Granted Patent B2

US 12,464,421 · App. 18/098,406 · Granted Nov 4, 2025

Inventors: Jin Wang (Princeton, NJ); Stephen E. Terry (Northport, NY); Arty Chandra (Roslyn, NY)

Assignee: InterDigital Patent Holdings, Inc.

H04W36/0061H04W36/0011H04W36/0058H04W36/0079H04W36/0085H04W56/001H04W36/0055H04W92/20

Abstract

Claims (35)

1 . A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:

transmitting a measurement report to a source base station;

receiving a handover command from the source base station in response to transmitting the measurement report, wherein the handover command includes timing adjustment information associated with a target base station and measurement configuration information associated with the target base station; and

performing a handover from the source base station to the target base station based on the handover command.

2 . The method of claim 1 , wherein the handover command further includes one or more of radio link control (RLC) configuration information, medium access control (MAC) configuration information, or physical channel configuration information associated with the target base station.

3 . The method of claim 1 , wherein the timing adjustment information indicates whether the WTRU is to perform a timing adjustment through a random access channel (RACH) procedure associated with the target base station.

4 . The method of claim 3 , wherein the timing adjustment information indicates whether the RACH procedure is to be performed with a dedicated RACH resource.

5 . The method of claim 1 , further comprising resetting radio link control (RLC) and hybrid automatic repeat request (HARQ) in response to receiving the handover command.

6 . The method of claim 1 , further comprising transmitting a handover complete message to the target base station, wherein the handover complete message includes information regarding a packet data convergence protocol (PDCP) sequence number (SN).

7 . The method of claim 6 , wherein the PDCP SN indicates a missing service data unit (SDU).

8 . The method of claim 7 , further comprising sending a radio link control (RLC) message to the target base station, wherein the RLC message indicates a successfully transmitted SDU.

9 . The method of claim 1 , further comprising:

determining that the handover from the source base station to the target base station is unsuccessful; and

transmitting a message to the source base station, wherein the message indicates a radio network temporary identifier (RNTI) of the WTRU and a cell identifier of a cell served by the source base station.

10 . A wireless transmit/receive unit (WTRU), comprising:

a processor configured to:

transmit a measurement report to a source base station;

receive a handover command from the source base station in response to transmitting the measurement report, wherein the handover command includes timing adjustment information associated with a target base station and measurement configuration information associated with the target base station; and

perform a handover from the source base station to the target base station based on the handover command.

11 . The WTRU of claim 10 , wherein the handover command further includes one or more of radio link control (RLC) configuration information, medium access control (MAC) configuration information, or physical channel configuration information associated with the target base station.

12 . The WTRU of claim 10 , wherein the timing adjustment information indicates whether the WTRU is to perform a timing adjustment through a random access channel (RACH) procedure associated with the target base station.

13 . The WTRU of claim 12 , wherein the timing adjustment information indicates whether the RACH procedure is to be performed with a dedicated RACH resource.

14 . The WTRU of claim 10 , wherein the processor is further configured to reset radio link control (RLC) and hybrid automatic repeat request (HARQ) in response to receiving the handover command.

15 . The WTRU of claim 10 , wherein the processor is further configured to transmit a handover complete message to the target base station, and wherein the handover complete message includes information regarding a packet data convergence protocol (PDCP) sequence number (SN).

16 . The WTRU of claim 15 , wherein the PDCP SN indicates a missing service data unit (SDU).

17 . The WTRU of claim 16 , wherein the processor is further configured to transmit a radio link control (RLC) message to the target base station, and wherein the RLC message indicates a successfully transmitted SDU.

18 . The WTRU of claim 10 , wherein the processor is further configured to:

determine that the handover from the source base station to the target base station is unsuccessful; and

transmit a message to the source base station, wherein the message indicates a radio network temporary identifier (RNTI) of the WTRU and a cell identifier of a cell served by the source base station.

19 . A source base station, comprising:

a processor configured to:

receive a measurement report from a wireless transmit/receive unit (WTRU);

make a handover decision based on the measurement report; and

transmit a handover command to the WTRU in response to making the handover decision, wherein the handover command includes timing adjustment information associated with a target base station and measurement configuration information associated with the target base station.

20 . The source base station of claim 19 , wherein the processor is further configured to receive a message from the WTRU, wherein the message indicates a handover failure, a radio network temporary identifier (RNTI) of the WTRU, and a cell identifier of a cell served by the source base station.

Assignments (1)

Continuity (7)

References Cited (271)