and/or receive) over a mmW communication link 184 to compensate for the extremely high path loss and short range. Further, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed to limit the various aspects disclosed herein.

[0051] Transmit beamforming is a technique for focusing an RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omni-directionally). With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal for the receiving device(s). To change the directionality of the RF signal when transmitting, a network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, a network node may use an array of antennas (referred to as a “phased array” or an “antenna array”) that creates a beam of RF waves that can be “steered” to point in different directions, without actually moving the antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while cancelling to suppress radiation in undesired directions.

[0052] Transmit beams may be quasi-co-located, meaning that they appear to the receiver (e.g., a UE) as having the same parameters, regardless of whether or not the transmitting antennas of the network node themselves are physically co-located. In NR, there are four types of quasi -co-1 ocati on (QCL) relations. Specifically, a QCL relation of a given type means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate the spatial receive parameter of a second reference RF signal transmitted on the same channel.

[0053] In receive beamforming, the receiver uses a receive beam to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and/or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., to increase the gain level of) the RF signals received from that direction. Thus, when a receiver is said to beamform in a certain direction, it means the beam gain in that direction is high relative to the beam gain along other directions, or the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal -to- interference-plus-noise ratio (SINR), etc.) of the RF signals received from that direction. [0054] Transmit and receive beams may be spatially related. A spatial relation means that parameters for a second beam (e.g., a transmit or receive beam) for a second reference signal can be derived from information about a first beam (e.g., a receive beam or a transmit beam) for a first reference signal. For example, a UE may use a particular receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam for sending an uplink reference signal (e.g., sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0055] Note that a “downlink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. If the UE is forming the downlink beam, however, it is a receive beam to receive the downlink reference signal. Similarly, an “uplink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the uplink beam, it is an uplink receive beam, and if a UE is forming the uplink beam, it is an uplink transmit beam.

[0056] The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency range designations FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is identified by the INTERNATIONAL TELECOMMUNICATION UNION® as a “millimeter wave” band.

[0057] The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz - 24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz - 71 GHz), FR4 (52.6 GHz - 114.25 GHz), and FR5 (114.25 GHz - 300 GHz). Each of these higher frequency bands falls within the EHF band.

[0058] With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band.

[0059] In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by a UE 104/182 and the cell in which the UE 104/182 either performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels, and may be a carrier in a licensed frequency (however, this is not always the case). A secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once the RRC connection is established between the UE 104 and the anchor carrier and that may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, for example, those that are UE-specific may not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104/182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carriers. The network is able to change the primary carrier of any UE 104/182 at any time. This is done, for example, to balance the load on different carriers. Because a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency / component carrier over which some base station is communicating, the term “cell,” “serving cell,” “component carrier,” “carrier frequency,” and the like can be used interchangeably.

[0060] For example, still referring to FIG. 1, one of the frequencies utilized by the macro cell base stations 102 may be an anchor carrier (or “PCell”) and other frequencies utilized by the macro cell base stations 102 and/or the mmW base station 180 may be secondary carriers (“SCells”). The simultaneous transmission and/or reception of multiple carriers enables the UE 104/182 to significantly increase its data transmission and/or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz), compared to that attained by a single 20 MHz carrier.

[0061] In the example of FIG. 1, any of the illustrated UEs (shown in FIG. 1 as a single UE 104 for simplicity) may receive signals 124 from one or more Earth orbiting space vehicles (SVs) 112 (e.g., satellites). In an aspect, the S Vs 112 may be part of a satellite positioning system that aUE 104 can use as an independent source of location information. A satellite positioning system typically includes a system of transmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) to determine their location on or above the Earth based, at least in part, on positioning signals (e.g., signals 124) received from the transmitters. Such a transmitter typically transmits a signal marked with a repeating pseudo-random noise (PN) code of a set number of chips. While typically located in SVs 112, transmitters may sometimes be located on ground-based control stations, base stations 102, and/or other UEs 104. A UE 104 may include one or more dedicated receivers specifically designed to receive signals 124 for deriving geo location information from the SVs 112.

[0062] In a satellite positioning system, the use of signals 124 can be augmented by various satellite-based augmentation systems (SBAS) that may be associated with or otherwise enabled for use with one or more global and/or regional navigation satellite systems. For example an SBAS may include an augmentation system(s) that provides integrity information, differential corrections, etc., such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multifunctional Satellite Augmentation System (MSAS), the Global Positioning System (GPS) Aided Geo Augmented Navigation or GPS and Geo Augmented Navigation system (GAGAN), and/or the like. Thus, as used herein, a satellite positioning system may include any combination of one or more global and/or regional navigation satellites associated with such one or more satellite positioning systems.

[0063] In an aspect, SVs 112 may additionally or alternatively be part of one or more nonterrestrial networks (NTNs). In an NTN, an SV 112 is connected to an earth station (also referred to as a ground station, NTN gateway, or gateway), which in turn is connected to an element in a 5G network, such as a modified base station 102 (without a terrestrial antenna) or a network node in a 5GC. This element would in turn provide access to other elements in the 5G network and ultimately to entities external to the 5G network, such as Internet web servers and other user devices. In that way, a UE 104 may receive communication signals (e.g., signals 124) from an SV 112 instead of, or in addition to, communication signals from a terrestrial base station 102.

[0064] Leveraging the increased data rates and decreased latency of NR, among other things, vehicle-to-everything (V2X) communication technologies are being implemented to support intelligent transportation systems (ITS) applications, such as wireless communications between vehicles (vehi cl e-to- vehicle (V2V)), between vehicles and the roadside infrastructure (vehicle-to-infrastructure (V2I)), and between vehicles and pedestrians (vehicle-to-pedestrian (V2P)). The goal is for vehicles to be able to sense the environment around them and communicate that information to other vehicles, infrastructure, and personal mobile devices. Such vehicle communication will enable safety, mobility, and environmental advancements that current technologies are unable to provide. Once fully implemented, the technology is expected to reduce unimpaired vehicle crashes by 80%.

[0065] Still referring to FIG. 1, the wireless communications system 100 may include multiple V-UEs 160 that may communicate with base stations 102 over communication links 120 using the Uu interface (i.e., the air interface between a UE and a base station). V-UEs 160 may also communicate directly with each other over a wireless sidelink 162, with a roadside unit (RSU) 164 (a roadside access point) over a wireless sidelink 166, or with sidelink-capable UEs 104 over a wireless sidelink 168 using the PC5 interface (i.e., the air interface between sidelink-capable UEs). A wireless sidelink (or just “sidelink”) is an adaptation of the core cellular (e.g., LTE, NR) standard that allows direct communication between two or more UEs without the communication needing to go through a base station. Sidelink communication may be unicast or multicast, and may be used for device- to-device (D2D) media-sharing, V2V communication, V2X communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, etc. One or more of a group of V-UEs 160 utilizing sidelink communications may be within the geographic coverage area 110 of a base station 102. Other V-UEs 160 in such a group may be outside the geographic coverage area 110 of a base station 102 or be otherwise unable to receive transmissions from a base station 102. In some cases, groups of V-UEs 160 communicating via sidelink communications may utilize a one-to-many (1:M) system in which each V-UE 160 transmits to every other V- UE 160 in the group. In some cases, a base station 102 facilitates the scheduling of resources for sidelink communications. In other cases, sidelink communications are carried out between V-UEs 160 without the involvement of a base station 102.

[0066] In an aspect, the sidelinks 162, 166, 168 may operate over a wireless communication medium of interest, which may be shared with other wireless communications between other vehicles and/or infrastructure access points, as well as other RATs. A “medium” may be composed of one or more time, frequency, and/or space communication resources (e.g., encompassing one or more channels across one or more carriers) associated with wireless communication between one or more transmitter / receiver pairs.

[0067] In an aspect, the sidelinks 162, 166, 168 may be cV2X links. A first generation of cV2X has been standardized in LTE, and the next generation is expected to be defined in NR. cV2X is a cellular technology that also enables device-to-device communications. In the U.S. and Europe, cV2X is expected to operate in the licensed ITS band in sub-6GHz. Other bands may be allocated in other countries. Thus, as a particular example, the medium of interest utilized by sidelinks 162, 166, 168 may correspond to at least a portion of the licensed ITS frequency band of sub-6GHz. However, the present disclosure is not limited to this frequency band or cellular technology. [0068] In an aspect, the sidelinks 162, 166, 168 may be dedicated short-range communications (DSRC) links. DSRC is a one-way or two-way short-range to medium-range wireless communication protocol that uses the wireless access for vehicular environments (WAVE) protocol, also known as IEEE 802. l ip, for V2V, V2I, and V2P communications. IEEE 802.1 Ip is an approved amendment to the IEEE 802.11 standard and operates in the licensed ITS band of 5.9 GHz (5.85-5.925 GHz) in the U.S. In Europe, IEEE 802.1 Ip operates in the ITS G5A band (5.875 - 5.905 MHz). Other bands may be allocated in other countries. The V2V communications briefly described above occur on the Safety Channel, which in the U.S. is typically a 10 MHz channel that is dedicated to the purpose of safety. The remainder of the DSRC band (the total bandwidth is 75 MHz) is intended for other services of interest to drivers, such as road rules, tolling, parking automation, etc. Thus, as a particular example, the mediums of interest utilized by sidelinks 162, 166, 168 may correspond to at least a portion of the licensed ITS frequency band of 5.9 GHz.

[0069] Alternatively, the medium of interest may correspond to at least a portion of an unlicensed frequency band shared among various RATs. Although different licensed frequency bands have been reserved for certain communication systems (e.g., by a government entity such as the Federal Communications Commission (FCC) in the United States), these systems, in particular those employing small cell access points, have recently extended operation into unlicensed frequency bands such as the Unlicensed National Information Infrastructure (U-NII) band used by wireless local area network (WLAN) technologies, most notably IEEE 802.1 lx WLAN technologies generally referred to as “Wi-Fi.” Example systems of this type include different variants of CDMA systems, TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single-carrier FDMA (SC-FDMA) systems, and so on.

[0070] Communications between the V-UEs 160 are referred to as V2V communications, communications between the V-UEs 160 and the one or more RSUs 164 are referred to as V2I communications, and communications between the V-UEs 160 and one or more UEs 104 (where the UEs 104 are P-UEs) are referred to as V2P communications. The V2V communications between V-UEs 160 may include, for example, information about the position, speed, acceleration, heading, and other vehicle data of the V-UEs 160. The V2I information received at a V-UE 160 from the one or more RSUs 164 may include, for example, road rules, parking automation information, etc. The V2P communications between a V-UE 160 and a UE 104 may include information about, for example, the position, speed, acceleration, and heading of the V-UE 160 and the position, speed (e.g., where the UE 104 is carried by a user on a bicycle), and heading of the UE 104.

[0071] Note that although FIG. 1 only illustrates two of the UEs as V-UEs (V-UEs 160), any of the illustrated UEs (e.g., UEs 104, 152, 182, 190) may be V-UEs. In addition, while only the V-UEs 160 and a single UE 104 have been illustrated as being connected over a sidelink, any of the UEs illustrated in FIG. 1, whether V-UEs, P-UEs, etc., may be capable of sidelink communication. Further, although only UE 182 was described as being capable of beam forming, any of the illustrated UEs, including V-UEs 160, may be capable of beam forming. Where V-UEs 160 are capable of beam forming, they may beam form towards each other (i.e., towards other V-UEs 160), towards RSUs 164, towards other UEs (e.g., UEs 104, 152, 182, 190), etc. Thus, in some cases, V-UEs 160 may utilize beamforming over sidelinks 162, 166, and 168.

[0072] The wireless communications system 100 may further include one or more UEs, such as UE 190, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In the example of FIG. 1, UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which UE 190 may indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 may be supported with any well-known D2D RAT, such as LTE Direct (LTE-D), WI-FI DIRECT®, BLUETOOTH®, and so on. As another example, the D2D P2P links 192 and 194 may be sidelinks, as described above with reference to sidelinks 162, 166, and 168.

[0073] FIG. 2A illustrates an example wireless network structure 200. For example, a 5GC 210 (also referred to as a Next Generation Core (NGC)) can be viewed functionally as control plane (C-plane) functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane (U-plane) functions 212, (e.g., UE gateway function, access to data networks, IP routing, etc.) which operate cooperatively to form the core network. User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 to the 5GC 210 and specifically to the user plane functions 212 and control plane functions 214, respectively. In an additional configuration, an ng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to the control plane functions 214 and NG-U 213 to user plane functions 212. Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaul connection 223. In some configurations, a Next Generation RAN (NG-RAN) 220 may have one or more gNBs 222, while other configurations include one or more of both ng-eNBs 224 and gNBs 222. Either (or both) gNB 222 or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of the UEs described herein).

[0074] Another optional aspect may include a location server 230, which may be in communication with the 5GC 210 to provide location assistance for UE(s) 204. The location server 230 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The location server 230 can be configured to support one or more location services for UEs 204 that can connect to the location server 230 via the core network, 5GC 210, and/or via the Internet (not illustrated). Further, the location server 230 may be integrated into a component of the core network, or alternatively may be external to the core network (e.g., a third party server, such as an original equipment manufacturer (OEM) server or service server).

[0075] FIG. 2B illustrates another example wireless network structure 240. A 5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewed functionally as control plane functions, provided by an access and mobility management function (AMF) 264, and user plane functions, provided by a user plane function (UPF) 262, which operate cooperatively to form the core network (i.e., 5GC 260). The functions of the AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transport for session management (SM) messages between one or more UEs 204 (e.g., any of the UEs described herein) and a session management function (SMF) 266, transparent proxy services for routing SM messages, access authentication and access authorization, transport for short message service (SMS) messages between the UE 204 and the short message service function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204, and receives the intermediate key that was established as a result of the UE 204 authentication process. In the case of authentication based on a UMTS (universal mobile telecommunications system) subscriber identity module (USIM), the AMF 264 retrieves the security material from the AUSF. The functions of the AMF 264 also include security context management (SCM). The SCM receives a key from the SEAF that it uses to derive access-network specific keys. The functionality of the AMF 264 also includes location services management for regulatory services, transport for location services messages between the UE 204 and a location management function (LMF) 270 (which acts as a location server 230), transport for location services messages between the NG-RAN 220 and the LMF 270, evolved packet system (EPS) bearer identifier allocation for interworking with the EPS, and UE 204 mobility event notification. In addition, the AMF 264 also supports functionalities for non-3GPP® (Third Generation Partnership Project) access networks.

[0076] Functions of the UPF 262 include acting as an anchor point for intra/inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point of interconnect to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink/ downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding of one or more “end markers” to the source RAN node. The UPF 262 may also support transfer of location services messages over a user plane between the UE 204 and a location server, such as an SLP 272.

[0077] The functions of the SMF 266 include session management, UE Internet protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering at the UPF 262 to route traffic to the proper destination, control of part of policy enforcement and QoS, and downlink data notification. The interface over which the SMF 266 communicates with the AMF 264 is referred to as the Ni l interface. [0078] Another optional aspect may include an LMF 270, which may be in communication with the 5GC 260 to provide location assistance for UEs 204. The LMF 270 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The LMF 270 can be configured to support one or more location services for UEs 204 that can connect to the LMF 270 via the core network, 5GC 260, and/or via the Internet (not illustrated). The SLP 272 may support similar functions to the LMF 270, but whereas the LMF 270 may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a control plane (e.g., using interfaces and protocols intended to convey signaling messages and not voice or data), the SLP 272 may communicate with UEs 204 and external clients (e.g., third-party server 274) over a user plane (e.g., using protocols intended to carry voice and/or data like the transmission control protocol (TCP) and/or IP).

[0079] Yet another optional aspect may include a third-party server 274, which may be in communication with the LMF 270, the SLP 272, the 5GC 260 (e.g., via the AMF 264 and/or the UPF 262), the NG-RAN 220, and/or the UE 204 to obtain location information (e.g., a location estimate) for the UE 204. As such, in some cases, the third-party server 274 may be referred to as a location services (LCS) client or an external client. The third- party server 274 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server.

[0080] User plane interface 263 and control plane interface 265 connect the 5GC 260, and specifically the UPF 262 and AMF 264, respectively, to one or more gNBs 222 and/or ng-eNBs 224 in the NG-RAN 220. The interface between gNB(s) 222 and/or ng-eNB(s) 224 and the AMF 264 is referred to as the “N2” interface, and the interface between gNB(s) 222 and/or ng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. The gNB(s) 222 and/or ng-eNB(s) 224 of the NG-RAN 220 may communicate directly with each other via backhaul connections 223, referred to as the “Xn-C” interface. One or more of gNBs 222 and/or ng-eNBs 224 may communicate with one or more UEs 204 over a wireless interface, referred to as the “Uu” interface. [0081] The functionality of a gNB 222 may be divided between a gNB central unit (gNB-CU) 226, one or more gNB distributed units (gNB-DUs) 228, and one or more gNB radio units (gNB-RUs) 229. A gNB-CU 226 is a logical node that includes the base station functions of transferring user data, mobility control, radio access network sharing, positioning, session management, and the like, except for those functions allocated exclusively to the gNB-DU(s) 228. More specifically, the gNB-CU 226 generally host the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB 222. A gNB-DU 228 is a logical node that generally hosts the radio link control (RLC) and medium access control (MAC) layer of the gNB 222. Its operation is controlled by the gNB-CU 226. One gNB-DU 228 can support one or more cells, and one cell is supported by only one gNB-DU 228. The interface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 is referred to as the “Fl” interface. The physical (PHY) layer functionality of a gNB 222 is generally hosted by one or more standalone gNB-RUs 229 that perform functions such as power amplification and signal transmission/reception. The interface between a gNB-DU 228 and a gNB-RU 229 is referred to as the “Fx” interface. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP, and PDCP layers, with a gNB-DU 228 via the RLC and MAC layers, and with a gNB-RU 229 via the PHY layer.

[0082] Deployment of communication systems, such as 5G NR systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, or a network equipment, such as a base station, or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a base station (such as a Node B (NB), evolved NB (eNB), NR base station, 5GNB, access point (AP), a transmit receive point (TRP), or a cell, etc.) may be implemented as an aggregated base station (also known as a standalone base station or a monolithic base station) or a disaggregated base station.

[0083] An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs)). In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also can be implemented as virtual units, i.e., a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU). [0084] Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (0-RAN (such as the network configuration sponsored by the 0-RAN ALLIANCE®)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C- RAN)). Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.

[0085] FIG. 2C illustrates an example disaggregated base station architecture 250, according to aspects of the disclosure. The disaggregated base station architecture 250 may include one or more central units (CUs) 280 (e.g., gNB-CU 226) that can communicate directly with a core network 267 (e.g., 5GC 210, 5GC 260) via a backhaul link, or indirectly with the core network 267 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 259 via an E2 link, or a Non-Real Time (Non-RT) RIC 257 associated with a Service Management and Orchestration (SMO) Framework 255, or both). A CU 280 may communicate with one or more DUs 285 (e.g., gNB-DUs 228) via respective midhaul links, such as an Fl interface. The DUs 285 may communicate with one or more radio units (RUs) 287 (e.g., gNB-RUs 229) via respective fronthaul links. The RUs 287 may communicate with respective UEs 204 via one or more radio frequency (RF) access links. In some implementations, the UE 204 may be simultaneously served by multiple RUs 287.

[0086] Each of the units, i.e., the CUs 280, the DUs 285, the RUs 287, as well as the Near-RT RICs 259, the Non-RT RICs 257 and the SMO Framework 255, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a RF transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

[0087] In some aspects, the CU 280 may host one or more higher layer control functions. Such control functions can include RRC, PDCP, service data adaptation protocol (SDAP), or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 280. The CU 280 may be configured to handle user plane functionality (i.e., Central Unit - User Plane (CU- UP)), control plane functionality (i.e., Central Unit - Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 280 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the El interface when implemented in an 0-RAN configuration. The CU 280 can be implemented to communicate with the DU 285, as necessary, for network control and signaling.

[0088] The DU 285 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 287. In some aspects, the DU 285 may host one or more of a RLC layer, a MAC layer, and one or more high PHY layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rd Generation Partnership Project (3GPP®). In some aspects, the DU 285 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 285, or with the control functions hosted by the CU 280. [0089] Lower-layer functionality can be implemented by one or more RUs 287. In some deployments, an RU 287, controlled by a DU 285, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s) 287 can be implemented to handle over the air (OTA) communication with one or more UEs 204. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU(s) 287 can be controlled by the corresponding DU 285. In some scenarios, this configuration can enable the DU(s) 285 and the CU 280 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

[0090] The SMO Framework 255 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 255 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an 01 interface). For virtualized network elements, the SMO Framework 255 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 269) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an 02 interface). Such virtualized network elements can include, but are not limited to, CUs 280, DUs 285, RUs 287 and Near-RT RICs 259. In some implementations, the SMO Framework 255 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 261, via an 01 interface. Additionally, in some implementations, the SMO Framework 255 can communicate directly with one or more RUs 287 via an 01 interface. The SMO Framework 255 also may include a Non-RT RIC 257 configured to support functionality of the SMO Framework 255.

[0091] The Non-RT RIC 257 may be configured to include a logical function that enables non- real-time control and optimization of RAN elements and resources, artificial intelligence/machine learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 259. The Non-RT RIC 257 may be coupled to or communicate with (such as via an Al interface) the Near- RT RIC 259. The Near-RT RIC 259 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 280, one or more DUs 285, or both, as well as an O-eNB, with the Near-RT RIC 259.

[0092] In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 259, the Non-RT RIC 257 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 259 and may be received at the SMO Framework 255 or the Non-RT RIC 257 from non-network data sources or from network functions. In some examples, the Non-RT RIC 257 or the Near-RT RIC 259 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 257 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 255 (such as reconfiguration via 01) or via creation of RAN management policies (such as Al policies).

[0093] FIGS. 3A, 3B, and 3C illustrate several example components (represented by corresponding blocks) that may be incorporated into a UE 302 (which may correspond to any of the UEs described herein), a base station 304 (which may correspond to any of the base stations described herein), and a network entity 306 (which may correspond to or embody any of the network functions described herein, including the location server 230 and the LMF 270, or alternatively may be independent from the NG-RAN 220 and/or 5GC 210/260 infrastructure depicted in FIGS. 2 A and 2B, such as a private network) to support the operations described herein. It will be appreciated that these components may be implemented in different types of apparatuses in different implementations (e.g., in an ASIC, in a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other apparatuses in a communication system. For example, other apparatuses in a system may include components similar to those described to provide similar functionality. Also, a given apparatus may contain one or more of the components. For example, an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and/or communicate via different technologies. [0094] The UE 302 and the base station 304 each include one or more wireless wide area network (WWAN) transceivers 310 and 350, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means fortuning, means for refraining from transmitting, etc.) via one or more wireless communication networks (not shown), such as an NR network, an LTE network, a GSM network, and/or the like. The WWAN transceivers 310 and 350 may each be connected to one or more antennas 316 and 356, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communication medium of interest (e.g., some set of time/frequency resources in a particular frequency spectrum). The WWAN transceivers 310 and 350 may be variously configured for transmitting and encoding signals 318 and 358 (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the WWAN transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, for transmitting and encoding signals 318 and 358, respectively, and one or more receivers 312 and 352, respectively, for receiving and decoding signals 318 and 358, respectively.

[0095] The LE 302 and the base station 304 each also include, at least in some cases, one or more short-range wireless transceivers 320 and 360, respectively. The short-range wireless transceivers 320 and 360 may be connected to one or more antennas 326 and 366, respectively, and provide means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) with other network nodes, such as other LEs, access points, base stations, etc., via at least one designated RAT (e.g., Wi-Fi, LTE Direct, BLLETOOTH®, ZIGBEE®, Z-WAVE®, PC5, dedicated short-range communications (DSRC), wireless access for vehicular environments (WAVE), near-field communication (NFC), ultra- wideband (UWB), etc.) over a wireless communication medium of interest. The short- range wireless transceivers 320 and 360 may be variously configured for transmitting and encoding signals 328 and 368 (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals 328 and 368 (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the short-range wireless transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, for transmitting and encoding signals 328 and 368, respectively, and one or more receivers 322 and 362, respectively, for receiving and decoding signals 328 and 368, respectively. As specific examples, the short-range wireless transceivers 320 and 360 may be Wi-Fi transceivers, BLUETOOTH® transceivers, ZIGBEE® and/or Z-WAVE® transceivers, NFC transceivers, UWB transceivers, or vehicle-to-vehicle (V2V) and/or vehicle-to- everything (V2X) transceivers.

[0096] The UE 302 and the base station 304 also include, at least in some cases, satellite signal receivers 330 and 370. The satellite signal receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, and may provide means for receiving and/or measuring satellite positioning/communication signals 338 and 378, respectively. Where the satellite signal receivers 330 and 370 are satellite positioning system receivers, the satellite positioning/communication signals 338 and 378 may be global positioning system (GPS) signals, global navigation satellite system (GLONASS®) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), QuasiZenith Satellite System (QZSS), etc. Where the satellite signal receivers 330 and 370 are non-terrestrial network (NTN) receivers, the satellite positioning/communication signals 338 and 378 may be communication signals (e.g., carrying control and/or user data) originating from a 5G network. The satellite signal receivers 330 and 370 may comprise any suitable hardware and/or software for receiving and processing satellite positioning/communication signals 338 and 378, respectively. The satellite signal receivers 330 and 370 may request information and operations as appropriate from the other systems, and, at least in some cases, perform calculations to determine locations of the UE 302 and the base station 304, respectively, using measurements obtained by any suitable satellite positioning system algorithm.

[0097] The base station 304 and the network entity 306 each include one or more network transceivers 380 and 390, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, etc.) with other network entities (e.g., other base stations 304, other network entities 306). For example, the base station 304 may employ the one or more network transceivers 380 to communicate with other base stations 304 or network entities 306 over one or more wired or wireless backhaul links. As another example, the network entity 306 may employ the one or more network transceivers 390 to communicate with one or more base station 304 over one or more wired or wireless backhaul links, or with other network entities 306 over one or more wired or wireless core network interfaces.

[0098] A transceiver may be configured to communicate over a wired or wireless link. A transceiver (whether a wired transceiver or a wireless transceiver) includes transmitter circuitry (e.g., transmitters 314, 324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352, 362). A transceiver may be an integrated device (e.g., embodying transmitter circuitry and receiver circuitry in a single device) in some implementations, may comprise separate transmitter circuitry and separate receiver circuitry in some implementations, or may be embodied in other ways in other implementations. The transmitter circuitry and receiver circuitry of a wired transceiver (e.g., network transceivers 380 and 390 in some implementations) may be coupled to one or more wired network interface ports. Wireless transmitter circuitry (e.g., transmitters 314, 324, 354, 364) may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, that permits the respective apparatus (e.g., UE 302, base station 304) to perform transmit “beamforming,” as described herein. Similarly, wireless receiver circuitry (e.g., receivers 312, 322, 352, 362) may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, that permits the respective apparatus (e.g., UE 302, base station 304) to perform receive beamforming, as described herein. In an aspect, the transmitter circuitry and receiver circuitry may share the same plurality of antennas (e.g., antennas 316, 326, 356, 366), such that the respective apparatus can only receive or transmit at a given time, not both at the same time. A wireless transceiver (e.g., WWAN transceivers 310 and 350, short-range wireless transceivers 320 and 360) may also include a network listen module (NLM) or the like for performing various measurements.

[0099] As used herein, the various wireless transceivers (e.g., transceivers 310, 320, 350, and 360, and network transceivers 380 and 390 in some implementations) and wired transceivers (e.g., network transceivers 380 and 390 in some implementations) may generally be characterized as “a transceiver,” “at least one transceiver,” or “one or more transceivers.” As such, whether a particular transceiver is a wired or wireless transceiver may be inferred from the type of communication performed. For example, backhaul communication between network devices or servers will generally relate to signaling via a wired transceiver, whereas wireless communication between a UE (e.g., UE 302) and a base station (e.g., base station 304) will generally relate to signaling via a wireless transceiver.

[0100] The UE 302, the base station 304, and the network entity 306 also include other components that may be used in conjunction with the operations as disclosed herein. The UE 302, the base station 304, and the network entity 306 include one or more processors 332, 384, and 394, respectively, for providing functionality relating to, for example, wireless communication, and for providing other processing functionality. The processors 332, 384, and 394 may therefore provide means for processing, such as means for determining, means for calculating, means for receiving, means for transmitting, means for indicating, etc. In an aspect, the processors 332, 384, and 394 may include, for example, one or more general purpose processors, multi-core processors, central processing units (CPUs), ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), other programmable logic devices or processing circuitry, or various combinations thereof.

[0101] The UE 302, the base station 304, and the network entity 306 include memory circuitry implementing memories 340, 386, and 396 (e.g., each including a memory device), respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on). The memories 340, 386, and 396 may therefore provide means for storing, means for retrieving, means for maintaining, etc. In some cases, the UE 302, the base station 304, and the network entity 306 may include positioning component 342, 388, and 398, respectively. The positioning component 342, 388, and 398 may be hardware circuits that are part of or coupled to the processors 332, 384, and 394, respectively, that, when executed, cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. In other aspects, the positioning component 342, 388, and 398 may be external to the processors 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the positioning component 342, 388, and 398 may be memory modules stored in the memories 340, 386, and 396, respectively, that, when executed by the processors 332, 384, and 394 (or a modem processing system, another processing system, etc.), cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. FIG. 3A illustrates possible locations of the positioning component 342, which may be, for example, part of the one or more WWAN transceivers 310, the memory 340, the one or more processors 332, or any combination thereof, or may be a standalone component. FIG. 3B illustrates possible locations of the positioning component 388, which may be, for example, part of the one or more WWAN transceivers 350, the memory 386, the one or more processors 384, or any combination thereof, or may be a standalone component. FIG. 3C illustrates possible locations of the positioning component 398, which may be, for example, part of the one or more network transceivers 390, the memory 396, the one or more processors 394, or any combination thereof, or may be a standalone component.

[0102] The UE 302 may include one or more sensors 344 coupled to the one or more processors 332 to provide means for sensing or detecting movement and/or orientation information that is independent of motion data derived from signals received by the one or more WWAN transceivers 310, the one or more short-range wireless transceivers 320, and/or the satellite signal receiver 330. By way of example, the sensor(s) 344 may include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric pressure altimeter), and/or any other type of movement detection sensor. Moreover, the sensor(s) 344 may include a plurality of different types of devices and combine their outputs in order to provide motion information. For example, the sensor(s) 344 may use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute positions in two-dimensional (2D) and/or three-dimensional (3D) coordinate systems.

[0103] In addition, the UE 302 includes a user interface 346 providing means for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on). Although not shown, the base station 304 and the network entity 306 may also include user interfaces.

[0104] Referring to the one or more processors 384 in more detail, in the downlink, IP packets from the network entity 306 may be provided to the processor 384. The one or more processors 384 may implement functionality for an RRC layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The one or more processors 384 may provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB), system information blocks (SIBs)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0105] The transmitter 354 and the receiver 352 may implement Layer- 1 (LI) functionality associated with various signal processing functions. Layer- 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The transmitter 354 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 302. Each spatial stream may then be provided to one or more different antennas 356. The transmitter 354 may modulate an RF carrier with a respective spatial stream for transmission.

[0106] At the UE 302, the receiver 312 receives a signal through its respective antenna(s) 316. The receiver 312 recovers information modulated onto an RF carrier and provides the information to the one or more processors 332. The transmitter 314 and the receiver 312 implement Lay er- 1 functionality associated with various signal processing functions. The receiver 312 may perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, they may be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 then converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 304. These soft decisions may be based on channel estimates computed by a channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 304 on the physical channel. The data and control signals are then provided to the one or more processors 332, which implements Layer-3 (L3) and Layer-2 (L2) functionality.

[0107] In the downlink, the one or more processors 332 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The one or more processors 332 are also responsible for error detection.

[0108] Similar to the functionality described in connection with the downlink transmission by the base station 304, the one or more processors 332 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); REC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0109] Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 304 may be used by the transmitter 314 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the transmitter 314 may be provided to different antenna(s) 316. The transmitter 314 may modulate an RF carrier with a respective spatial stream for transmission.

[0110] The uplink transmission is processed at the base station 304 in a manner similar to that described in connection with the receiver function at the UE 302. The receiver 352 receives a signal through its respective antenna(s) 356. The receiver 352 recovers information modulated onto an RF carrier and provides the information to the one or more processors 384.

[0111] In the uplink, the one or more processors 384 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 302. IP packets from the one or more processors 384 may be provided to the core network. The one or more processors 384 are also responsible for error detection.

[0112] For convenience, the UE 302, the base station 304, and/or the network entity 306 are shown in FIGS. 3 A, 3B, and 3C as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated components may have different functionality in different designs. In particular, various components in FIGS. 3A to 3C are optional in alternative configurations and the various aspects include configurations that may vary due to design choice, costs, use of the device, or other considerations. For example, in case of FIG. 3A, a particular implementation of UE 302 may omit the WWAN transceiver(s) 310 (e.g., a wearable device or tablet computer or personal computer (PC) or laptop may have Wi-Fi and/or BLUETOOTH® capability without cellular capability), or may omit the short- range wireless transceiver(s) 320 (e.g., cellular-only, etc.), or may omit the satellite signal receiver 330, or may omit the sensor(s) 344, and so on. In another example, in case of FIG. 3B, a particular implementation of the base station 304 may omit the WWAN transceiver(s) 350 (e.g., a Wi-Fi “hotspot” access point without cellular capability), or may omit the short-range wireless transceiver s) 360 (e.g., cellular-only, etc.), or may omit the satellite signal receiver 370, and so on. For brevity, illustration of the various alternative configurations is not provided herein, but would be readily understandable to one skilled in the art.

[0113] The various components of the UE 302, the base station 304, and the network entity 306 may be communicatively coupled to each other over data buses 334, 382, and 392, respectively. In an aspect, the data buses 334, 382, and 392 may form, or be part of, a communication interface of the UE 302, the base station 304, and the network entity 306, respectively. For example, where different logical entities are embodied in the same device (e.g., gNB and location server functionality incorporated into the same base station 304), the data buses 334, 382, and 392 may provide communication between them.

[0114] The components of FIGS. 3A, 3B, and 3C may be implemented in various ways. In some implementations, the components of FIGS. 3 A, 3B, and 3C may be implemented in one or more circuits such as, for example, one or more processors and/or one or more ASICs (which may include one or more processors). Here, each circuit may use and/or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by blocks 310 to 346 may be implemented by processor and memory component(s) of the UE 302 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). Similarly, some or all of the functionality represented by blocks 350 to 388 may be implemented by processor and memory component(s) of the base station 304 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). Also, some or all of the functionality represented by blocks 390 to 398 may be implemented by processor and memory component(s) of the network entity 306 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). For simplicity, various operations, acts, and/or functions are described herein as being performed “by a UE,” “by a base station,” “by a network entity,” etc. However, as will be appreciated, such operations, acts, and/or functions may actually be performed by specific components or combinations of components of the UE 302, base station 304, network entity 306, etc., such as the processors 332, 384, 394, the transceivers 310, 320, 350, and 360, the memories 340, 386, and 396, the positioning component 342, 388, and 398, etc.

[0115] In some designs, the network entity 306 may be implemented as a core network component. In other designs, the network entity 306 may be distinct from a network operator or operation of the cellular network infrastructure (e.g., NG RAN 220 and/or 5GC 210/260). For example, the network entity 306 may be a component of a private network that may be configured to communicate with the UE 302 via the base station 304 or independently from the base station 304 (e.g., over a non-cellular communication link, such as Wi-Fi).

[0116] NR supports a number of cellular network-based positioning technologies, including downlink-based, uplink-based, and downlink-and-uplink-based positioning methods. Downlink-based positioning methods include observed time difference of arrival (OTDOA) in LTE, downlink time difference of arrival (DL-TDOA) in NR, and downlink angle-of-departure (DL-AoD) in NR. FIG. 4 illustrates examples of various positioning methods, according to aspects of the disclosure. In an OTDOA or DL-TDOA positioning procedure, illustrated by scenario 410, a UE measures the differences between the times of arrival (ToAs) of reference signals (e.g., positioning reference signals (PRS)) received from pairs of base stations, referred to as reference signal time difference (RSTD) or time difference of arrival (TDOA) measurements, and reports them to a positioning entity. More specifically, the UE receives the identifiers (IDs) of a reference base station (e.g., a serving base station) and multiple non-reference base stations in assistance data. The UE then measures the RSTD between the reference base station and each of the non-reference base stations. Based on the known locations of the involved base stations and the RSTD measurements, the positioning entity (e.g., the UE for UE-based positioning or a location server for UE-assisted positioning) can estimate the UE’s location.

[0117] For DL-AoD positioning, illustrated by scenario 420, the positioning entity uses a measurement report from the UE of received signal strength measurements of multiple downlink transmit beams to determine the angle(s) between the UE and the transmitting base station(s). The positioning entity can then estimate the location of the UE based on the determined angle(s) and the known location(s) of the transmitting base station(s).

[0118] Uplink-based positioning methods include uplink time difference of arrival (UL-TDOA) and uplink angle-of-arrival (UL-AoA). UL-TDOA is similar to DL-TDOA, but is based on uplink reference signals (e.g., sounding reference signals (SRS)) transmitted by the UE to multiple base stations. Specifically, a UE transmits one or more uplink reference signals that are measured by a reference base station and a plurality of non-reference base stations. Each base station then reports the reception time (referred to as the relative time of arrival (RTOA)) of the reference signal(s) to a positioning entity (e.g., a location server) that knows the locations and relative timing of the involved base stations. Based on the reception-to-reception (Rx-Rx) time difference between the reported RTOA of the reference base station and the reported RTOA of each non-reference base station, the known locations of the base stations, and their known timing offsets, the positioning entity can estimate the location of the UE using TDOA.

[0119] For UL-AoA positioning, one or more base stations measure the received signal strength of one or more uplink reference signals (e.g., SRS) received from a UE on one or more uplink receive beams. The positioning entity uses the signal strength measurements and the angle(s) of the receive beam(s) to determine the angle(s) between the UE and the base station(s). Based on the determined angle(s) and the known location(s) of the base station(s), the positioning entity can then estimate the location of the UE.

[0120] Downlink-and-uplink-based positioning methods include enhanced cell-ID (E-CID) positioning and multi -round-trip-time (RTT) positioning (also referred to as “multi-cell RTT” and “multi -RTT”). In an RTT procedure, a first entity (e.g., a base station or a UE) transmits a first RTT-related signal (e.g., a PRS or SRS) to a second entity (e.g., a UE or base station), which transmits a second RTT-related signal (e.g., an SRS or PRS) back to the first entity. Each entity measures the time difference between the time of arrival (ToA) of the received RTT-related signal and the transmission time of the transmitted RTT-related signal. This time difference is referred to as a reception-to-transmission (Rx- Tx) time difference. The Rx-Tx time difference measurement may be made, or may be adjusted, to include only a time difference between nearest slot boundaries for the received and transmitted signals. Both entities may then send their Rx-Tx time difference measurement to a location server (e.g., an LMF 270), which calculates the round trip propagation time (i.e., RTT) between the two entities from the two Rx-Tx time difference measurements (e.g., as the sum of the two Rx-Tx time difference measurements). Alternatively, one entity may send its Rx-Tx time difference measurement to the other entity, which then calculates the RTT. The distance between the two entities can be determined from the RTT and the known signal speed (e.g., the speed of light). For multi- RTT positioning, illustrated by scenario 430, a first entity (e.g., a UE or base station) performs an RTT positioning procedure with multiple second entities (e.g., multiple base stations or UEs) to enable the location of the first entity to be determined (e.g., using multilateration) based on distances to, and the known locations of, the second entities. RTT and multi-RTT methods can be combined with other positioning techniques, such as UL-AoA and DL-AoD, to improve location accuracy, as illustrated by scenario 440.

[0121] The E-CID positioning method is based on radio resource management (RRM) measurements. In E-CID, the UE reports the serving cell ID, the timing advance (TA), and the identifiers, estimated timing, and signal strength of detected neighbor base stations. The location of the UE is then estimated based on this information and the known locations of the base station(s).

[0122] To assist positioning operations, a location server (e.g., location server 230, LMF 270, SLP 272) may provide assistance data to the UE. For example, the assistance data may include identifiers of the base stations (or the cells/TRPs of the base stations) from which to measure reference signals, the reference signal configuration parameters (e.g., the number of consecutive slots including PRS, periodicity of the consecutive slots including PRS, muting sequence, frequency hopping sequence, reference signal identifier, reference signal bandwidth, etc.), and/or other parameters applicable to the particular positioning method. Alternatively, the assistance data may originate directly from the base stations themselves (e.g., in periodically broadcasted overhead messages, etc.). In some cases, the UE may be able to detect neighbor network nodes itself without the use of assistance data.

[0123] In the case of an OTDOA or DL-TDOA positioning procedure, the assistance data may further include an expected RSTD value and an associated uncertainty, or search window, around the expected RSTD. In some cases, the value range of the expected RSTD may be +/- 500 microseconds (ps). In some cases, when any of the resources used for the positioning measurement are in FR1, the value range for the uncertainty of the expected RSTD may be +/- 32 ps. In other cases, when all of the resources used for the positioning measurement(s) are in FR2, the value range for the uncertainty of the expected RSTD may be +/- 8 ps.

[0124] A location estimate may be referred to by other names, such as a position estimate, location, position, position fix, fix, or the like. A location estimate may be geodetic and comprise coordinates (e.g., latitude, longitude, and possibly altitude) or may be civic and comprise a street address, postal address, or some other verbal description of a location. A location estimate may further be defined relative to some other known location or defined in absolute terms (e.g., using latitude, longitude, and possibly altitude). A location estimate may include an expected error or uncertainty (e.g., by including an area or volume within which the location is expected to be included with some specified or default level of confidence).

[0125] NR supports, or enables, various sidelink positioning techniques. FIG. 5A illustrates various scenarios of interest for sidelink-only or joint Uu and sidelink positioning, according to aspects of the disclosure. In scenario 510, at least one peer UE with a known location can improve the Uu-based positioning (e.g., multi-cell round-trip-time (RTT), downlink time difference of arrival (DL-TDOA), etc.) of a target UE by providing an additional anchor (e.g., using sidelink RTT (SL-RTT)). In scenario 520, a low-end (e.g., reduced capacity, or “RedCap”) target UE may obtain the assistance of premium UEs to determine its location using, e.g., sidelink positioning and ranging procedures with the premium UEs. Compared to the low-end UE, the premium UEs may have more capabilities, such as more sensors, a faster processor, more memory, more antenna elements, higher transmit power capability, access to additional frequency bands, or any combination thereof. In scenario 530, a relay UE (e.g., with a known location) participates in the positioning estimation of a remote UE without performing uplink positioning reference signal (PRS) transmission over the Uu interface. Scenario 540 illustrates the joint positioning of multiple UEs. Specifically, in scenario 540, two UEs with unknown positions can be jointly located in non-line-of-sight (NLOS) conditions by utilizing constraints from nearby UEs.

[0126] FIG. 5B illustrates additional scenarios of interest for sidelink-only or joint Uu and sidelink positioning, according to aspects of the disclosure. In scenario 550, UEs used for public safety (e.g., by police, firefighters, and/or the like) may perform peer-to-peer (P2P) positioning and ranging for public safety and other uses. For example, in scenario 550, the public safety UEs may be out of coverage of a network and determine a location or a relative distance and a relative position among the public safety UEs using sidelink positioning techniques. Similarly, scenario 560 shows multiple UEs that are out of coverage and determine a location or a relative distance and a relative position using sidelink positioning techniques, such as SL-RTT.

[0127] Specific reference signals for positioning have been defined for both downlink and sidelink positioning use cases, referred to as “positioning reference signals” or “PRS.” A collection of resource elements (REs) that are used for transmission of PRS is referred to as a “PRS resource.” The collection of resource elements can span multiple physical resource blocks (PRBs) in the frequency domain and ‘N’ (such as 1 or more) consecutive symbol(s) within a slot in the time domain. In a given OFDM symbol in the time domain, a PRS resource occupies consecutive PRBs in the frequency domain.

[0128] The transmission of a PRS resource within a given PRB has a particular comb size (also referred to as the “comb density”). A comb size ‘N’ represents the subcarrier spacing (or frequency/tone spacing) within each symbol of a PRS resource configuration. Specifically, for a comb size ‘N,’ PRS are transmitted in every Nth subcarrier of a symbol of a PRB. For example, for comb-4, for each symbol of the PRS resource configuration, REs corresponding to every fourth subcarrier (such as subcarriers 0, 4, 8) are used to transmit PRS of the PRS resource. Currently, comb sizes of comb-2, comb-4, comb-6, and comb- 12 are supported for DL-PRS.

[0129] Currently, a DL-PRS resource may span 2, 4, 6, or 12 consecutive symbols within a slot with a fully frequency-domain staggered pattern. A DL-PRS resource can be configured in any higher layer configured downlink or flexible (FL) symbol of a slot. There may be a constant energy per resource element (EPRE) for all REs of a given DL-PRS resource. The following are the frequency offsets from symbol to symbol for comb sizes 2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1 }; 4-symbol comb-2: {0, 1, 0, 1 }; 6-symbol comb-2: {0, 1, 0, 1, 0, 1 }; 12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 }; 4-symbol comb-4: {0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 6-symbol comb-6: {0, 3, 1, 4, 2, 5}; 12-symbol comb-6: {0, 3, 1, 4, 2, 5, 0, 3, 1, 4, 2, 5}; and 12-symbol comb-12: {0, 6, 3, 9, 1, 7, 4, 10, 2, 8, 5, 11 }.

[0130] A “PRS resource set” is a set of PRS resources used for the transmission of PRS signals, where each PRS resource has a PRS resource ID. In addition, the PRS resources in a PRS resource set are associated with the same TRP. A PRS resource set is identified by a PRS resource set ID and is associated with a particular TRP (identified by a TRP ID). In addition, the PRS resources in a PRS resource set have the same periodicity, a common muting pattern configuration, and the same repetition factor (such as “PRS- ResourceRepetitionF actor”) across slots. The periodicity is the time from the first repetition of the first PRS resource of a first PRS instance to the same first repetition of the same first PRS resource of the next PRS instance. The periodicity may have a length selected from 2^Ap*{4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, with p = 0, 1, 2, 3. The repetition factor may have a length selected from { 1, 2, 4, 6, 8, 16, 32} slots.

[0131] A PRS resource ID in a PRS resource set is associated with a single beam (or beam ID) transmitted from a single TRP (where a TRP may transmit one or more beams). That is, each PRS resource of a PRS resource set may be transmitted on a different beam, and as such, a “PRS resource,” or simply “resource,” also can be referred to as a “beam.” Note that this does not have any implications on whether the TRPs and the beams on which PRS are transmitted are known to the UE.

[0132] A “PRS instance” or “PRS occasion” is one instance of a periodically repeated time window (such as a group of one or more consecutive slots) where PRS are expected to be transmitted. A PRS occasion also may be referred to as a “PRS positioning occasion,” a “PRS positioning instance, a “positioning occasion,” “a positioning instance,” a “positioning repetition,” or simply an “occasion,” an “instance,” or a “repetition.”

[0133] A “positioning frequency layer” (also referred to simply as a “frequency layer”) is a collection of one or more PRS resource sets across one or more TRPs that have the same values for certain parameters. Specifically, the collection of PRS resource sets has the same subcarrier spacing and cyclic prefix (CP) type (meaning all numerologies supported for the physical downlink shared channel (PDSCH) are also supported for PRS), the same Point A, the same value of the downlink PRS bandwidth, the same start PRB (and center frequency), and the same comb-size. The Point A parameter takes the value of the parameter “ARFCN-ValueNR” (where “ARFCN” stands for “absolute radio-frequency channel number”) and is an identifier/code that specifies a pair of physical radio channel used for transmission and reception. The downlink PRS bandwidth may have a granularity of four PRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. Currently, up to four frequency layers have been defined, and up to two PRS resource sets may be configured per TRP per frequency layer. [0134] The concept of a frequency layer is somewhat like the concept of component carriers and bandwidth parts (BWPs), but different in that component carriers and BWPs are used by one base station (or a macro cell base station and a small cell base station) to transmit data channels, while frequency layers are used by several (usually three or more) base stations to transmit PRS. A UE may indicate the number of frequency layers it can support when it sends the network its positioning capabilities, such as during an LTE positioning protocol (LPP) session. For example, a UE may indicate whether it can support one or four positioning frequency layers.

[0135] Note that the terms “positioning reference signal” and “PRS” may refer to downlink, uplink, or sidelink positioning reference signals, unless otherwise indicated by the context. If needed to further distinguish the type of PRS, a downlink positioning reference signal may be referred to as a “DL-PRS,” an uplink positioning reference signal (e.g., an SRS-for-positioning) may be referred to as an “UL-PRS,” and a sidelink positioning reference signal may be referred to as an “SL-PRS .” In addition, for signals that may be transmitted in the downlink, uplink, and/or sidelink (e.g., demodulation reference signals (DMRS)), the signals may be prepended with “DL,” “UL,” or “SL” to distinguish the direction. For example, “UL-DMRS” is different from “DL-DMRS.”

[0136] FIG. 6 is a diagram 600 illustrating an example PRS configuration for two TRPs (labeled “TRP1” and “TRP2”) operating in the same positioning frequency layer (labeled “Positioning Frequency Layer 1”), according to aspects of the disclosure. For a positioning session, a UE may be provided with assistance data indicating the illustrated PRS configuration. In the example of FIG. 6, the first TRP (“TRP1”) is associated with (e.g., transmits) two PRS resource sets, labeled “PRS Resource Set 1” and “PRS Resource Set 2,” and the second TRP (“TRP2”) is associated with one PRS resource set, labeled “PRS Resource Set 3.” Each PRS resource set comprises at least two PRS resources. Specifically, the first PRS resource set (“PRS Resource Set 1”) includes PRS resources labeled “PRS Resource 1” and “PRS Resource 2,” the second PRS resource set (“PRS Resource Set 2”) includes PRS resources labeled “PRS Resource 3” and “PRS Resource 4,” and the third PRS resource set (“PRS Resource Set 3”) includes PRS resources labeled “PRS Resource 5” and “PRS Resource 6.”

[0137] When a UE is configured in the assistance data of a positioning method with a number of PRS resources beyond its capability, the UE assumes the PRS resources in the assistance data are sorted in a decreasing order of measurement priority. Currently, the 64 TRPs per frequency layer are sorted according to priority and the two PRS resource sets per TRP of the frequency layer are sorted according to priority. However, the four frequency layers may or may not be sorted according to priority, and the 64 PRS resources of the PRS resource set per TRP per frequency layer may or may not be sorted according to priority. The reference indicated by the assistance data parameter “nr-DL-PRS- Referencelnfo” for each frequency layer has the highest priority, at least for DL-TDOA positioning procedures.

[0138] Long-Term Evolution (LTE) positioning protocol (LPP) is used point-to-point between a location server (e.g., LMF 270) and a target device (e.g., a UE) in order to position the target device using position-related measurements obtained by one or more reference sources (physical entities or parts of physical entities that provide signals that can be measured by a target device in order to obtain the location of the target device). An LPP session is used between a location server and a target device in order to obtain location- related measurements or a location estimate or to transfer assistance data. Currently, a single LPP session is used to support a single location request and multiple LPP sessions can be used between the same endpoints to support multiple different location requests. Each LPP session comprises one or more LPP transactions (or procedures), with each LPP transaction performing a single operation (capability exchange, assistance data transfer, or location information transfer). Each LPP transaction involves the exchange of one or more LPP messages between the location server and the target device. The general format of an LPP message consists of a set of common fields followed by a body. The body (which may be empty) contains information specific to a particular message type. Each message type contains information specific to one or more positioning methods and/or information common to all positioning methods.

[0139] An LPP session generally includes at least a capability transfer or indication procedure, an assistance data transfer or delivery procedure, and a location information transfer or delivery procedure. FIG. 7 illustrates an example LPP capability transfer procedure 710, LPP assistance data transfer procedure 730, and LPP location information transfer procedure 750 between a target device (labeled “Target”) and a location server (labeled “Server”), according to aspects of the disclosure. [0140] The purpose of an LPP capability transfer procedure 710 is to enable the transfer of capabilities from the target device (e.g., a UE 204) to the location server (e.g., an LMF 270). Capabilities in this context refer to positioning and protocol capabilities related to LPP and the positioning methods supported by LPP. In the LPP capability transfer procedure 710, the location server (e.g., an LMF 270) indicates the types of capabilities needed from the target device (e.g., UE 204) in an LPP Request Capabilities message. The target device responds with an LPP Provide Capabilities message. The capabilities included in the LPP Provide Capabilities message should correspond to any capability types specified in the LPP Request Capabilities message. Specifically, for each positioning method for which a request for capabilities is included in the LPP Request Capabilities message, if the target device supports this positioning method, the target device includes the capabilities of the target device for that supported positioning method in the LPP Provide Capabilities message. For an LPP capability indication procedure, the target device provides unsolicited (i.e., without receiving an LPP Request Capabilities message) capabilities to the location server in an LPP Provide Capabilities message.

[0141] The purpose of an LPP assistance data transfer procedure 730 is to enable the target device to request assistance data from the location server to assist in positioning, and to enable the location server to transfer assistance data to the target device in the absence of a request. In the LPP assistance data transfer procedure 730, the target device sends an LPP Request Assistance Data message to the location server. The location server responds to the target device with an LPP Provide Assistance Data message containing assistance data. The transferred assistance data should match or be a subset of the assistance data requested in the LPP Request Assistance Data. The location server may also provide any not requested information that it considers useful to the target device. The location server may also transmit one or more additional LPP Provide Assistance Data messages to the target device containing further assistance data. For an LPP assistance data delivery procedure, the location server provides unsolicited assistance data necessary for positioning. The assistance data may be provided periodically or non-periodically.

[0142] The purpose of an LPP location information transfer procedure 750 is to enable the location server to request location measurement data and/or a location estimate from the target device, and to enable the target device to transfer location measurement data and/or a location estimate to a location server in the absence of a request. In an LPP location information transfer procedure 750, the location server sends an LPP Request Location Information message to the target device to request location information, indicating the type of location information needed and potentially the associated QoS. The target device responds with an LPP Provide Location Information message to the location server to transfer location information. The location information transferred should match or be a subset of the location information requested by the LPP Request Location Information unless the location server explicitly allows additional location information. More specifically, if the requested information is compatible with the target device’s capabilities and configuration, the target device includes the requested information in an LPP Provide Location Information message. Otherwise, if the target device does not support one or more of the requested positioning methods, the target device continues to process the message as if it contained only information for the supported positioning methods and handles the signaling content of the unsupported positioning methods by LPP error detection. If requested by the LPP Request Lactation Information message, the target device sends additional LPP Provide Location Information messages to the location server to transfer additional location information. An LPP location information delivery procedure supports the delivery of positioning estimations based on unsolicited service.

[0143] LPP also defines procedures related to error indication for when a receiving endpoint (target device or location server) receives erroneous or unexpected data or detects that certain data are missing. Specifically, when a receiving endpoint determines that a received LPP message contains an error, it can return an Error message to the transmitting endpoint indicating the error or errors and discard the received/erroneous message. If the receiving endpoint is able to determine that the erroneous LPP message is an LPP Error or Abort Message, then the receiving endpoint discards the received message without returning an Error message to the transmitting endpoint.

[0144] LPP also defines procedures related to abort indication to allow a target device or location server to abort an ongoing procedure due to some unexpected event (e.g., cancellation of a location request by an LCS client). An Abort procedure can also be used to stop an ongoing procedure (e.g., periodic location reporting from the target device). In an Abort procedure, a first endpoint determines that procedure P must be aborted and sends an Abort message to a second endpoint carrying the transaction ID for procedure P. The second endpoint then aborts procedure P. [0145] As described above, for sidelink positioning, in order to obtain a location estimate of a target UE, positioning methods make use of reference signals (e.g., SL-PRS) transmitted between UEs, and the resulting measurements can be used to locate the target UE. In some scenarios, based on the type of the anchor UE(s) (e.g., RSUs that can be utilized as TRPs for positioning purposes), then both time-based and angle-based positioning methods may be applicable. Currently, at least the following positioning methods are expected to be supported for sidelink positioning: RTT-type solutions using sidelink, SL- AoA, and SL-TDOA.

[0146] For SL-TDOA positioning methods, the target UE position is estimated based on measurements obtained by multiple anchor UEs of SL-PRS transmitted by the target UE, and/or based on measurements obtained by the target UE of SL-PRS transmitted by the multiple anchor UEs. The SL-TDOA positioning method is therefore similar to the DL- TDOA positioning method or the UL-TDOA positioning method. Specifically, for a sidelink-only TDOA positioning procedure, SL-PRS are transmitted from multiple anchor UEs to a target UE (e.g., similar to DL-TDOA operation) and/or from a target UE to multiple anchor UEs (e.g., similar to UL-TDOA operation) at least for the purpose of determining an absolute position estimate of the target UE.

[0147] Joint TDOA positioning is a positioning technique where both DL-PRS from one or more TRPs and SL-PRS from one or more anchor UEs are transmitted to and measured by the target UE. FIG. 8 is a diagram 800 illustrating an example joint TDOA positioning method, according to aspects of the disclosure. As shown in FIG. 8, a target UE measures a DL-RSTD between a pair of TRPs (labeled “TRP1” and “TRP2”), a SL-RSTD between a pair of anchor UEs (labeled “Anchor UE1” and “Anchor UE2”), and a joint downlink and sidelink RSTD between one of the TRPs (TRP1) and one of the anchor UEs (Anchor UE1). That is, a joint downlink and sidelink RSTD measurement (or simply “joint RSTD”) is an RSTD measurement between a DL-PRS and a SL-PRS.

[0148] In the example of FIG. 8, the target UE’s position cannot be calculated by either the DL- RSTD measurements or the SL-RSTD measurements since DL-TDOA-based positioning uses at least three anchor nodes, where one of the anchor nodes is a reference node. Accordingly, in scenarios like the one illustrated in FIG. 8, both the downlink and sidelink measurements need to be merged. For example, the RSTD measurements between the target UE and the TRPs and the target UE and the sidelink anchor UEs would be used to determine the location of the target UE.

[0149] DL-TDOA and UL-TDOA positioning methods need time synchronization information between the reference TRP and a list of neighboring TRPs to meet the positioning accuracy requirements. Typically, anchor UEs and TRPs are not accurately time synchronized. Even if the TRPs are synchronized with each other, the anchor UEs may not be synchronized with each other or with the TRPs. For example, different anchor UEs might have different synchronization points, such as GPS, TRP, UE, etc. Accordingly, selecting one reference point for both the sidelink and Uu measurements in a joint TDOA positioning procedure might not be suitable. In addition, as illustrated in FIG. 8, independent reporting for sidelink and Uu measurements may not be sufficient for the location server (e.g., LMF 270) to calculate the joint positioning estimate for sidelink and Uu cases, as there may not be enough sidelink-only or Uu-only RSTD measurements. In such cases, the UE may need to report joint RSTD measurements.

[0150] Note that the term “Uu” refers to the air interface between a TRP and a UE. As such, a “Uu measurement” refers to a downlink measurement (e.g., a measurement of DL-PRS resources) or an uplink measurement (e.g., a measurement of UL-PRS resources, such as SRS for positioning resources). Further, as a TRP transmits one or more DL-PRS resources to be measured by a target UE, the target UE may interchangeably be described as measuring the TRP or measuring the one or more DL-PRS resources transmitted by the TRP. Similarly, as an anchor UE transmits one or more SL-PRS resources to be measured by a target UE, the target UE may interchangeably be described as measuring the anchor UE or measuring the one or more SL-PRS resources transmitted by the anchor UE. Likewise, as a target UE may transmit one or more UL-PRS resources and/or one or more SL-PRS resources, a TRP or anchor UE may interchangeably be described as measuring the target UE or measuring the one or more PRS resources transmitted by the target UE.

[0151] The present disclosure provides techniques for determining and reporting a reference node for joint downlink and sidelink TDOA positioning. FIG. 9 illustrates an example method 900 of wireless communication, according to aspects of the disclosure. In an aspect, method 900 may be performed by a UE (e.g., any of the UEs described herein). [0152] At operation 910, the UE obtains (e.g., from LMF 270) at least one reference node for one or more joint downlink and sidelink RSTD measurements and (1) one or more DL- RSTD measurements, (2) one or more SL-RSTD measurements, or (3) both. In an aspect, operation 910 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0153] At operation 920, the UE determines the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first DL-PRS resources transmitted by one or more first TRPs or (2) one or more first SL-PRS resources transmitted by one or more first sidelink anchor UEs. In an aspect, operation 910 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0154] As a first technique described herein, a location server may support different types of reference node configurations. In some cases, a first configuration may be a common reference node for both SL-RSTD measurements and DL-RSTD measurements. That is, the UE uses a common reference node for the downlink measurements and the sidelink measurements. In this case, the location server configures (or the UE reports) a single reference node for all DL-RSTD measurements, SL-RSTD measurements, and joint DL/SL-RSTD measurements (e.g., the joint RSTD measurement illustrated in FIG. 8).

[0155] In some cases, a second reference node configuration supported by a location server may be independent reference nodes for SL-RSTD measurements and DL-RSTD measurements. That is, the UE uses a TRP as the reference node for downlink measurements and a sidelink anchor UE as the reference node for sidelink measurements. For cross/joint downlink and sidelink measurements (e.g., the joint RSTD measurement in FIG. 8), the UE may determine whether to use a TRP (e.g., TRP1 in FIG. 8) or an anchor UE (e.g., Anchor UE1 in FIG 8) as the reference node for cross/joint downlink and sidelink measurements. In this case, the location server configures (or the UE reports) two reference nodes, one for all DL-RSTDs and one for all SL-RSTDs, and then, the UE uses either the downlink or sidelink reference node for the joint RSTD measurements. [0156] With reference to FIG. 9, where the at least one reference node is a reference TRP and a reference sidelink anchor UE, the one or more reference signal resources may be one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE. In this case, the UE may determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs. The UE may further determine the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0157] With continued reference to FIG. 9, in this case, determining the one or more joint downlink and sidelink RSTD measurements at operation 920 may include the UE determining the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and the one or more first DL-PRS resources transmitted by the one or more first TRPs or the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs. Alternatively, determining the one or more joint downlink and sidelink RSTD measurements at operation 920 may include the UE determining the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and the one or more first DL-PRS resources transmitted by the one or more first TRPs or the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs.

[0158] In some cases, a third reference node configuration supported by a location server may be different reference nodes for downlink measurements, sidelink measurements, and joint measurements. That is, a reference TRP may be configured to and/or reported by the UE for all DL-RSTD measurements, a reference anchor UE may be configured to and/or reported by the UE for all SL-RSTD measurements, and a reference node (either a TRP or an anchor UE) may be configured to and/or reported by the UE for all j oint/cross downlink and sidelink RSTD measurements. The reference node for all the joint RSTD measurements may be the same as or different than the first and the second reference nodes. [0159] With reference to FIG. 9, where the at least one reference node is three reference nodes, the three reference nodes may be a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements. The reference node may be a TRP or a sidelink anchor UE. In this case, the one or more reference signal resources may be one or more DL-PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node.

[0160] With continued reference to FIG. 9, where the at least one reference node is three reference nodes, the UE may further determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs. The UE may further determine the one or more SL-RSTD measurements based on the one or more SL- PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0161] In some cases, the at least one reference node may be obtained at operation 910 as an indication from a location server. In this case, the location server may signal the at least one reference node to the UE in an LPP Provide Assistance Data message or an LPP Provide Location Information message. However, the at least one UE may instead determine at least one second reference node different from the at least one reference node. In this case, the UE may report an indication of the at least one second reference node to the location server. The UE may report the at least one second reference node in an LPP Provide Location Information message.

[0162] The present disclosure further provides techniques for selecting time varying reference nodes for sidelink positioning (e.g., SL-TDOA). For example, for Mode 2 sidelink resource allocation (where the involved UEs negotiate the sidelink resources to use for the positioning session), the target UE selects the reference node for the sidelink measurements (e.g., measurements of SL-PRS resources). For cases where only the target UE is aware of the sidelink anchor UEs (e.g., for UE-based positioning and Mode 2 resource allocation), the target UE can sort all the anchor UEs based on their timing error group (TEG) timing error margin values or synchronization priorities. The target UE may form multiple groups of anchor UEs, and each group may have multiple sidelink anchor UEs. The target UE may select the reference anchor UE having a minimum TEG timing error margin value or a higher synchronization priority. For UE-assisted positioning cases, the target UE may report the selected reference anchor UE to the location server.

[0163] In some cases, all the anchor UEs may have the same TEG and the same synchronization priority. In such cases, instead of selecting the same reference anchor UE for each measurement occasion (the typical measurement occasion for Uu measurements is 160 ms), the target UE may use different reference anchor UEs for different positioning sessions or different reporting occasion within a single positioning session. In this case, all the reference anchor UEs may belong to the same TEG. However, for every reporting occasion, the target UE may select a different reference anchor UE, or the target UE may select a reference anchor UE every T ms or every N consecutive measurement occasions.

[0164] With reference to FIG. 9, the at least one reference node may be a first sidelink anchor UE of a plurality of sidelink anchor UEs and the plurality of sidelink anchor UEs may belong to a same TEG. In this case, a different sidelink anchor UE of the plurality of sidelink anchor UEs may be selected as the at least one reference node (1) every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements, (2) every T milliseconds (ms), where T is an integer greater than or equal to 1, or (3) every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

[0165] In some cases, after obtaining measurements from multiple reference anchor UEs, the location server or serving base station may assist the target UE to select the reference anchor UE for the remainder of the positioning session. The selection of the best reference anchor UE may be signaled through LPP, RRC, MAC control element (MAC- CE), or downlink control information (DCI).

[0166] With reference to FIG. 9, the UE may receive a selection of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling. Alternatively, the UE may transmit an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

[0167] In some cases, the location server may provide signaling to support the joint downlink and sidelink measurements between sidelink anchor UEs and TRPs. Where the location server is aware of all the sidelink anchor UEs configured for positioning a target UE, the location server may provide the configuration in the positioning assistance data (e.g., an LPP Provide Assistance Data message). The assistance data may identify all the SL-PRS resources (transmitted by the involved sidelink anchor UEs) and DL-PRS resources (transmitted by the involved TRPs) for which the target UE is expected/configured to report joint RSTD measurements. The location server may configure each pair of SL- PRS and DL-PRS to be measured and reported with a unique identifier. The target UE can then report each joint RSTD measurement with the identifier provided in the assistance data. In this case, the target UE would not need to report the PRS ID(s) of the measured DL-PRS resource(s) or the sidelink anchor UE ID(s) of the anchor UE(s) transmitting the measured SL-PRS resource(s).

[0168] With reference to FIG. 9, the UE may receive, from a location server (e.g., in an LPP Provide Assistance Data message or an LPP Request Location Information message), a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources. The UE may further receive, from the location server (e.g., in an LPP Provide Assistance Data message or an LPP Request Location Information message), a set of identifiers, where each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources. The UE may further report, to the location server (e.g., in an LPP Provide Location Information message), a subset of the set of identifiers, where each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL-PRS resources and a SL-PRS resource of the one or more first SL-PRS resources. In some cases, the subset of the set of identifiers may be reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

[0169] In some cases, the location server may configure a minimum, recommended, or requested number of measurements that need to be reported by the UE for joint sidelink and downlink measurements. It would then be up to UE implementation which pairs of SL- PRS and DL-PRS resources to select for the joint RSTD measurements. In some cases, the target UE may select the PRS resources with high signal-to-noise ratio (SNR) and good (e.g., above some threshold) line of sight indicator. [0170] With reference to FIG. 9, the UE may receive, from a location server (e.g., in an LPP Request Location Information message), a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements. The UE may further report, to the location server (e.g., in an LPP Provide Location Information message), the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request. In some cases, the request may indicate a number of the one or more joint downlink and sidelink RSTD measurements to report.

[0171] Different priority rules may be used to determine the order in which to measure the SL- PRS resources transmitted by anchor UEs. Priority rules for DL-PRS resource measurements are already defined, as discussed above with reference to FIG. 6. Specifically, the UE assumes the DL-PRS resources in the assistance data are sorted in a decreasing order of measurement priority. For SL-PRS resources, the location server may provide a sidelink priority rule in the assistance data.

[0172] As a first option, there may be an independent priority rule for Uu and sidelink resources. That is, there is one priority rule for DL-PRS resources and another priority rule for SL- PRS resources. There is no relation between the downlink priority rule and the sidelink priority rule. As a second option, there may be a common priority rule for Uu and sidelink resources. That is, there may be the same priority rule for DL-PRS resources and SL- PRS resources.

[0173] FIG. 10 illustrates different example priority rules for measuring SL-PRS resources, according to aspects of the disclosure. In FIG. 10, each TRP block (labeled “TRP1,” “TRP2,” and “TRP3”) represents the one or more DL-PRS resources transmitted by a respective TRP (i.e., “TRP1,” “TRP2,” or “TRP3”). Each UE block (labeled “UE1,” “UE2,” and “UE3”) represents the one or more SL-PRS resources transmitted by a respective sidelink anchor UE (i.e., “UE1,” “UE2,” or “UE3”). The index number of each TRP and UE indicates the relative priority of that TRP and UE. That is, TRP1 has a higher priority than TRP2, which has a higher priority than TRP3. Likewise, UE1 has a higher priority than UE2, which has a higher priority than UE3.

[0174] Diagram 1010 illustrates a first priority rule (denoted “Case 1”) for measuring SL-PRS resources. In this case, a target UE will first measure all the DL-PRS resources in the priority order indicated in the assistance data. The target UE will then measure all the SL-PRS resources in priority order. In the example of diagram 1010, TRP1 is the reference node, and thus, the remaining PRS resources are measured with respect to the DL-PRS resource(s) transmitted by TRP1.

[0175] Diagram 1020 illustrates a second priority rule (denoted “Case 2”) for measuring SL-PRS resources. In this case, a target UE will first measure all the SL-PRS resources in the priority order indicated in the assistance data. The target UE will then measure all the DL-PRS resources in priority order. In the example of diagram 1020, TRP1 is the reference node, and thus, the remaining PRS resources are measured with respect to the DL-PRS resource(s) transmitted by TRP1.

[0176] Diagram 1030 illustrates a third priority rule (denoted “Case 3”) for measuring SL-PRS resources. In this case, the priority rule is defined over all the DL-PRS resources and SL- PRS resources. The target UE will follow the common priority rule setting provided by the location server. The priority rule may be provided as a list of DL-PRS and SL-PRS identifiers, or a list of TRP and anchor UE identifiers, or the like.

[0177] FIG. 11 illustrates an example method 1100 of wireless communication, according to aspects of the disclosure. In an aspect, method 1100 may be performed by a UE (e.g., any of the UEs described herein).

[0178] At 1110, the UE receives, from a location server (e.g., in an LPP Provide Assistance Data message or an LPP Request Location Information message), a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources. In an aspect, operation 1110 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0179] In an aspect, the priority rule for measuring the plurality of SL-PRS resources may be independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources may be a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

[0180] At 1120, the UE measures a plurality of DL-PRS resources, including the one or more first DL-PRS resources, in a priority order based on the priority rule. In an aspect, operation 1120 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0181] At 1130, the UE measures the plurality of SL-PRS resources in a priority order based on the priority rule. In an aspect, operation 1130 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0182] In some cases, all of the plurality of SL-PRS resources may be measured after all of the plurality of DL-PRS resources are measured, or all of the plurality of DL-PRS resources may be measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL-PRS resources may be alternated with measurements of the plurality of DL-PRS resources.

[0183] With reference back to the first technique described herein, where a location server may support a configuration for a common reference node for both SL-RSTD measurements and DL-RSTD measurements, FIG. 12 illustrates an example method 1200 of wireless communication, according to aspects of the disclosure. In an aspect, method 1200 may be performed by a UE (e.g., any of the UEs described herein).

[0184] At 1210, the UE obtains a single reference node for one or more DL-RSTD measurements and one or more SL-RSTD measurements. In an aspect, operation 1210 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0185] At 1220, the UE determines the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first TRPs. In an aspect, operation 1220 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0186] At 1230, the UE determines the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first SL-PRS resources transmitted by one or more first sidelink anchor UEs. In an aspect, operation 1230 may be performed by the one or more WWAN transceivers 310, the one or more processors 332, memory 340, and/or positioning component 342, any or all of which may be considered means for performing this operation.

[0187] In an aspect, the method 1200 may further include (not shown), determining one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and (1) one or more second DL- PRS resources transmitted by one or more second TRPs or (2) one or more second SL- PRS resources transmitted by one or more second sidelink anchor UEs.

[0188] In an aspect, the single reference node may be a reference TRP or a reference sidelink anchor UE.

[0189] In an aspect, the single reference node may be obtained as an indication from a location server (e.g., LMF 270). However, the UE may instead determine a second single reference node different from the single reference node. In that case, the method 1200 may further include (not shown) reporting, to the location server (e.g., LMF 270), an indication of the second single reference node.

[0190] As will be appreciated, a technical advantage of the methods 900, 1100, and 1200 is enabling the UE to select a reference node for joint positioning measurements (e.g., joint RSTD measurements).

[0191] In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the example clauses have more features than are explicitly mentioned in each clause. Rather, the various aspects of the disclosure may include fewer than all features of an individual example clause disclosed. Therefore, the following clauses should hereby be deemed to be incorporated in the description, wherein each clause by itself can stand as a separate example. Although each dependent clause can refer in the clauses to a specific combination with one of the other clauses, the aspect(s) of that dependent clause are not limited to the specific combination. It will be appreciated that other example clauses can also include a combination of the dependent clause aspect(s) with the subject matter of any other dependent clause or independent clause or a combination of any feature with other dependent and independent clauses. The various aspects disclosed herein expressly include these combinations, unless it is explicitly expressed or can be readily inferred that a specific combination is not intended (e.g., contradictory aspects, such as defining an element as both an electrical insulator and an electrical conductor). Furthermore, it is also intended that aspects of a clause can be included in any other independent clause, even if the clause is not directly dependent on the independent clause.

[0192] Implementation examples are described in the following numbered clauses:

[0193] Clause 1. A method of wireless communication performed by a user equipment (UE), comprising: obtaining at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determining the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0194] Clause 2. The method of clause 1, wherein: the at least one reference node consists of a reference TRP and a reference sidelink anchor UE, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE.

[0195] Clause 3. The method of clause 2, further comprising: determining the one or more DL- RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determining the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0196] Clause 4. The method of any of clauses 2 to 3, wherein determining the one or more joint downlink and sidelink RSTD measurements comprises: determining the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs; or determining the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs.

[0197] Clause 5. The method of any of clauses 1 to 4, wherein: the at least one reference node consists of three reference nodes, the three reference nodes are a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements, and the one or more reference signal resources comprise one or more DL- PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node.

[0198] Clause 6. The method of clause 5, further comprising: determining the one or more DL- RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determining the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0199] Clause 7. The method of any of clauses 5 to 6, wherein the reference node is: a TRP, or a sidelink anchor UE.

[0200] Clause 8. The method of any of clauses 1 to 7, wherein the at least one reference node is obtained from a location server.

[0201] Clause 9. The method of clause 8, further comprising: determining at least one second reference node different than the at least one reference node; and reporting, to the location server, an indication of the at least one second reference node.

[0202] Clause 10. The method of any of clauses 1 to 9, further comprising: receiving, from a location server, a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources; receiving, from the location server, a set of identifiers, wherein each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources; and reporting, to the location server, a subset of the set of identifiers, wherein each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL-PRS resources and a SL-PRS resource of the one or more first SL-PRS resources.

[0203] Clause 11. The method of clause 10, wherein the subset of the set of identifiers is reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

[0204] Clause 12. The method of any of clauses 1 to 11, further comprising: receiving, from a location server, a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements; and reporting, to a location server, the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request.

[0205] Clause 13. The method of clause 12, wherein the request indicates a number of the one or more joint downlink and sidelink RSTD measurements to report.

[0206] Clause 14. The method of any of clauses 1 to 13, wherein: the at least one reference node is a first sidelink anchor UE of a plurality of sidelink anchor UEs, and the plurality of sidelink anchor UEs belong to a same timing error group (TEG).

[0207] Clause 15. The method of clause 14, wherein a different sidelink anchor UE of the plurality of sidelink anchor UEs is selected as the at least one reference node: every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements, every T milliseconds (ms), where T is an integer greater than or equal to 1, or every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

[0208] Clause 16. The method of any of clauses 14 to 15, further comprising: receiving a selection of the first sidelink anchor UE via Long-Term Evolution (LTE) positioning protocol (LPP) signaling, radio resource control (RRC) signaling, medium access control control element (MAC-CE) signaling, or downlink control information (DCI) signaling; or transmitting an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

[0209] Clause 17. The method of any of clauses 1 to 16, further comprising: receiving, from a location server, a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources. [0210] Clause 18. The method of clause 17, wherein: the priority rule for measuring the plurality of SL-PRS resources is independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources is a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

[0211] Clause 19. The method of any of clauses 17 to 18, further comprising: measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, in a priority order based on the priority rule; and measuring the plurality of SL-PRS resources in a priority order based on the priority rule.

[0212] Clause 20. The method of clause 19, wherein: all of the plurality of SL-PRS resources are measured after all of the plurality of DL-PRS resources are measured, all of the plurality of DL-PRS resources are measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL-PRS resources are alternated with measurements of the plurality of DL-PRS resources.

[0213] Clause 21. A method of wireless communication performed by a user equipment (UE), comprising: obtaining a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determining the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determining the one or more SL- RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL- PRS) resources transmitted by one or more first sidelink anchor UEs.

[0214] Clause 22. The method of clause 21, further comprising: determining one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and (1) one or more second DL-PRS resources transmitted by one or more second TRPs or (2) one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0215] Clause 23. The method of any of clauses 21 to 22, wherein the single reference node is: a reference TRP, or a reference sidelink anchor UE. [0216] Clause 24. The method of any of clauses 21 to 23, wherein the single reference node is obtained from a location server.:

[0217] Clause 25. The method of clause 24, further comprising: determining a second single reference node different from the single reference node; and reporting, to the location server, an indication of the second single reference node.

[0218] Clause 26. A user equipment (UE), comprising: one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: obtain at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determine the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs. [0219] Clause 27. The UE of clause 26, wherein: the at least one reference node consists of a reference TRP and a reference sidelink anchor UE, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE.

[0220] Clause 28. The UE of clause 27, wherein the one or more processors, either alone or in combination, are further configured to: determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determine the one or more SL-RSTD measurements based on the one or more SL- PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0221] Clause 29. The UE of any of clauses 27 to 28, wherein the one or more processors configured to determine the one or more j oint downlink and sidelink RSTD measurements comprises the one or more processors, either alone or in combination, configured to: determine the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs; or determine the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs.

[0222] Clause 30. The UE of any of clauses 26 to 29, wherein: the at least one reference node consists of three reference nodes, the three reference nodes are a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements, and the one or more reference signal resources comprise one or more DL- PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node.

[0223] Clause 31. The UE of clause 30, wherein the one or more processors, either alone or in combination, are further configured to: determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determine the one or more SL-RSTD measurements based on the one or more SL- PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0224] Clause 32. The UE of any of clauses 30 to 31, wherein the reference node is: a TRP, or a sidelink anchor UE.

[0225] Clause 33. The UE of any of clauses 26 to 32, wherein the at least one reference node is obtained from a location server.

[0226] Clause 34. The UE of clause 33, wherein the one or more processors, either alone or in combination, are further configured to: determine at least one second reference node different than the at least one reference node; and report, via the one or more transceivers, to the location server, an indication of the at least one second reference node. [0227] Clause 35. The UE of any of clauses 26 to 34, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, from a location server, a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources; receive, via the one or more transceivers, from the location server, a set of identifiers, wherein each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources; and report, via the one or more transceivers, to the location server, a subset of the set of identifiers, wherein each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL- PRS resources and a SL-PRS resource of the one or more first SL-PRS resources.

[0228] Clause 36. The UE of clause 35, wherein the subset of the set of identifiers is reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

[0229] Clause 37. The UE of any of clauses 26 to 36, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, from a location server, a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements; and report, via the one or more transceivers, to a location server, the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request.

[0230] Clause 38. The UE of clause 37, wherein the request indicates a number of the one or more joint downlink and sidelink RSTD measurements to report.

[0231] Clause 39. The UE of any of clauses 26 to 38, wherein: the at least one reference node is a first sidelink anchor UE of a plurality of sidelink anchor UEs, and the plurality of sidelink anchor UEs belong to a same timing error group (TEG).

[0232] Clause 40. The UE of clause 39, wherein a different sidelink anchor UE of the plurality of sidelink anchor UEs is selected as the at least one reference node: every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements, every T milliseconds (ms), where T is an integer greater than or equal to 1, or every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

[0233] Clause 41. The UE of any of clauses 39 to 40, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, a selection of the first sidelink anchor UE via Long-Term Evolution (LTE) positioning protocol (LPP) signaling, radio resource control (RRC) signaling, medium access control control element (MAC-CE) signaling, or downlink control information (DCI) signaling; or transmit, via the one or more transceivers, an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

[0234] Clause 42. The UE of any of clauses 26 to 41, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, from a location server, a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources.

[0235] Clause 43. The UE of clause 42, wherein: the priority rule for measuring the plurality of SL-PRS resources is independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources is a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

[0236] Clause 44. The UE of any of clauses 42 to 43, wherein the one or more processors, either alone or in combination, are further configured to: measure a plurality of DL-PRS resources, including the one or more first DL-PRS resources, in a priority order based on the priority rule; and measure the plurality of SL-PRS resources in a priority order based on the priority rule.

[0237] Clause 45. The UE of clause 44, wherein: all of the plurality of SL-PRS resources are measured after all of the plurality of DL-PRS resources are measured, all of the plurality of DL-PRS resources are measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL-PRS resources are alternated with measurements of the plurality of DL-PRS resources.

[0238] Clause 46. A user equipment (UE), comprising: one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: obtain a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determine the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determine the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs. [0239] Clause 47. The UE of clause 46, wherein the one or more processors, either alone or in combination, are further configured to: determine one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and (1) one or more second DL-PRS resources transmitted by one or more second TRPs or (2) one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0240] Clause 48. The UE of any of clauses 46 to 47, wherein the single reference node is: a reference TRP, or a reference sidelink anchor UE.

[0241] Clause 49. The UE of any of clauses 46 to 48, wherein the single reference node is obtained from a location server.:

[0242] Clause 50. The UE of clause 49, wherein the one or more processors, either alone or in combination, are further configured to: determine a second single reference node different from the single reference node; and report, via the one or more transceivers, to the location server, an indication of the second single reference node.

[0243] Clause 51. A user equipment (UE), comprising: means for obtaining at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and means for determining the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0244] Clause 52. The UE of clause 51, wherein: the at least one reference node consists of a reference TRP and a reference sidelink anchor UE, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE.

[0245] Clause 53. The UE of clause 52, further comprising: means for determining the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and means for determining the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0246] Clause 54. The UE of any of clauses 52 to 53, wherein the means for determining the one or more joint downlink and sidelink RSTD measurements comprises: means for determining the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs; or means for determining the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs.

[0247] Clause 55. The UE of any of clauses 51 to 54, wherein: the at least one reference node consists of three reference nodes, the three reference nodes are a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements, and the one or more reference signal resources comprise one or more DL- PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node. [0248] Clause 56. The UE of clause 55, further comprising: means for determining the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and means for determining the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0249] Clause 57. The UE of any of clauses 55 to 56, wherein the reference node is: a TRP, or a sidelink anchor UE.

[0250] Clause 58. The UE of any of clauses 51 to 57, wherein the at least one reference node is obtained from a location server.

[0251] Clause 59. The UE of clause 58, further comprising: means for determining at least one second reference node different than the at least one reference node; and means for reporting, to the location server, an indication of the at least one second reference node.

[0252] Clause 60. The UE of any of clauses 51 to 59, further comprising: means for receiving, from a location server, a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources; means for receiving, from the location server, a set of identifiers, wherein each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources; and means for reporting, to the location server, a subset of the set of identifiers, wherein each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL-PRS resources and a SL-PRS resource of the one or more first SL-PRS resources.

[0253] Clause 61. The UE of clause 60, wherein the subset of the set of identifiers is reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

[0254] Clause 62. The UE of any of clauses 51 to 61, further comprising: means for receiving, from a location server, a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL- RSTD measurements; and means for reporting, to a location server, the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request.

[0255] Clause 63. The UE of clause 62, wherein the request indicates a number of the one or more joint downlink and sidelink RSTD measurements to report.

[0256] Clause 64. The UE of any of clauses 51 to 63, wherein: the at least one reference node is a first sidelink anchor UE of a plurality of sidelink anchor UEs, and the plurality of sidelink anchor UEs belong to a same timing error group (TEG).

[0257] Clause 65. The UE of clause 64, wherein a different sidelink anchor UE of the plurality of sidelink anchor UEs is selected as the at least one reference node: every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements, every T milliseconds (ms), where T is an integer greater than or equal to 1, or every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

[0258] Clause 66. The UE of any of clauses 64 to 65, further comprising: means for receiving a selection of the first sidelink anchor UE via Long-Term Evolution (LTE) positioning protocol (LPP) signaling, radio resource control (RRC) signaling, medium access control control element (MAC-CE) signaling, or downlink control information (DCI) signaling; or means for transmitting an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

[0259] Clause 67. The UE of any of clauses 51 to 66, further comprising: means for receiving, from a location server, a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources.

[0260] Clause 68. The UE of clause 67, wherein: the priority rule for measuring the plurality of SL-PRS resources is independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources is a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

[0261] Clause 69. The UE of any of clauses 67 to 68, further comprising: means for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, in a priority order based on the priority rule; and means for measuring the plurality of SL-PRS resources in a priority order based on the priority rule. [0262] Clause 70. The UE of clause 69, wherein: all of the plurality of SL-PRS resources are measured after all of the plurality of DL-PRS resources are measured, all of the plurality of DL-PRS resources are measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL-PRS resources are alternated with measurements of the plurality of DL-PRS resources.

[0263] Clause 71. A user equipment (UE), comprising: means for obtaining a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; means for determining the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and means for determining the one or more SL- RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL- PRS) resources transmitted by one or more first sidelink anchor UEs.

[0264] Clause 72. The UE of clause 71, further comprising: means for determining one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and (1) one or more second DL- PRS resources transmitted by one or more second TRPs or (2) one or more second SL- PRS resources transmitted by one or more second sidelink anchor UEs.

[0265] Clause 73. The UE of any of clauses 71 to 72, wherein the single reference node is: a reference TRP, or a reference sidelink anchor UE.

[0266] Clause 74. The UE of any of clauses 71 to 73, wherein the single reference node is obtained from a location server.:

[0267] Clause 75. The UE of clause 74, further comprising: means for determining a second single reference node different from the single reference node; and means for reporting, to the location server, an indication of the second single reference node.

[0268] Clause 76. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: obtain at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determine the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0269] Clause 77. The non-transitory computer-readable medium of clause 76, wherein: the at least one reference node consists of a reference TRP and a reference sidelink anchor UE, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE.

[0270] Clause 78. The non-transitory computer-readable medium of clause 77, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determine the one or more SL- RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0271] Clause 79. The non-transitory computer-readable medium of any of clauses 77 to 78, wherein the computer-executable instructions that, when executed by the UE, cause the UE to determine the one or more joint downlink and sidelink RSTD measurements comprise computer-executable instructions that, when executed by the UE, cause the UE to: determine the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs; or determine the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs. [0272] Clause 80. The non-transitory computer-readable medium of any of clauses 76 to 79, wherein: the at least one reference node consists of three reference nodes, the three reference nodes are a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node.

[0273] Clause 81. The non-transitory computer-readable medium of clause 80, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determine the one or more SL- RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

[0274] Clause 82. The non-transitory computer-readable medium of any of clauses 80 to 81, wherein the reference node is: a TRP, or a sidelink anchor UE.

[0275] Clause 83. The non-transitory computer-readable medium of any of clauses 76 to 82, wherein the at least one reference node is obtained from a location server.

[0276] Clause 84. The non-transitory computer-readable medium of clause 83, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: determine at least one second reference node different than the at least one reference node; and report, to the location server, an indication of the at least one second reference node.

[0277] Clause 85. The non-transitory computer-readable medium of any of clauses 76 to 84, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: receive, from a location server, a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources; receive, from the location server, a set of identifiers, wherein each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources; and report, to the location server, a subset of the set of identifiers, wherein each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL-PRS resources and a SL-PRS resource of the one or more first SL-PRS resources.

[0278] Clause 86. The non-transitory computer-readable medium of clause 85, wherein the subset of the set of identifiers is reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

[0279] Clause 87. The non-transitory computer-readable medium of any of clauses 76 to 86, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: receive, from a location server, a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements; and report, to a location server, the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request.

[0280] Clause 88. The non-transitory computer-readable medium of clause 87, wherein the request indicates a number of the one or more joint downlink and sidelink RSTD measurements to report.

[0281] Clause 89. The non-transitory computer-readable medium of any of clauses 76 to 88, wherein: the at least one reference node is a first sidelink anchor UE of a plurality of sidelink anchor UEs, and the plurality of sidelink anchor UEs belong to a same timing error group (TEG).

[0282] Clause 90. The non-transitory computer-readable medium of clause 89, wherein a different sidelink anchor UE of the plurality of sidelink anchor UEs is selected as the at least one reference node: every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements, every T milliseconds (ms), where T is an integer greater than or equal to 1, or every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

[0283] Clause 91. The non-transitory computer-readable medium of any of clauses 89 to 90, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: receive a selection of the first sidelink anchor UE via Long-Term Evolution (LTE) positioning protocol (LPP) signaling, radio resource control (RRC) signaling, medium access control control element (MAC-CE) signaling, or downlink control information (DCI) signaling; or transmit an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

[0284] Clause 92. The non-transitory computer-readable medium of any of clauses 76 to 91, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: receive, from a location server, a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources.

[0285] Clause 93. The non-transitory computer-readable medium of clause 92, wherein: the priority rule for measuring the plurality of SL-PRS resources is independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources is a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

[0286] Clause 94. The non-transitory computer-readable medium of any of clauses 92 to 93, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: measure a plurality of DL-PRS resources, including the one or more first DL-PRS resources, in a priority order based on the priority rule; and measure the plurality of SL-PRS resources in a priority order based on the priority rule.

[0287] Clause 95. The non-transitory computer-readable medium of clause 94, wherein: all of the plurality of SL-PRS resources are measured after all of the plurality of DL-PRS resources are measured, all of the plurality of DL-PRS resources are measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL- PRS resources are alternated with measurements of the plurality of DL-PRS resources.

[0288] Clause 96. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: obtain a single reference node for one or more downlink reference signal time difference (DL- RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determine the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determine the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

[0289] Clause 97. The non-transitory computer-readable medium of clause 96, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: determine one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and

(1) one or more second DL-PRS resources transmitted by one or more second TRPs or

(2) one or more second SL-PRS resources transmitted by one or more second sidelink anchor LEs.

[0290] Clause 98. The non-transitory computer-readable medium of any of clauses 96 to 97, wherein the single reference node is: a reference TRP, or a reference sidelink anchor LE.

[0291] Clause 99. The non-transitory computer-readable medium of any of clauses 96 to 98, wherein the single reference node is obtained from a location server.:

[0292] Clause 100. The non-transitory computer-readable medium of clause 99, further comprising computer-executable instructions that, when executed by the LE, cause the LE to: determine a second single reference node different from the single reference node; and report, to the location server, an indication of the second single reference node.

[0293] Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0294] Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0295] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an ASIC, a field-programable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general -purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0296] The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An example storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

[0297] In one or more example aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0298] While the foregoing disclosure shows illustrative aspects of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. For example, the functions, steps and/or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Further, no component, function, action, or instruction described or claimed herein should be construed as critical or essential unless explicitly described as such. Furthermore, as used herein, the terms “set,” “group,” and the like are intended to include one or more of the stated elements. Also, as used herein, the terms “has,” “have,” “having,” “comprises,” “comprising,” “includes,” “including,” and the like does not preclude the presence of one or more additional elements (e.g., an element “having” A may also have B). Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of’) or the alternatives are mutually exclusive (e.g., “one or more” should not be interpreted as “one and more”). Furthermore, although components, functions, actions, and instructions may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Accordingly, as used herein, the articles “a,” “an,” “the,” and “said” are intended to include one or more of the stated elements. Additionally, as used herein, the terms “at least one” and “one or more” encompass “one” component, function, action, or instruction performing or capable of performing a described or claimed functionality and also “two or more” components, functions, actions, or instructions performing or capable of performing a described or claimed functionality in combination.

Claims

CLAIMS What is claimed is:

1. A method of wireless communication performed by a user equipment (UE), comprising: obtaining at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determining the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

2. The method of claim 1, wherein: the at least one reference node consists of a reference TRP and a reference sidelink anchor UE, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE.

3. The method of claim 2, further comprising: determining the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determining the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

4. The method of claim 2, wherein determining the one or more joint downlink and sidelink RSTD measurements comprises: determining the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs; or determining the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs.

5. The method of claim 1, wherein: the at least one reference node consists of three reference nodes, the three reference nodes are a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node.

6. The method of claim 5, further comprising: determining the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determining the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

7. The method of claim 5, wherein the reference node is: a TRP, or a sidelink anchor UE.

8. The method of claim 1, wherein the at least one reference node is obtained from a location server.

9. The method of claim 8, further comprising: determining at least one second reference node different than the at least one reference node; and reporting, to the location server, an indication of the at least one second reference node.

10. The method of claim 1, further comprising: receiving, from a location server, a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources; receiving, from the location server, a set of identifiers, wherein each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources; and reporting, to the location server, a subset of the set of identifiers, wherein each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL-PRS resources and a SL-PRS resource of the one or more first SL-PRS resources.

11. The method of claim 10, wherein the subset of the set of identifiers is reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

12. The method of claim 1, further comprising: receiving, from a location server, a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements; and reporting, to a location server, the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request.

13. The method of claim 12, wherein the request indicates a number of the one or more joint downlink and sidelink RSTD measurements to report.

14. The method of claim 1, wherein: the at least one reference node is a first sidelink anchor UE of a plurality of sidelink anchor UEs, and the plurality of sidelink anchor UEs belong to a same timing error group (TEG).

15. The method of claim 14, wherein a different sidelink anchor UE of the plurality of sidelink anchor UEs is selected as the at least one reference node: every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL- RSTD measurements, every T milliseconds (ms), where T is an integer greater than or equal to 1, or every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

16. The method of claim 14, further comprising: receiving a selection of the first sidelink anchor UE via Long-Term Evolution (LTE) positioning protocol (LPP) signaling, radio resource control (RRC) signaling, medium access control control element (MAC-CE) signaling, or downlink control information (DCI) signaling; or transmitting an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

17. The method of claim 1, further comprising: receiving, from a location server, a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources.

18. The method of claim 17, wherein: the priority rule for measuring the plurality of SL-PRS resources is independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources is a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

19. The method of claim 17, further comprising: measuring a plurality of DL-PRS resources, including the one or more first DL- PRS resources, in a priority order based on the priority rule; and measuring the plurality of SL-PRS resources in a priority order based on the priority rule.

20. The method of claim 19, wherein: all of the plurality of SL-PRS resources are measured after all of the plurality of DL-PRS resources are measured, all of the plurality of DL-PRS resources are measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL-PRS resources are alternated with measurements of the plurality of DL-PRS resources.

21. A method of wireless communication performed by a user equipment (UE), comprising: obtaining a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determining the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determining the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

22. The method of claim 21, further comprising: determining one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and (1) one or more second DL-PRS resources transmitted by one or more second TRPs or (2) one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

23. The method of claim 21, wherein the single reference node is: a reference TRP, or a reference sidelink anchor UE.

24. The method of claim 21, wherein the single reference node is obtained from a location server. :

25. The method of claim 24, further comprising: determining a second single reference node different from the single reference node; and reporting, to the location server, an indication of the second single reference node.

26. A user equipment (UE), comprising: one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: obtain at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determine the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

27. The UE of claim 26, wherein: the at least one reference node consists of a reference TRP and a reference sidelink anchor UE, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP and one or more SL-PRS resources transmitted by the reference sidelink anchor UE.

28. The UE of claim 27, wherein the one or more processors, either alone or in combination, are further configured to: determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determine the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

29. The UE of claim 27, wherein the one or more processors configured to determine the one or more joint downlink and sidelink RSTD measurements comprises the one or more processors, either alone or in combination, configured to: determine the one or more joint downlink and sidelink RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs; or determine the one or more joint downlink and sidelink RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and (1) the one or more first DL-PRS resources transmitted by the one or more first TRPs or (2) the one or more first SL-PRS resources transmitted by the one or more first sidelink anchor UEs.

30. The UE of claim 26, wherein: the at least one reference node consists of three reference nodes, the three reference nodes are a reference TRP for the one or more DL-RSTD measurements, a reference sidelink anchor UE for the one or more SL-RSTD measurements, and a reference node for the joint downlink and sidelink RSTD measurements, and the one or more reference signal resources comprise one or more DL-PRS resources transmitted by the reference TRP, one or more SL-PRS resources transmitted by the reference sidelink anchor UE, and one or more PRS resources transmitted by the reference node.

31. The UE of claim 30, wherein the one or more processors, either alone or in combination, are further configured to: determine the one or more DL-RSTD measurements based on the one or more DL-PRS resources transmitted by the reference TRP and one or more second DL-PRS resources transmitted by one or more second TRPs; and determine the one or more SL-RSTD measurements based on the one or more SL-PRS resources transmitted by the reference sidelink anchor UE and one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

32. The UE of claim 30, wherein the reference node is: a TRP, or a sidelink anchor UE.

33. The UE of claim 26, wherein the at least one reference node is obtained from a location server.

34. The UE of claim 33, wherein the one or more processors, either alone or in combination, are further configured to: determine at least one second reference node different than the at least one reference node; and report, via the one or more transceivers, to the location server, an indication of the at least one second reference node.

35. The UE of claim 26, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, from a location server, a configuration of the one or more reference signal resources, the one or more first DL-PRS resources, and the one or more SL-PRS resources; receive, via the one or more transceivers, from the location server, a set of identifiers, wherein each identifier of the set of identifiers identifies a pair of a DL-PRS resource of a plurality of DL-PRS resources, including the one or more first DL-PRS resources, and a SL-PRS resource of a plurality of SL-PRS resources, including the one or more first SL-PRS resources; and report, via the one or more transceivers, to the location server, a subset of the set of identifiers, wherein each identifier of the subset of the set of identifiers identifies a pair of a DL-PRS resource of the one or more first DL-PRS resources and a SL-PRS resource of the one or more first SL-PRS resources.

36. The UE of claim 35, wherein the subset of the set of identifiers is reported to the location server instead of identifiers of the one or more first DL-PRS resources and the one or more first SL-PRS resources.

37. The UE of claim 26, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, from a location server, a request to obtain the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements; and report, via the one or more transceivers, to a location server, the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL-RSTD measurements in response to the request.

38. The UE of claim 37, wherein the request indicates a number of the one or more joint downlink and sidelink RSTD measurements to report.

39. The UE of claim 26, wherein: the at least one reference node is a first sidelink anchor UE of a plurality of sidelink anchor UEs, and the plurality of sidelink anchor UEs belong to a same timing error group (TEG).

40. The UE of claim 39, wherein a different sidelink anchor UE of the plurality of sidelink anchor UEs is selected as the at least one reference node: every reporting occasion of the one or more joint downlink and sidelink RSTD measurements, the one or more DL-RSTD measurements, and the one or more SL- RSTD measurements, every T milliseconds (ms), where T is an integer greater than or equal to 1, or every N consecutive measurement occasions, where N is an integer greater than or equal to 1.

41. The UE of claim 39, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, a selection of the first sidelink anchor UE via Long-Term Evolution (LTE) positioning protocol (LPP) signaling, radio resource control (RRC) signaling, medium access control control element (MAC-CE) signaling, or downlink control information (DCI) signaling; or transmit, via the one or more transceivers, an indication of the first sidelink anchor UE via LPP signaling, RRC signaling, MAC-CE signaling, or DCI signaling.

42. The UE of claim 26, wherein the one or more processors, either alone or in combination, are further configured to: receive, via the one or more transceivers, from a location server, a priority rule for measuring at least a plurality of SL-PRS resources, including the one or more first SL-PRS resources.

43. The UE of claim 42, wherein: the priority rule for measuring the plurality of SL-PRS resources is independent of a second priority rule for measuring a plurality of DL-PRS resources, including the one or more first DL-PRS resources, or the priority rule for measuring the plurality of SL-PRS resources is a common priority rule for measuring both the plurality of SL-PRS resources and the plurality of DL-PRS resources.

44. The UE of claim 42, wherein the one or more processors, either alone or in combination, are further configured to: measure a plurality of DL-PRS resources, including the one or more first DL- PRS resources, in a priority order based on the priority rule; and measure the plurality of SL-PRS resources in a priority order based on the priority rule.

45. The UE of claim 44, wherein: all of the plurality of SL-PRS resources are measured after all of the plurality of DL-PRS resources are measured, all of the plurality of DL-PRS resources are measured after all of the plurality of SL-PRS resources are measured, or measurements of the plurality of SL-PRS resources are alternated with measurements of the plurality of DL-PRS resources.

46. A user equipment (UE), comprising: one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: obtain a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL- RSTD) measurements; determine the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determine the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

47. The UE of claim 46, wherein the one or more processors, either alone or in combination, are further configured to: determine one or more joint downlink and sidelink RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and (1) one or more second DL-PRS resources transmitted by one or more second TRPs or (2) one or more second SL-PRS resources transmitted by one or more second sidelink anchor UEs.

48. The UE of claim 46, wherein the single reference node is: a reference TRP, or a reference sidelink anchor UE.

49. The UE of claim 46, wherein the single reference node is obtained from a location server.:

50. The UE of claim 49, wherein the one or more processors, either alone or in combination, are further configured to: determine a second single reference node different from the single reference node; and report, via the one or more transceivers, to the location server, an indication of the second single reference node.

51. A user equipment (UE), comprising: means for obtaining at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL- RSTD) measurements, or (3) both; and means for determining the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

52. A user equipment (UE), comprising: means for obtaining a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL- RSTD) measurements; means for determining the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and means for determining the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

53. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: obtain at least one reference node for one or more joint downlink and sidelink reference signal time difference (RSTD) measurements and (1) one or more downlink RSTD (DL-RSTD) measurements, (2) one or more sidelink RSTD (SL-RSTD) measurements, or (3) both; and determine the one or more joint downlink and sidelink RSTD measurements based on one or more reference signal resources transmitted by the at least one reference node and (1) one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs) or (2) one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.

54. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: obtain a single reference node for one or more downlink reference signal time difference (DL-RSTD) measurements and one or more sidelink RSTD (SL-RSTD) measurements; determine the one or more DL-RSTD measurements based on one or more reference signal resources transmitted by the single reference node and one or more first downlink positioning reference signal (DL-PRS) resources transmitted by one or more first transmission-reception points (TRPs); and determine the one or more SL-RSTD measurements based on the one or more reference signal resources transmitted by the single reference node and one or more first sidelink positioning reference signal (SL-PRS) resources transmitted by one or more first sidelink anchor UEs.