Granted Patent B2

US 12,739,931 · App. 18/267,244 · Granted Sep 15, 2026

Inventors: Lianhai Wu (Beijing, CN); Jing Han (Beijing, CN); Jie Hu (Beijing, CN); Min Xu (Beijing, CN); Haiming Wang (Beijing, CN)

Assignee: Lenovo (Beijing) Limited

H04W76/27H04W36/037H04W36/08H04W36/023H04W88/04

Abstract

Claims (81)

1 . An apparatus for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the apparatus to:

establish, at a first user equipment (UE), a radio resource control (RRC) connection with a base station (BS) via a second UE, wherein a PC5 RRC connection between the first UE and the second UE has been established and an RRC connection between the second UE and the BS has been established;

receive an RRC reconfiguration message including a path switch indication from the BS, wherein the path switch indication indicates a switch to a target cell of the BS using a Uu interface and the path switch indication is indicated by a reconfiguration with sync information element (IE);

transmit, in response to receiving the path switch indication, a PC5 link release indication to the second UE;

release, in response to receiving the path switch indication, the PC5 RRC connection between the first UE and the second UE;

perform, in response to the path switch indication, a random access (RA) with the BS; and

transmit, in response to accessing the target cell, an RRC reconfiguration complete message to the BS.

2 . The apparatus of claim 1 , wherein in response to receiving the path switch indication, the at least one processor is configured to cause the apparatus to at least one of:

retain at least one of a service data adaptation protocol (SDAP) configuration, a packet data convergence protocol (PDCP) configuration, and an RRC configuration at the first UE;

continue to transmit data, signaling, or both terminated at the second UE to the second UE; or

continue to receive data, signaling, or both originated from either the BS or the second UE from the second UE.

3 . The apparatus of claim 2 , wherein to continue to receive data, signaling, or both comprises one or more of to:

receive an end-mark indication indicating a last downlink (DL) data associated with the first UE;

receive one of an RRC message, a control protocol data unit (PDU) on an adaptation layer, or a medium access control (MAC) control element (CE) which indicates a completion of DL data forwarding; or

receive a PC5 link release indication from the second UE in response to the completion of DL data forwarding.

4 . The apparatus of claim 3 , wherein the at least one processor is configured to cause the apparatus to:

release the PC5 RRC connection between the first UE and the second UE in response to at least one of:

the end-mark indication;

in response to one or more of the completion of DL data forwarding indicated by the RRC message, the control PDU on the adaptation layer, or the MAC CE; or

in response to the PC5 link release indication.

5 . The apparatus of claim 1 , wherein the RRC reconfiguration complete message indicates at least one of:

whether the PC5 RRC connection between the first UE and the second UE is released;

a radio link failure (RLF) indication for a PC5 link in response to an RLF on the PC5 RRC connection between the first UE and the second UE is detected; or

whether downlink (DL) data forwarding is completed.

6 . The apparatus of claim 1 , wherein the at least one processor is configured to cause the apparatus to:

receive a PC5 link release indication from the BS; and

release the PC5 RRC connection between the first UE and the second UE in response to receiving the PC5 link release indication.

7 . The apparatus of claim 1 , wherein the RRC reconfiguration message indicates whether uplink (UL) data from the first UE to the BS buffered at the second UE is transmitted to the BS or not, and the processor is configured to cause the apparatus to, after the reception of the RRC reconfiguration message, continue to transmit UL data from the first UE to the BS buffered at the second UE to the BS.

8 . The apparatus of claim 1 , wherein the RRC reconfiguration message indicates whether downlink (DL) data to the first UE buffered at the second UE is transmitted to the first UE or not.

9 . An apparatus for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the apparatus to:

establish a radio resource control (RRC) connection between a second user equipment (UE) and a base station (BS);

establish a PC5 RRC connection between a first UE and the second UE;

receive, at the second UE from the BS, an RRC reconfiguration message that indicates a release of the first UE;

in response to receiving the RRC configuration message, release the PC5 RRC connection between the first UE and the second UE, the RRC configuration message indicates a list of the first UE;

in response to receiving the RRC configuration message, transmit a PC5 link release indication to the first UE; and

receive a PC5 link release indication from the first UE.

10 . The apparatus of claim 9 , wherein the RRC reconfiguration message indicates at least one of:

whether uplink (UL) data from the first UE to the BS buffered at the second UE is transmitted to the BS or not; or

whether downlink (DL) data to the first UE buffered at the second UE is transmitted to the first UE or not; and

the processor is configured to cause the apparatus to, after the reception of the RRC reconfiguration message, at least one of:

continue to transmit UL data from the first UE to the BS buffered at the second UE to the BS; or

continue to transmit DL data, DL signaling, or both originated from either the BS or the second UE to the first UE.

11 . The apparatus of claim 10 , wherein to continue to transmit UL data, the at least one processor is configured to cause the apparatus to at least one of:

transmit an end-mark indication indicating a last UL data associated with the first UE; or

transmit at least one of an RRC message, a control protocol data unit (PDU) on an adaptation layer, or a medium access control (MAC) control element (CE) which indicates a completion of UL data forwarding.

12 . The apparatus of claim 10 , wherein to continue to transmit DL data, DL signaling, or both, the at least one processor is configured to cause the apparatus to at least one of:

transmit an end-mark indication indicating a last DL data associated with the first UE; or

transmit at least one of an RRC message, a control protocol data unit (PDU) on an adaptation layer, or a medium access control (MAC) control element (CE) which indicates a completion of DL data forwarding.

13 . The apparatus of claim 10 , wherein the at least one processor is configured to cause the apparatus to at least one of:

release, in response to a completion of UL data forwarding, Uu configuration associated with the first UE; or

in response to a completion of DL data forwarding, at least one of:

transmit a PC5 link release indication to the first UE; or

release the PC5 RRC connection between the first UE and the second UE.

14 . The apparatus of claim 9 , wherein the at least one processor is configured to cause the apparatus to, in response to receiving the RRC reconfiguration message,

clear a downlink (DL) buffer associated with the first UE.

15 . The apparatus of claim 9 , wherein the at least one processor is configured to cause the apparatus to release the PC5 RRC connection between the first UE and the second UE in response to receiving the PC5 link release indication.

16 . The apparatus of claim 9 , wherein the at least one processor is configured to cause the apparatus to, in response to receiving the RRC reconfiguration message, cause the second UE to release one or more of the first UE, a configuration associated with the first UE, or a bearer mapping associated with the first UE.

17 . A method, comprising:

establishing, at a first user equipment (UE), a radio resource control (RRC) connection with a base station (BS) via a second UE, a PC5 RRC connection between the first UE and the second UE being established and an RRC connection between the second UE and the BS being established;

receiving an RRC reconfiguration message including a path switching indication from the BS, the path switching indication indicating a switch to a target cell of the BS using a Uu interface, wherein the path switch indication is indicated by a reconfiguration with sync information element (IE);

transmitting, in response to receiving the path switch indication, a PC5 link release indication to the second UE;

releasing, in response to receiving the path switch indication, the PC5 RRC connection between the first UE and the second UE;

performing, in response to the path switch indication, a random access (RA) with the BS; and

transmitting, in response to accessing the target cell, an RRC reconfiguration complete message to the BS.

18 . The method of claim 17 , further comprising, in response to receiving the path switch indication, at least one of:

retaining at least one of a service data adaptation protocol (SDAP) configuration, a packet data convergence protocol (PDCP) configuration, or an RRC configuration at the first UE;

continuing to transmit data, signaling, or both terminated at the second UE to the second UE; or

continuing to receive data, signaling, or both originated from either the BS or the second UE from the second UE.

19 . The method of claim 18 , wherein continuing to receive data, signaling, or both comprises at least one of:

receiving an end-mark indication indicating a last downlink (DL) data associated with the first UE;

receiving one of an RRC message, a control protocol data unit (PDU) on an adaptation layer and a medium access control (MAC) control element (CE) which indicates a completion of DL data forwarding; or

receiving a PC5 link release indication from the second UE in response to the completion of DL data forwarding.

20 . The method of claim 19 , further comprising:

releasing the PC5 RRC connection between the first UE and the second UE in response to at least one of:

the end-mark indication;

the completion of DL data forwarding indicated by one or more of the RRC message, the control PDU on the adaptation layer or the MAC CE; or

the PC5 link release indication.

Assignments (1)

Continuity (1)

References Cited (16)