Method and apparatus for sidelink logical channel establishment in a wireless communication system

Abstract

A method and apparatus are disclosed from the perspective of a first UE (User Equipment) to perform sidelink logical channel (SL LCH) establishment. In one embodiment, the method includes the first UE storing a list of sidelink configurations, wherein each entry in the list contains one sidelink configuration and at least one PC5 QoS identifier (PQI) associated with the one sidelink configuration. The method further includes the first UE selecting an entry in the list according to a PQI of a PC5 QoS flow from a sidelink service. The method also includes the first UE establishing a SL LCH for the PC5 QoS flow according to a sidelink configuration of the entry and assigning an identity for the SL LCH. In addition, the method includes the first UE transmitting information to a second UE for the second UE to establish the SL LCH, wherein the information includes at least the identity of the SL LCH, an identity of the PC5 QoS flow, and Transmission-Reception (TX-RX) aligned parameters included in the sidelink configuration. Furthermore, the method includes the first UE transmitting sidelink packet(s) from the PC 5 QoS flow on the SL LCH.

What is claimed is: 
     
         1 . A method for a first User Equipment (UE) to perform sidelink logical channel (SL LCH) establishment, comprising:
 storing a list of sidelink radio bearer (SLRB) configurations, wherein each entry in the list contains a SLRB configuration and at least one PC5 QoS identifier (PQI) associated with the SLRB configuration, wherein each SLRB configuration includes at least a Sequence Number (SN) length and a Radio Link Control (RLC) mode, and does not include a sidelink logical channel (SL LCH) identity;   selecting an entry in the list according to a PQI of a PC5 QoS flow from a sidelink service;   establishing a SL LCH for the PC5 QoS flow according to the SLRB configuration of the entry and assigning an identity for the SL LCH; and   transmitting information to a second UE to establish the SL LCH for the second UE.   
     
     
         2 . The method of  claim 1 , wherein the information includes at least the identity of the SL LCH, an identity of the PC5 QoS flow, and the SN length and the RLC mode included in the SLRB configuration. 
     
     
         3 . The method of  claim 1 , further including transmitting one or more sidelink packets from the PC5 QoS flow on the SL LCH. 
     
     
         4 . The method of  claim 1 , wherein each SLRB configuration also includes TX-only parameters. 
     
     
         5 . The method of  claim 4 , wherein the TX-only parameters are parameters that are used for the first UE to perform transmission on the SL LCH associated with the SLRB configuration. 
     
     
         6 . The method of  claim 1 , wherein the information is transmitted after a unicast link has been established between the first UE and the second UE. 
     
     
         7 . The method of  claim 1 , wherein the information is transmitted via a PC5 Radio Resource Control (RRC) message. 
     
     
         8 . The method of  claim 1 , wherein the list of SLRB configurations are predefined in the first UE. 
     
     
         9 . The method of  claim 1 , wherein the list of SLRB configurations are provisioned via a system information broadcasted by a base station. 
     
     
         10 . The method of  claim 1 , wherein the list of SLRB configurations are specified in a RRC specification. 
     
     
         11 . A first communication device, comprising:
 a memory; and   a processor operatively coupled to the memory, wherein the processor is configured to execute program code to:
 store a list of sidelink radio bearer (SLRB) configurations, wherein each entry in the list contains a SLRB configuration and at least one PC5 QoS identifier (PQI) associated with the SLRB configuration, wherein each SLRB configuration includes at least a Sequence Number (SN) length and a Radio Link Control (RLC) mode, and does not include a sidelink logical channel (SL LCH) identity; 
 select an entry in the list according to a PQI of a PC5 QoS flow from a sidelink service; 
 establish a SL LCH for the PC5 QoS flow according to the SLRB configuration of the entry and assigning an identity for the SL LCH; and 
 transmit information to a second User Equipment (UE) to establish the SL LCH for the second UE. 
   
     
     
         12 . The device of  claim 11 , wherein the information includes at least the identity of the SL LCH, an identity of the PC5 QoS flow, and the SN length and the RLC mode included in the SLRB configuration. 
     
     
         13 . The device of  claim 11 , wherein the processor is further configured to execute program code to: transmit one or more sidelink packets from the PC5 QoS flow on the SL LCH. 
     
     
         14 . The device of  claim 11 , wherein each SLRB configuration also includes TX-only parameters. 
     
     
         15 . The device of  claim 14 , wherein the TX-only parameters are parameters that are used for the first communication device to perform transmission on the SL LCH associated with the SLRB configuration. 
     
     
         16 . The device of  claim 11 , wherein the information is transmitted after a unicast link has been established between the first communication device and the second UE. 
     
     
         17 . The device of  claim 11 , wherein the information is transmitted via a PC5 Radio Resource Control (RRC) message. 
     
     
         18 . The device of  claim 11 , wherein the list of SLRB configurations are predefined in the first communication device. 
     
     
         19 . The device of  claim 11 , wherein the list of SLRB configurations are provisioned via a system information broadcasted by a base station. 
     
     
         20 . The device of  claim 11 , wherein the list of SLRB configurations are specified in a RRC specification.