Method and apparatus for requesting sidelink transmission resources in a wireless communication system

Abstract

A method and apparatus are disclosed from the perspective of a first User Equipment (UE) to request dedicated sidelink configuration. In one embodiment, the method includes the first UE transmitting a first Radio Resource Control (RRC) message to a network node, wherein the first RRC message includes a sidelink Quality of Service (QoS) information, and wherein a presence of an identity of a sidelink QoS flow in the sidelink QoS information is mandatory and a presence of a QoS profile of the sidelink QoS flow in the sidelink QoS information is optional. The method also includes the first UE receiving a second RRC message from the network node, wherein the second RRC message includes a dedicated sidelink configuration and the identity of the sidelink QoS flow associated with the dedicated sidelink configuration.

What is claimed is: 
     
         1 . A method for a first User Equipment (UE) to request dedicated sidelink configuration, comprising:
 transmitting a first Radio Resource Control (RRC) message to a network node, wherein the first RRC message includes a sidelink Quality of Service (QoS) information, and wherein the sidelink QoS information includes an identity of a sidelink QoS flow and a QoS profile of the sidelink QoS flow if there is data available for transmission from the sidelink QoS flow; and   receiving a second RRC message from the network node, wherein the second RRC message includes a dedicated sidelink configuration and the identity of the sidelink QoS flow associated with the dedicated sidelink configuration.   
     
     
         2 . The method of  claim 1 , wherein the sidelink QoS information does not include the QoS profile of the sidelink QoS flow if there is no data available for transmission from the sidelink QoS flow. 
     
     
         3 . The method of  claim 1 , further comprising receiving a first sidelink RRC message from a second UE. 
     
     
         4 . The method of  claim 3 , wherein the first sidelink RRC message is a RRCReconfigurationSidelink message. 
     
     
         5 . The method of  claim 3 , wherein the first sidelink RRC message includes a Sidelink Radio Bearer (SLRB) configuration for reception, an index to the SLRB configuration, and/or a logical channel configuration. 
     
     
         6 . The method of  claim 3 , wherein the first sidelink RRC message is received before transmitting the first RRC message to the network node. 
     
     
         7 . The method of  claim 3 , further comprising:
 associating a counter SLRB configured by the dedicated sidelink configuration with a SLRB configured by the first sidelink RRC message according to the identity of the sidelink QoS flow.   
     
     
         8 . The method of  claim 7 , wherein the SLRB is used for transmitting packets from the second UE to the first UE and the counter SLRB is used for transmitting packets from the first UE to the second UE. 
     
     
         9 . The method of  claim 1 , wherein the first RRC message is a SidelinkUEInformationNR message. 
     
     
         10 . The method of  claim 1 , wherein the second RRC message is a RRCReconfiguration message. 
     
     
         11 . The method of  claim 1 , wherein the network node is a base station. 
     
     
         12 . A first User Equipment (UE), comprising:
 a processor; and   a memory operatively coupled to the processor, wherein the processor is configured to execute a program code to:
 transmit a first Radio Resource Control (RRC) message to a network node, wherein the first RRC message includes a sidelink Quality of Service (QoS) information, and wherein the sidelink QoS information includes an identity of a sidelink QoS flow and a QoS profile of the sidelink QoS flow if there is data available for transmission from the sidelink QoS flow; and 
 receive a second RRC message from the network node, wherein the second RRC message includes a dedicated sidelink configuration and the identity of the sidelink QoS flow associated with the dedicated sidelink configuration. 
   
     
     
         13 . The UE of  claim 12 , wherein the sidelink QoS information does not include the QoS profile of the sidelink QoS flow if there is no data available for transmission from the sidelink QoS flow. 
     
     
         14 . The UE of  claim 12 , wherein the processor is further configured to execute a program code to receive a first sidelink RRC message from a second UE. 
     
     
         15 . The UE of  claim 14 , wherein the first sidelink RRC message is a RRCReconfigurationSidelink message. 
     
     
         16 . The UE of  claim 14 , wherein the first sidelink RRC message is received before transmitting the first RRC message to the network node. 
     
     
         17 . The UE of  claim 14 , wherein the first sidelink RRC message includes a Sidelink Radio Bearer (SLRB) configuration for reception, an index to the SLRB configuration, and/or a logical channel configuration. 
     
     
         18 . The UE of  claim 14 , wherein the processor is further configured to execute a program code to associate a counter SLRB configured by the dedicated sidelink configuration with a SLRB configured by the first sidelink RRC message according to the identity of the sidelink QoS flow. 
     
     
         19 . The UE of  claim 18 , wherein the SLRB is used for transmitting packets from the second UE to the first UE and the counter SLRB is used for transmitting packets from the first UE to the second UE. 
     
     
         20 . The UE of  claim 12 , wherein the first RRC message is a SidelinkUEInformationNR message and the second RRC message is a RRCReconfiguration message.