Relay adaptation layer configuration for a sidelink interface

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a relay user equipment (UE) may establish a sidelink unicast link with a remote UE via a sidelink signaling interface. The relay UE may identify configuration information for an adaptation layer of the sidelink signaling interface, the configuration information including at least one of: a remote UE identifier associated with the sidelink unicast link for a relay service, bearer identifier information identifying one or more bearers between the remote UE and a network entity for the relay service, a radio link control (RLC) channel mapping between a bearer identifier and one or more RLC channels, or data routing information associated with the relay service. The relay UE may relay communications between the remote UE and the network entity based at least in part on the configuration information. Numerous other aspects are described.

1 . A method of wireless communication performed by a relay user equipment (UE), comprising:
 establishing a sidelink unicast link with a remote UE via a sidelink signaling interface;   identifying configuration information for an adaptation layer of the sidelink signaling interface, the configuration information including at least one of:
 a remote UE identifier for the remote UE identifying the sidelink unicast link between the remote UE and the relay UE for a relay service, 
 bearer identifier information identifying one or more bearers between the remote UE and a network entity associated with the relay service, 
 radio link control (RLC) channel mapping information, wherein the RLC channel mapping information includes a mapping between a bearer identifier and one or more RLC channels of the sidelink unicast link and one or more RLC channels of a link with the network entity, or 
 data routing information associated with the relay service; and 
   relaying communications between the remote UE and the network entity based at least in part on the configuration information for the adaptation layer of the sidelink signaling interface.   
     
     
         2 . The method of  claim 1 , wherein the sidelink signaling interface is a ProSe sidelink (PC5) interface and the link with the network entity is via a Uu interface. 
     
     
         3 . The method of  claim 1 , wherein relaying communications between the remote UE and the network entity is based at least in part on a sidelink signaling interface adaptation layer header, wherein the sidelink signaling interface adaptation layer header indicates at least one of:
 the remote UE identifier of the remote UE,   a bearer identifier of a bearer between the remote UE and a network entity associated with the relay service, or   a path identifier for the data routing associated with the relay service.   
     
     
         4 . The method of  claim 1 , wherein the remote UE identifier corresponds to a unique index assigned to each remote UE, of a plurality of remote UEs, in communication with the relay UE via respective sidelink unicast links. 
     
     
         5 . The method of  claim 1 , further comprising:
 assigning remote UE identifiers to each remote UE, of a plurality of remote UEs, in communication with the relay UE.   
     
     
         6 . The method of  claim 1 , wherein establishing the sidelink unicast link with the remote UE comprises:
 assigning the remote UE identifier to the remote UE including a unique index associated with the sidelink unicast link; and   transmitting, to the remote UE, an indication of the remote UE identifier via a sidelink signaling interface message.   
     
     
         7 . The method of  claim 1 , further comprising:
 assigning a unique index associated with the sidelink unicast link; and   transmitting information indicating the unique index to the network entity via a radio resource control message.   
     
     
         8 . The method of  claim 1 , wherein identifying the configuration information comprises:
 receiving, from the network entity, a relaying configuration indicating at least part of the configuration information.   
     
     
         9 . The method of  claim 1 , wherein identifying the configuration information comprises:
 receiving, from the network entity, an indication of the remote UE identifier via a radio resource control message.   
     
     
         10 . The method of  claim 9 , wherein receiving, from the network entity, the indication of the remote UE identifier comprises:
 receiving, from the network entity, an indication of remote UE identifiers for each remote UE, of a plurality of remote UEs, in communication with the relay UE.   
     
     
         11 . The method of  claim 9 , wherein receiving, from the network entity, the indication of the remote UE identifier comprises:
 receiving, from the network entity, an indication of a cell radio network temporary identifier (C-RNTI) for each remote UE, of a plurality of remote UEs, in communication with the relay UE.   
     
     
         12 . The method of  claim 9 , wherein receiving, from the network entity, the indication of the remote UE identifier comprises:
 receiving, from the network entity, an indication of a temporary identifier for each remote UE, of a plurality of remote UEs, in communication with the relay UE, wherein the temporary identifier is unique among the plurality of remote UEs in communication with the relay UE.   
     
     
         13 . The method of  claim 1 , wherein identifying the configuration information comprises:
 receiving, from the network entity, the bearer identifier information including an indication of a bearer identifier identifying a bearer between the remote UE and the network entity associated with the relay service, wherein the bearer identifier is the same as a data radio bearer (DRB) identifier of a DRB between the remote UE and the network entity or the same as a signaling radio bearer (SRB) identifier of an SRB between the remote UE and the network entity.   
     
     
         14 . The method of  claim 1 , wherein identifying the configuration information comprises:
 receiving, from the network entity, the bearer identifier information including an indication of a bearer identifier identifying a bearer between the remote UE and the network entity associated with the relay service, wherein the bearer identifier is a unique identifier associated with the bearer between the remote UE and the network entity to be used with the relay service.   
     
     
         15 . The method of  claim 1 , wherein identifying the configuration information comprises:
 receiving, from the network entity, an indication of a default bearer identifier identifying a signaling radio bearer (SRB) associated with radio resource control messages.   
     
     
         16 . The method of  claim 15 , further comprising:
 receiving, from the remote UE via the sidelink unicast link, a radio resource control setup request message, wherein the radio resource control setup request message includes the default bearer identifier;   determining that the radio resource control setup request message is to be transmitted using the SRB associated with radio resource control messages based at least in part on the default bearer identifier; and   relaying the radio resource control setup request message to the network entity via an RLC channel for the SRB associated with radio resource control messages.   
     
     
         17 . The method of  claim 16 , further comprising:
 receiving, from the network entity, a relaying configuration via a radio resource control message indicating the bearer identifier based at least in part on relaying the radio resource control setup request message to the network entity; and   relaying the radio resource control message indicating the bearer identifier to the remote UE based at least in part on the relaying configuration.   
     
     
         18 . The method of  claim 1 , wherein relaying communications between the remote UE and the network entity comprises:
 receiving, from the remote UE via the sidelink unicast link, a packet data convergence protocol (PDCP) packet data unit (PDU) that includes an adaptation layer header that indicates at least one of:   the remote UE identifier associated with the remote UE, or   a bearer identifier;   identifying an RLC channel of the link with the network entity based at least in part on the RLC channel mapping information and the bearer identifier;   generating a Uu PDCP PDU for the link with the network entity that includes an adaptation layer header that indicates at least one of:   the remote UE identifier associated with the remote UE, or   the bearer identifier; and   transmitting, to the network entity via the RLC channel, the Uu PDCP PDU for the link with the network entity that includes the adaptation layer header.   
     
     
         19 . The method of  claim 1 , wherein relaying communications between the remote UE and the network entity comprises:
 receiving, from the network entity, a Uu packet data convergence protocol (PDCP) packet data unit (PDU) that includes an adaptation layer header that indicates at least one of:   the remote UE identifier associated with the remote UE, or   a bearer identifier;   identifying an RLC channel of the sidelink unicast link based at least in part on the RLC channel mapping information and the bearer identifier;   generating a PDCP PDU for the sidelink unicast link that includes an adaptation layer header that indicates at least one of:   the remote UE identifier associated with the remote UE, or   the bearer identifier; and   transmitting, to the remote UE via the RLC channel, the PDCP PDU for the sidelink unicast link that includes the adaptation layer header.   
     
     
         20 . The method of  claim 1 , further comprising:
 performing a privacy update procedure with at least one of the remote UE or the network entity, wherein the privacy update procedure includes updating information included in configuration information.   
     
     
         21 . The method of  claim 20 , wherein performing the privacy update procedure comprises:
 performing the privacy update procedure according to a periodic schedule.   
     
     
         22 . The method of  claim 20 , wherein performing the privacy update procedure comprises:
 detecting a trigger event associated with a privacy update; and   performing the privacy update procedure based at least in part on detecting the trigger event.   
     
     
         23 . The method of  claim 20 , wherein performing the privacy update procedure comprises:
 modifying the remote UE identifier for the remote UE to a modified remote UE identifier;   communicating, with the remote UE via the sidelink unicast link, to indicate the modified remote UE identifier; and   communicating, with the network entity, to indicate the modified remote UE identifier.   
     
     
         24 . The method of  claim 20 , wherein performing the privacy update procedure comprises:
 receiving, from the network entity, an indication of modified identifier information for at least one of the adaptation layer of the sidelink signaling interface or the adaption layer of the link with the network entity;   modifying the configuration information based at least in part on the modified identifier information;   communicating, with the remote UE via the sidelink unicast link, to indicate the modified identifier information; and   communicating, with the network entity, to indicate that the configuration information for the sidelink signaling interface has been modified at the relay UE and the remote UE based at least in part on communicating with the remote UE to indicate the modified identifier information.   
     
     
         25 . The method of  claim 24 , further comprising:
 receiving, from the remote UE, a signal that includes a previous identifier, that is modified by the modified identifier information to a modified identifier, in an adaptation layer header of the signal after receiving the indication of the modified identifier information and prior to receiving a signal that includes an indication of the modified identifier; and   relaying, to the network entity via an RLC channel, the signal based at least in part on the previous identifier.   
     
     
         26 . The method of  claim 24 , further comprising:
 receiving, from the remote UE or the network entity, a signal that includes an indication of a modified identifier, indicated in the modified identifier information, in an adaptation layer header of the signal; and   refraining from relaying communications using a previous identifier based at least in part on receiving the signal that includes the indication of the modified identifier in the adaptation layer header of the signal.   
     
     
         27 - 65 . (canceled) 
     
     
         66 . A relay user equipment (UE) for wireless communication, comprising:
 a memory; and   one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:
 establish a sidelink unicast link with a remote UE via a sidelink signaling interface; 
 identify configuration information for an adaptation layer of the sidelink signaling interface, the configuration information including at least one of: 
 a remote UE identifier for the remote UE identifying the sidelink unicast link between the remote UE and the relay UE for a relay service, 
 bearer identifier information identifying one or more bearers between the remote UE and a network entity associated with the relay service, 
 radio link control (RLC) channel mapping information, wherein the RLC channel mapping information includes a mapping between a bearer identifier and one or more RLC channels of the sidelink unicast link and one or more RLC channels of a link with the network entity, or 
 data routing information associated with the relay service; and 
 relay communications between the remote UE and the network entity based at least in part on the configuration information for the adaptation layer of the sidelink signaling interface. 
   
     
     
         67 - 68 . (canceled) 
     
     
         69 . A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:
 one or more instructions that, when executed by one or more processors of a relay user equipment (UE), cause the relay UE to:
 establish a sidelink unicast link with a remote UE via a sidelink signaling interface; 
 identify configuration information for an adaptation layer of the sidelink signaling interface, the configuration information including at least one of: 
 a remote UE identifier for the remote UE identifying the sidelink unicast link between the remote UE and the relay UE for a relay service, 
 bearer identifier information identifying one or more bearers between the remote UE and a network entity associated with the relay service, 
 radio link control (RLC) channel mapping information, wherein the RLC channel mapping information includes a mapping between a bearer identifier and one or more RLC channels of the sidelink unicast link and one or more RLC channels of a link with the network entity, or 
 data routing information associated with the relay service; and 
 relay communications between the remote UE and the network entity based at least in part on the configuration information for the adaptation layer of the sidelink signaling interface. 
   
     
     
         70 - 71 . (canceled) 
     
     
         72 . An apparatus for wireless communication, comprising:
 means for establishing a sidelink unicast link with a remote user equipment (UE) via a sidelink signaling interface;   means for identifying configuration information for an adaptation layer of the sidelink signaling interface, the configuration information including at least one of:
 a remote UE identifier for the remote UE identifying the sidelink unicast link between the remote UE and the apparatus for a relay service, 
 bearer identifier information identifying one or more bearers between the remote UE and a network entity associated with the relay service, 
 radio link control (RLC) channel mapping information, wherein the RLC channel mapping information includes a mapping between a bearer identifier and one or more RLC channels of the sidelink unicast link and one or more RLC channels of a link with the network entity, or 
 data routing information associated with the relay service; and 
   means for relaying communications between the remote UE and the network entity based at least in part on the configuration information for the adaptation layer of the sidelink signaling interface.   
     
     
         73 - 74 . (canceled)