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WO2022067861A1 - Double connectivité en liaison directe et relayée par liaison latérale pour continuité de service en liaison latérale dans des réseaux à liaison latérale de mode 1 - Google Patents

Double connectivité en liaison directe et relayée par liaison latérale pour continuité de service en liaison latérale dans des réseaux à liaison latérale de mode 1 Download PDF

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Publication number
WO2022067861A1
WO2022067861A1 PCT/CN2020/119795 CN2020119795W WO2022067861A1 WO 2022067861 A1 WO2022067861 A1 WO 2022067861A1 CN 2020119795 W CN2020119795 W CN 2020119795W WO 2022067861 A1 WO2022067861 A1 WO 2022067861A1
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WO
WIPO (PCT)
Prior art keywords
sidelink
base station
connection
direct link
rrc
Prior art date
Application number
PCT/CN2020/119795
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English (en)
Inventor
Sourjya Dutta
Kapil Gulati
Peng Cheng
Karthika Paladugu
Hong Cheng
Original Assignee
Qualcomm Incorporated
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Qualcomm Incorporated filed Critical Qualcomm Incorporated
Priority to PCT/CN2020/119795 priority Critical patent/WO2022067861A1/fr
Publication of WO2022067861A1 publication Critical patent/WO2022067861A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/14—Direct-mode setup
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/23—Manipulation of direct-mode connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/02—Terminal devices
    • H04W88/04—Terminal devices adapted for relaying to or from another terminal or user
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W92/00—Interfaces specially adapted for wireless communication networks
    • H04W92/16—Interfaces between hierarchically similar devices
    • H04W92/18—Interfaces between hierarchically similar devices between terminal devices

Definitions

  • the present disclosure relates generally to communication systems, and more particularly, to direct link and sidelink-relayed dual connectivity for sidelink service continuity in Mode 1 sidelink networks.
  • Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts.
  • Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
  • CDMA code division multiple access
  • TDMA time division multiple access
  • FDMA frequency division multiple access
  • OFDMA orthogonal frequency division multiple access
  • SC-FDMA single-carrier frequency division multiple access
  • TD-SCDMA time division synchronous code division multiple access
  • 5G New Radio is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements.
  • 3GPP Third Generation Partnership Project
  • 5G NR includes services associated with enhanced mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra-reliable low latency communications (URLLC) .
  • eMBB enhanced mobile broadband
  • mMTC massive machine type communications
  • URLLC ultra-reliable low latency communications
  • Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard.
  • Aspects of wireless communication may comprise direct communication between devices, such as based on sidelink. There exists a need for further improvements in sidelink communication technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
  • wireless communication includes direct communication between devices, such as device-to-device (D2D) , vehicle-to-everything (V2X) , and the like.
  • D2D device-to-device
  • V2X vehicle-to-everything
  • improvements related to direct communication between devices may be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
  • a base station may provide a user equipment (UE) with access to a core network.
  • Mode 1 sidelink operation entails sidelink resource allocation to be performed by a base station (e.g., gNB1) .
  • the base station may configure sidelink UEs, receive a signal radio bearer (SRB) , and provide sidelink scheduling grants to the sidelink UEs to use for their sidelink transmissions.
  • SRB signal radio bearer
  • mm-wave millimeter wave
  • FR2 Frequency Range 2
  • coverage holes may exist for cellular connections (e.g., Uu direct link connections) .
  • the cellular connections from mm-wave base stations may have smaller coverage areas and may be more susceptible to blockages (e.g., foliage, temporary installations, etc. ) . This may occur in V2X environments when an obstruction is positioned between the UEs and the base station.
  • a first UE e.g., UE-B
  • the line-of-sight between the first UE and the base station may be obstructed by a large object (e.g., large truck) such that the communication link from the first UE to the base station is blocked.
  • the UE-B may attempt to initiate a radio resource control (RRC) reestablishment with a second base station (e.g., gNB2) .
  • RRC radio resource control
  • gNB2 radio resource control
  • resynchronizing to the second base station may not be ideal, as given its direction and position relative to the second base station, the first UE may soon thereafter lose connection to the second base station (e.g., gNB2) .
  • the loss of the cellular connection coverage may require the UE to stop sidelink transmissions.
  • a semi-persistent scheduling (SPS) sidelink grant may no longer be used if the UE initiates operation of radio link failure (RLF) procedures.
  • exception resource pools may be used by switching the UE from a Mode 1 based operation (e.g., centralized manner) to a Mode 2 based operation (e.g., distributed manner) .
  • the exception resource pool may be utilized during a handover or occurrence of an RLF event.
  • the resource selection may be based on the Mode 2 operation.
  • the Mode 1 sidelink operation can suffer.
  • the UE may initiate a handover operation to a non-optimal base station, and may lose the new connection soon thereafter.
  • the UE may still have sidelink connections with other UEs.
  • the first UE e.g., UE-B
  • a second UE e.g., UE-A
  • the first UE may notify the second UE about the blockage with the first base station.
  • the second UE may notify the first UE, based on historical connection information, to not reestablish a connection with a base station.
  • the first UE may instead use the second UE as a relay station until the blocking event is terminated.
  • the first UE may trigger a RRC reestablishment operation.
  • the peer sidelink UEs can serve as relay stations to improve the uplink coverage performance of the blocked UE (e.g., the first UE) .
  • the present disclosure provides for dual connectivity with Uu direct link connections and sidelink-based relays between UEs and the core network.
  • a sidelink-relayed connection to a second direct link connection to the network may serve as a fallback option if a first direct link connection to the network is lost or suffers a radio link failure.
  • the sidelink-relayed connection may primarily facilitate control-plane signaling between the UEs and the network, in particular, for Mode 1 sidelink control.
  • the UE may trigger an event to additionally set up an alternate control-plane connection via sidelink (e.g., UE-network relay) and maintain the sidelink-relayed control-plane connection active in the event that the Uu direct link connection is lost in a radio link failure event or during a handover procedure.
  • sidelink e.g., UE-network relay
  • the Mode 1 sidelink scheduling is based on Uu direct link connection. If the Uu direct link connection to the base station is lost, then the UE may switch to the sidelink connection to establish the sidelink-relayed control-plane connection for control plane Mode 1 sidelink operation.
  • the UE may tear down the dual connectivity sidelink connection when the signal quality of the Uu direct link connection improves and increases greater than the predetermined threshold (after recovery or handover operation) . If the obstruction-based coverage holes can occur at any given time, the UE may maintain the sidelink-relayed control plane connection active at all times. Otherwise, the UE may be configured by the base station via the Uu direct link connection.
  • the subject technology can achieve higher reliability for FR2 sidelink Mode 1 based operations.
  • the apparatus is a UE.
  • the apparatus can determine a set of sidelink stations operable to serve as relay stations and forward control plane signaling between the UE and a first base station.
  • the apparatus can obtain one or more measurements of a direct link connection with the first base station.
  • the apparatus can establish a sidelink connection with at least one sidelink station of the set of sidelink stations based on the one or more measurements.
  • the apparatus also can communicate, with the first base station through at least one sidelink station over the sidelink connection, the control plane signaling.
  • the apparatus is a UE.
  • the apparatus can receive a sidelink connection with a second UE based on a status of a first direct link connection between the second UE and a first base station.
  • the apparatus also can communicate, with the first base station through a second direct link connection between the first UE and the first base station, control plane signaling associated with the second UE when the status indicates an occurrence of a RLF event in the first direct link connection.
  • the apparatus is a BS.
  • the apparatus can receive, from a first UE through a first direct link connection between the first UE and the first BS, an indication of a set of sidelink UEs operable to serve as relay stations and forward control plane signaling between the first UE and the first BS.
  • the apparatus also can receive, from a second UE of the set of sidelink UEs through a second direct link connection between the second UE and the first BS, control plane signaling forwarded between the first UE and the second UE based on an occurrence of a RLF event in the first direct link connection.
  • the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims.
  • the following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.
  • FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.
  • FIGS. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a first 5G/NR frame, DL channels within a 5G/NR subframe, a second 5G/NR frame, and UL channels within a 5G/NR subframe, respectively.
  • FIG. 2E illustrates example aspects of a sidelink slot structure.
  • FIG. 3 is a diagram illustrating an example of a first device and a second device involved in sidelink communication.
  • FIG. 4 illustrates an example of sidelink communication between wireless devices, in accordance with one or more of aspects of the present disclosure.
  • FIG. 5 is a flowchart of a process of wireless communication, in accordance with one or more of aspects of the present disclosure.
  • FIG. 6 is a flowchart of a process of wireless communication, in accordance with one or more of aspects of the present disclosure.
  • FIGS. 7A and 7B are diagrams illustrating example communication flows for sidelink-relayed dual connectivity for Mode 1 sidelink service continuity, in accordance with one or more of aspects of the present disclosure.
  • FIG. 8 is a flowchart of a process of wireless communication, in accordance with one or more of aspects of the present disclosure.
  • FIG. 9 is a diagram illustrating an example of a hardware implementation for an example apparatus.
  • FIG. 10 is a diagram illustrating an example of a hardware implementation for an example apparatus.
  • processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure.
  • processors in the processing system may execute software.
  • Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
  • the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium.
  • Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer.
  • such computer-readable media can include a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.
  • RAM random-access memory
  • ROM read-only memory
  • EEPROM electrically erasable programmable ROM
  • optical disk storage magnetic disk storage
  • magnetic disk storage other magnetic storage devices
  • combinations of the aforementioned types of computer-readable media or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.
  • FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100.
  • Some wireless communication may be exchanged directly between wireless devices based on sidelink.
  • the communication may be based on vehicle-to-anything (V2X) or other device-to-device (D2D) communication, such as Proximity Services (ProSe) , etc.
  • Sidelink communication may be exchanged based on a PC5 interface, for example.
  • control information may be indicated by a transmitting UE in multiple SCI parts.
  • the SCI may indicate resources that the UE intends to use, for example, for a sidelink transmission.
  • the UE may transmit a first part of control information indicating information about resource reservation in a physical sidelink control channel (PSCCH) region, and may transmit a second part of the control information in a PSSCH region.
  • a first stage control e.g., SCI-1
  • SCI-2 may be transmitted on a PSCCH and may contain information for resource allocation and information related to the decoding of a second stage control (e.g., SCI-2) .
  • the second stage control (SCI-2) may be transmitted on a PSSCH and may contain information for decoding data (SCH) .
  • control information may be indicated through a combination of the first SCI part included in the PSCCH region (e.g., the SCI-1) and the second SCI part included in the PSSCH region (e.g., the SCI-2) .
  • control information may be indicated in a media access control (MAC) control element (MAC-CE) portion of the PSSCH.
  • MAC media access control
  • sidelink communication may include vehicle-based communication such as vehicle-to-vehicle (V2V) , vehicle-to-infrastructure (V2I) (e.g., from the vehicle-based communication device to road infrastructure nodes such as a Road Side Unit (RSU) ) , vehicle-to-network (V2N) (e.g., from the vehicle-based communication device to one or more network nodes, such as a base station) , vehicle-to-pedestrian (V2P) , cellular vehicle-to-everything (C-V2X) , and/or a combination thereof and/or with other devices, which can be collectively referred to as V2X communications.
  • V2V vehicle-to-vehicle
  • V2I vehicle-to-infrastructure
  • V2N vehicle-to-network
  • V2P vehicle-to-pedestrian
  • C-V2X cellular vehicle-to-everything
  • a UE 104 e.g., a transmitting Vehicle User Equipment (VUE) or other UE 104, may be configured to transmit messages directly to another UE 104.
  • the communication may be based on V2X or other D2D communication, such as Proximity Services (ProSe) , etc.
  • Communication based on V2X and/or D2D may also be transmitted and received by other transmitting and receiving devices, such as Road Side Unit (RSU) 107, etc.
  • RSU Road Side Unit
  • aspects of the communication may be based on PC5 or sidelink communication e.g., as described in connection with the example in FIG. 2E.
  • the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.
  • the wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and a Core Network (e.g., 5GC) 190.
  • the base stations 102 may include macro cells (high power cellular base station) and/or small cells (low power cellular base station) .
  • the macro cells include base stations.
  • the small cells include femtocells, picocells, and microcells.
  • the base stations 102 configured for 4G LTE may interface with the EPC 160 through backhaul links 132 (e.g., S1 interface) .
  • the base stations 102 configured for NR may interface with Core Network 190 through backhaul links 184.
  • UMTS Universal Mobile Telecommunications System
  • NR Next Generation RAN
  • the base stations 102 may perform one or more of the following functions: transfer of 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, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages.
  • NAS non-access stratum
  • RAN radio access network
  • MBMS multimedia broadcast multicast service
  • RIM RAN information management
  • the base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or Core Network 190) with each other over backhaul links 134 (e.g., X2 interface) .
  • the backhaul links 134 may be wired or wireless.
  • 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. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102.
  • a network that includes both small cell and macro cells may be known as a heterogeneous network.
  • a heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) .
  • eNBs Home Evolved Node Bs
  • HeNBs Home Evolved Node Bs
  • CSG closed subscriber group
  • the communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (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 multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity.
  • the communication links may be through one or more carriers.
  • the base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc.
  • the component carriers may include a primary component carrier and one or more secondary component carriers.
  • a primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .
  • D2D communication link 158 may use the DL/UL WWAN spectrum.
  • the D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) .
  • sidelink channels such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) .
  • sidelink channels such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) .
  • D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia,
  • the wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum.
  • AP Wi-Fi access point
  • STAs Wi-Fi stations
  • communication links 154 in a 5 GHz unlicensed frequency spectrum.
  • the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.
  • CCA clear channel assessment
  • the small cell 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.
  • a base station 102 may include an eNB, gNodeB (gNB) , or other type of base station.
  • Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE 104.
  • mmW millimeter wave
  • mmW millimeter wave
  • mmW base station 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 the 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 has extremely high path loss and a short range.
  • the mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range.
  • FIG. 1 illustrates that a base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182'.
  • the UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182”.
  • the UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions.
  • the base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions.
  • the base station 180 /UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 /UE 104.
  • the transmit and receive directions for the base station 180 may or may not be the same.
  • the transmit and receive directions for the UE 104 may or may not be the same. Although beamformed signals are illustrated between UE 104 and base station 102/180, aspects of beamforming may similarly may be applied by UE 104 or RSU 107 to communicate with another UE 104 or RSU 107, such as based on V2X, V2V, or D2D communication.
  • the EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172.
  • MME Mobility Management Entity
  • MBMS Multimedia Broadcast Multicast Service
  • BM-SC Broadcast Multicast Service Center
  • PDN Packet Data Network
  • the MME 162 may be in communication with a Home Subscriber Server (HSS) 174.
  • HSS Home Subscriber Server
  • the MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160.
  • the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172.
  • IP Internet protocol
  • the PDN Gateway 172 provides UE IP address allocation as well as other functions.
  • the PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176.
  • the IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services.
  • the BM-SC 170 may provide functions for MBMS user service provisioning and delivery.
  • the BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions.
  • PLMN public land mobile network
  • the MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.
  • MMSFN Multicast Broadcast Single Frequency Network
  • the Core Network 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195.
  • the AMF 192 may be in communication with a Unified Data Management (UDM) 196.
  • the AMF 192 is the control node that processes the signaling between the UEs 104 and the Core Network 190.
  • the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195.
  • the UPF 195 provides UE IP address allocation as well as other functions.
  • the UPF 195 is connected to the IP Services 197.
  • the IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services.
  • IMS IP Multimedia Subsystem
  • the base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology.
  • the base station 102 provides an access point to the EPC 160 or Core Network 190 for a UE 104.
  • Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device.
  • SIP session initiation protocol
  • PDA personal digital assistant
  • the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) .
  • the UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.
  • V2P vehicle-to-pedestrian
  • P2V pedestrian-to-vehicle
  • the concepts and various aspects described herein may be applicable to other similar areas, such as D2D communication, IoT communication, vehicle-to-everything (V2X) communication, or other standards/protocols for communication in wireless/access networks.
  • D2D communication vehicle-to-pedestrian
  • IoT vehicle-to-vehicle
  • V2X vehicle-to-everything
  • the UE 104 may include a dual connectivity relay configuration component 198 that is configured to determine a set of sidelink stations operable to serve as relay stations and forward a control plane signaling between the UE and a first base station.
  • the dual connectivity relay configuration component 198 also may be configured to obtain one or more measurements of a direct link connection with the first base station.
  • the dual connectivity relay configuration component 198 also may be configured to establish a sidelink connection with at least one sidelink station of the set of sidelink stations based on the one or more measurements.
  • the dual connectivity relay configuration component 198 also may be configured to communicate, with the first base station through the at least one sidelink station over the sidelink connection, the control plane signaling.
  • the base station 102/180 may include a relaying component 199 that is configured to receive a sidelink connection with a second UE based on a status of a first direct link connection between the second UE and a first base station.
  • the relaying component 199 also may be configured to communicate, with the first base station through a second direct link connection between the first UE and the first base station, a control plane signaling associated with the second UE when the status indicates an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • RLF radio link failure
  • FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G/NR frame structure.
  • FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G/NR subframe.
  • FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G/NR frame structure.
  • FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G/NR subframe.
  • the 5G/NR frame structure may be FDD in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be TDD in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL.
  • the 5G/NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and X is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL) .
  • subframes 3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61.
  • Slot formats 0, 1 are all DL, UL, respectively.
  • Other slot formats 2-61 include a mix of DL, UL, and flexible symbols.
  • UEs are configured with the slot format (dynamically through DCI, or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G/NR frame structure that is TDD.
  • RRC radio resource control
  • a frame (10 ms) may be divided into 10 equally sized subframes (1 ms) .
  • Each subframe may include one or more time slots.
  • Subframes may also include mini-slots, which may include 7, 4, or 2 symbols.
  • Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols.
  • the symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols.
  • the symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission) .
  • the number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies ⁇ 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology ⁇ , there are 14 symbols/slot and 2 ⁇ slots/subframe.
  • the subcarrier spacing and symbol length/duration are a function of the numerology.
  • the subcarrier spacing may be equal to 2 ⁇ *15 kHz, where ⁇ is the numerology 0 to 5.
  • ⁇ is the numerology 0 to 5.
  • the symbol length/duration is inversely related to the subcarrier spacing.
  • the subcarrier spacing is 15 kHz and symbol duration is approximately 66.7 ⁇ s.
  • a resource grid may be used to represent the frame structure.
  • Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers.
  • RB resource block
  • PRBs physical RBs
  • the resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.
  • the RS may include demodulation RS (DM-RS) (indicated as R x for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE.
  • DM-RS demodulation RS
  • CSI-RS channel state information reference signals
  • the RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .
  • BRS beam measurement RS
  • BRRS beam refinement RS
  • PT-RS phase tracking RS
  • FIG. 2B illustrates an example of various DL channels within a subframe of a frame.
  • the physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol.
  • the DCI carries DFI.
  • the DFI may be used for handling the HARQ-ACK protocol in conjunction with a CG transmission in the uplink.
  • the DFI may be transmitted using the PDCCH scrambled with CS-RNTI, such that no new physical channel is defined.
  • the DCI format 0_1 frame structure is reused with a DFI flag indicating whether the remainder of the DCI is to be interpreted as an uplink scheduling grant or downlink feedback information.
  • a 1 bit flag serving as an explicit indication
  • the remainder of the DCI is interpreted as a bitmap to indicate positive or negative acknowledgment for each HARQ process contained within the DFI.
  • the DFI size may be aligned with the UL grant DCI format 0_1 size.
  • reserved bits may be included to ensure the overall size of the DFI is equivalent to the DCI format 0_1 frame structure size regardless whether the DCI format 0_1 frame structure size carries an uplink grant or downlink feedback information, thus, the number of blind decoding attempts is not increased. In this regard, the UE blind decoding complexity is not increased due to matching sizes.
  • the content of DFI includes: (1) a 1 bit UL/downlink (DL) flag, (2) a 0-or 3-bit carrier indicator field (CIF) , 3 bits are used in the case of a cross carrier scheduled is configured, (3) the 1-bit DFI flag, used to distinguish between DCI format 0_1 based activation/deactivation and DFI, (4) 16-bit HARQ-ACK bitmap, (5) 2-bit transmit power control (TPC) command, and (6) any zero-padding to match the length of the DCI format 0_1 frame structure.
  • DL UL/downlink
  • CIF carrier indicator field
  • a primary synchronization signal may be within symbol 2 of particular subframes of a frame.
  • the PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity.
  • a secondary synchronization signal may be within symbol 4 of particular subframes of a frame.
  • the SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DM-RS.
  • PCI physical cell identifier
  • the physical broadcast channel which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block.
  • the MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) .
  • the physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.
  • SIBs system information blocks
  • some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station.
  • the UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) .
  • the PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH.
  • the PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used.
  • the UE may transmit sounding reference signals (SRS) .
  • the SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.
  • FIG. 2D illustrates an example of various UL channels within a subframe of a frame.
  • the PUCCH may be located as indicated in one configuration.
  • the PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and HARQ ACK/NACK feedback.
  • UCI uplink control information
  • the PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.
  • BSR buffer status report
  • PHR power headroom report
  • FIG. 2E illustrates example diagram 290 illustrating non-limiting examples of time and frequency resources that may be used for wireless communication based on sidelink.
  • the time and frequency resources may be based on a slot structure.
  • a different structure may be used.
  • the slot structure may be within a 5G/NR frame structure in some examples.
  • LTE, LTE-A, CDMA, GSM, and other wireless technologies This is merely one example, and other wireless communication technologies may have a different frame structure and/or different channels.
  • a frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots.
  • Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols.
  • Diagram 290 illustrates a single slot transmission, e.g., which may correspond to a 0.5 ms transmission time interval (TTI) .
  • TTI transmission time interval
  • a resource grid may be used to represent the frame structure.
  • Each time slot may include a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers.
  • the resource grid is divided into multiple resource elements (REs) .
  • the number of bits carried by each RE depends on the modulation scheme.
  • Diagram 290 also illustrates multiple subchannels, where each subchannel may include multiple RBs. For example, one subchannel in sidelink communication may include 10-100 RBs.
  • the first symbol of a subframe may be a symbol for automatic gain control (AGC) .
  • AGC automatic gain control
  • Some of the REs may include control information, e.g., along with PSCCH and/or PSSCH.
  • the control information may include Sidelink Control Information (SCI) .
  • the PSCCH can include a first-stage SCI.
  • a PSCCH resource may start at a first symbol of a slot, and may occupy 1, 2 or 3 symbols.
  • the PSCCH may occupy up to one subchannel with the lowest subcarrier index.
  • FIG. 2E also illustrates symbol (s) that may include PSSCH.
  • the symbols in FIG. 2E that are indicated for PSCCH or PSSCH indicate that the symbols include PSCCH or PSSCH REs.
  • Such symbols corresponding to PSSCH may also include REs that include a second-stage SCI and/or data. At least one symbol may be used for feedback (e.g., PSFCH) , as described herein.
  • PSFCH Feedback
  • symbols 12 and 13 are indicated for PSFCH, which indicates that these symbols include PSFCH REs.
  • symbol 12 of the PSFCH may be a duplication of symbol 13.
  • a gap symbol prior to and/or after the feedback may be used for turnaround between reception of data and transmission of the feedback.
  • symbol 10 includes a gap symbol to enable turnaround for feedback in symbol 11.
  • Another symbol, e.g., at the end of the slot (symbol 14) may be used as a gap.
  • the gap enables a device to switch from operating as a transmitting device to prepare to operate as a receiving device, e.g., in the following slot.
  • Data may be transmitted in the remaining REs, as illustrated.
  • the data may include the data message described herein.
  • the position of any of the PSCCH, PSSCH, PSFCH, and gap symbols may be different than the example illustrated in FIG. 2E.
  • the present disclosure provides for dual connectivity with Uu direct link connections and sidelink-based relays between UEs and the core network.
  • a sidelink-relayed connection to a second direct link connection to the network may serve as a fallback option if a first direct link connection to the network is lost or suffers a radio link failure.
  • the sidelink-relayed connection may primarily facilitate control-plane signaling between the UEs and the network, in particular, for Mode 1 sidelink control.
  • the UE may trigger an event to additionally set up an alternate control-plane connection via sidelink (e.g., UE-network relay) and maintain the sidelink-relayed control-plane connection active in the event that the Uu direct link connection is lost in a radio link failure event or during a handover procedure.
  • sidelink e.g., UE-network relay
  • the Mode 1 sidelink scheduling is based on Uu direct link connection. If the Uu direct link connection to the base station is lost, then the UE may switch to the sidelink connection to establish the sidelink-relayed control-plane connection for control plane Mode 1 sidelink operation.
  • the UE may tear down the dual connectivity sidelink connection when the signal quality of the Uu direct link connection improves and increases greater than the predetermined threshold (after recovery or handover operation) . If the obstruction-based coverage holes can occur at any given time, the UE may maintain the sidelink-relayed control plane connection active at all times. Otherwise, the UE may be configured by the base station via the Uu direct link connection.
  • the subject technology can achieve higher reliability for FR2 sidelink Mode 1 based operations.
  • FIG. 3 is a block diagram of a first wireless communication device 310 in communication with a second wireless communication device 350.
  • the communication may be based on sidelink, e.g., using a PC5 interface.
  • the devices 310 and 350 may communicate based on V2X or other D2D communication.
  • the devices 310 and the 350 may include a UE, an RSU, a base station, etc.
  • the device 310 may be a UE and the device 350 may be a UE.
  • Packets may be provided to a controller/processor 375 that implements layer 3 and layer 2 functionality.
  • Layer 3 includes a radio resource control (RRC) layer
  • layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer.
  • RRC radio resource control
  • PDCP packet data convergence protocol
  • RLC radio link control
  • MAC medium access control
  • the transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 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 TX processor 316 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) ) .
  • BPSK binary phase-shift keying
  • QPSK quadrature phase-shift keying
  • M-PSK M-phase-shift keying
  • M-QAM M-quadrature amplitude modulation
  • the coded and modulated symbols may then be split into parallel streams.
  • Each stream may then be mapped to an 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.
  • IFFT Inverse Fast Fourier Transform
  • the OFDM stream is spatially precoded to produce multiple spatial streams.
  • Channel estimates from a channel estimator 374 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 device 350.
  • Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX.
  • Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.
  • each receiver 354RX receives a signal through its respective antenna 352.
  • Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356.
  • the TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions.
  • the RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the device 350. If multiple spatial streams are destined for the device 350, they may be combined by the RX processor 356 into a single OFDM symbol stream.
  • the RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) .
  • FFT Fast Fourier Transform
  • 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 device 310. These soft decisions may be based on channel estimates computed by the channel estimator 358.
  • the soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by device 310 on the physical channel.
  • the data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.
  • the controller/processor 359 can be associated with a memory 360 that stores program codes and data.
  • the memory 360 may be referred to as a computer-readable medium.
  • the controller/processor 359 may provide demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing.
  • the controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.
  • the controller/processor 359 may provide 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) ; RLC 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 TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.
  • RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting
  • PDCP layer functionality associated
  • Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by device 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing.
  • the spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.
  • Each receiver 318RX receives a signal through its respective antenna 320.
  • Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.
  • the controller/processor 375 can be associated with a memory 376 that stores program codes and data.
  • the memory 376 may be referred to as a computer-readable medium.
  • the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing.
  • the controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.
  • At least one of the TX processor 368, the RX processor 356, or the controller/processor 359 of device 350 or the TX 316, the RX processor 370, or the controller/processor 375 may be configured to perform aspects described in connection with the cooperative relay configuration component 198 and/or the relaying component 199 of FIG. 1.
  • FIG. 4 illustrates an example 400 of dual connectivity with direct link communication and sidelink communication between wireless devices.
  • the communication may be based on a slot structure comprising aspects described in connection with FIGS. 2A-2E or another slot structure.
  • the example 400 illustrates UEs 402, 404, 406, 408, RSU 407, and base stations 430, 432. Although the example in FIG. 4 is described for the UEs 402, 404, 406, 408, aspects may be applied to other wireless devices configured for communication based on sidelink, such as an RSU, an IAB node, etc.
  • the UEs 402, 404, 406, 408 may each be capable of operating as a transmitting device in addition to operating as a receiving device.
  • the UEs 402, 406, 408 are illustrated as respectively transmitting transmissions 414, 416 and 420.
  • the transmissions 414, 416 or 420 may be broadcast or multicast to nearby devices.
  • the UE 402 may transmit communication intended for receipt by other UEs within a range 401 of the UE 402.
  • the transmissions 414, 416, or 420 may be groupcast to nearby devices that a member of a group.
  • the transmissions 414, 416, or 420 may be unicast from one UE to another UE.
  • the RSU 407 may receive communication from and/or transmit communication 418 to the UEs 402, 404, 406, 408.
  • sidelink communication may include V2X communication.
  • V2X communication involves the wireless exchange of information directly between not only vehicles (e.g., UEs 402, 404, 406, 408, 410) themselves, but also directly between vehicles and infrastructure (e.g., RSU 107) , such as streetlights, buildings, traffic cameras, tollbooths or other stationary objects, vehicles and a pedestrian (not shown) , and vehicles and wireless communication networks (e.g., base station 430, 432) .
  • V2X communication enables UEs 402-410 (as, or as part of, the vehicles) to obtain information related to the weather, nearby accidents, road conditions, activities of nearby vehicles and pedestrians, objects nearby the vehicle, and other pertinent information that may be utilized to improve the vehicle driving experience and increase vehicle safety.
  • V2X data may enable autonomous driving and improve road safety and traffic efficiency.
  • the exchanged V2X data may be utilized by a V2X connected vehicle (e.g., UEs 402-410) to provide in-vehicle collision warnings, road hazard warnings, approaching emergency vehicle warnings, pre-/post-crash warnings and information, emergency brake warnings, traffic jam ahead warnings, lane change warnings, intelligent navigation services, and other similar information.
  • V2X data received by a V2X connected UE of a pedestrian (or cyclist) may be utilized to trigger a warning sound, vibration, flashing light, etc., in case of imminent danger.
  • the UE 402, 404, 406, 408 and/or the RSU 407 may include a dual connectivity relay configuration component, similar to the dual connectivity relay configuration component 198 described in connection with FIG. 1.
  • the UE 402, 404, 406, 408 and/or the RSU 407 may additionally or alternatively include a relaying component, similar to the relaying component 199 described in connection with FIG. 1.
  • Resource allocation refers to how a resource is allocated to a device to use for transmitting a packet.
  • resource allocation may be performed in a centralized manner (Mode 1) or a distributed manner (Mode 2) .
  • Mode 1 resource allocations for sidelink communication are determined by a base station (e.g., BS 430, 432) .
  • the base station 430 may transmit an indication to a UE (e.g., 402) that indicates the resources that are allocated to the UE 402 to use to transmit sidelink communication (e.g., sidelink data packets to other UEs) .
  • the resource allocations for sidelink communication are determined by the communicating UE.
  • a transmitting UE may autonomously determine resource allocations for transmitting sidelink control and data to one or more receiving UEs.
  • the transmitting UE may determine the resources to use for communicating from a resource pool.
  • a resource pool refers to a collection of time and/or frequency resources on which sidelink communication may occur.
  • a transmitter (Tx) UE 402 and a receiver (Rx) UE 408 may communicate with one another via a sidelink channel (e.g., 454) .
  • a base station e.g., 430
  • the Tx UE 402 via a first access link (e.g., 442) .
  • the base station 430 may communicate with the Rx UE 408 via a second access link (e.g., 446) .
  • the Tx UE 402 and/or the Rx UE 408 may correspond to one or more UEs described elsewhere herein, such as the UE 104 of FIG. 1.
  • a direct link connection between UEs 104 may be referred to as a sidelink
  • a direct link between a base station 102/180 and a UE 104 e.g., via a Uu interface
  • Sidelink communications may be transmitted via the sidelink
  • access link communications may be transmitted via the access link.
  • An access link communication may be either a downlink communication (from a base station 102/180 to a UE 104) or an uplink communication (from a UE 104 to a base station 102/180) .
  • the UE 402 may operate in Mode 1, in which resource selection and/or scheduling is performed by the base station 102/180. That is, in Mode 1, the base station 430 assigns resources for transmitting sidelink communications.
  • the base station 430 may transmit downlink control information (DCI) (e.g., in DCI format 3_0) that indicates a resource allocation (e.g., time and/or frequency resources) and/or a transmission timing.
  • DCI downlink control information
  • a MCS value for sidelink transmissions may be selected by a UE 402 (e.g., within limits set by the base station 430) .
  • Mode 1 may support dynamic grants or configured grants for scheduling sidelink transmissions.
  • the configured grants may be type 1 (e.g., which may be activated by the base station 430 via radio resource control (RRC) signaling) or type 2.
  • RRC radio resource control
  • a first base station e.g., 430
  • the base station 430 may configure sidelink UEs (e.g., 402, 406, 408) via downlink control links (e.g., 442, 444, 446) .
  • the base station 430 may receive a signal radio bearer (SRB) from the sidelink UEs, and provide sidelink scheduling grants to the sidelink UEs to use for their sidelink transmissions.
  • a second base station e.g., 432 may configure UE 410 via a downlink control link 448.
  • the UE 402 may operate in Mode 2, in which resource selection and/or scheduling is performed by the UE 402. That is, the transmitting UE 402 may autonomously determine resources for sidelink transmissions. In this case, the transmitting UE 402 may perform channel sensing by performing blind decoding of all PSCCH channels in order to determine resources that are reserved for sidelink transmissions (e.g., by other transmitting UEs) . In this way, the transmitting UE 402 may determine available resources, which may be reported to an upper layer of the transmitting UE 402 where resource usage is determined.
  • the receiving UE 408 operates according to the same behavior in Mode 1 or Mode 2. In some aspects, the UE 402 may perform resource selection and/or scheduling by sensing channel availability for transmissions.
  • the UE 402 may measure a received signal strength indicator (RSSI) parameter (e.g., a sidelink-RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure a reference signal received power (RSRP) parameter (e.g., a PSSCH-RSRP parameter) associated with various sidelink channels, may measure a reference signal received quality (RSRQ) parameter (e.g., a PSSCH-RSRQ parameter) associated with various sidelink channels, and/or the like, and may select a channel for transmission of a sidelink communication based at least in part on the measurement (s) .
  • RSSI received signal strength indicator
  • RSRP reference signal received power
  • RSRQ reference signal received quality
  • a transmitting UE 402 may transmit a transmission 414 comprising a control information (e.g., sidelink control information (SCI) ) and/or a corresponding data channel, that may be received by receiving UEs 406, 408 via sidelink configuration links 452, 454.
  • the SCI may include information for decoding the corresponding data and may also be used by receiving device to avoid interference by refraining from transmitting on the occupied resources during a data transmission.
  • the SCI may reserve resources for sidelink communication.
  • the number of TTIs, as well as the RBs that will be occupied by the data transmission, may be indicated in SCI from the transmitting device.
  • coverage holes may exist for cellular connections (e.g., Uu direct link connections) .
  • the cellular connections from mm-wave base stations may have smaller coverage areas and may be more susceptible to blockages (e.g., foliage, temporary installations, etc. ) . This may occur in V2X environments when an obstruction is positioned between the UEs and the BS 430.
  • a first UE e.g., UE 402
  • the line-of-sight between the UE 402 and the BS 430 may be obstructed by a large object (e.g., UE 404) such that the communication link (e.g., 412) from the UE 402 to the BS 430 is blocked.
  • the UE 402 may attempt to initiate a RRC reestablishment with a second base station (e.g., BS 432) via downlink configuration link 460.
  • a second base station e.g., BS 432
  • resynchronizing to the BS 432 may not be ideal, as given its direction and position relative to the BS 432, the UE 402 may soon thereafter lose connection to the BS 432.
  • the loss of the cellular connection coverage (e.g., via Uu direct link connection) with the BS 430 may require the UE 402 to stop sidelink transmissions.
  • a semi-persistent scheduling (SPS) sidelink grant may no longer be used if the UE 402 initiates operation of radio link failure (RLF) procedures.
  • exception resource pools may be used by switching the UE 402 from a Mode 1 based operation (e.g., centralized manner) to a Mode 2 based operation (e.g., distributed manner) .
  • the exception resource pool may be utilized during a handover or occurrence of an RLF event.
  • the resource selection may be based on the Mode 2 operation.
  • the Mode 1 sidelink operation can suffer.
  • the UE 402 may initiate a handover operation to a non-optimal base station (e.g., BS 432) , and may lose the new connection soon thereafter.
  • a non-optimal base station e.g., BS 432
  • the UE may still have sidelink connections with other UEs.
  • the first UE e.g., UE-B
  • a second UE e.g., UE 406, 408
  • the UE 402 may notify the UE 408 about the blockage with the BS 430.
  • the UE 408 may notify the UE 402, based on historical connection information, to not reestablish a connection with a base station.
  • the UE 402 may instead use the UE 408 as a relay station until the blocking event is terminated.
  • the peer sidelink UEs (e.g., UEs 406, 408) can serve as relay stations to improve Mode 1 sidelink performance by forwarding control signaling from the BS 430 with the blocked UE (e.g., UE 402) through Mode 1 sidelink operations.
  • the present disclosure provides for dual connectivity with Uu direct link connections and sidelink-based relays between UEs and the core network.
  • a sidelink-relayed connection to a second direct link connection to the network may serve as a fallback option if a first direct link connection to the network is lost or suffers a radio link failure.
  • the sidelink-relayed connection may primarily facilitate control-plane signaling between the UEs and the network, in particular, for Mode 1 sidelink control.
  • the UE may trigger an event to additionally set up an alternate control-plane connection via sidelink (e.g., UE-network relay) and maintain the sidelink-relayed control-plane connection active in the event that the Uu direct link connection is lost in a radio link failure event or during a handover procedure.
  • sidelink e.g., UE-network relay
  • the Mode 1 sidelink scheduling is based on Uu direct link connection. If the Uu direct link connection to the base station is lost, then the UE may switch to the sidelink connection to establish the sidelink-relayed control-plane connection for control plane Mode 1 sidelink operation.
  • the UE may tear down the dual connectivity sidelink connection when the signal quality of the Uu direct link connection improves and increases greater than the predetermined threshold (after recovery or handover operation) . If the obstruction-based coverage holes can occur at any given time, the UE may maintain the sidelink-relayed control plane connection active at all times. Otherwise, the UE may be configured by the base station via the Uu direct link connection.
  • the subject technology can achieve higher reliability for FR2 sidelink Mode 1 based operations.
  • FIG. 5 is a flowchart of a process 500 of wireless communication, in accordance with one or more of aspects of the present disclosure.
  • the process 500 may be performed by a wireless communication device (e.g., the UE 104, 402, 404, 406, 408, 410; the device 350, the RSU 107, 407; the apparatus 902, which may include memory, a cellular baseband processor 904, and one or more components configured to perform the 500) .
  • the process 500 includes a number of enumerated steps, but embodiments of the process 500 may include additional steps before, after, and in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order.
  • the process 500 enables a wireless communication device to facilitate dual connectivity with Uu direct link connections and sidelink-based relays between UEs and a core network.
  • a sidelink-relayed connection to a second direct link connection to the network may serve as a fallback option if a first direct link connection to the network is lost or suffers a radio link failure.
  • the sidelink-relayed connection may primarily facilitate control-plane signaling between the UEs and the network, in particular, for Mode 1 sidelink control.
  • the UE may trigger an event to additionally set up an alternate control-plane connection via sidelink (e.g., UE-network relay) and maintain the sidelink-relayed control-plane connection active in the event that the Uu direct link connection is lost in a radio link failure event or during a handover procedure.
  • sidelink e.g., UE-network relay
  • the Mode 1 sidelink scheduling is based on Uu direct link connection. If the Uu direct link connection to the base station is lost, then the UE may switch to the sidelink connection to establish the sidelink-relayed control-plane connection for control plane Mode 1 sidelink operation.
  • the UE may tear down the dual connectivity sidelink connection when the signal quality of the Uu direct link connection improves and increases greater than the predetermined threshold (after recovery or handover operation) . If the obstruction-based coverage holes can occur at any given time, the UE may maintain the sidelink-relayed control plane connection active at all times. Otherwise, the UE may be configured by the base station via the Uu direct link connection.
  • the subject technology can achieve higher reliability for FR2 sidelink Mode 1 based operations.
  • the wireless communication device may determine a set of sidelink stations operable to serve as relay stations and forward a control plane signaling between the wireless communication device and a first base station.
  • the set of sidelink stations operable to serve as relay stations may be determined, e.g., by the determination component 948 of the apparatus 902 in FIG. 9.
  • the wireless communication device may establish a first signaling radio bearer (SRB1) with the first base station.
  • SRB1 first signaling radio bearer
  • the wireless communication device may provide an indication of the set of sidelink stations to the first base station over the SRB1.
  • the indication of the set of sidelink station may be provided, e.g., by the sidelink relay component 946 of the apparatus 902 through coordination with the measurement component 944 of the apparatus 902 in FIG. 9.
  • the wireless communication device may transmit, to the first base station, a radio resource control (RRC) connection update request that includes the indication of the set of sidelink stations.
  • RRC radio resource control
  • the wireless communication device may receive, from the first base station, a RRC connection update response that includes an indication of whether the first base station accepts the set of sidelink stations to serve as relay stations or provides a subset listing of sidelink stations from the set of sidelink stations accepted by the first base station. For example, the first base station may accept all the indicated peers as relays or may prune the list sent by the wireless communication device based on its own measurements or peer relay capabilities.
  • the RRC connection update response may be received, e.g., by the processor component 950 of the apparatus 902 through coordination with the reception component 930 of the apparatus 902 in FIG. 9.
  • the wireless communication device may receive, from the first base station, one or more sidelink scheduling grants assigned to the wireless communication device.
  • the wireless communication device may establish a relay signal radio bearer (SRBr) to a sidelink station of the set of sidelink stations using a respective one of the one or more sidelink scheduling grants.
  • SRBr relay signal radio bearer
  • the SRBr to the sidelink station is transitioned into an inactive state when the direct link connection between the wireless communication device and the first base station is active.
  • the SRBr may be activated when the RLF is detected.
  • the wireless communication device may obtain one or more measurements of a direct link connection with the first base station.
  • the one or more measurements of a direct link connection may be obtained, e.g., by the measurement component 944 of the apparatus 902 through coordination with the direct link component 942 of the apparatus 902 in FIG. 9.
  • the wireless communication device may measure a received signal strength indicator (RSSI) parameter (e.g., a sidelink-RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure a reference signal received power (RSRP) parameter (e.g., a PSSCH-RSRP parameter) associated with various sidelink channels, may measure a reference signal received quality (RSRQ) parameter (e.g., a PSSCH-RSRQ parameter) associated with various sidelink channels, and/or the like.
  • RSSI received signal strength indicator
  • RSRP reference signal received power
  • RSRQ reference signal received quality
  • the wireless communication device may determine whether the one or more measurements of the direct link connection with the first base station is lesser than a predetermined threshold. In this regard, the wireless communication device may establish the sidelink connection with the at least one sidelink station when the one or more measurements of the direct link connection is lesser than the predetermined threshold. In one or more implementations, the wireless communication device may determine whether the one or more measurements of the direct link connection with the first base station is greater than a predetermined threshold. In some aspects, the wireless communication device may terminate the relay signal radio bearer with the at least one sidelink station when the one or more measurements of the direct link connection is greater than the predetermined threshold. In other aspects, the wireless communication device may maintain the relay signal radio bearer with the at least one sidelink station when the one or more measurements of the direct link connection is not greater than the predetermined threshold.
  • the wireless communication device may establish a sidelink connection with at least one sidelink station of the set of sidelink stations based on the one or more measurements. For example, if the one or more measurements of the direct link connection fall below a predetermined threshold, the wireless communication device may initiate a request to connect to the at least one sidelink station to have the sidelink connection serve as a fallback option in the event the direct link connection is lost or suffers a RLF event.
  • the sidelink connection may be established, e.g., by the sidelink relay component 946 of the apparatus 902 through coordination with the configuration component 940 of the apparatus 902 in FIG. 9.
  • the wireless communication device may determine an occurrence of a radio link failure (RLF) event in the direct link connection between the wireless communication device and the first base station.
  • the occurrence of the RLF event may be determined, e.g., by the determination component 948 of the apparatus 902 through coordination with the direct link component 942 of the apparatus 902 in FIG. 9.
  • the wireless communication device may transition the SRBr from the inactive state to an active state based on the occurrence of the RLF event.
  • the wireless communication device may transition the SRBr to the sidelink station into an active state when the direct link connection between the wireless communication device and the first base station is active.
  • the wireless communication device may keep one of the signal radio bearers active.
  • the SRB1 may be split between the SRB1 and SRBr.
  • the SRB1 may be prioritized over the SRBr and designated as a primary signal radio bearer.
  • the wireless communication device may refrain from initiating a RRC reestablishment procedure with the first base station.
  • the wireless communication device may communicate, with the first base station through the at least one sidelink station over the sidelink connection, the control plane signaling.
  • the control plane signaling may be communicated, e.g., by the direct link component 942 of the apparatus 902 through coordination with the processor component 950 and the transmission component 934 of the apparatus 902 in FIG. 9.
  • the wireless communication device may only transmit and receive control signaling (exclusion of any data transmissions) .
  • the wireless communication device may communicate, with the sidelink station of the set of sidelink stations, a RRC connection resume request that includes an indication of a direct link connection failure with the first base station based on the occurrence of the RLF event.
  • the RRC connection resume request may be communicated, e.g., by the direct link component 942 of the apparatus 902 through coordination with the processor component 950 and the transmission component 934 of the apparatus 902 in FIG. 9.
  • the wireless communication device may receive, from the sidelink station, a RRC reconfiguration request originating from the first base station based on the indication of the direct link connection failure in the RRC connection resume request.
  • the RRC reconfiguration request may include an indication to the wireless communication device to initiate a handover from the first base station to a second base station.
  • the wireless communication device may receive, from the sidelink station, a RRC connection release for the wireless communication device to release the SRBr to the sidelink station.
  • the RRC connection release may be transmitted separately from the RRC reconfiguration request in some implementations, or the RRC connection release may be transmitted concurrently with the RCC reconfiguration request in other implementations.
  • the wireless communication device may receive, from the sidelink station, a connection resume message based on an inactive state of the SRBr.
  • the connection resume message may include an indication to the wireless communication device to utilize a sidelink station of the set of sidelink stations as a relay station to resume communication of the control plane signaling with the first base station based on the indication of the direct link connection failure in the RRC connection resume request.
  • the wireless communication device may transmit, to the sidelink station, a resume complete message in response to the connection resume message.
  • the wireless communication device may determine whether each sidelink station of the set of sidelink stations sends a RRC response indicating a rejection of the RRC connection resume request. In this regard, the wireless communication device may initiate a RRC reestablishment operation with a second base station different from the first base station when each sidelink station sends a RRC response indicating the rejection of the RRC connection resume request.
  • the wireless communication device may communicate, with the sidelink station of the set of sidelink stations, a RRC connection update message that includes an indication of a direct link connection failure with the first base station based on the occurrence of the RLF event.
  • the wireless communication device may determine whether each sidelink station of the set of sidelink stations sends a RRC response indicating a rejection of the RRC connection update message; and initiating a RRC reestablishment operation with a second base station different from the first base station when each sidelink station sends a RRC response indicating the rejection of the RRC connection update message.
  • the wireless communication device may determine whether the direct link connection with the first base station is established by a predetermined time (e.g., T RLF ) after the indication of the direct link connection failure is communicated to one or more sidelink stations of the set of sidelink stations.
  • the direct link connection established by the predetermined time may be determined, e.g., by the determination component 948 of the apparatus 902 through coordination with the direct link component 942 of the apparatus 902 in FIG. 9.
  • the wireless communication device may perform a comparison operation between a time duration of the direct link reestablishment and a predetermined time. If the direct link connection with the first base station is established by the predetermined time, then the process 500 proceeds to block 522. Otherwise, the process 500 reverts back to block 518. In this regard, the amount of time elapsed to establish the direct link connection may exceed beyond the predetermined time.
  • the wireless communication may initiate a RRC reestablishment operation when the direct link connection with the first base station is not established by the predetermined time.
  • the wireless communication device may initiate the RRC reestablishment operation with the first base station in some implementations, or may initiate the RRC reestablishment operation with a second base station different from the first base station in other implementations.
  • the wireless communication device may determine that the direct link connection between the wireless communication device and the first base station is lost. In this regard, the wireless communication device may switch to the sidelink connection with the at least one sidelink station for control plane Mode 1 sidelink operation.
  • FIG. 6 is a flowchart of a process 600 of wireless communication, in accordance with one or more of aspects of the present disclosure.
  • the process 600 may be performed by a wireless communication device (e.g., the UE 104, 402, 404, 406, 408, 410; the device 350, the RSU 107, 407; the apparatus 902, which may include memory, a cellular baseband processor 904, and one or more components configured to perform the 600) .
  • the process 600 includes a number of enumerated steps, but embodiments of the process 600 may include additional steps before, after, and in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order. Optional aspects are illustrated with a dashed line.
  • the wireless communication device may receive a sidelink connection with a second UE based on a status of a first direct link connection between the second UE and a first base station.
  • the sidelink connection with the second UE may be received, e.g., by the sidelink relay component 946 of the apparatus 902 through coordination with the reception component 930 of the apparatus 902 in FIG. 9.
  • the wireless communication device may receive, from the second UE through the sidelink connection, a relay signal radio bearer (SRBr) based on one or more sidelink scheduling grants assigned to the second UE.
  • SRBr relay signal radio bearer
  • the wireless communication device may communicate, with the first base station through a second direct link connection between the wireless communication device and the first base station, a control plane signaling associated with the second UE when the status indicates an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • the control plane signaling may be communicated, e.g., by the direct link component 942 of the apparatus 902 through coordination with the processor component 950 and the transmission component 934 of the apparatus 902 in FIG. 9.
  • the wireless communication device may receive, from the second UE over the sidelink connection, a RRC connection resume request based on an inactive state of the SRBr.
  • the RRC connection resume request may be received, e.g., by the sidelink relay component 946 of the apparatus 902 through coordination with the reception component 930 of the apparatus 902 in FIG. 9.
  • the RRC connection resume request may include an indication of a direct link connection failure between the second UE and the first base station based on the occurrence of the RLF event.
  • the wireless communication device may determine whether a lost connection with the first base station through the second direct link connection to the first base station has occurred.
  • the wireless communication device may determine whether the second direct link connection to the first base station is reestablished after the lost connection with the first base station through the second direct link connection has occurred.
  • the wireless communication device may communicate, with the second UE through the sidelink connection, a RRC response indicating a rejection of the RRC connection resume request when the second direct link connection to the first base station is not reestablished.
  • the wireless communication device may receive, from the second UE over the sidelink connection, a RRC connection update message based on an active state of the SRBr.
  • the RRC connection update message may be received, e.g., by the sidelink relay component 946 of the apparatus 902 through coordination with the reception component 930 of the apparatus 902 in FIG. 9.
  • the RRC connection update message may include an indication of a direct link connection failure between the second UE and the first base station based on the occurrence of the RLF event.
  • the wireless communication device may communicate, with the first base station through the second direct link connection, an uplink information transfer message that includes the indication of the direct link connection failure between the second UE and the first base station.
  • the wireless communication device may receive, from the first base station through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the RRC connection update message.
  • the wireless communication device may communicate, with the first base station through the second direct link connection, an uplink information transfer message that includes the indication of the direct link connection failure between the second UE and the first base station.
  • the uplink information transfer message may be communicated, e.g., by the direct link component 942 of the apparatus 902 through coordination with the transmission component 934 of the apparatus 902 in FIG. 9.
  • the uplink information transfer message may include one or more measurements of the sidelink connection between the wireless communication device and the second UE.
  • the wireless communication device may include its sidelink channel measurement to the second UE (e.g., SL-RSRP) in the uplink information transfer message.
  • the wireless communication device may receive, from the first base station through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the RRC connection resume request.
  • the RRC reconfiguration request may be received, e.g., by the configuration component 940 of the apparatus 902 through coordination with the reception component 930 of the apparatus 902 in FIG. 9.
  • the RRC reconfiguration request may include an indication to the second UE to utilize the wireless communication device as a relay station to resume communication of the control plane signaling with the first base station.
  • the wireless communication device may communicate, with the second UE through the sidelink connection, a RRC connection release for the UE to release the SRBr to the wireless communication device.
  • the wireless communication device may communicate, with the second UE through the sidelink connection, a RRC connection resume message or the RRC reconfiguration request.
  • the wireless communication device may communicate, with the second UE through the sidelink connection, a connection resume message based on an inactive state of the SRBr.
  • the connection resume message includes the indication of the RRC reconfiguration request.
  • the wireless communication device may receive, from the second UE, a resume complete message in response to the connection resume message.
  • FIGS. 7A and 7B are diagrams illustrating example communication flows for sidelink-relayed dual connectivity for Mode 1 sidelink service continuity, in accordance with one or more of aspects of the present disclosure.
  • diagram 700 provides a communication flow for indicating use of a relay after determination of a RLF event.
  • the UE e.g., UE-1
  • the UE may determine an occurrence of a radio link failure (RLF) event in the direct link connection between the UE-1 and a first base station (e.g., BS) .
  • RLF radio link failure
  • the UE-1 may communicate, with the sidelink station of the set of sidelink stations, a RRC connection resume request that includes an indication of a direct link connection failure with the first base station based on the occurrence of the RLF event.
  • the relay UE e.g., UE-R
  • the relay UE may communicate, with the first base station through a second direct link connection, an uplink information transfer message that includes the indication of the direct link connection failure between the relay UE and the first base station.
  • the base station e.g., BS
  • the UE-1 may receive, through the sidelink channel, a connection resume message based on an inactive state of the SRBr.
  • the connection resume message may include an indication to the UE to utilize a sidelink station of the set of sidelink stations as a relay station to resume communication of the control plane signaling with the first base station based on the indication of the direct link connection failure in the RRC connection resume request.
  • the UE-1 may transmit, to the sidelink station, a resume complete message in response to the connection resume message.
  • diagram 750 provides a communication flow for indicating a handover after determination of a RLF event.
  • the UE e.g., UE-1
  • the UE-1 may determine an occurrence of a radio link failure (RLF) event in the direct link connection between the UE-1 and a first base station (e.g., BS) .
  • the UE-1 may communicate, with the sidelink station of the set of sidelink stations, a RRC connection resume request that includes an indication of a direct link connection failure with the first base station based on the occurrence of the RLF event.
  • RLF radio link failure
  • the relay UE may communicate, with the first base station through a second direct link connection, an uplink information transfer message that includes the indication of the direct link connection failure between the relay UE and the first base station.
  • the base station e.g., BS
  • the relay UE may communicate, with the relay UE through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the RRC connection resume request.
  • the RRC reconfiguration request includes an indication to the first UE to initiate an inter-cell handover from the first BS to a second BS.At 760, the relay UE may forward the RRC reconfiguration request to the UE-1.
  • the relay UE may communicate, with the UE-1 through the sidelink connection, a RRC connection release for the UE-1 to release the SRBr to the relay UE.
  • the UE-1 may resynchronize with a second base station via the handover procedure.
  • FIG. 8 is a flowchart of a process of wireless communication, in accordance with one or more of aspects of the present disclosure.
  • the process 800 may be performed by a wireless communication device (e.g., the BS 102, 180, 430, 432; the device 310; the apparatus 1002, which may include memory, a cellular baseband processor 1004, and one or more components configured to perform the 800) .
  • the process 800 includes a number of enumerated steps, but embodiments of the process 800 may include additional steps before, after, and in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order. Optional aspects are illustrated with a dashed line.
  • a first base station may receive, from a first UE through a first direct link connection between the first UE and the first BS, an indication of a set of sidelink UEs operable to serve as relay stations and forward a control plane signaling between the first UE and the first BS.
  • the indication of the set of sidelink UEs may be received, e.g., by the configuration component 1040 of the apparatus 1002 through coordination with the reception component 1030 of the apparatus 1002 in FIG. 10.
  • the first BS may receive, from the first UE, a first signaling radio bearer (SRB1) with the first BS.
  • the first BS may receive the indication of the set of sidelink UEs over the SRB1.
  • the first BS may receive, from the first UE, a RRC connection update request that includes the indication of the set of sidelink UEs.
  • the first BS may communicate, with the first UE through the first direct link connection, a RRC connection update response in response to the RRC connection update request.
  • the RRC connection update response may be communicated, e.g., by the configuration component 1040 of the apparatus 1002 through coordination with the transmission component 1034 of the apparatus 1002 in FIG. 10.
  • the RRC connection update response may include an indication of whether the first BS accepts the set of sidelink UEs to serve as relay UEs or provides a subset listing of sidelink UEs from the set of sidelink UEs accepted by the first BS.
  • the wireless communication device may transmit, to the first UE, one or more sidelink scheduling grants assigned to the first UE.
  • the first BS may receive, from a second UE of the set of sidelink UEs through a second direct link connection between the second UE and the first BS, control plane signaling forwarded between the first UE and the second UE based on an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • the control plane signaling may be received, e.g., by the control signaling component 1042 of the apparatus 1002 through coordination with the reception component 1030 of the apparatus 1002 in FIG. 10.
  • the first BS may receive, from the second UE through the second direct link connection, an uplink information transfer message that includes an indication of a direct link connection failure between the first UE and the first BS based on a radio resource control (RRC) connection resume request forwarded between the first UE and the second UE that indicates an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • RRC radio resource control
  • the uplink information transfer message may be received, e.g., by the processor component 1046 of the apparatus 1002 through coordination with the reception component 1030 of the apparatus 1002 in FIG. 10.
  • the first BS may transmit, to the second UE through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the uplink information transfer message.
  • the RRC reconfiguration request may be transmitted, e.g., by the configuration component 1040 of the apparatus 1002 through coordination with the transmission component 1034 of the apparatus 1002 in FIG. 10.
  • the RRC reconfiguration request includes an indication to the first UE to initiate an inter-cell handover from the first BS to a second BS.
  • the RRC reconfiguration request includes an indication to the first UE to utilize the second UE as a relay UE to resume communication of the control plane signaling with the first BS.
  • the first BS may receive a plurality of uplink information transfer messages respectively from a plurality of sidelink UEs of the set of sidelink UEs, each of the plurality of uplink information transfer messages comprising an indication of a direct link connection failure between the first UE and the first BS and a sidelink measurement of a sidelink connection between the first UE and a respective one of the plurality of sidelink UEs.
  • the first BS may obtain a direct link measurement of a respective direct link connection with each of the plurality of sidelink UEs; selecting one of the plurality of sidelink UEs as a relay to the first UE based on one or more of the direct link measurement or the sidelink measurement.
  • the first BS may transmit, to the selected one of the plurality of sidelink UEs, the RRC reconfiguration request in response to a corresponding one of the plurality of uplink information transfer messages.
  • FIG. 9 is a diagram 900 illustrating an example of a hardware implementation for an apparatus 902.
  • the apparatus 902 may be a UE or other wireless device that communicates based on direct link and/or sidelink.
  • the apparatus 902 includes a cellular baseband processor 904 (also referred to as a modem) coupled to a cellular RF transceiver 922 and one or more subscriber identity modules (SIM) cards 920, an application processor 906 coupled to a secure digital (SD) card 908 and a screen 910, a Bluetooth module 912, a wireless local area network (WLAN) module 914, a Global Positioning System (GPS) module 916, and a power supply 918.
  • SIM subscriber identity modules
  • the cellular baseband processor 904 communicates through the cellular RF transceiver 922 with other wireless devices, such as a UE 104 and/or base station 102/180.
  • the cellular baseband processor 904 may include a computer-readable medium /memory.
  • the cellular baseband processor 904 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory.
  • the software when executed by the cellular baseband processor 904, causes the cellular baseband processor 904 to perform the various functions described supra.
  • the computer-readable medium /memory may also be used for storing data that is manipulated by the cellular baseband processor 904 when executing software.
  • the cellular baseband processor 904 further includes a reception component 930, a relay communication manager 932, and a transmission component 934.
  • the relay communication manager 932 includes the one or more illustrated components.
  • the components within the relay communication manager 932 may be stored in the computer-readable medium /memory and/or configured as hardware within the cellular baseband processor 904.
  • the cellular baseband processor 904 may be a component of the device 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359.
  • the apparatus 902 may be a modem chip and include just the baseband processor 904, and in another configuration, the apparatus 902 may be the entire wireless device (e.g., see the device 350 of FIG. 3) and include the additional modules of the apparatus 902.
  • the relay communication manager 932 includes a configuration component 940, a direct link component 942, a measurement component 944, a sidelink relay component 946, a determination component 948 and/or a processor component 950 configured to perform the aspects described in connection with methods in FIG. 5 and/or FIG. 6.
  • the apparatus is illustrated as including components to perform the method of FIG. 5 and/or FIG. 6, because the wireless device may operate as a transmitting device at times and may operate as a receiving device at other times.
  • the apparatus 902 may include components for the method of FIG. 5 without including components configured to perform the method of FIG. 6, or may include components for the method of FIG. 6 without including components configured to perform the method of FIG. 5.
  • the apparatus 902 may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIG. 5 and/or 6. As such, each block in the aforementioned flowcharts of FIG. 5 and/or 6 may be performed by a component and the apparatus may include one or more of those components.
  • the components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.
  • the apparatus 902 includes means for determining a set of sidelink stations operable to serve as relay stations and forward a control plane signaling between the UE and a first base station.
  • the apparatus 902 also may include means for obtaining one or more measurements of a direct link connection with the first base stations.
  • the apparatus 902 also may include means for establishing a sidelink connection with at least one sidelink station of the set of sidelink stations based on the one or more measurements.
  • the apparatus 902 may further include means for communicating, with the first base station through the at least one sidelink station over the sidelink connection, the control plane signaling.
  • the apparatus 902 may further include means for receiving a sidelink connection with a second UE based on a status of a first direct link connection between the second UE and a first base station.
  • the apparatus 902 may further include means for communicating, with the first base station through a second direct link connection between the first UE and the first base station, a control plane signaling associated with the second UE when the status indicates an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • RLF radio link failure
  • the aforementioned means may be one or more of the aforementioned components of the apparatus 902 configured to perform the functions recited by the aforementioned means.
  • the apparatus 902 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359.
  • the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.
  • FIG. 10 is a diagram 1000 illustrating an example of a hardware implementation for an apparatus 1002.
  • the apparatus 1002 may be a base station or other wireless device that communicates based on downlink/uplink.
  • the apparatus 1002 includes a cellular baseband processor 1004 (also referred to as a modem) coupled to a RF transceiver 1024, a processor 1020 and a memory 1022.
  • the cellular baseband processor 1004 communicates through the RF transceiver 1024 with other wireless devices, such as a UE 104.
  • the cellular baseband processor 1004 may include a computer-readable medium /memory.
  • the cellular baseband processor 1004 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory.
  • the software when executed by the cellular baseband processor 1004, causes the cellular baseband processor 1004 to perform the various functions described supra.
  • the computer-readable medium /memory may also be used for storing data that is manipulated by the cellular baseband processor 1004 when executing software.
  • the processor 1020 is responsible for general processing, including the execution of software stored on the computer-readable medium/memory 1022.
  • the software when executed by the processor 1020, causes the apparatus 1002 to perform the various functions described supra for any particular apparatus.
  • the computer-readable medium/memory 1022 may also be used for storing data that is manipulated by the processor 1020 when executing software.
  • the cellular baseband processor 1004 further includes a reception component 1030, a relay communication manager 1032, and a transmission component 1034.
  • the relay communication manager 1032 includes the one or more illustrated components.
  • the components within the relay communication manager 1032 may be stored in the computer- readable medium /memory and/or configured as hardware within the cellular baseband processor 1004.
  • the cellular baseband processor 1004 may be a component of the device 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.
  • the apparatus 1002 may be a modem chip and include just the baseband processor 1004, and in another configuration, the apparatus 1002 may be the entire wireless device (e.g., see the device 310 of FIG. 3) and include the additional modules of the apparatus 1002.
  • the relay communication manager 1032 includes a configuration component 1040, a control signaling component 1042, a determination component 1044, and/or a processor component 1046 configured to perform the aspects described in connection with methods in FIG. 8.
  • the apparatus is illustrated as including components to perform the method of FIG. 8, because the wireless device may operate as a transmitting device at times and may operate as a receiving device at other times. In other examples, the apparatus 1002 may include components for the method of FIG. 8.
  • the apparatus 1002 may include additional components that perform each of the blocks of the algorithm in the aforementioned flowchart of FIG. 8. As such, each block in the aforementioned flowchart of FIG. 8 may be performed by a component and the apparatus may include one or more of those components.
  • the components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.
  • the apparatus 1002 includes means for receiving, from a first user equipment (UE) through a first direct link connection between the first UE and the first BS, an indication of a set of sidelink UEs operable to serve as relay stations and forward a control plane signaling between the first UE and the first BS.
  • the apparatus 1002 may further include means for receiving, from a second UE of the set of sidelink UEs through a second direct link connection between the second UE and the first BS, control plane signaling forwarded between the first UE and the second UE based on an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • RLF radio link failure
  • the aforementioned means may be one or more of the aforementioned components of the apparatus 1002 configured to perform the functions recited by the aforementioned means.
  • the apparatus 1002 may include the TX Processor 316 , the RX Processor 370, and the controller/processor 375.
  • the aforementioned means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the aforementioned means.
  • Example 1 is a method of wireless communication performed by a first user equipment (UE) , comprising: determining a set of sidelink stations operable to serve as relay stations and forward a control plane signaling between the UE and a first base station; obtaining one or more measurements of a direct link connection with the first base station; establishing a sidelink connection with at least one sidelink station of the set of sidelink stations based on the one or more measurements; and communicating, with the first base station through the at least one sidelink station over the sidelink connection, the control plane signaling.
  • UE user equipment
  • Example 2 the method of Example 1 further includes establishing a first signaling radio bearer (SRB1) with the first base station; and providing an indication of the set of sidelink stations to the first base station over the SRB1.
  • SRB1 signaling radio bearer
  • Example 3 the method of any of Example 1 or Example 2 further includes that the providing the indication comprises transmitting, to the first base station, a radio resource control (RRC) connection update request that includes the indication of the set of sidelink stations.
  • RRC radio resource control
  • Example 4 the method of any of Examples 1 to 3 further includes receiving, from the first base station, a RRC connection update response comprising an indication of whether the first base station accepts the set of sidelink stations to serve as relay stations or provides a subset listing of sidelink stations from the set of sidelink stations accepted by the first base station.
  • Example 5 the method of any of Examples 1 to 4 further includes that the receiving the RRC connection update response comprises receiving, from the first base station, one or more sidelink scheduling grants assigned to the UE, and further comprising: establishing a relay signal radio bearer (SRBr) to a sidelink station of the set of sidelink stations using a respective one of the one or more sidelink scheduling grants.
  • SRBr relay signal radio bearer
  • Example 6 the method of any of Examples 1 to 5 further includes that the SRBr to the sidelink station is transitioned into an inactive state when the direct link connection between the UE and the first base station is active.
  • Example 7 the method of any of Examples 1 to 6 further includes determining an occurrence of a radio link failure (RLF) event in the direct link connection between the UE and the first base station; and transitioning the SRBr from the inactive state to an active state based on the occurrence of the RLF event.
  • RLF radio link failure
  • Example 8 the method of any of Examples 1 to 7 further includes that the SRBr to the sidelink station is transitioned into an active state when the direct link connection between the UE and the first base station is active.
  • Example 9 the method of any of Examples 1 to 8 further includes that the SRB1 is prioritized over the SRBr and is designated as a primary signal radio bearer.
  • Example 10 the method of any of Examples 1 to 9 further includes determining an occurrence of a radio link failure (RLF) event in the direct link connection between the UE and the first base station; and refraining from initiating a RRC reestablishment procedure with the first base station.
  • RLF radio link failure
  • Example 11 the method of any of Examples 1 to 10 further includes determining an occurrence of a radio link failure (RLF) event in the direct link connection between the UE and the first base station; and communicating, with the sidelink station of the set of sidelink stations, a RRC connection resume request comprising an indication of a direct link connection failure with the first base station based on the occurrence of the RLF event.
  • RLF radio link failure
  • Example 12 the method of any of Examples 1 to 11 further includes receiving, from the sidelink station, a RRC reconfiguration request originating from the first base station based on the indication of the direct link connection failure in the RRC connection resume request.
  • Example 13 the method of any of Examples 1 to 12 further includes that the RRC reconfiguration request comprises an indication to the UE to initiate a handover from the first base station to a second base station.
  • Example 14 the method of Example 13 further includes receiving, from the sidelink station, a RRC connection release for the UE to release the SRBr to the sidelink station.
  • Example 15 the method of any of Examples 1 to 10 further includes receiving, from the sidelink station, a connection resume message based on an inactive state of the SRBr, the connection resume message comprising an indication to the UE to utilize a sidelink station of the set of sidelink stations as a relay station to resume communication of the control plane signaling with the first base station based on the indication of the direct link connection failure in the RRC connection resume request; and transmitting, to the sidelink station, a resume complete message in response to the connection resume message.
  • Example 16 the method of any of Examples 1 to 15 further includes determining whether the direct link connection with the first base station is established by a predetermined time after the indication of the direct link connection failure is communicated to one or more sidelink stations of the set of sidelink stations; and initiating a RRC reestablishment operation with a second base station different from the first base station when the direct link connection with the first base station is not established by the predetermined time.
  • Example 17 the method of any of Examples 1 to 16 includes determining whether each sidelink station of the set of sidelink stations sends a RRC response indicating a rejection of the RRC connection resume request; and initiating a RRC reestablishment operation with a second base station different from the first base station when each sidelink station sends a RRC response indicating the rejection of the RRC connection resume request.
  • Example 18 the method of any of Examples 1 to 17 includes communicating, with the sidelink station of the set of sidelink stations, a RRC connection update message comprising an indication of a direct link connection failure with the first base station based on the occurrence of the RLF event.
  • Example 19 the method of any of Examples 1 to 18 includes determining whether the direct link connection with the first base station is established by a predetermined time after the indication of the direct link connection failure is communicated to one or more sidelink stations of the set of sidelink stations; and initiating a RRC reestablishment operation with a second base station different from the first base station when the direct link connection with the first base station is not established by the predetermined time.
  • Example 20 the method of any of Examples 1 to 19 includes determining whether each sidelink station of the set of sidelink stations sends a RRC response indicating a rejection of the RRC connection update message; and initiating a RRC reestablishment operation with a second base station different from the first base station when each sidelink station sends a RRC response indicating the rejection of the RRC connection update message.
  • Example 21 the method of any of Examples 1 to 20 includes determining whether the one or more measurements of the direct link connection with the first base station is lesser than a predetermined threshold, wherein the establishing the sidelink connection with the at least one sidelink station of the set of sidelink stations comprises establishing the sidelink connection with the at least one sidelink station when the one or more measurements of the direct link connection is lesser than the predetermined threshold.
  • Example 22 the method of any of Examples 1 to 21 includes determining whether the one or more measurements of the direct link connection with the first base station is greater than a predetermined threshold; terminating a relay signal radio bearer with the at least one sidelink station when the one or more measurements of the direct link connection is greater than the predetermined threshold; and maintaining the relay signal radio bearer with the at least one sidelink station when the one or more measurements of the direct link connection is not greater than the predetermined threshold.
  • Example 23 the method of any of Examples 1 to 22 includes determining that the direct link connection between the UE and the first base station is lost; and switching to the sidelink connection with the at least one sidelink station for control plane mode 1 sidelink operation.
  • Example 24 is a device including one or more processors and one or more memories in electronic communication with the one or more processors storing instructions executable by the one or more processors to cause a system or an apparatus to implement a method as in any of Examples 1 to 23.
  • Example 25 is a system or apparatus including means for implementing a method or realizing an apparatus as in any of Examples 1 to 23.
  • Example 26 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement a method as in any of Examples 1 to 23.
  • Example 27 is a method of wireless communication at a first UE, comprising: receiving a sidelink connection with a second UE based on a status of a first direct link connection between the second UE and a first base station; and communicating, with the first base station through a second direct link connection between the first UE and the first base station, a control plane signaling associated with the second UE when the status indicates an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • RLF radio link failure
  • Example 28 the method of Example 27 further includes receiving, from the second UE through the sidelink connection, a relay signal radio bearer (SRBr) based on one or more sidelink scheduling grants assigned to the second UE.
  • SRBr relay signal radio bearer
  • Example 29 the method of any of Example 27 or Example 28 further includes receiving, from the second UE over the sidelink connection, a RRC connection resume request based on an inactive state of the SRBr, the RRC connection resume request comprising an indication of a direct link connection failure between the second UE and the first base station based on the occurrence of the RLF event; communicating, with the first base station through the second direct link connection, an uplink information transfer message comprising the indication of the direct link connection failure between the second UE and the first base station; and receiving, from the first base station through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the RRC connection resume request.
  • Example 30 the method of any of Examples 27 to 29 further includes that the uplink information transfer message comprises one or more measurements of the sidelink connection between the first UE and the second UE.
  • Example 31 the method of any of Examples 27 to 30 further includes that the RRC reconfiguration request comprises an indication to the second UE to initiate a handover from the first base station to a second base station.
  • Example 32 the method of any of Examples 27 to 31 further includes communicating, with the second UE through the sidelink connection, a RRC connection release for the UE to release the SRBr to the first UE.
  • Example 33 the method of any of Examples 27 to 32 further includes that the RRC reconfiguration request comprises an indication to the second UE to utilize the first UE as a relay station to resume communication of the control plane signaling with the first base station, and further comprising: communicating, with the second UE through the sidelink connection, a connection resume message based on an inactive state of the SRBr, the connection resume message comprising the indication of the RRC reconfiguration request; and receiving, from the second UE, a resume complete message in response to the connection resume message.
  • the RRC reconfiguration request comprises an indication to the second UE to utilize the first UE as a relay station to resume communication of the control plane signaling with the first base station, and further comprising: communicating, with the second UE through the sidelink connection, a connection resume message based on an inactive state of the SRBr, the connection resume message comprising the indication of the RRC reconfiguration request; and receiving, from the second UE, a resume complete message in response to the connection resume message.
  • Example 34 the method of any of Examples 27 to 33 further includes determining whether a lost connection with the first base station through the second direct link connection to the first base station has occurred; determining whether the second direct link connection to the first base station is reestablished after the lost connection with the first base station through the second direct link connection has occurred; and communicating, with the second UE through the sidelink connection, a RRC response indicating a rejection of the RRC connection resume request when the second direct link connection to the first base station is not reestablished.
  • Example 35 the method of any of Examples 27 to 34 further includes receiving, from the second UE over the sidelink connection, a RRC connection update message based on an active state of the SRBr, the RRC connection update message comprising an indication of a direct link connection failure between the second UE and the first base station based on the occurrence of the RLF event; communicating, with the first base station through the second direct link connection, an uplink information transfer message comprising the indication of the direct link connection failure between the second UE and the first base station; and receiving, from the first base station through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the RRC connection update message.
  • Example 36 is a device including one or more processors and one or more memories in electronic communication with the one or more processors storing instructions executable by the one or more processors to cause a system or an apparatus to implement a method as in any of Examples 27 to 35.
  • Example 37 is a system or apparatus including means for implementing a method or realizing an apparatus as in any of Examples 27 to 35.
  • Example 38 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement a method as in any of Examples 27 to 35.
  • Example 39 is a method of wireless communication at a first base station (BS) , comprising: receiving, from a first user equipment (UE) through a first direct link connection between the first UE and the first BS, an indication of a set of sidelink UEs operable to serve as relay stations and forward a control plane signaling between the first UE and the first BS; and receiving, from a second UE of the set of sidelink UEs through a second direct link connection between the second UE and the first BS, control plane signaling forwarded between the first UE and the second UE based on an occurrence of a radio link failure (RLF) event in the first direct link connection.
  • RLF radio link failure
  • Example 40 the method of Example 39 further includes receiving, from the first UE, a first signaling radio bearer (SRB1) with the first BS, wherein the receiving comprises receiving the indication of the set of sidelink UEs over the SRB1.
  • SRB1 signaling radio bearer
  • Example 41 the method of any of Example 39 or Example 40 further includes that the receiving the indication comprises receiving, from the first UE, a radio resource control (RRC) connection update request that includes the indication of the set of sidelink UEs.
  • RRC radio resource control
  • Example 42 the method of any of Examples 39 to 41 further includes communicating, with the first UE through the first direct link connection, a RRC connection update response in response to the RRC connection update request, the RRC connection update response comprising an indication of whether the first BS accepts the set of sidelink UEs to serve as relay UEs or provides a subset listing of sidelink UEs from the set of sidelink UEs accepted by the first BS.
  • Example 43 the method of any of Examples 39 to 43 further includes that the communicating the RRC connection update response comprises transmitting, to the first UE, one or more sidelink scheduling grants assigned to the first UE.
  • Example 44 the method of any of Examples 39 to 43 further includes receiving, from the second UE through the second direct link connection, an uplink information transfer message comprising an indication of a direct link connection failure between the first UE and the first BS based on a radio resource control (RRC) connection resume request forwarded between the first UE and the second UE that indicates an occurrence of a radio link failure (RLF) event in the first direct link connection; and transmitting, to the second UE through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the uplink information transfer message.
  • RRC radio resource control
  • Example 45 the method of any of Examples 39 to 44 further includes that the RRC reconfiguration request comprises an indication to the first UE to initiate a handover from the first BS to a second BS.
  • Example 46 the method of any of Examples 39 to 45 further includes that the RRC reconfiguration request comprises an indication to the first UE to utilize the second UE as a relay UE to resume communication of the control plane signaling with the first BS.
  • Example 47 the method of any of Examples 39 to 46 further includes receiving, from the second UE through the second direct link connection, an uplink information transfer message comprising an indication of a direct link connection failure between the first UE and the first BS based on a radio resource control (RRC) connection update message forwarded between the first UE and the second UE that indicates an occurrence of a radio link failure (RLF) event in the first direct link connection; and transmitting, to the second UE through the second direct link connection, a RRC reconfiguration request based on the indication of the direct link connection failure in the uplink information transfer message.
  • RRC radio resource control
  • Example 48 the method of any of Examples 39 to 47 further includes receiving a plurality of uplink information transfer messages respectively from a plurality of sidelink UEs of the set of sidelink UEs, each of the plurality of uplink information transfer messages comprising an indication of a direct link connection failure between the first UE and the first BS and a sidelink measurement of a sidelink connection between the first UE and a respective one of the plurality of sidelink UEs; obtaining a direct link measurement of a respective direct link connection with each of the plurality of sidelink UEs; selecting one of the plurality of sidelink UEs as a relay to the first UE based on one or more of the direct link measurement or the sidelink measurement; and transmitting, to the selected one of the plurality of sidelink UEs, a radio resource control (RRC) reconfiguration request in response to a corresponding one of the plurality of uplink information transfer messages.
  • RRC radio resource control
  • Example 49 is a device including one or more processors and one or more memories in electronic communication with the one or more processors storing instructions executable by the one or more processors to cause a system or an apparatus to implement a method as in any of Examples 39 to 48.
  • Example 50 is a system or apparatus including means for implementing a method or realizing an apparatus as in any of Examples 39 to 48.
  • Example 51 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement a method as in any of Examples 39 to 48.
  • Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C.
  • combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne des appareils, des procédés et des supports lisibles par ordinateur pour une double connectivité en liaison directe et relayée par liaison latérale pour la continuité de service en liaison latérale dans des réseaux à liaison latérale de mode 1. Un exemple de procédé de communication sans fil au niveau d'un équipement utilisateur (UE) comprend la détermination d'un ensemble de stations de liaison latérale utilisables pour servir de stations relais et transférer une signalisation de plan de commande entre l'UE et une première station de base. Le procédé comprend l'obtention d'une ou de plusieurs mesures d'une connexion en liaison directe avec la première station de base et l'établissement d'une connexion en liaison latérale avec au moins une station de liaison latérale de l'ensemble de stations de liaison latérale sur la base de la ou des mesures. Le procédé comprend également la communication, avec la première station de base par l'intermédiaire de la ou des stations de liaison latérale sur la connexion en liaison latérale, de la signalisation de plan de commande.
PCT/CN2020/119795 2020-10-02 2020-10-02 Double connectivité en liaison directe et relayée par liaison latérale pour continuité de service en liaison latérale dans des réseaux à liaison latérale de mode 1 WO2022067861A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024051808A1 (fr) * 2022-09-09 2024-03-14 中国移动通信有限公司研究院 Procédé et appareil de configuration de liaison, équipement utilisateur distant, dispositif de réseau et support de stockage
WO2024125534A1 (fr) * 2022-12-13 2024-06-20 中国移动通信有限公司研究院 Procédé et appareil de double connectivité, terminal, dispositif de réseau et élément de réseau
WO2024207377A1 (fr) * 2023-04-06 2024-10-10 Nec Corporation Procédé, dispositif et support de stockage informatique de communication
WO2025026275A1 (fr) * 2023-08-01 2025-02-06 维沃移动通信有限公司 Procédé et appareil d'établissement de trajet, ue et dispositif côté réseau

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106304258A (zh) * 2015-05-15 2017-01-04 中兴通讯股份有限公司 中继选择及发现的方法、装置及系统
CN110945936A (zh) * 2017-05-04 2020-03-31 弗劳恩霍夫应用研究促进协会 Ue组，ue组管理者ue和ue组成员ue
US20200170075A1 (en) * 2017-05-05 2020-05-28 Zte Corporation Signaling transmission method and device, and computer readable storage medium
US20200288535A1 (en) * 2016-03-16 2020-09-10 Nec Corporation Apparatus and method for providing communication based on device-to-device relay service in mobile communication system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106304258A (zh) * 2015-05-15 2017-01-04 中兴通讯股份有限公司 中继选择及发现的方法、装置及系统
US20200288535A1 (en) * 2016-03-16 2020-09-10 Nec Corporation Apparatus and method for providing communication based on device-to-device relay service in mobile communication system
CN110945936A (zh) * 2017-05-04 2020-03-31 弗劳恩霍夫应用研究促进协会 Ue组，ue组管理者ue和ue组成员ue
US20200170075A1 (en) * 2017-05-05 2020-05-28 Zte Corporation Signaling transmission method and device, and computer readable storage medium

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LG ELECTRONICS INC.: "Scope and scenarios for NR sidelink relay", 3GPP DRAFT; R2-2008017, vol. RAN WG2, 7 August 2020 (2020-08-07), pages 1 - 3, XP051912638 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024051808A1 (fr) * 2022-09-09 2024-03-14 中国移动通信有限公司研究院 Procédé et appareil de configuration de liaison, équipement utilisateur distant, dispositif de réseau et support de stockage
WO2024125534A1 (fr) * 2022-12-13 2024-06-20 中国移动通信有限公司研究院 Procédé et appareil de double connectivité, terminal, dispositif de réseau et élément de réseau
WO2024207377A1 (fr) * 2023-04-06 2024-10-10 Nec Corporation Procédé, dispositif et support de stockage informatique de communication
WO2025026275A1 (fr) * 2023-08-01 2025-02-06 维沃移动通信有限公司 Procédé et appareil d'établissement de trajet, ue et dispositif côté réseau

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