Method and apparatus for improving one-to-one sidelink communication in a wireless communication system
A method and apparatus are disclosed from the perspective of a User Equipment (UE) for the UE to request sidelink resources for an one-to-one V2X (Vehicle-to-Everything) sidelink communication, wherein the UE supports both LTE (Long Term Evolution) RAT (Radio Access Technology) and NR (New Radio) RAT. In one embodiment, the method includes the UE initiating a one-to-one V2X sidelink communication. The method further includes the UE transmitting a RRC (Radio Resource Control) message to a network node to request sidelink resources from NR RAT for the one-to-one V2X sidelink communication and not transmitting any RRC message to the network node to request sidelink resources from LTE RAT for the one-to-one V2X sidelink communication.
1. A method for a UE (User Equipment) to request sidelink resources for a one-to-one V2X (Vehicle-to-Everything) sidelink communication, comprising:
initiating the one-to-one V2X sidelink communication;
transmitting a RRC (Radio Resource Control) message to a network node to request sidelink resources for the one-to-one V2X sidelink communication, wherein the RRC message includes QoS (Quality of Service) information of a V2X service and a Cast Type of the one-to-one V2X sidelink communication; and
receiving an AS (Access Stratum) layer configuration for the one-to-one V2X sidelink communication from the network node, wherein the AS layer configuration includes the Cast Type of the one-to-one V2X sidelink communication.
2. The method of claim 1 , wherein the network node is a base station (or gNB).
3. The method of claim 1 , wherein the RRC message is a SidelinkUEInformation.
4. The method of claim 1 , further comprising:
transmitting a BSR (Buffer Status Report) for indicating buffer sizes for the one-to-one V2X sidelink communications for requesting sidelink resources.
5. The method of claim 1 , wherein the UE is in RRC_CONNECTED state.
6. The method of claim 1 , wherein the Cast Type is set to Unicast.
7. The method of claim 1 , wherein the RRC message also includes a service flow identity.
8. The method of claim 1 , wherein the RRC message further includes a destination of the one-to-one V2X sidelink communication.
9. A UE (User Equipment), comprising:
a control circuit;
a processor installed in the control circuit; and
a memory installed in the control circuit and operatively coupled to the processor;
wherein the processor is configured to execute a program code stored in the memory to:
initiate a one-to-one V2X (Vehicle-to-Everything) sidelink communication;
transmit a RRC (Radio Resource Control) message to a network node to request sidelink resources for the one-to-one V2X sidelink communication, wherein the RRC message includes QoS (Quality of Service) information of a V2X service and a Cast Type of the one-to-one V2X sidelink communication; and
receive an AS (Access Stratum) layer configuration for the one-to-one V2X sidelink communication from the network node, wherein the AS layer configuration includes the Cast Type of the one-to-one V2X sidelink communication.
10. The UE of claim 9 , wherein the network node is a base station (or gNB).
11. The UE of claim 9 , wherein the RRC message is a SidelinkUEInformation.
12. The UE of claim 9 , wherein the processor is further configured to execute a program code stored in the memory to:
transmit a BSR (Buffer Status Report) for indicating buffer sizes for the one-to-one V2X sidelink communications for requesting sidelink resources.
13. The UE of claim 9 , wherein the UE is in RRC_CONNECTED state.
14. The method of claim 9 , wherein the Cast Type is set to Unicast.
15. The method of claim 9 , wherein the RRC message also includes a service flow identity.
16. The method of claim 9 , wherein the RRC message further includes a destination of the one-to-one V2X sidelink communication.