Method and apparatus for controlling ue state transition in a wireless communication system

Abstract

Methods and apparatuses are provided to avoid unintended UE state transition, and the risk of packet loss due to unintended UE state transition is reduced. The methods and apparatuses are also provided to avoid unintended BWP switching, and the risk of packet loss due to unintended BWP switching is reduced. A device (e.g., UE) is configured by a network node with at least a serving cell and the serving cell is configured with one or multiple bandwidth parts (BWPs) and a timer. The device monitors and receives an information from physical downlink control channel (PDCCH) on an active BWP, wherein the PDCCH is addressed to a group-common RNTI (GC-RNTI) used for multicast or broadcast service (MBS), and wherein the information indicates downlink assignment on the active BWP and the device starts or restarts the timer.

What is claimed is: 
     
         1 . A method for a device, comprising:
 configuring the device by a network node with at least a serving cell, wherein the serving cell is configured with one or more bandwidth parts (BWPs) and a timer, and wherein the serving cell is activated;   monitoring physical downlink control channel (PDCCH) on a BWP, wherein the BWP is active and the active BWP is associated with an active downlink (DL) BWP;   receiving an information from PDCCH, wherein the PDCCH is addressed to a group-common radio network temporary identifier (GC-RNTI) used for multicast or broadcast service (MBS), and the information indicates downlink assignment on the active BWP; and   starting or restarting the timer associated with the active DL BWP in response to the reception of downlink assignment, wherein the timer is a bwp-InactivityTimer.   
     
     
         2 . The method of  claim 1 , wherein the device is a User Equipment (UE). 
     
     
         3 . The method of  claim 1 , wherein the network node is a gNB. 
     
     
         4 . The method of  claim 1 , wherein if the bwp-InactivityTimer expires, the device performs BWP switching to a BWP indicated by defaultDownlinkBWP-Id. 
     
     
         5 . The method of  claim 4 , wherein the BWP indicated by defaultDownlinkBWP-Id is one of the one or more BWPs. 
     
     
         6 . The method of  claim 1 , wherein if the bwp-InactivityTimer expires, the device performs BWP switching to a BWP indicated by initialDownlinkBWP. 
     
     
         7 . The method of  claim 6 , wherein the BWP indicated by initialDownlinkBWP is one of the one or more BWPs. 
     
     
         8 . The method of  claim 1 , wherein the active BWP is associated with an active DL BWP and an active UL BWP. 
     
     
         9 . The method of  claim 8 , wherein the active DL BWP and the active UL BWP of the active BWP are paired. 
     
     
         10 . The method of  claim 1 , wherein the active BWP is one of the one or more BWPs. 
     
     
         11 . A device, comprising:
 a memory; and   a processor operatively coupled to the memory, wherein the processor is configured to execute a program code to:
 configure the device by a network node with at least a serving cell, wherein the serving cell is configured with one or more bandwidth parts (BWPs) and a timer, and wherein the serving cell is activated; 
 monitor physical downlink control channel (PDCCH) on a BWP, wherein the BWP is active and the active BWP is associated with an active downlink (DL) BWP; 
 receive an information from PDCCH, wherein the PDCCH is addressed to a group-common radio network temporary identifier (GC-RNTI) used for multicast or broadcast service (MBS), and the information indicates downlink assignment on the active BWP; and 
 start or restart the timer associated with the active DL BWP in response to the reception of downlink assignment, wherein the timer is a bwp-InactivityTimer. 
   
     
     
         12 . The device of  claim 11 , wherein the device is a User Equipment (UE). 
     
     
         13 . The device of  claim 11 , wherein the network node is a gNB. 
     
     
         14 . The device of  claim 11 , wherein if the bwp-InactivityTimer expires, the device performs BWP switching to a BWP indicated by defaultDownlinkBWP-Id. 
     
     
         15 . The device of  claim 14 , wherein the BWP indicated by defaultDownlinkBWP-Id is one of the one or more BWPs. 
     
     
         16 . The device of  claim 11 , wherein if the bwp-InactivityTimer expires, the device performs BWP switching to a BWP indicated by initialDownlinkBWP. 
     
     
         17 . The device of  claim 16 , wherein the BWP indicated by initialDownlinkBWP is one of the one or more BWPs. 
     
     
         18 . The device of  claim 11 , wherein the active BWP is associated with an active DL BWP and an active UL BWP. 
     
     
         19 . The device of  claim 18 , wherein the active DL BWP and the active UL BWP of the active BWP are paired. 
     
     
         20 . The device of  claim 11 , wherein the active BWP is one of the one or more BWPs.