WO2024235578A1

WO2024235578A1 - Method, apparatus and computer program

Info

Publication number: WO2024235578A1
Application number: PCT/EP2024/060990
Authority: WO
Inventors: Taylan SAHIN; Torsten WILDSCHEK; Ryan Keating; Diomidis Michalopoulos; Stepan Kucera; Prajwal KESHAVAMURTHY
Original assignee: Nokia Technologies Oy
Priority date: 2023-05-12
Filing date: 2024-04-23
Publication date: 2024-11-21
Also published as: GB2629846A; GB202307064D0

Abstract

There is provided an apparatus comprising means for providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station, and means for receiving, from the at least one second base station via the core network entity, information related to the resource allocation. The apparatus also comprises means for determining a further resource allocation for sidelink based on the received information, and means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

Description

METHOD, APPARATUS AND COMPUTER PROGRAM

Field

The present application relates to a method, apparatus, and computer program for a wireless communication system.

Background

A communication system may be a facility that enables communication sessions between two or more entities such as user terminals, base stations/access points and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system may be provided, for example, by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

Summary

According to an aspect, there is provided an apparatus comprising: means for providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; means for receiving, from the at least one second base station via the core network entity, information related to the resource allocation; means for determining a further resource allocation for sidelink based on the received information; and means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

In an example, the resource allocation at the first base station is for a plurality of user equipments.

In an example, the resource allocation at the first base station is for: a first user equipment of a plurality of user equipments, and a second user equipment of the plurality of user equipments, wherein the first user equipment is associated with the first base station and the second user equipment is associated with the at least one second base station.

In an example, the first user equipment is served by the first base station, and the second user equipment is served by the second base station.

In an example, the means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation comprises: means for causing a transmission of the further resource allocation to the core network entity.

In an example, the apparatus comprises: means for determining the resource allocation for sidelink.

In an example, the further resource allocation is for use by the plurality of user equipments for sidelink positioning.

In an example, the means for determining the resource allocation for sidelink comprises: means for, based on a received scheduling request from a first user equipment of the plurality of user equipments, determining the resource allocation for sidelink.

In an example, the means for causing a transmission of the further resource allocation to the core network entity comprises: means for causing a transmission, to the at least one second base station via the core network entity, the further resource allocation

In an example, the means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation comprises: means for providing, to the first user equipment, the further resource allocation.

In an example, the transmission of the further resource allocation uses New Radio positioning protocol A.

In an example, the information received from the at least one second base station comprises an indication that the at least one second base station accepts or rejects the resource allocation.

In an example, the information received from the at least one second base station comprises a proposed resource allocation of the at least one second base station, wherein the proposed resource allocation of the at least one second base station is different to the resource allocation at the first base station.

In an example, the resource allocation is a scheduling allocation. In an example, the core network entity is a location management function.

In an example, one of: the apparatus is for the first base station, the apparatus is comprised in the first base station, and the apparatus is the first base station.

According to an aspect, there is provided an apparatus comprising: means for receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; means for providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; means for receiving, from the at least one second base station, information related to the resource allocation; and means for providing, to the first base station, the information related to the resource allocation.

In an example, the apparatus comprises: means for receiving, from the first base station, a further resource allocation for sidelink at the first base station, wherein the further resource allocation is different to the resource allocation.

In an example, the apparatus comprises: means for providing, to the at least one second base station the further resource allocation.

In an example, the information received from the at least one second base station comprises at least one of: an indication that the at least one second base station accepts or rejects the resource allocation; a proposed resource allocation of the at least one second base station, wherein the proposed resource allocation of the at least one second base station is different to the resource allocation at the first base station.

In an example, one of: the apparatus is for the core network entity, the apparatus is comprised in the core network entity, and the apparatus is the core network entity.

According to an aspect, there is provided a method comprising: providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; receiving, from the at least one second base station via the core network entity, information related to the resource allocation; determining a further resource allocation for sidelink based on the received information; and causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation. In an example, the resource allocation at the first base station is for a plurality of user equipments.

In an example, the causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation comprises: causing a transmission of the further resource allocation to the core network entity.

In an example, the method comprises: determining the resource allocation for sidelink.

In an example, the determining the resource allocation for sidelink comprises: based on a received scheduling request from a first user equipment of the plurality of user equipments, determining the resource allocation for sidelink.

In an example, the causing a transmission of the further resource allocation to the core network entity comprises: causing a transmission, to the at least one second base station via the core network entity, the further resource allocation

In an example, the causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation comprises: providing, to the first user equipment, the further resource allocation.

In an example, the resource allocation is a scheduling allocation.

In an example, the core network entity is a location management function.

In an example, the method is performed by the first base station.

According to an aspect, there is provided a method comprising: receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; receiving, from the at least one second base station, information related to the resource allocation; and providing, to the first base station, the information related to the resource allocation.

In an example, the method comprises: receiving, from the first base station, a further resource allocation for sidelink at the first base station, wherein the further resource allocation is different to the resource allocation.

In an example, the method comprises: providing, to the at least one second base station the further resource allocation.

In an example, the method is performed by the core network entity.

According to an aspect, there is provided an apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform: providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; receiving, from the at least one second base station via the core network entity, information related to the resource allocation; determining a further resource allocation for sidelink based on the received information; and causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation. In an example, the resource allocation at the first base station is for a plurality of user equipments.

In an example, the apparatus is caused to perform: determining the resource allocation for sidelink.

In an example, the resource allocation is a scheduling allocation.

In an example, the core network entity is a location management function.

According to an aspect, there is provided an apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform: receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; receiving, from the at least one second base station, information related to the resource allocation; and providing, to the first base station, the information related to the resource allocation.

In an example, the apparatus is caused to perform: receiving, from the first base station, a further resource allocation for sidelink at the first base station, wherein the further resource allocation is different to the resource allocation.

In an example, the apparatus is caused to perform: providing, to the at least one second base station the further resource allocation.

According to an aspect, there is provided a computer program comprising instructions, which when executed by an apparatus, cause the apparatus to perform at least the following: providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; receiving, from the at least one second base station via the core network entity, information related to the resource allocation; determining a further resource allocation for sidelink based on the received information; and causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

According to an aspect, there is provided a computer program comprising instructions, which when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; receiving, from the at least one second base station, information related to the resource allocation; and providing, to the first base station, the information related to the resource allocation.

According to an aspect, there is provided an apparatus comprising: circuitry configured to perform providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; circuitry configured to perform receiving, from the at least one second base station via the core network entity, information related to the resource allocation; circuitry configured to perform determining a further resource allocation for sidelink based on the received information; circuitry configured to perform causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

According to an aspect, there is provided an apparatus comprising: circuitry configured to perform receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; circuitry configured to perform providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; circuitry configured to perform receiving, from the at least one second base station, information related to the resource allocation; and circuitry configured to perform providing, to the first base station, the information related to the resource allocation.

A computer product stored on a medium may cause an apparatus to perform the methods as described herein. A non-transitory computer readable medium comprising program instructions, that, when executed by an apparatus, cause the apparatus to perform the methods as described herein.

An electronic device may comprise apparatus as described herein.

In the above, various aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described above.

Various other aspects and further embodiments are also described in the following detailed description and in the attached claims.

According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

List of abbreviations:

AF: Application Function

AMF: Access and Mobility Management Function

AN: Access Network

BS: Base Station

CN: Core Network

D2D: Device-to-device

DL: Downlink eNB: eNodeB gNB: gNodeB

HoT: Industrial Internet of Things

LMF: Location management function

LTE: Long Term Evolution

LPP: LTE position protocol

NEF: Network Exposure Function

NG-RAN: Next Generation Radio Access Network

NF: Network Function

NR: New Radio

NRPPa: New Radio Positioning Protocol A

NRF: Network Repository Function NW: Network

MS: Mobile Station

OOC: Out-of-coverage

PCF Policy Control Function

PLMN: Public Land Mobile Network

ProSe: Proximity services

PRS: Positioning reference signal

RA: Resource allocation

RAN: Radio Access Network

RF: Radio Frequency

SA: Scheduling assignment

SR: Scheduling request

SMF: Session Management Function

SL: Sidelink

UE: User Equipment

UDR: Unified Data Repository

UDM: Unified Data Management

UL: Uplink

UPF: User Plane Function

3GPP: 3^rd Generation Partnership Project

5G: 5^th Generation

5GC: 5G Core network

5G-AN: 5G Radio Access Network

5GS: 5G System

Description of Figures

Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 shows a schematic representation of a 5G system;

Figure 2 shows a schematic representation of a control apparatus;

Figure 3 shows a schematic representation of a terminal;

Figure 4 shows a schematic representation of sidelink position determination for user equipments; Figure 5 shows an example signalling diagram resulting in unsuccessful sidelink positioning reference signal reception due to resource conflicts;

Figures 6a and 6b show an example signalling diagram for communications between user equipments and network entities;

Figure 7 shows an example method flow diagram performed by an apparatus;

Figure 8 shows an example method flow diagram performed by an apparatus; and

Figure 9 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the method of Figure 7 or Figure 8.

Detailed description

Before explaining in detail some examples of the present disclosure, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 3 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in Figure 1 , mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices 102 are provided wireless access via at least one base station (not shown) or similar wireless transmitting and/or receiving node or point. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices. The communication device may access a carrier provided by a station or access point, and transmit and/or receive communications on the carrier.

In the following certain examples are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the examples of the disclosure, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to Figures 1 , 2 and 3 to assist in understanding the technology underlying the described examples. Figure 1 shows a schematic representation of a wireless communication system 100. The wireless communication system 100 comprises one more devices 102 such as user equipments (UEs), or terminals. The wireless communication system 100 also comprises a 5G system (5GS), as shown in Figure. The 5GS comprises a 5G radio access network (5G-RAN) 106, a 5G core network (5GC) 104 comprising one or more network functions (NF), one or more application functions (AFs) 108, and one or more data networks (DNs) 110.

The 5G-RAN 106 may comprise one or more gNodeB (gNB) distributed unit (DU) functions connected to one or more gNodeB (gNB) centralized unit (CU) functions.

The 5GC 104 comprises an access management function (AMF) 112, a session management function (SMF) 114, an authentication server function (AUSF) 116, a user data management (UDM) 118, a user plane function (UPF) 120, a network exposure function (NEF) 122 and/or other NFs (such as a location management function (LMF) (not shown)). Some of the examples as shown below may be applicable to 3GPP 5G standards. However, some examples may also be applicable to 5G-advanced, 4G, 3G and other 3GPP standards.

In a wireless communication system 100, such as that shown in Figure 1 , mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices are provided with wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. The terminal is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices. The communication device may access a carrier provided by a base station or access point, and transmit and/or receive communications on the carrier.

Figure 2 illustrates an example of a control apparatus 200. The control apparatus 200 may be for controlling a function of one or more network entities/network functions, such as the entities of the 5G-RAN or the 5GC as illustrated on Figure 1. The control apparatus 200 comprises at least one random access memory (RAM) 211a, at least one read only memory (ROM) 211 b, at least one processor 212, 213 and an input/output interface 214. The at least one processor 212, 213 is coupled to the RAM 211a and the ROM 211 b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects or examples. The software code 215 may be stored in the ROM 211 b. The control apparatus 200 may be interconnected with another control apparatus 200 controlling another entity/function of the 5G-AN or the 5GC. In some examples, each function of the 5G-AN or the 5GC comprises a control apparatus 200. In alternative examples, two or more functions of the 5G-AN or the 5GC may share a control apparatus. The control apparatus 200 may comprise one or more circuits, or circuitry (not shown) which may be configured to perform one or more of the present aspects or examples.

Figure 3 illustrates an example of a terminal 300, such as the terminal illustrated in Figure 1 . The terminal 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples of a terminal are a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device or any combinations of these or the like. The terminal 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.

The terminal 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 3, a transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

The terminal 300 is provided with at least one processor 301 , at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302a. The terminal 300 may comprise one or more circuits, or circuitry (not shown) which may be configured to perform one or more of the present aspects or examples.

The processor, storage and other relevant control apparatus may be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304. The device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device.

A function/entity that is central to 5G positioning architecture is the location management function (LMF). The LMF receives measurements and assistance information from the NG-RAN as well as from UEs and other mobile devices. From the UEs, information is received via the AMF over ‘NLs’ interface. The LMF uses received measurements and assistance information to compute the position of the UE. An NR positioning protocol A (NRPPa) protocol was introduced in NR to carry the positioning information between the NG-RAN and the LMF. The LMF may configure UEs using the LTE positioning protocol (LPP). The configuration messages are provided to the UE via the AMF.

To enable more accurate positioning in 5G NR, measurements signals are used called positioning reference signals (NR PRS) in the downlink and sounding reference signals (SRS) for positioning in the uplink. PRS may cover the whole NR bandwidth and transmitting PRS over multiple symbols can be aggregated to accumulate power.

The LMF is the network function/entity in the 5G Core Network (5GC) that supports the following functionality: location determination for a UE, obtaining downlink location measurements or a location estimate from the UE, obtaining uplink location measurements from the NG RAN, and obtaining non-UE associated assistance data from the NG RAN.

In 3GPP Rel-18 sidelink (SL) positioning work item, there is support for resource allocation for SL positioning reference signal (PRS) including resource allocation scheme 1 and resource allocation scheme 2. Regarding scheme 1 , for SL PRS which network-controlled allocation, it was considered transmitting to a UE to receive SL-PRS resource allocation through dynamic grant or through configured grant type 1/type 2 from a base station (gNB). SL PRS transmission may take place in SL resource pools that might be dedicated for SL positioning, or may be shared with SL communications, referred to as dedicated pools and shared pools, respectively.

One or more of the following examples are relevant to SL positioning. SL positioning is based on the transmissions of SL PRS between an anchor UE and one or more target UEs to enable localization of the one or more target UEs. The use of SL PRS may allow for position determination with precise latency and accuracy requirements of the corresponding SL positioning session. Figure 4 illustrates a SL positioning scenario where a target UE is performing an SL positioning session.

Figure 4 shows a schematic representation of sidelink position determination for user equipments.

There is a first anchor UE 401 , and a second anchor UE 403. The first 401 and second anchor UEs 403 are attempting to determine the position of a target UE 405. The location/position of the target UE 405 is unknown to the other UEs. In order to determine the location/position, both the first 401 and second anchor UEs 403 transmit SL PRS to the target UE 405. Based on the transmission of the SL PRS the location/position may be determined.

With respect to resource allocation for SL PRS transmissions, a ‘Scheme 1 ’ and a ‘Scheme 2’ have been introduced, which are based on NR SL Mode 1 (which is network-controlled) and NR SL Mode 2 (which is UE autonomous) resource allocation. Regarding Scheme 1 SL-PRS resource allocation, a transmitting UE receives a SL- PRS resource allocation signalling from the network. Consider one or more of the following options: Option. 1 : through higher layers from the LMF, Option. 2: through Dynamic grant, or through configured grant type 1/type 2 from gNB. With option 2, this enables gNBs to allocate resources for SL PRS transmissions in the form of dynamic grants or configured grants of type 1 or type 2, as in legacy SL communication. SL PRS transmissions may take place in SL resource pools that might be dedicated for SL positioning or shared with SL communications, referred to as dedicated pools and shared pools, respectively.

SL positioning typically involves multiple UEs that would transmit SL PRS, especially to estimate the absolute position of the target UE. Multiple UEs transmitting SL PRS might be served by different gNBs. Some UEs may be out-of-coverage (OOC) of any gNBs. If the resource allocations/pools used for SL positioning across different gNBs, for in-coverage and OOC UEs, are overlapping in time/frequency domain, this may lead to conflicts in SL resource allocation. For example, when each gNB applies Scheme 1 , as discussed above. A gNB is not aware of another gNB’s SL resource allocation for SL. Therefore, the SL resources the gNB allocates to the UEs it is serving may conflict with the resources allocated for other UEs served by different gNBs. This problem is illustrated in Figure 5.

Figure 5 shows an example signalling diagram resulting in unsuccessful sidelink positioning reference signal reception due to resource conflicts.

At S501 , there is a UE discovery procedure. There is also capability information exchange.

AS502, an OOC UE, referred to as UE4, performs a Scheme 2 resource allocation procedure.

At S503, a UE3 provides an SL scheduling request (SR) to gNB3. gNB3 provides cell 3, which is serving UE3.

At S504, gNB3 provides an SL scheduling assignment (SA) to UE3.

S503 and S504 form a Scheme 1 resource allocation procedure.

At S505, a UE2 provides an SL scheduling request (SR) to gNB2. gNB2 provides cell 2, which is serving UE2.

At S506, gNB2 provides an SL scheduling assignment (SA) to UE2.

At S507, a UE1 provides an SL scheduling request (SR) to gNB1. gNB1 provides cell 1 , which is serving UE1 .

At S508, gNB1 provides an SL scheduling assignment (SA) to UE1 .

At S509, UE1 provides SL PRS UE2, UE3 and UE4. UE1 uses resources from the SA received from gNB1 .

At S510, UE2 provides an SL PRS to UE1 using indicated resources from gNB2.

At S511 , UE3 provides an SL PRS to UE1 using indicated resources from gNB3.

At S512, UE4 provides an SL PRS to UE1 using indicated resources from the Scheme 2.

At S513, there is an unsuccessful SL PSR reception at UE1 , UE2, UE3 and UE4 due to resource conflicts.

When UEs involved in SL positioning will transmit SL PRS to each other, such as in the signalling of Figure 5. UE1 , UE2, and UE3 that are in coverage utilize resource allocation Scheme 1. However each of these UEs is served by a different gNB. The OOC UE4 utilizes resource allocation Scheme 2. In a scenario whereby resource allocations/pools configured for these UEs are overlapping, the UEs may get a conflicting resource grant. For example, the UEs the resource grants may be using the same time/frequency resources. This results in unsuccessful SL PRS reception at the UEs, either due to half-duplex problem (a UE cannot transmit and receive at the same time) or interference.

As resource pools used for SL positioning for different UEs may be overlapping in time/frequency domain, this may lead to conflict in SL resource allocation in Scheme 1 . SL resources allocated to UEs by one gNB may conflict with the resources allocated for other UEs served by different gNBs.

In the case of dedicated resource pools for SL positioning, a problem arises from UEs performing SL positioning resulting in interference or half-duplex issues that results from the conflicting resource usage, which may degrade the SL positioning quality of service. The resulting problems may be worse when resource pools are shared between SL positioning and SL communication. In this case, the conflicts in resource allocation may also degrade the quality of SL communications, when UEs sharing the resources are served by different gNBs.

One or more of the examples presented below may address one or more of the problems identified above.

In examples, there is provided an apparatus (e.g. a first base station) that is configured for providing, to at least one second base station via a core network entity (e.g. via an LMF), an indication of a resource allocation for sidelink at a first base station. The apparatus receives, from the at least one second base station via the core network entity, information related to the resource allocation. The apparatus then determines a further resource allocation for sidelink based on the received information, and causes a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

In some examples, a resource allocation is performed for all UEs involved in SL positioning by a single base station/gNB. The gNB may serve a target UE. To avoid resource conflicts, the gNB informs other gNBs serving other UEs about the resource allocation (proposed) by gNB1 .The communications between gNBs may be performed centrally via an LMF.

In some examples, the other gNBs either accept or reject the proposed resource allocation, and respond to the gNB via the LMF. In this way, the other gNBs provide feedback to the gNB. In some examples, the other gNBs provide one or more preferred (or nonpreferred) resource allocations for their own served UEs, which they communicate back to the gNB, via the LMF. In this way, the other gNBs provide feedback to the gNB.

In some examples, a (final) resource allocation is determined by the gNB based on the feedback from the other gNBs. The determined resource allocation is communicated to the other gNBs so that any further potential resource conflicts with the other UEs served by each gNB are avoided.

In some examples, there are a plurality of rounds of feedback between the gNB and the other gNBs. Said another way, the process between the gNB and the other gNBs may be iterative.

In some examples, the coordination among gNBs is optional. For example, the other gNBs may have to directly obey (i.e., is to accept/cannot reject) the resource allocation proposed by gNB1 (e.g. in S605/S606). For example, in S608 and S610, gNB2 and gNB3 respectively will provide an ‘accept’ response. In this example, it may be considered that there is no coordination among gNBs. This may be considered a ‘0’ iterative example.

In some examples, the other gNBs are informed about the determined resource allocation of the gNB via the UEs involved in SL positioning.

In some examples, the other gNBs are informed about the determined resource allocation of the gNB via the LMF.

These examples will all be discussed in more detail below.

Figures 6a and 6b show an example signalling diagram for communications between user equipments and network entities.

In the following example, there are communications between user equipments (UEs). In other examples, one or more of the UEs are replaced by other mobile devices such as terminals, smartphones, user devices, or any other device capable of sidelink communications. In the following examples, the UEs are served by a plurality of base stations which are referred to as gNB1 , gNB2, etc. It should be understood than ‘gNBT may be referred to as ‘base station T, and so on. The terms ‘gNB’ and ‘base station’ may be used interchangeably. At S601 , an OOC UE (UE4) provides an indication to a UE1 that UE4 is OOC. UE4 may also indicate its last serving cell. The indication may be provided during a discovery procedure.

At S602, a UE3 provides an indication to UE1 that its cell identity (ID) is 3. UE3 is connected to cell 3 which is provided by a gNB3. The indication may be provided during a discovery procedure.

At S603, a UE2 provides an indication to UE1 that its cell ID is 2. UE2 is connected to cell 2 which is provided by a gNB2. The indication may be provided during a discovery procedure.

At S604, UE1 provides a scheduling request (SR) for UE1 , UE2, UE3 and UE4 to a gNB1 .

In some examples, UE1 is a target UE for sidelink positioning (e.g. 405 of Figure 4). In other examples, UE1 is a server UE (in SL positioning), or another UE.

At S605, gNB1 determines a resource allocation for all UEs for sidelink. In this context, all of the UEs includes UE1 , UE2, UE3 and UE4. The resource allocation may be termed a scheduling assignment. In the following, the terms “resource allocation”, “resource pool” and “scheduling assignment” may be used interchangeably.

The resource allocation for sidelink may be resources for sidelink positioning, such as, for example, for SL PRSs.

The determined resource allocation may be referred to as a first, preliminary, or proposed resource allocation.

At S606, the gNB1 provides the resource allocation to an LMF. The LMF is a core network entity. In other examples, the LMF is replaced with another suitable core network entity.

The resource allocation may be provided using NRPPa. In the following, any communications between gNB and LMF may use NRPPa. In other examples, other suitable messages and/or protocols are used.

At S607, the LMF provides the resource allocation to gNB2. The resource allocation comprises an allocation for UE2, which is served by gNB2.

At S608, gNB2 provides information related to the resource allocation to the LMF. The information may comprise an ‘accept’ or ‘reject’ for the resource allocation. The information may comprise a confidence level for the resource allocation, or any other suitable feedback information. For example, when the resource allocation (from gNB1 ) does not overlap with resources assigned/scheduled by gNB2 for UE2, then gNB2 may accept the resource allocation. When the resource allocation (from gNB1 ) does overlap with resources assigned/scheduled by gNB2 for UE2, then gNB2 may reject the resource allocation.

In some examples, when gNB2 rejects the resource allocation, gNB2 also provides an alternative resource allocation. The alternative resource allocation being different to the resource allocation from gNB1 . The alternative resource allocation may be for the UE2 (i.e. gNB2 does not propose changes to the resource allocation for UE1 , UE3 and UE4).

At S609, the LMF provides the resource allocation to gNB3. The resource allocation comprises an allocation for UE3, which is served by gNB3.

At S610, gNB2 provides information related to the resource allocation to the LMF. The information may comprise an ‘accept’ or ‘reject’ for the resource allocation. The information may comprise a confidence level for the resource allocation, or any other suitable feedback information.

In some examples, when gNB3 rejects the resource allocation, gNB3 also provides an alternative resource allocation. The alternative resource allocation being different to the resource allocation from gNB1 . The alternative resource allocation may be for the UE3 (i.e. gNB3 does not propose changes to the resource allocation for UE1 , UE2 and UE4).

At S611 , the LMF provides the information from gNB2 and gNB3 to gNB1. In this way, the LMF forwards any received information from gNB2 and/or gNB3 to gNB1 . The information may comprise alternative resource allocation(s), when provided by the other gNBs.

At S612, the gNB1 determines a further resource allocation for sidelink based on the received information. The further resource allocation is for all UEs.

The further resource allocation may be referred to as a finalised/updated/second resource allocation in other examples.

When the information received from gNB2 and/or gNB3 comprises an alternative resource allocation, then gNB1 uses the alternative resource allocation(s) to determine the further resource allocation. For example, the gNB1 may use the alternative resource allocation as the further resource allocation. For example, the gNB1 may determine a similar resource allocation to the alternative resource allocation. For example, similar in frequency and/or time. At S613, the gNB1 provides the further resource allocation to the LMF. In some examples, the gNB1 causes a transmission of the further resource allocation (or an indication of the further resource allocation) to the LMF.

In some examples, gNB1 will refrain from providing the further resource allocation to the LMF. For example, the gNB1 will refrain when gNB2 and gNB3 are to be informed of the further resource allocation via UE, as described in more detail below.

At S614, the gNB1 provides/transmits the further resource allocation/SA to UE1. In some examples, the gNBI causes a transmission of an indication of the further resource allocation to UE1. The resources are allocated for all UEs, including UE1 , UE2, UE3, UE4.

At S615, UE1 forwards, to UE2, the resource allocation/SA for UE2.

At S616, UE1 forwards, to UE3, the resource allocation/SA for UE3.

At S617, UE1 forwards, to UE4, the resource allocation/SA for UE4.

Steps from S618 to S619 form a first alternative of how the gNBs are informed of the resource allocation. Steps from S620 to S623 form a second alternative.

At S618, the LMF provides an indication of the further resource allocation/SA for all UEs to gNB2.

At S619, the LMF provides an indication of the further resource allocation/SA for all UEs to gNB3.

At S620, UE1 provides an indication of the further resource allocation/SA for all UEs to UE2.

At S621 , UE1 provides an indication of the further resource allocation/SA for all UEs to UE3.

At S622, UE2 provides an indication to gNB2 (which serves UE2) of the further resource allocation/SA for all UEs.

At S623, UE3 provides an indication to gNB3 (which serves UE3) of the further resource allocation/SA for all UEs.

In this way, the other gNBs (namely gNB2 and gNB3) are informed about the scheduling decision (i.e. the further resource allocation) of gNB1 from either: i) the LMF, or via the UEs that the respective gNB is serving, which are involved in SL positioning.

In some examples, UE4 is informed of the further resource allocation/SA indirectly, when the transmissions happen. When in-coverage UEs transmit SL, the associated control information transmitted over SL may inform any UEs in proximity (including UE4).

At S624, UE1 transmits an SL PRS to UE2, UE3 and UE4. The transmission uses resources from the further resource allocation.

At S625, UE2 transmits an SL PRS to UE1 .

At S626, UE3 transmits an SL PRS to UE1 .

At S627, UE4 transmits an SL PRS to UE1 .

At S628, there is a successful reception of the SL PRSs at UE1 , UE2, UE3 and UE4 respectively. There is a successful reception as there is no conflict the in resources used for the SL PRS transmissions.

In this way, as shown in Figures 6a and 6b, there is a resource allocation coordination between gNB1 and other gNBs (i.e. gNB2, gNB3). gNB1 determines a further resource allocation using information received from the other gNBs. gNB1 causes a transmission of the further resource allocation so that the other gNBs are informed of the further resource allocation. In a first example, the further resource allocation is transmitted from the gNB1 to the LMF, which is then provided to the other gNBs. In a second example, the gNB1 provides the further resource allocation to each of the UEs (UE1 , UE2, UE3, UE4). Each of the UEs then provides the further resource allocation to its serving gNB. In this way, with either of the first and second examples, the other gNBs will be informed of the further resource allocation.

It should be understood that even though four UEs (UE1 to UE4) are shown in the example of Figures 6a and 6b, in other examples, there are more or less than four UEs communicating with each other. For example, the mechanism proposed is equally applicable for a system with two UEs, each served by a different cell/gNB.

It should be understood that, in other examples, one or more of the steps of Figures 6a and 6b may not be performed or may be performed in a different order.

In some examples, the resource allocation methods of Figures 6a and 6b apply not only to SL PRS transmission but to any transmission using SL resources. For example, SL, device to device (D2D), proximity services (ProSe) discovery, data communication, sensing, and associated control signalling, etc.

In some examples, instead of time/frequency resources for a specific SL PRS transmission by each UE, a gNB allocates (a subset of) a resource pool for the group of UEs (UE1 , UE2, UE3, UE4). The allocated resources may be either scheduled by one UE for other UEs, or utilized among UEs in a distributed manner. For example, with a Mode 2/Scheme 2 type of resource allocation mechanism.

In some examples, in addition to, or instead of, time/frequency resources, the UEs (UE1 , UE2, UE3, UE4) may be allocated with other types of resources. For example, resources in the code domain, power domain, space/direction domain, etc.

In some examples, the UEs (UE1 , UE2, UE3, UE4) are informed about the further resource allocation (e.g., given by gNB1 ) via their own serving gNBs. For example, gNB2 is informed by UE2. In this example, each gNB retrieves the resource allocation information for the respective UE it is serving via the LMF.

In some examples, the UEs are informed about the further resource allocation (e.g., given by gNB1 ) but via the LMF using LPP and/or sidelink positioning protocol (SLPP) signalling.

In some examples, the characteristics of SL PRS transmission for which resources are to be allocated, such as its bandwidth, periodicity, etc. may be determined by the LMF or a UE, which depends on the positioning quality of service (QoS) requirements. For example, determined by a server UE, client UE, target UE, etc.

In some examples, when the resource allocation procedure of Figures 6a and 6b is triggered, the LMF may perform at least one of: i) select a gNB to do the resource allocation (which is gNB in the example of Figure 6a/6b), ii) determine a preferred SA for every UE and communicate with each serving gNB to determine whether the SA is acceptable or not. Each serving gNB may provide feedback information to the LMF.

In some examples, the gNB that is to allocate the resources (i.e. gNB1 in Figure 6a/6b) is determined by a target UE and/or server UE, which may select its own serving gNB to send the request. In other examples, the target/server UE selects another UE served by a different gNB to send the request. In this example, the target/server UE indicates to other UEs involved in SL positioning that it will send the scheduling request to its own gNB, or request that another UE sends the scheduling request. For example, in one example, the last serving gNB of an OOC UE is selected to allocate resources. For this, the OOC UE indicates an ID of its last serving gNB to other UEs. If there is matching UE (currently being) served by the same gNB, that matching UE indicates to the server/target UE its gNB ID, and the server/target UE selects the matching UE to send the scheduling request.

In some examples, gNB to LMF signalling is be implemented via NRPPa. One or more of the previous examples provide a mechanism whereby a base station/gNB is able to allocate resources for sidelink for UEs taking in account the allocations of other base stations/gNBs that are associated with the UEs. This has the advantage that subsequent transmissions between the UEs, using the allocated resources, do not result in resource conflict. This means that interference and halfduplex collisions are less likely to occur. Overall, this means that sidelink positioning and subsequent sidelink communications will have a lower latency, higher accuracy, better reliability, and be more efficient.

Figure 7 shows an example method flow performed by an apparatus. The apparatus may be comprised within a base station (e.g. a gNB). The apparatus may be for a base station. The apparatus may be a base station.

In S701 , the method comprises providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station.

In S703, the method comprises receiving, from the at least one second base station via the core network entity, information related to the resource allocation.

In S705, the method comprises determining a further resource allocation for sidelink based on the received information.

In S707, the method comprises causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

Figure 8 shows an example method flow performed by an apparatus. The apparatus may be comprised within a core network entity. The apparatus may be for a core network entity. The apparatus may be a core network entity. The core network entity may be an LMF.

In S801 , the method comprises receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station.

In S803, the method comprises providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station.

In S805, the method comprises receiving, from the at least one second base station, information related to the resource allocation.

In S807, the method comprises providing, to the first base station, the information related to the resource allocation. Figure 9 shows a schematic representation of non-volatile memory media 900a (e.g. computer disc (CD) or digital versatile disc (DVD)) and 900b (e.g. universal serial bus (USB) memory stick) storing instructions and/or parameters 902 which when executed by a processor allow the processor to perform one or more of the steps of the methods of Figure 7 and Figure 8.

It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

The examples may thus vary within the scope of the attached claims. In general, some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The examples may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

The term “non-transitory”, as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. RAM vs ROM).

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of: <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and”, or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Alternatively, or additionally some examples may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and/or method steps previously described. That circuitry may be provided in the base station and/or in the communications device.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analogue and/or digital circuitry);

(b) combinations of hardware circuits and software, such as:

(i) a combination of analogue and/or digital hardware circuit(s) with software/firmware and

(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and

(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example integrated device. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device. The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of some embodiments. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

Claims:

1 . An apparatus comprising: means for providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; means for receiving, from the at least one second base station via the core network entity, information related to the resource allocation; means for determining a further resource allocation for sidelink based on the received information; and means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

2. The apparatus according to claim 1 , wherein the resource allocation at the first base station is for a plurality of user equipments.

3. The apparatus according to claim 1 , wherein the resource allocation at the first base station is for: a first user equipment of a plurality of user equipments, and a second user equipment of the plurality of user equipments, wherein the first user equipment is associated with the first base station and the second user equipment is associated with the at least one second base station.

4. The apparatus according to any of claims 1 to 3, wherein the means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation comprises: means for causing a transmission of the further resource allocation to the core network entity.

5. The apparatus according to any of claims 1 to 4, wherein the apparatus comprises: means for determining the resource allocation for sidelink.

6. The apparatus according to any of claims 1 to 5, wherein the further resource allocation is for use by the plurality of user equipments for sidelink positioning.

7. The apparatus according to claim 5, wherein the means for determining the resource allocation for sidelink comprises: means for, based on a received scheduling request from a first user equipment of the plurality of user equipments, determining the resource allocation for sidelink.

8. The apparatus according to any of claims 1 to 7, wherein the means for causing a transmission of the further resource allocation to the core network entity comprises: means for causing a transmission, to the at least one second base station via the core network entity, the further resource allocation

9. The apparatus according to any of claims 1 to 8, wherein the means for causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation comprises: means for providing, to the first user equipment, the further resource allocation.

10. The apparatus according to any of claims 1 to 9, wherein the transmission of the further resource allocation uses New Radio positioning protocol A.

11. The apparatus according to any of claims 1 to 10, wherein the information received from the at least one second base station comprises an indication that the at least one second base station accepts or rejects the resource allocation.

12. The apparatus according to any of claims 1 to 11 , wherein the information received from the at least one second base station comprises a proposed resource allocation of the at least one second base station, wherein the proposed resource allocation of the at least one second base station is different to the resource allocation at the first base station.

13. The apparatus according to any of claims 1 to 12, wherein the resource allocation is a scheduling allocation.

14. The apparatus according to any of claims 1 to 13, wherein one of: the apparatus is for the first base station, the apparatus is comprised in the first base station, and the apparatus is the first base station.

15. An apparatus comprising: means for receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; means for providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; means for receiving, from the at least one second base station, information related to the resource allocation; and means for providing, to the first base station, the information related to the resource allocation.

16. The apparatus according to claim 15, wherein the apparatus comprises: means for receiving, from the first base station, a further resource allocation for sidelink at the first base station, wherein the further resource allocation is different to the resource allocation.

17. The apparatus according to claim 16, wherein the apparatus comprises: means for providing, to the at least one second base station the further resource allocation.

18. The apparatus according to any of claims 15 to 17, wherein the transmission of the further resource allocation uses New Radio positioning protocol A.

19. The apparatus according to any of claims 15 to 18, wherein the information received from the at least one second base station comprises at least one of: an indication that the at least one second base station accepts or rejects the resource allocation; a proposed resource allocation of the at least one second base station, wherein the proposed resource allocation of the at least one second base station is different to the resource allocation at the first base station.

20. The apparatus according to any of claims 15 to 19, wherein one of: the apparatus is for the core network entity, the apparatus is comprised in the core network entity, and the apparatus is the core network entity.

21. The apparatus according to any of claims 1 to 20, wherein the core network entity is a location management function.

22. A method comprising: providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; receiving, from the at least one second base station via the core network entity, information related to the resource allocation; determining a further resource allocation for sidelink based on the received information; and causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

23. A method comprising: receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; receiving, from the at least one second base station, information related to the resource allocation; and providing, to the first base station, the information related to the resource allocation.

24. A computer program comprising instructions, which when executed by an apparatus, cause the apparatus to perform at least the following: providing, to at least one second base station via a core network entity, an indication of a resource allocation for sidelink at a first base station; receiving, from the at least one second base station via the core network entity, information related to the resource allocation; determining a further resource allocation for sidelink based on the received information; and causing a transmission of the further resource allocation so that the at least one second base station is informed of the further resource allocation.

25. A computer program comprising instructions, which when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a first base station, an indication of a resource allocation for sidelink at a first base station; providing, to at least one second base station, the indication of the resource allocation for sidelink at the first base station; receiving, from the at least one second base station, information related to the resource allocation; and providing, to the first base station, the information related to the resource allocation.