Granted Patent B2

US 12,634,772 · App. 18/046,383 · Granted May 19, 2026

Inventors: Shiyang Leng (Allen, TX); Kyeongin Jeong (Allen, TX)

Assignee: Samsung Electronics Co., Ltd.

H04W36/0058

Abstract

Claims (82)

1 . A user equipment (UE) in a wireless communication system, the UE comprising:

a transceiver configured to receive, from a serving base station (BS), a message including layer 1/layer 2 (L1/L2) mobility configuration information including a timer duration value for a timer that is enabled or disabled when receiving a transmission configuration indicator (TCI) state switch; and

a processor operably coupled to the transceiver, the processor configured to measure, based on a channel status information-reference signal (CSI-RS) received from at least one candidate cell of a candidate BS, L1-reference signal received power (L1-RSRP), L1-reference signal received quality (L1-RSRQ), and L1-signal to interference and noise ratio (L1-SINR) of the at least one candidate cell,

wherein the transceiver is further configured to:

report the L1-RSRP, the L1-RSRQ, and the L1-SINR of the at least one candidate cell, and

receive an L1/L2 signal to trigger a handover (HO) operation to a target cell, the L1/L2 signal including the TCI state switch instructing the UE to use beams associated with the candidate BS.

2 . The UE of claim 1 , wherein the processor is further configured to perform the HO operation to the target cell without a random-access channel (RACH-less).

3 . The UE of claim 1 , wherein the transceiver is further configured to:

receive, from the target cell, a TCI state using an inter-cell beam management operation or an inter-cell multi-transmission and reception point (TRP) operation;

transmit, to the target cell, an L1 measurement result including the L1-RSRP, the L1-RSRQ, and the L1-SINR of the at least one candidate cell; and

receive, from the target cell, the L1/L2 signal to trigger the HO operation to the target cell.

4 . The UE of claim 1 , wherein the L1/L2 mobility configuration information includes:

information of a TCI state for each of the at least one candidate cell;

information of measurement and report configuration for the at least one candidate cell and measurement report quantities;

information of reference signals comprising at least one of synchronization signal (SS)/physical broadcasting channel (PBCH) blocks (SSBs) and CSI-RSs; and

the measurement report quantities comprise the L1-RSRP, the L1-RSRQ, and the L1-SINR.

5 . The UE of claim 1 , wherein the at least one candidate cell includes:

a special cell (SpCell) and secondary cells (SCells);

a subset of the SpCell and the SCells with an indication of being a candidate cell for the SpCell and the SCells;

configuration information for cells in a same cell group with a serving cell, the configuration information including serving cell configuration information and delta configuration information that is determined based on a current SpCell and a SCell with an indication of being a reference cell; and

configuration information for assistant cells configured for an inter-cell beam management operation or an inter-cell multi-transmit and reception point (TRP) operation, including an indication of being the candidate cell.

6 . The UE of claim 1 , wherein the processor is further configured to trigger the HO operation based on one of:

a medium access control control element (MAC CE) including at least one of a one-bit HO indication, a target cell logical identification (ID), a target cell TCI state to be activated, and a one-bit indication of HO operation without a random-access channel (RACH-less HO); or

downlink control channel (DCI) information.

7 . The UE of claim 1 , wherein the transceiver is further configured to transmit, to the target cell, a cell-radio network temporary identifier (C-RNTI) medium access control control element (MAC CE) for confirming a HO operation completion when executing a HO operation without a random-access channel (RACH-less HO).

8 . The UE of claim 1 , wherein the processor is further configured to:

start the timer based on the timer duration value when the UE receives the TCI state switch instructing the UE to use a beam received from the at least one candidate cell of the candidate BS,

re-start the timer when the UE receives the TCI state switch instructing the UE to use a beam from a cell that is different than the at least one candidate cell,

stop the timer when the UE receives the TCI state switch instructing the UE to use a beam from a serving cell, and

execute the HO operation to the at least one candidate cell when the timer for the at least one candidate cell expires.

9 . The UE of claim 8 , wherein:

the L1/L2 mobility configuration information further includes a maximum counter value; and

the processor is further configured to:

set a counter based on the maximum counter value when the UE receives the TCI state switch instructing the UE to use the beam from the at least one candidate cell,

increase the counter by one when the UE receives the TCI state switch instructing the UE to use the beam from the at least one candidate cell, and

execute the HO operation to the at least one candidate cell when the counter reaches the maximum counter value for the at least one candidate cell.

10 . A base station (BS) in a wireless communication system, the BS comprising:

a processor configured to generate a message including layer 1/layer 2 (L1/L2) mobility configuration information; and

a transceiver operably connected to the processor, the transceiver configured to:

transmit, to a user equipment (UE), the message including the L1/L2 mobility configuration information including a timer duration value for a timer that is enabled or disabled when the UE receives a transmission configuration indicator (TCI) state switch,

receive, from the UE, a report including L1-reference signal received power (L1-RSRP), L1-reference signal received quality (L1-RSRQ), and L1-signal to interference and noise ratio (L1-SINR) of at least one candidate cell, wherein the L1-RSRP, the L1-RSRQ and the L1-SINR are based on a channel status information-reference signal (CSI-RS) corresponding to the at least one candidate cell of a candidate BS, and

transmit a L1/L2 signal to the UE for triggering a handover (HO) operation to a target cell, including the TCI state switch instructing the UE to use beams associated with the candidate BS.

11 . The BS of claim 10 , wherein the L1/L2 mobility configuration information includes:

information of TCI state for each of the at least one candidate cell;

information of measurement and report configuration for the at least one candidate cell and measurement report quantities;

information of reference signals comprising at least one of synchronization signal (SS)/physical broadcasting channel (PBCH) blocks (SSBs) and CSI-RSs; and

the measurement report quantities comprise the L1-RSRP, the L1-RSRQ, and the L1-SINR.

12 . A method of a user equipment (UE) in a wireless communication system, the method comprising:

receiving, from a serving base station (BS), a message including layer 1/layer 2 (L1/L2) mobility configuration information including a timer duration value for a timer that is enabled or disabled when receiving a transmission configuration indicator (TCI) state switch;

measuring, based on a channel status information-reference signal (CSI-RS) received from at least one candidate cell of a candidate BS, L1-reference signal received power (L1-RSRP), L1-reference signal received quality (L1-RSRQ), and L1-signal to interference and noise ratio (L1-SINR) of the at least one candidate cell;

reporting the L1-RSRP, the L1-RSRQ, and the L1-SINR of the at least one candidate cell; and

receiving an L1/L2 signal to trigger a handover (HO) operation to a target cell,

wherein the L1/L2 signal includes the TCI state switch instructing the UE to use beams associated with the candidate BS.

13 . The method of claim 12 , further comprising performing the HO operation to the target cell without a random-access channel (RACH-less).

14 . The method of claim 12 , further comprising:

receiving, from the target cell, a TCI state using an inter-cell beam management operation or an inter-cell multi-transmission and reception point (TRP) operation;

transmitting, to the target cell, an L1 measurement result including the L1-RSRP, the L1-RSRQ, and the L1-SINR of the at least one candidate cell; and

receiving, from the target cell, the L1/L2 signal to trigger the HO operation to the target cell.

15 . The method of claim 12 , wherein the L1/L2 mobility configuration information includes:

information of TCI state for each of the at least one candidate cell;

information of measurement and report configuration for the at least one candidate cell and measurement report quantities;

information of reference signals comprising at least one of synchronization signal (SS)/physical broadcasting channel (PBCH) blocks (SSBs) and CSI-RSs; and

the measurement report quantities comprise the L1-RSRP, the L1-RSRQ, and the L1-SINR.

16 . The method of claim 12 , wherein the at least one candidate cell includes:

a special cell (SpCell) and secondary cells (SCells);

a subset of the SpCell and the SCells with an indication of being a candidate cell for the SpCell and the SCells;

configuration information for cells in a same cell group with a serving cell, the configuration information including serving cell configuration information and delta configuration information that is determined based on a current SpCell and a SCell with an indication of being a reference cell; and

configuration information for assistant cells configured for an inter-cell beam management operation or an inter-cell multi-transmit and reception point (TRP) operation, including an indication of being the candidate cell.

17 . The method of claim 12 , further comprising triggering the HO operation based on one of:

a medium access control control element (MAC CE) including at least one of a one-bit HO indication, a target cell logical identification (ID), a target cell TCI state to be activated, and a one-bit indication of HO operation without a random-access channel (RACH-less HO); and

downlink control channel (DCI) information.

18 . The method of claim 12 , further comprising transmitting, to the target cell, a cell-radio network temporary identifier (C-RNTI) medium access control control element (MAC CE) for confirming a HO operation completion when executing a HO operation without a random-access channel (RACH-less HO).

19 . The method of claim 12 , further comprising:

starting the timer based on the timer duration value when the UE receives the TCI state switch instructing the UE to use a beam received from the at least one candidate cell of the candidate BS;

re-starting the timer when the UE receives the TCI state switch instructing the UE to use a beam from a cell that is different than the at least one candidate cell;

stopping the timer when the UE receives the TCI state switch instructing the UE to use a beam from a serving cell; and

executing the HO operation to the at least one candidate cell when the timer for the at least one candidate cell expires.

20 . The method of claim 19 , further comprising:

setting a counter based on a maximum counter value when the UE receives the TCI state switch instructing the UE to use the beam from the at least one candidate cell;

increasing the counter by one when the UE receives the TCI state switch instructing the UE to use the beam from the at least one candidate cell; and

executing the HO operation to the at least one candidate cell when the counter reaches the maximum counter value for the at least one candidate cell,

wherein the L1/L2 mobility configuration information further includes the maximum counter value.

Assignments (1)

Continuity (5)

References Cited (15)