Method and apparatus for failure handling in serving cell change in a wireless communication system

Patent metadata

Field	Value
Publication number	US-2023308962-A1
Application number	US-202318126109-A
Country	US
Kind code	A1
Filing date	Mar 24, 2023
Priority date	Mar 28, 2022
Publication date	Sep 28, 2023
Grant date	—

Abstract

A method for a User Equipment (UE) in a wireless communication system can comprise receiving, from a first cell, a first signaling indicative of a configuration of at least a second cell, receiving, from the first cell, a second signaling to switch a Special Cell (SpCell) of the UE to the second cell, wherein the second signaling comprises at least one of a Physical Downlink Control Channel (PDCCH) signaling or a Medium Access Control (MAC) Control Element (CE), performing a procedure to switch the SpCell of the UE in response to the second signaling, performing one or more actions in response to detecting a failure of the procedure, including: initiating a random access procedure on the second cell, transmitting a report to a network of the first cell, wherein the report indicates the unsuccessful switching of the SpCell to the second cell, or initiating a RRC connection re-establishment procedure.

First claim

What is claimed is:

1 . A method of a User Equipment (UE), comprising:
receiving, from a first cell, a first signaling indicative of a configuration of at least a second cell; receiving, from the first cell, a second signaling to switch a Special Cell (SpCell) of the UE to the second cell, wherein the second signaling comprises at least one of a Physical Downlink Control Channel (PDCCH) signaling or a Medium Access Control (MAC) Control Element (CE); performing a procedure to switch the SpCell of the UE in response to the second signaling; and performing one or more actions in response to detecting a failure of the procedure, the one or more actions including:
initiating a random access procedure on the second cell;
transmitting a report to a network of the first cell, wherein the report indicates the unsuccessful switching of the SpCell to the second cell; or
initiating a Radio Resource Control (RRC) connection re-establishment procedure.

2 . The method of claim 1 , wherein the failure of the procedure is detected based on expiration of a timer.

3 . The method of claim 2 , further comprising starting the timer in response to reception of the second signaling or transmission of a mobility complete message, wherein the mobility complete message is generated in response to the second signaling.

4 . The method of claim 2 , further comprising stopping the timer in response to completion of the procedure.

5 . The method of claim 1 , wherein the failure of the procedure is detected based on quality of at least one reference signal associated with an Uplink (UL) grant on the second cell being lower than a threshold.

6 . The method of claim 5 , wherein the at least one reference signal is indicated via the first signaling or the second signaling.

7 . The method of claim 5 , wherein the UL grant is indicated via the first signaling or the second signaling.

8 . The method of claim 1 , wherein the failure of the procedure is detected based on number of Scheduling Request (SR) transmissions on the second cell being equal to or larger than a maximum value.

9 . The method of claim 1 , further comprising considering a time alignment information of the second cell to be invalid in response to detecting the failure of the procedure.

10 . The method of claim 1 , further comprising switching to an initial or a default Bandwidth Part (BWP) of the second cell in response to detecting the failure of the procedure.

11 . The method of claim 1 , further comprising discarding configured grant for the second cell in response to detecting the failure of the procedure.

12 . The method of claim 1 , wherein the random access procedure is for beam failure recovery.

13 . The method of claim 1 , further comprising prioritizing selecting a third Cell indicated in the first signaling and/or the second signaling during the RRC connection re-establishment procedure.

14 . The method of claim 1 , wherein the failure of the procedure is detected based on number of transmissions for a mobility complete message on the second cell being equal to or larger than a maximum value.

15 . A User Equipment (UE), comprising:
a memory; and a processor operatively coupled to the memory, wherein the processor is configured to execute program code to:
receive, from a first cell, a first signaling indicative of a configuration of at least a second cell;
receive, from the first cell, a second signaling to switch a Special Cell (SpCell) of the UE to the second cell, wherein the second signaling comprises at least one of a Physical Downlink Control Channel (PDCCH) signaling or a Medium Access Control (MAC) Control Element (CE);
perform a procedure to switch the SpCell of the UE in response to the second signaling; and
perform one or more actions in response to detecting a failure of the procedure, the one or more actions including:
initiate a random access procedure on the second cell;
transmit a report to a network of the first cell, wherein the report indicates the unsuccessful switching of the SpCell to the second cell; or
initiate a Radio Resource Control (RRC) connection re-establishment procedure.

16 . The UE of claim 15 , wherein the failure of the procedure is detected based on expiration of a timer, is detected based on number of Scheduling Request (SR) transmissions on the second cell being equal to or larger than a maximum value, or is detected based on number of transmissions for a mobility complete message on the second cell being equal to or larger than a maximum value.

17 . The UE of claim 16 , wherein the processor is further configured to execute program code to:
start the timer in response to reception of the second signaling or transmission of a mobility complete message, wherein the mobility complete message is generated in response to the second signaling; and stop the timer in response to completion of the procedure.

18 . The UE of claim 15 , wherein the failure of the procedure is detected based on quality of at least one reference signal associated with an Uplink (UL) grant on the second cell being lower than a threshold, and wherein the at least one reference signal is indicated via the first signaling or the second signaling.

19 . The UE of claim 15 , wherein the processor is further configured to execute program code to:
in response to detecting the failure of the procedure, consider a time alignment information of the second cell to be invalid, switch to an initial or a default Bandwidth Part (BWP) of the second cell, and/or discard configured grant for the second cell.

20 . The UE of claim 15 , wherein the processor is further configured to execute program code to prioritize selecting a third Cell indicated in the first signaling and/or the second signaling during the RRC connection re-establishment procedure.

Assignees

• Asustek Comp Inc

Inventors

• Kung Yi-Hsuan
• Guo Yu-Hsuan

Classifications

• H04W36/249

  according to timing information · CPC title

• H04W36/0085

  Hand-off measurements · CPC title

• H04W36/0079 Primary

  in case of hand-off failure or rejection · CPC title

• H04W36/0064

  of control information between different access points · CPC title

• H04W36/00835

  Determination of neighbour cell lists · CPC title