Method and apparatus for requesting resource for control element transmission in a wireless communication system

Abstract

A method and apparatus are disclosed from the perspective of a UE, wherein the UE is allocated with multiple SR configurations by a network node. In one embodiment, the method includes the UE triggering a MAC control element if a timer expires. The method also includes the UE triggering a SR for the MAC control element. The method also includes the UE transmitting the SR based on a first SR configuration of the multiple SR configurations, wherein the first SR configuration is associated with a highest priority logical channel having data available for transmission when the MAC control element is triggered.

What is claimed is: 
     
         1 . A method of a User Equipment (UE), comprising:
 receiving multiple Scheduling Request (SR) configurations from a network node;   triggering a first SR for a first Medium Access Control (MAC) control element;   selecting a first SR configuration among the multiple SR configurations based on a SR configuration characteristic; and   transmitting the first SR to the network node according to the first SR configuration of the multiple SR configurations.   
     
     
         2 . The method of  claim 1 , wherein the first MAC control element is a sidelink Buffer Status Report (BSR) or a BSR. 
     
     
         3 . The method of  claim 1 , wherein the first MAC control element is triggered due to a timer expiry. 
     
     
         4 . The method of  claim 3 , wherein the timer is a retxBSR-Timer. 
     
     
         5 . The method of  claim 3 , further comprising triggering the first MAC control element if the UE has data for any logical channels that belong to a Logical Channel Group (LCG). 
     
     
         6 . The method of  claim 1 , wherein the SR configuration characteristic is the first SR configuration having the closest SR transmission opportunity after the first MAC control element is triggered. 
     
     
         7 . The method of  claim 1 , further comprising:
 triggering a second MAC control element for an uplink data of a first logical channel;   triggering a second SR for the second MAC control element; and   transmitting the second SR to the network node according to a second SR configuration of the multiple SR configurations.   
     
     
         8 . The method of  claim 7 , wherein the second SR configuration is selected based on an association between the first logical channel and the second SR configuration. 
     
     
         9 . The method of  claim 7 , further comprising performing the second SR transmission according to the second SR configuration without suspending or stopping performance of a third SR transmission according to the first SR configuration. 
     
     
         10 . The method of  claim 7 , further comprising stopping performance of a third SR transmission according to the first SR configuration when the UE triggers the second MAC control element. 
     
     
         11 . A User Equipment (UE), comprising:
 a memory; and   a processor operatively coupled with the memory, wherein the processor is configured to execute program code to:
 receive multiple Scheduling Request (SR) configurations from a network node; 
 trigger a first SR for a first Medium Access Control (MAC) control element; 
 select a first SR configuration among the multiple SR configurations based on a SR configuration characteristic; and 
 transmit the first SR to the network node according to the first SR configuration of the multiple SR configurations. 
   
     
     
         12 . The UE of  claim 11 , wherein the first MAC control element is a sidelink Buffer Status Report (BSR) or a BSR. 
     
     
         13 . The UE of  claim 11 , wherein the first MAC control element is triggered due to a timer expiry. 
     
     
         14 . The UE of  claim 13 , wherein the timer is a retxBSR-Timer. 
     
     
         15 . The UE of  claim 13 , wherein the processor is further configured to execute program code to trigger the first MAC control element if the UE has data for any logical channels that belong to a Logical Channel Group (LCG). 
     
     
         16 . The UE of  claim 11 , wherein the SR configuration characteristic is the first SR configuration having the closest SR transmission opportunity after the first MAC control element is triggered. 
     
     
         17 . The UE of  claim 11 , wherein the processor is further configured to execute program code to:
 trigger a second MAC control element for an uplink data of a first logical channel;   trigger a second SR for the second MAC control element; and   transmit the second SR to the network node according to a second SR configuration of the multiple SR configurations.   
     
     
         18 . The UE of  claim 17 , wherein the second SR configuration is selected based on an association between the first logical channel and the second SR configuration. 
     
     
         19 . The UE of  claim 17 , wherein the processor is further configured to execute program code to perform the second SR transmission according to the second SR configuration without suspending or stopping performing of a third SR transmission according to the first SR configuration. 
     
     
         20 . The UE of  claim 17 , wherein the processor is further configured to execute program code to stop performance of a third SR transmission according to the first SR configuration when the UE triggers the second MAC control element.