Method and apparatus of handling bwp inactivity timer during random access procedure in a wireless communication system

Patent metadata

Field	Value
Publication number	US-2019182870-A1
Application number	US-201816158683-A
Country	US
Kind code	A1
Filing date	Oct 12, 2018
Priority date	Dec 13, 2017
Publication date	Jun 13, 2019
Grant date	—

Abstract

Methods and apparatuses of handling a bandwidth part (BWP) inactivity timer during a Random Access procedure in a wireless communication system are disclosed herein. In one method, a user equipment (UE) starts a BWP timer for a serving cell operating in a paired spectrum. The UE initiates a contention-based Random Access (RA) procedure on the serving cell and stops the BWP timer. The UE starts the BWP timer upon successful completion of the RA procedure, wherein the UE considers the contention-based RA procedure successfully completed if a Physical Downlink Control Channel (PDCCH) addressed to a Cell Network Temporary Identifier (C-RNTI) of the UE is received and the PDCCH contains an uplink grant for a new transmission.

First claim

1 . A method of a user equipment (UE), the method comprising:
starting a bandwidth part (BWP) timer for a serving cell operating in a paired spectrum; initiating a contention-based Random Access (RA) procedure on the serving cell and stopping the BWP timer; and starting the BWP timer upon successful completion of the RA procedure, wherein the UE considers the contention-based RA procedure successfully completed if a Physical Downlink Control Channel (PDCCH) addressed to a Cell Network Temporary Identifier (C-RNTI) of the UE is received and the PDCCH contains an uplink grant for a new transmission.

2 . The method of claim 1 , further comprising:
not starting the BWP timer upon successful completion of the RA procedure, if an active downlink (DL) BWP associated with the BWP timer upon successful completion of the RA procedure is either a DL BWP indicated by Default-DL-BWP (in case Default-DL-BWP is configured) or an initial DL BWP (in case Default-DL-BWP is not configured).

3 . The method of claim 1 , wherein the BWP timer is associated with an active downlink (DL) BWP of the Serving Cell, and wherein upon expiry of the BWP timer, the UE performs BWP switching to either a BWP indicated by a Default-DL-BWP if the Default-DL-BWP is configured for the Serving Cell or an initial DL BWP if the Default-DL-BWP is not configured for the Serving Cell.

4 . The method of claim 1 , wherein the Serving Cell is a special cell, a primary cell, or a primary secondary cell.

5 . The method of claim 1 , wherein the contention-based RA procedure is initiated due to the uplink data arrival.

6 . The method of claim 1 , further comprising:
not starting or restarting the BWP timer for the Serving Cell when receiving a PDCCH indicating a downlink assignment for a random access response reception or an uplink grant for Msg3 transmission during the contention-based RA procedure.

7 . The method of claim 6 , wherein Msg3 is a message transmitted on an uplink shared channel (UL-SCH) containing a C-RNTI Medium Access Control (MAC) control element (CE) as part of the contention-based RA procedure.

8 . A user equipment (UE), comprising:
a control circuit; a processor installed in the control circuit; a memory installed in the control circuit and coupled to the processor; wherein the processor is configured to execute a program code stored in the memory to: start a bandwidth part (BWP) timer for a serving cell operating in a paired spectrum; initiate a contention-based Random Access (RA) procedure on the serving cell and stopping the BWP timer; and start the BWP timer upon successful completion of the RA procedure, wherein the UE considers the contention-based RA procedure successfully completed if a Physical Downlink Control Channel (PDCCH) addressed to a Cell Network Temporary Identifier (C-RNTI) of the UE is received and the PDCCH contains an uplink grant for a new transmission.

9 . The UE of claim 8 , wherein the processor is further configured to execute a program code stored in the memory to:
not start the BWP timer upon successful completion of the RA procedure, if an active downlink (DL) BWP associated with the BWP timer upon successful completion of the RA procedure is either a DL BWP indicated by Default-DL-BWP (in case Default-DL-BWP is configured) or an initial DL BWP (in case Default-DL-BWP is not configured).

10 . The UE of claim 8 , wherein the BWP timer is associated with an active downlink (DL) BWP of the Serving Cell, and wherein upon expiry of the BWP timer, the UE performs BWP switching to either a BWP indicated by a Default-DL-BWP if the Default-DL-BWP is configured for the Serving Cell or an initial DL BWP if the Default-DL-BWP is not configured for the Serving Cell.

11 . The UE of claim 8 , wherein the Serving Cell is a special cell, a primary cell, or a primary secondary cell.

12 . The UE of claim 8 , wherein the contention-based RA procedure is initiated due to the uplink data arrival.

13 . The UE of claim 8 , wherein the processor is configured to execute a program code stored in the memory to:
not start or restart the BWP timer for the Serving Cell when receiving a PDCCH indicating a downlink assignment for a random access response reception or an uplink grant for Msg3 transmission during the contention-based RA procedure.

14 . The UE of claim 13 , wherein Msg3 is a message transmitted on an uplink shared channel (UL-SCH) containing a C-RNTI Medium Access Control (MAC) control element (CE) as part of the contention-based RA procedure.

Assignees

• Asustek Comp Inc

Inventors

• Shih Tun-Huai
• Kuo Richard Lee-Chee

Classifications

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W74/004 Primary

  in the uplink, i.e. towards network · CPC title

• H04W88/02

  Terminal devices · CPC title

• H04W16/32

  Hierarchical cell structures · CPC title