Network triggered inter-cell mobility

Abstract

In wireless communications, devices may change, add, or handoff between cells of network access for inter-cell mobility. This may include Layer 1 and / or Layer 2 (L1 / L2) signaling for a User Equipment (UE) moving between cells in the network. The signaling can reduce mobility interruption time and improve robustness of handover. The mobility may be triggered by a network or a UE. Layer 1 and / or layer 3 (L1 / L3) measurements are used for inter-cell mobility. Mobility may be coordinated based on interactions between centralized units (CUs) and distributed units (DUs). These processes may reduce interruption time and improve reliability.

Description

[0001] This application is a divisional application of an invention patent application with an application date of January 21, 2022, an application number of 202280089631.8, and an invention name of “Inter-cell mobility triggered by the network”. Technical Field

[0002] The present application relates generally to wireless communications and more particularly to improved signaling for inter-cell mobility in mobile device communication systems. Background Art

[0003] Wireless communication technology is driving the world towards an increasingly connected and networked society. Wireless communication relies on effective network resource management and allocation between user mobile stations and wireless access network nodes (including but not limited to wireless base stations). The next generation of networks is expected to provide high-speed, low-latency and ultra-reliable communication capabilities and meet the needs of different industries and users. User mobile stations or user equipment (UE) are becoming more and more complex and the amount of data transmitted is increasing. In order to improve communication, meet the reliability requirements of vertical industries and support the next generation of network services, communication improvements are needed. Summary of the invention

[0004] This document relates to methods, systems, and devices for layer 1 and / or layer 2 (L1 / L2) signaling of user equipment (UE) moving between cells in a network. The signaling can reduce mobility interruption time and improve the robustness of handover. The mobility can be triggered by the network or the UE. Layer 1 and / or layer 3 (L1 / L3) measurements are used for inter-cell mobility. Mobility can be coordinated based on interactions between a centralized unit (CU) and a distributed unit (DU).

[0005] In one embodiment, a wireless communication method includes: receiving a configuration message, the configuration message including multiple candidate cells, the multiple candidate cells having a configuration and cell identification ("ID") information for each candidate cell; sending a measurement report, the measurement report including at least one of a layer 1 ("L1") measurement or a layer 3 ("L3") measurement for at least one of the candidate cells; receiving a command to identify at least one of the candidate cells based on the measurement report; and sending a communication to the identified at least one candidate cell based on the command and the configuration of the identified candidate cell.

[0006] The measurement report and communication are sent from a user equipment ("UE") to a base station, wherein the UE receives configuration messages and commands from the base station. The command is layer 1 or layer 2 ("L1 / L2") signaling, and the communication sent to the identified candidate cell is L1 / L2 signaling, wherein the L1 signaling includes at least one of the following: downlink control information ("DCI"), uplink control information ("UCI"), physical layer confirmation ("ACK") signaling, and further, wherein the L2 signaling includes a media access control unit ("MAC CE"). The command includes cell ID information of the identified candidate cell, and the identified candidate cell is the cell to be activated. The cell ID information includes at least one of the following: a candidate cell configuration index, a serving cell ID, a physical cell identity ("PCI"), a PCI and a frequency, a reference signal ("RS") ID associated with the candidate cell, or a transmit configuration indication ("TCI") state ID associated with the candidate cell. The candidate cells include a separate list for any candidate cell configured as a special cell ("SpCell") or any candidate cell configured as a secondary cell ("SCell"), wherein the identification is based on the separate list. The candidate cells include a list, wherein each candidate cell can be configured as a special cell ("SpCell") or a secondary cell ("SCell"). The candidate cells include a list, wherein each cell can be configured as a candidate cell for both a special cell ("SpCell") and a secondary cell ("SCell"). The measurement report is triggered from the UE based on a condition, wherein the condition includes at least one of the following: an event satisfied based on a layer 1 measurement of at least one candidate cell, an indication of a lack of synchronization from a serving cell or a special cell ("SpCell"), or a failure of a serving cell or SpCell. The command includes at least one of: a timing advance ("TA") value or a compensated TA value of the identified candidate cell, a cell radio network temporary identifier ("C-RNTI") of the identified candidate cell, an activated DL / UL bandwidth part ("BWP") ID of the identified candidate cell, an initial TCI state of the identified candidate cell, a serving cell ID of the identified candidate cell, an indication of whether to skip the RACH process for the identified candidate cell, an indication of whether the UE maintains a connection with the current serving cell; an indication of whether the identified candidate cell is activated as a special cell ("SpCell"); an indication of whether to activate PDCP replication after accessing the identified candidate cell.

[0007] The method also includes: activating a stored cell configuration of the identified candidate cell; applying the stored cell configuration of the identified candidate cell; or performing a move from the current serving cell to the identified candidate cell. The method also includes: starting a timer for activation or mobility, wherein the timer is a media access control ("MAC") layer timer or a radio resource control ("RRC") layer timer. Stopping the timer based on a condition, wherein the condition includes at least one of: successful transmission of a communication to the identified candidate cell, failure of the current serving cell, or information from an upper layer indicating the stop of the timer. The method also includes determining a failure of activation or mobility based on expiration of the timer. The method also includes reporting a failure of activation or mobility to a base station, wherein the failure is reported via MAC CE or RRC signaling; notifying an upper layer of a failure of activation or mobility; or, selecting another cell among the candidate cells to perform another activation of the selected another cell or perform another mobility to the selected another cell. The method also includes activating the identified candidate cell, wherein when the identified candidate cell is activated as a primary cell ("PCell"), the serving cell identifier is set to zero; wherein when the identified candidate cell is activated as a secondary cell ("SCell") or a primary secondary cell ("PSCell"), the serving cell identifier is set based on the received identifier for the identified candidate cell. The method also includes: receiving a message from a base station; based on the reception of the message, removing the stored candidate cell configuration. The method also includes: receiving a message from a base station, wherein the message includes at least one of the following: an indicator for removing all stored candidate cell configurations or an indicator for removing some of the candidate cells; and removing the stored candidate cell configuration based on the indicator or the indicated candidate cell to be removed. The message is at least one of a handover command, a primary secondary cell ("PSCell") add or / change command, or a message for commanding the release of a radio resource control ("RRC") connection or suspending an RRC connection. The method also includes receiving a message from a base station to resume a suspended radio resource control ("RRC") connection; wherein the message includes one or more candidate cells to be resumed, activated, maintained or restored. A candidate cell refers to a candidate cell group, wherein a candidate cell group (cellgroup) is at least one of a candidate primary cell group ("MCG") or a candidate secondary cell group ("SCG").

[0008] In another embodiment, a wireless communication method includes: sending a configuration message, the configuration message including a plurality of candidate cells, the plurality of candidate cells having configuration and cell identification ("ID") information for each candidate cell; receiving a measurement report, the measurement report including at least one of a layer 1 ("L1") measurement or a layer 3 ("L3") measurement for at least one of the candidate cells; sending a command identifying at least one of the candidate cells based on the measurement report; and receiving a communication at the identified at least one candidate cell based on the command and the configuration of the identified candidate cell. The sending of the configuration message and the command is from a base station to a user equipment ("UE"), wherein the base station receives the measurement report and the communication from the UE. The command is layer 1 or layer 2 ("L1 / L2") signaling, and the communication received at the identified candidate cell is L1 / L2 signaling, wherein the L1 signaling includes at least one of the following: downlink control information ("DCI"), uplink control information ("UCI"), physical layer acknowledgement ("ACK") signaling, wherein the L2 signaling includes a media access control element ("MAC CE"). The command includes cell ID information of the identified candidate cell, and the identified candidate cell is the cell to be activated. The cell ID information includes at least one of the following: a candidate cell configuration index, a serving cell ID, a physical cell identity ("PCI"), a PCI and a frequency, a reference signal ("RS") ID associated with the candidate cell, or a transmit configuration indication ("TCI") state ID associated with the candidate cell. The candidate cell includes a separate list for any candidate cell in a candidate cell configured as a special cell ("SpCell"), or any candidate cell in a candidate cell configured as a secondary cell ("SCell"), wherein the identification is based on a separate list. The candidate cell includes a list, wherein each cell can be configured as a special cell ("SpCell") or a secondary cell ("SCell"). The candidate cell includes a list, wherein each cell can be configured as a candidate cell for both a special cell ("SpCell") and a secondary cell ("SCell"). The command includes at least one of the following: a timing advance ("TA") value or a compensated TA value of the identified candidate cell, a cell radio network temporary identifier ("C-RNTI") of the identified candidate cell, an activated DL / UL bandwidth part ("BWP") ID of the identified candidate cell, an initial TCI state of the identified candidate cell, a serving cell ID of the identified candidate cell, an indication of whether to skip the RACH process for the identified candidate cell, an indication of whether the UE maintains a connection with the current serving cell; an indication of whether the identified candidate cell is activated as a SpCell; an indication of whether to activate PDCP replication after accessing the identified candidate cell.

[0009] The method also includes sending a message to the UE, wherein the message includes at least one of the following: an indicator for removing all stored candidate cell configurations, or an indication of multiple candidate cells to be removed; wherein the UE removes the stored candidate cell configurations based on the indicator or the indicated multiple candidate cells to be removed. The message is at least one of the following: a handover command, a primary secondary cell ("PSCell") addition or / change command, or a message for commanding the release of a radio resource control ("RRC") connection or suspending an RRC connection. The method also includes: sending a message to the UE to resume a suspended RRC connection, wherein the message includes at least one of the candidate cells to be resumed, activated, maintained or restored. The candidate cell refers to a candidate cell group, wherein the candidate cell group is at least one of a candidate primary cell group ("MCG") or a candidate secondary cell group ("SCG").

[0010] In another embodiment, a wireless communication method includes: receiving a configuration message including a plurality of candidate cells having a configuration, cell identification ("ID") information, and one or more execution conditions; evaluating the execution conditions for subsequent cells to identify at least one of the candidate cells; and sending a communication to the candidate cell based on the configuration of the identified at least one candidate cell. The sending of the communication is from a user equipment ("UE") to a base station, wherein the UE receives the configuration message from the base station and the UE evaluates the execution conditions. The communication to the identified at least one candidate cell is layer 1 or layer 2 ("L1 / L2") signaling, wherein the L1 signaling includes at least one of the following: downlink control information ("DCI"), uplink control information ("UCI"), physical layer acknowledgement ("ACK") signaling, wherein the L2 signaling includes a media access control unit ("MAC CE"). The evaluation includes comparing the measurement results of the candidate cells with the execution conditions, wherein the identified at least one candidate cell satisfies the execution conditions. The execution condition includes at least one of the following: a list of measurement configuration identifier information indicating the execution condition, a measurement event based on L1 measurement for the candidate cell, or a measurement event based on L3 measurement for the candidate cell. The configuration message includes at least one of the following: information indicating that multiple candidate cells can be identified together, or at least one execution condition that can identify multiple candidate cells together. The communication includes cell ID information of at least one identified candidate cell, or information indicating which candidate cells have been identified together. The cell ID information includes at least one of the following: a candidate cell configuration index, a serving cell ID, a physical cell identifier ("PCI"), a PCI and a frequency, a reference signal ("RS") ID associated with the candidate cell, or a transmission configuration indication ("TCI") state ID associated with the candidate cell. Sending a communication to at least one identified candidate cell is based on a condition that includes at least one of an indication of asynchrony from a serving cell or a special cell ("SpCell"), or a failure of a serving cell or SpCell. The candidate cells include a separate list for any candidate cell configured as a special cell ("SpCell") or any candidate cell configured as a secondary cell ("SCell"), wherein the identification is based on the separate list. The candidate cells include a list, wherein each candidate cell can be configured as a special cell ("SpCell") or a secondary cell ("SCell"). The candidate cells include a list, wherein each candidate cell can be configured as a candidate cell for both a special cell ("SpCell") and a secondary cell ("SCell").

[0011] The method also includes: activating a stored cell configuration of at least one identified candidate cell; applying a stored cell configuration of at least one identified candidate cell; or performing mobility from a current serving cell to at least one identified candidate cell. The method also includes: starting a timer for activation or mobility, wherein the timer is a media access control ("MAC") layer timer or a radio resource control ("RRC") layer timer. Stopping the timer based on a condition, wherein the condition includes at least one of: successful transmission of a communication to at least one identified candidate cell, failure of the current serving cell, or information from an upper layer indicating the stop of the timer. The method also includes determining a failure of activation or mobility based on expiration of the timer. The method also includes reporting a failure of activation or mobility to a base station, wherein the failure is reported via MAC CE or RRC signaling; notifying an upper layer of a failure of activation or mobility; or, selecting another cell among the stored candidate cells to perform another activation of the selected another cell or perform another mobility to the selected another cell. The method also includes activating at least one identified candidate cell, wherein when the at least one identified candidate cell is activated as a primary cell ("PCell"), the serving cell identifier is set to zero, and when the at least one identified candidate cell is activated as a secondary cell ("SCell") or a primary secondary cell ("PSCell"), the serving cell identifier is set based on a received identifier for the at least one identified candidate cell. The method also includes: receiving a message from a base station; based on the reception of the message, removing the stored candidate cell configuration. The method also includes: receiving a message from a base station, wherein the message includes at least one of the following: an indicator for removing all stored candidate cell configurations or an indicator for multiple candidate cells to be removed; and removing the stored candidate cell configuration based on the indicator or the indicated candidate cell to be removed. The message is at least one of the following: a handover command, a primary secondary cell ("PSCell") add or / change command, or a message for commanding the release of a radio resource control ("RRC") connection or suspending an RRC connection. The method also includes receiving a message from a base station to resume the suspended RRC connection; wherein the message includes at least one candidate cell to be resumed, activated, maintained or restored. The candidate cell includes a candidate cell group, which is at least one of a candidate primary cell group ("MCG") or a candidate secondary cell group ("SCG").

[0012] In another embodiment, a wireless communication method includes: sending a configuration message, the configuration message including multiple candidate cells, the multiple candidate cells having a configuration, cell identification ("ID") information, and one or more execution conditions; and receiving a communication at a candidate cell identified in the candidate cells, the identified candidate cell being identified based on an evaluation of the candidate cell and its configuration. The sending of the configuration message is from a base station to a user equipment ("UE"), wherein the communication is received from the UE at the identified candidate cell of the base station. The communication is layer 1 or layer 2 ("L1 / L2") signaling, wherein the L1 signaling includes at least one of the following: downlink control information ("DCI"), uplink control information ("UCI"), physical layer acknowledgement ("ACK") signaling, wherein the L2 signaling includes a media access control element ("MAC CE"). Receiving the communication at the identified candidate cell is based on a condition, the condition including at least one of the following: the identified candidate cell satisfies a trigger condition, an event triggered by an out-of-sync indication from a serving cell or a special cell ("SpCell"), or a failure of the serving cell or SpCell. The execution condition includes at least one of the following: a list of measurement configuration identifier information indicating the execution condition, a measurement event based on L1 measurement for the candidate cell, or a measurement event based on L3 measurement for the candidate cell. The configuration message includes at least one of the following: information indicating that multiple candidate cells can be identified together, or an execution condition for multiple candidate cells to be identified together. The communication includes cell ID information of the identified candidate cell, or information indicating that multiple candidate cells have been identified together. The cell ID information includes at least one of the following: a candidate cell configuration index, a serving cell ID, a physical cell identifier ("PCI"), a PCI and a frequency, a reference signal ("RS") ID associated with the candidate cell, or a transmission configuration indication ("TCI") state ID associated with the candidate cell. The candidate cell includes a separate list for any candidate cell in a candidate cell configured as a special cell ("SpCell"), or any candidate cell in a candidate cell configured as a secondary cell ("SCell"), wherein the identification is based on a separate list. The candidate cells include a list in which each cell can be configured as a candidate special cell ("SpCell") or a candidate secondary cell ("SCell"). The candidate cells include a list in which each candidate cell can be configured as a candidate cell for both a special cell ("SpCell") and a secondary cell ("SCell").

[0013] The method also includes sending a message to the UE, wherein the message includes at least one of the following: an indicator for removing all stored candidate cell configurations or a list of candidate cells to be removed; wherein the UE removes the stored candidate cell configurations based on the indicator or the indicated list of candidate cells to be removed. The message is at least one of a handover command, a primary secondary cell ("PSCell") addition or / change command, or a message for commanding the release of an RRC connection or suspending an RRC connection. The method also includes: sending a message to the UE to resume a suspended RRC connection; wherein the message includes one or a list of candidate cells to be resumed, activated, maintained or restored. A candidate cell refers to a candidate cell group, wherein the candidate cell group is at least one of a candidate primary cell group ("MCG") or a candidate secondary cell group ("SCG").

[0014] In another embodiment, a wireless communication method includes: sending a request message including multiple candidate cells from a centralized unit ("CU") to a distributed unit ("DU") to request the DU to configure at least one of the candidate cells for mobility based on layer 1 or layer 2 ("L1 / L2") signaling ("L1 / L2 mobility"); and receiving a response message from the DU at the CU, the response message including a candidate cell list and a configuration for each of the candidate cells, wherein the candidate cell list is used to identify at least one of the candidate cells that have been configured. The request message includes at least one of the following: an indication of initiating the process for L1 / L2 mobility, or an indication of initiating the process for a type of L1 / L2 mobility. The type of L1 / L2 mobility includes at least one of mobility triggered by a network ("NW"), mobility triggered by a CU, mobility triggered by a DU, or mobility triggered by a user equipment ("UE").

[0015] The method also includes sending one or more trigger events from the CU to the DU, through which the DU can trigger L1 / L2 mobility. The method also includes receiving one or more trigger events from the DU at the CU, through which the CU can trigger L1 / L2 mobility. The method also includes: sending a configuration message of L1 / L2 mobility to be sent to the UE from the CU to the DU, wherein the configuration message includes at least one of the following: at least one identified in the candidate cell list or candidate cells and a configuration for each candidate cell, or one or more execution conditions for each candidate cell; and receiving confirmation of the configuration message from the UE through the DU. The method also includes: sending at least one of the candidate cells from the CU to the DU to request the DU to activate the candidate cell via L1 / L2 mobility. The DU sends L1 / L2 signaling to the UE to indicate at least one of the candidate cells to be activated via L1 / L2 mobility.

[0016] The method also includes receiving at least one of the candidate cells from the DU at the CU to identify at least one of the candidate cells that has been successfully activated via L1 / L2 mobility. The DU receives L1 / L2 signaling from the UE to identify that at least one of the candidate cells has been successfully activated via L1 / L2 mobility. The method also includes sending an indication from the CU to the DU to instruct the DU to stop sending L1 / L2 signaling for triggering L1 / L2 mobility. The method also includes sending an indication from the CU to the DU to instruct the DU to restart sending L1 / L2 signaling for triggering L1 / L2 mobility. The CU and the DU are part of a base station for communicating with a user equipment ("UE"), and the UE is used to transmit L1 / L2 signaling. The CU provides upper layer support, including PDCP and RRC layers; wherein the DU provides lower layer support, including RLC, MAC and physical layers; wherein one or more DUs are configured to be linked to a shared CU.

[0017] In another embodiment, a wireless communication method includes: receiving a request message including multiple candidate cells from a centralized unit ("CU") at a distributed unit ("DU") to request the DU to configure at least one of the candidate cells for mobility based on layer 1 or layer 2 ("L1 / L2") signaling ("L1 / L2 mobility"); and sending a response message from the DU to the CU, the response message including a candidate cell list and a configuration for each candidate cell, wherein the candidate cell list is used to identify at least one of the configured candidate cells. The request message includes at least one of the following: an indication of initiating the process for L1 / L2 mobility, or an indication of initiating the process for a type of L1 / L2 mobility. The type of L1 / L2 mobility includes at least one of mobility triggered by a network ("NW"), mobility triggered by a CU, mobility triggered by a DU, or mobility triggered by a user equipment ("UE").

[0018] The method also includes receiving one or more trigger events from the CU at the DU, through which the DU can trigger L1 / L2 mobility. The method also includes sending one or more trigger events from the DU to the CU, through which the CU can trigger L1 / L2 mobility. The method also includes: receiving a configuration message for L1 / L2 mobility from the CU at the DU, wherein the configuration message includes at least one of the following: at least one candidate cell identified in the candidate cell list or candidate cells and a configuration for each candidate cell, or one or more execution conditions for each candidate cell; sending a configuration message for L1 / L2 mobility from the DU to the UE; and receiving a confirmation of the configuration message from the UE at the DU; and sending a confirmation of the configuration message from the DU to the CU. The method also includes receiving at least one candidate cell of the candidate cells from the CU at the DU to request the DU to activate the candidate cell via L1 / L2 mobility. The method also includes sending L1 / L2 signaling from the DU to the UE to indicate at least one of the candidate cells to be activated via L1 / L2 mobility. The method also includes receiving L1 / L2 signaling from the UE at the DU to identify at least one of the candidate cells that have been successfully activated via L1 / L2 mobility. The method also includes sending at least one of the candidate cells from the DU to the CU to identify at least one of the candidate cells that have been successfully activated via L1 / L2 mobility. The method also includes: receiving an indication from the CU at the DU, the indication indicating that the DU should stop sending L1 / L2 signaling for triggering L1 / L2 mobility; and stopping sending L1 / L2 signaling from the DU to the UE for triggering L1 / L2 mobility. The method also includes: receiving an indication from the CU at the DU, the indication indicating that the DU should resend L1 / L2 signaling for triggering L1 / L2 mobility; and restarting the sending of L1 / L2 signaling from the DU to the UE for triggering L1 / L2 mobility. The CU and the DU are part of a base station for communicating with a user equipment ("UE"), and the UE is further used to transmit the L1 / L2 signaling. The CU provides upper layer support, including PDCP and RRC layers; the DU provides lower layer support, including RLC, MAC and physical layers; and one or more DUs are configured to be linked to a shared CU.

[0019] In another embodiment, a wireless communication method includes: receiving a configuration message, the configuration message including multiple candidate cells and a configuration for each candidate cell and a measurement configuration for at least one candidate cell; and performing measurements on at least one candidate cell based on the measurement configuration. The method also includes: receiving a command that identifies at least one of the candidate cells based on the measurement; and triggering layer 1 or layer 2 ("L1 / L2") mobility from a current serving cell to the identified candidate cell based on the command and the configuration of the identified candidate cell. The method also includes: evaluating measurements for the candidate cells to identify at least one of the candidate cells; and triggering layer 1 or layer 2 ("L1 / L2") mobility from the current serving cell to the identified candidate cell based on evaluating whether the measurements of the identified candidate cell meet the execution conditions and configuration of the identified candidate cell; wherein the execution conditions are included in the configuration message for each candidate cell. Performing measurements, evaluating measurements, or triggering L1 / L2 mobility is performed at a device ("UE"), and further, wherein the UE receives the configuration message or command from a base station. The measurement configuration includes at least one of a layer 1 ("L1") measurement configuration or a layer 3 ("L3") measurement configuration for at least one of a neighbor cell or a candidate cell.

[0020] The L1 measurement configuration includes a reference signal ("RS") resource for each candidate cell or neighboring cell, wherein the RS resource includes: an RS resource identifier, and at least one of a synchronization signal block ("SSB") resource, a channel state information reference signal ("CSI-RS") resource, or a temporary reference signal ("TRS") resource. The RS resources for the candidate cell or neighboring cell are configured within an RS resource set for the current serving cell, or are configured by a separate structure for listing RS resources for the candidate cell or neighboring cell. The L1 measurement configuration includes a threshold for the L1 reference signal received power ("RSRP") measurement of the serving cell to control the L1 measurement for the candidate cell or neighboring cell. The method also includes: when it is determined that the L1 RSRP measurement result of the serving cell becomes worse than the threshold, the UE performs L1 measurement for the candidate cell or neighboring cell.

[0021] The L1 measurement configuration includes a report configuration for triggering a measurement report based on an L1 measurement for a candidate cell or a neighboring cell, wherein the report configuration includes a report configuration identifier and a measurement report type. The measurement report type includes a type of report triggered based on a measurement report event, wherein the measurement report event includes an L1 measurement of a neighboring cell becoming better than a threshold, an L1 measurement of a neighboring cell becoming better than an L1 measurement of a serving cell with an offset added, an L1 measurement of a serving cell becoming worse than a first threshold and an L1 measurement of a neighboring cell becoming better than a second threshold, or an L1 measurement of a serving cell becoming worse than a first threshold and an L3 measurement of a neighboring cell becoming better than a second threshold. The method also includes triggering a measurement report based on comparing whether a measurement for at least one of the neighboring cells or the candidate cells satisfies at least one of the measurement report events. The method also includes receiving a second command, which identifies at least one of at least one cell identifier or at least one RS resource identifier of a candidate cell or a neighboring cell. The method also includes: performing measurements based on the identified RS resource identifier or the cell identifier of the candidate cell or the neighboring cell; or reporting measurements based on the identified RS resource identifier or the cell identifier of the candidate cell or the neighboring cell. The command or the second command is layer 1 or layer 2 ("L1 / L2") signaling, wherein the L1 signaling includes downlink control information ("DCI") and the L2 signaling includes a media access control element ("MAC CE"). The L3 measurement configuration includes a measurement information list, wherein the measurement information includes at least one of a candidate cell identifier or a cell base offset based on an L3 measurement threshold for the candidate cell. The L3 measurement configuration includes a measurement information list, which includes at least one of a candidate cell identifier, a frequency information list, or a measurement object information list. The frequency information includes at least one of a frequency or a frequency base offset based on an L3 measurement threshold for the candidate cell; wherein the measurement object information includes at least one of a measurement object identifier or a measurement object base offset based on an L3 measurement threshold for the candidate cell. The method also includes applying the L3 measurement configuration associated with the identified candidate cell based on a trigger of L1 / L2 mobility to the identified candidate cell.

[0022] In another embodiment, a wireless communication method includes: sending a configuration message, the configuration message including multiple candidate cells and a configuration for each candidate cell and a measurement configuration for at least one candidate cell; and receiving a measurement report for at least one candidate cell, the measurement report being based on the measurement configuration. The method also includes sending a command that identifies at least one of the candidate cells based on the measurement report, wherein the command is configured to trigger layer 1 or layer 2 ("L1 / L2") mobility from a current serving cell to the identified candidate cell based on the command and the identified configuration. The transmission of the configuration message and the command is from a base station to a user equipment ("UE"), and the base station receives the measurement report from the UE. The measurement configuration includes at least one of a layer 1 ("L1") measurement configuration or a layer 3 ("L3") measurement configuration for at least one of a neighboring cell or a candidate cell. The method also includes: an RS resource identifier; and at least one of: a synchronization signal block ("SSB") resource, a channel state information reference signal ("CSI-RS") resource, or a temporary reference signal ("TRS") resource. The RS resources for the candidate cell or neighboring cell are configured within the RS resource set for the current serving cell, or by a separate structure for listing the RS resources of the candidate cell or neighboring cell. The L1 measurement configuration includes a threshold for the L1 reference signal received power ("RSRP") measurement of the serving cell to control the L1 measurement for the candidate cell or neighboring cell. The L1 measurement configuration includes a report configuration for triggering a measurement report based on the L1 measurement for the candidate cell or neighboring cell. The report configuration includes a report configuration identifier and a measurement report type.

[0023] The measurement report type includes a type of report triggered based on a measurement report event, wherein the measurement report event includes an L1 measurement of a neighboring cell becoming better than a threshold, an L1 measurement of a neighboring cell becoming better than an L1 measurement of a serving cell with an offset added, an L1 measurement of a serving cell becoming worse than a first threshold and an L1 measurement of a neighboring cell becoming better than a second threshold, or an L1 measurement of a serving cell becoming worse than a first threshold and an L3 measurement result of a neighboring cell becoming better than a second threshold. The method also includes sending a second command that identifies at least one of at least one cell identifier or at least one RS resource identifier of a candidate cell or a neighboring cell. The method also includes receiving a measurement based on an identified RS resource identifier or an identified cell identifier of a candidate cell or a neighboring cell. The command or the second command is layer 1 or layer 2 ("L1 / L2") signaling, wherein the L1 signaling includes downlink control information ("DCI") and the L2 signaling includes a media access control unit ("MAC CE"). The L3 measurement configuration includes a measurement information list, wherein the measurement information includes at least one of a candidate cell identifier or a cell base offset based on an L3 measurement threshold for the candidate cell. The L3 measurement configuration includes a measurement information list, wherein the measurement information list includes at least one of a candidate cell identifier, a frequency information list, or a measurement object information list. The frequency information includes at least one of a frequency or a frequency base offset based on an L3 measurement threshold for the candidate cell; wherein the measurement object information includes at least one of a measurement object identifier or a measurement object base offset based on an L3 measurement threshold for the candidate cell.

[0024] In one embodiment, the wireless communication device includes a processor and a memory, and the processor is configured to read the code from the memory and implement any one of the above embodiments.

[0025] In one embodiment, a computer program product includes a computer readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement any one of the above embodiments.

[0026] In some embodiments, there is a wireless communication device including a processor and a memory, wherein the processor is configured to read code from the memory and implement any method described in any embodiment. In some embodiments, a computer program product includes a computer-readable program medium code stored thereon, which, when executed by the processor, causes the processor to implement any method described in any embodiment. The above and other aspects and their implementation are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 An example base station is shown.

[0028] Figure 2 An example random access (RA) messaging environment is shown.

[0029] Figure 3 The network architecture of the base station central unit (CU) and the base station distributed unit (DU) is shown.

[0030] Figure 4 An embodiment of intra-user equipment (UE) DU mobility is shown.

[0031] Figure 5 Embodiments of user equipment (UE) intra-CU and inter-DU mobility are shown.

[0032] Figure 6 An embodiment of user equipment (UE) inter-CU mobility is shown.

[0033] Figure 7 An embodiment of network triggered inter-cell mobility is shown.

[0034] Figure 8 An embodiment of inter-cell mobility triggered by a user equipment (UE) is shown.

[0035] Fig. 9 An embodiment of intra-DU mobility based on CU-initiated candidate cell preparation is shown.

[0036] Fig.10 An embodiment of intra-DU mobility based on DU-initiated candidate cell preparation is shown.

[0037] Fig.11 An embodiment of inter-DU mobility based on CU-initiated candidate cell preparation is shown.

[0038] Fig.12 An embodiment of inter-DU mobility based on DU-initiated candidate cell preparation is shown.

[0039] Fig.13 An embodiment of intra-DU mobility based on CU trigger determination is shown.

[0040] Fig.14 An embodiment of intra-DU mobility based on DU trigger determination is shown.

[0041] Fig.15 An embodiment of intra-DU mobility based on UE triggered determination is shown.

[0042] Fig.16 An embodiment of inter-DU mobility based on CU trigger determination is shown.

[0043] Fig.17 An embodiment of inter-DU mobility based on DU trigger determination is shown.

[0044] Fig.18 An embodiment of inter-DU mobility based on UE-triggered determination is shown. DETAILED DESCRIPTION

[0045] The present disclosure will now be described in detail below with reference to the accompanying drawings, which form a part of the present disclosure and show specific examples of embodiments by way of illustration. However, it is noted that the present disclosure may be embodied in a variety of different forms, and therefore, the subject matter covered or claimed is intended to be construed as not limited to any embodiment set forth below.

[0046] Throughout the specification and claims, terms may have slightly different meanings that are implied or suggested by the context beyond the explicitly stated meaning. Likewise, the phrases "in one embodiment" or "in some embodiments" as used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" as used herein do not necessarily refer to different embodiments. The phrases "in one implementation" or "in some implementations" as used herein do not necessarily refer to the same implementation, and the phrases "in another implementation" or "in other implementations" as used herein do not necessarily refer to different implementations. For example, the claimed subject matter is intended to include all or part of a combination of exemplary embodiments or implementations.

[0047] In general, terms can be understood at least in part according to the use in the context. For example, terms such as "and", "or" or "and / or" as used herein can include multiple meanings, and multiple meanings can depend at least in part on the context in which these terms are used. Generally, if "or" is used to associate a list such as A, B or C, it is intended to mean A, B and C (herein used with an inclusive meaning) and A, B or C (herein used with an exclusive meaning). In addition, the terms "one or more" or "at least one" used herein depend at least in part on the context and can be used to describe any feature, structure or characteristic in the singular sense, or can be used to describe a combination of features, structures or characteristics in the plural sense. Similarly, terms such as "one", "an" or "the" can also be understood to convey singular usage or convey plural usage, at least in part depending on the context. In addition, the term "based on" or "determined by..." can be understood to not necessarily be intended to convey a set of exclusive factors, but on the contrary can allow the presence of additional factors that are not necessarily clearly described, which also depends at least in part on the context.

[0048] Radio Resource Control ("RRC") is a protocol layer of the IP layer (network layer) between the UE and the base station. There may be various Radio Resource Control (RRC) states, such as RRC connected (RRC_CONNECTED), RRC inactive (RRC_INACTIVE), and RRC idle (RRC_IDLE) states. RRC messages are transmitted via the Packet Data Convergence Protocol ("PDCP"). As described, the UE can send data through a random access channel ("RACH") protocol scheme or a configured grant ("CG") scheme. CG can be used to reduce the waste of periodically allocated resources by enabling multiple devices to share periodic resources. A base station or node can assign CG resources to eliminate packet transmission delays and improve the utilization of allocated periodic radio resources. The CG scheme is only one example of a protocol scheme for communication, and other examples including but not limited to RACH are also possible. The wireless communication described herein may be through radio access.

[0049] As follows about Figure 1-Figure 6 As described, a network provider may include several network nodes (ie, base stations) for providing network access to user equipment ("UE") devices. In some embodiments, a network node is referred to as a base station. Figure 4-Figure 6 The diagram illustrates cell mobility in which a UE device moves between cells. Control signaling may be used to facilitate such mobility. Control signaling supports transmission of downlink and uplink transport channels and may be referred to as layer 1 and / or layer 2 ("L1 / L2") signaling, which indicates that the corresponding information originates in part from the physical layer (layer 1) and in part from the media access control (MAC) (layer 2). Specifically, layer 1 may include the physical layer, while layer 2 may include MAC, RLC, and PDCP. L1 / L2 mobility based on L1 / L2 signaling may have lower latency, lower overhead, and reduced interruption time.

[0050] There may be a master node ("MN") and one or more secondary nodes ("SN"). The MN may include a master cell group ("MCG") and the SN may each include a secondary cell group ("SCG"). The MCG is a group of cells provided by the master node ("MN"), and the SCG is a group of cells provided by the secondary node ("SN"). The MCG may include a primary cell ("PCell") and one or more secondary cells ("SCell"). The SCG may include a primary secondary cell ("PSCell") and one or more secondary cells ("SCell"). Each primary cell may be connected to multiple secondary cells. The primary cell (PCell, PSCell) is the primary cell of its respective group (MCG, SCG, respectively) and may initiate initial access. The primary cell may be used for signaling and may be referred to as a special cell ("spCell"), where spCell=PCell+PSCell. The mobility between cells described in these embodiments may be based on PCell, PSCell and / or SCell.

[0051] A user equipment ("UE") device may move between nodes or cells, in which case a handover or change / addition operation may occur to improve the network reliability of the UE as the UE moves. The movement may be from a source cell to a target cell based on several potential target cells referred to as candidates. Movement between cells may also include several target cells as potential candidate cells. Conditional handover ("CHO") and conditional PSCell addition / change ("CPAC") are described below. CPAC may include conditional PSCell change ("CPC") and / or conditional PSCell addition ("CPA").

[0052] Conditional Handover ("CHO") can reduce handover interruption time and improve mobility reliability. CHO is a handover performed by the UE when one or more execution conditions are met. The UE may evaluate the execution condition(s) after receiving the CHO configuration and may stop evaluating the execution condition(s) once the handover is triggered. The CHO configuration may include a candidate PCell configuration generated by a candidate target node and the corresponding execution condition(s) for the candidate cell.

[0053] Conditional PSCell Addition / Change ("CPAC") may include a UE having a network configuration for initiating access to a candidate PSCell to consider whether the PSCell is suitable for SN addition or SN change including intra-SN change. The consideration may be based on (multiple) configured conditions. UEs in a wireless network may operate in dual connectivity ("DC"), including intra-E-UTRA DC or multi-radio DC ("MR-DC"). In the example of intra-E-UTRA DC, both the MN and the SN provide E-UTRA access. In the example of MR-DC, one node may provide new radio ("NR") access while another node provides E-UTRA or NR access.

[0054] Figure 1 An example base station 102 is shown. A base station may also be referred to as a radio network node and may be, for example, Figure 3-Figure 6 102 may also be identified as a Node B (NB, such as an eNB or gNB) in the context of mobile telecommunications. An example base station may include radio Tx / Rx circuitry 113 to receive and transmit with user equipment (UE) 104. The base station may also include network interface circuitry 116 to couple the base station to the core network 110, such as optical or wired interconnects, Ethernet, and / or other data transmission media / protocols.

[0055] The base station may also include system circuitry 122. System circuitry 122 may include processor(s) 124 and / or memory 126. Memory 126 may include operations 128 and control parameters 130. Operations 128 may include instructions 124 for execution on one or more of the processors to support functionality of the base station. For example, the operations may process random access transmission requests from multiple UEs. Control parameters 130 may include parameters or support execution of operations 128. For example, control parameters may include network protocol settings, random access message transmission format rules, bandwidth parameters, radio frequency mapping assignments, and / or other parameters.

[0056] Figure 2 Example random access messaging environment 200. In a random access messaging environment, a UE 104 may communicate with a base station 102 via a random access channel 252. In this example, the UE 104 supports one or more subscriber identity modules (SIMs), such as SIM1 202. An electrical and physical interface 206 connects SIM1 202 to the rest of the user equipment hardware, such as via a system bus 210.

[0057] The mobile device 200 includes a communication interface 212, a system logic 214, and a user interface 218. The system logic 214 may include any combination of hardware, software, firmware, or other logic. The system logic 214 may be implemented, for example, with one or more systems on a chip (SoC), application specific integrated circuits (ASICs), discrete analog and digital circuits, and other circuits. The system logic 214 is part of the implementation of any desired functionality in the UE 104. In this regard, the system logic 214 may include logic that facilitates, for example, decoding and playing music and video (e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback); running applications; accepting user input; saving and retrieving application data; establishing, maintaining, and terminating cellular telephone calls or data connections (e.g., Internet connections); establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying relevant information on the user interface 218. The user interface 218 and input 228 may include a graphical user interface, a touch-sensitive display, tactile feedback or other tactile output, voice or facial recognition input, buttons, switches, speakers, and other user interface elements. Additional examples of input 228 include microphones, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headphone and microphone input / output jacks, universal serial bus (USB) connectors, memory card slots, radiation sensors (e.g., IR sensors), and other types of inputs.

[0058] The system logic 214 may include one or more processors 216 and memory 220. The memory 220 stores, for example, control instructions 222 that the processor 216 executes to implement the desired functionality of the UE 104. The control parameters 224 provide and specify configuration and operating options for the control instructions 222. The memory 220 may also store any BT, WiFi, 3G, 4G, 5G, or other data 226 that the UE 104 will send or has received through the communication interface 212. In various implementations, system power may be provided by a power storage device such as a battery 282.

[0059] In the communication interface 212, radio frequency (RF) transmit (Tx) and receive (Rx) circuitry 230 processes the transmission of signals via one or more antennas 232.

[0060] The communication interface 212 may include one or more transceivers. The transceiver may be a wireless transceiver that includes modulation / demodulation circuitry, digital-to-analog converters (DACs), shaping tables, analog-to-digital converters (ADCs), filters, waveform shapers, filters, preamplifiers, power amplifiers, and / or other logic for transmitting and receiving via one or more antennas or (for some devices) via a physical (e.g., wired) medium.

[0061] The signals transmitted and received may conform to any of a variety of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, bit rates, and encodings. As a specific example, the communication interface 212 may include a transceiver that supports transmission and reception under 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High Speed ​​Packet Access (HSPA)+, and 4G / Long Term Evolution (LTE) standards. However, the techniques described below are applicable to other wireless communication technologies, whether from the Third Generation Partnership Project (3GPP), the GSM Association, 3GPP2, IEEE, or other partners or standards bodies.

[0062] Multiple RAN nodes (e.g., eNB, gNB) of the same or different radio access technologies ("RAT") may be deployed in the same or different frequency carriers in certain geographic areas, and they may interact with each other via dual connectivity operations to provide joint communication services for (multiple) the same target UEs. The multi-RAT dual connectivity ("MR-DC") architecture may have a non-co-located master node ("MN") and a secondary node ("SN"). The access mobility function ("AMF") and the session management function ("SMF") may be control plane entities, while the user plane function ("UPF") is a user plane entity in a new radio ("NR") or 5GC. The signaling connection between the AMF / SMF and the master node ("MN") may be a next generation control plane ("NG-C") / MN interface. The signaling connection between the MN and the SN may be an Xn control plane ("Xn-C") interface. The signaling connection between the MN and the UE is a Uu control plane ("Uu-C") RRC interface. All of these connections manage the configuration and operation of MR-DC. The user plane connection between the user plane function ("UPF") and the MN may be an instance of the NG-U(MN) interface.

[0063] Figure 3 The network architecture of the base station central unit (CU) and the base station distributed unit (DU) is shown. Figure 3 A base station (labeled "gNB") is illustrated in communication with the entire network (labeled "5GC"). The base stations can communicate with each other via a control plane interface ("Xn-C"). One base station is shown with one CU connected to two DUs via an F1 interface. This is just one example of an arrangement of a base station, and in some embodiments, there may be one or any number of DUs connected to a single CU.

[0064] A base station can be divided into two physical entities, referred to as a centralized unit ("CU") and a distributed unit ("DU"). Typically, a CU can provide support for higher layers of a protocol stack, such as SDAP, PDCP, and RRC, while a DU can provide support for lower layers of a protocol stack, such as RLC, MAC, and the physical layer. In addition to those functions specifically assigned to a DU, a CU may include operations for forwarding of user data, mobility control, radio access network sharing, session management, and the like. (DUs) are logical nodes (multiples) with a subset of base station functionality and may be controlled by a CU.

[0065] The CU can be a logical node for the RRC, SDAP and PDCP protocols of the hosting base station or the RRC and PDCP protocols of the base station, which controls the operation of one or more DUs. The DU can be a logical node for the RLC, MAC and PHY layers of the hosting base station, and its operation can be at least partially controlled by the CU. A single DU can support one or more cells. However, each cell is supported only by a single DU. Each base station can support many cells. As described in the embodiments of this document, cell mobility between cells can come from different CUs or DUs or can be inside the CU and / or DU.

[0066] L1 / L2 mobility

[0067] The L1 / L2-based inter-cell mobility described herein may occur in a number of different examples. For L1 / L2 mobility, there may be intra-DU mobility, in which the UE changes cells within a single DU. Examples of intra-DU mobility include: 1) PCell changes within one DU (which may also include PCell changes and SCell changes); 2) PSCell changes within one DU (which may also include PSCell changes and SCell changes); 3) PCell changes within one DU and PSCell changes within one DU (which may also include SCell changes within a cell group). In another L1 / L2 mobility embodiment, there may be intra-CU and inter-DU mobility, in which the UE changes cells between different DUs but within a single CU. Examples of intra-CU and inter-DU mobility include: 1) PCell changes across DUs but within one CU (which may also include PCell changes and SCell changes); 2) PSCell changes across DUs but within one CU (which may also include PSCell changes and SCell changes). In another mobility embodiment, there may be inter-CU mobility, in which the UE changes cells between different CUs. Examples of inter-CU mobility include: 1) PCell change across CUs (which may also include PCell change and SCell change); 2) PSCell change across CUs (which may also include PSCell change and SCell change). In another embodiment, there may be SCell change / addition, and the example may include SCell addition / change within a cell group. Figure 4-Figure 6 An embodiment of UE mobility between cells is illustrated.

[0068] Figure 4 An embodiment of intra-DU mobility of a user equipment (UE) is shown. A base station may include a CU and at least one DU. In this embodiment, a single DU with multiple cells is shown. Both cell 1 and cell 2 are from a single DU. In this example, UE 402 may move from cell 1 to cell 2, and Figure 4 4 has a UE trajectory from cell 1 to cell 2. Mobility from a cell may occur when UE 402 is located in a position between two cells and is making its way to a third position within cell 2. This is intra-DU mobility because the UE is moving cells within a single DU.

[0069] Figure 5An embodiment of intra-CU and inter-DU mobility of a user equipment (UE) is shown. In this embodiment, a base station may include one CU and two DUs (DU_1 and DU_2). Although each DU may have multiple cells, for this example, each DU is shown as providing a single cell, such that DU_1 provides cell 1 and DU_2 provides cell 2. In this example, UE 502 may move from cell 1 to cell 2, and Figure 5 4 has a UE trajectory from cell 1 to cell 2, which also results in a transfer from DU_1 to DU_2. Mobility from a cell can occur when the UE 402 is located in a position between two cells and is making its way to a third position within cell 2. This is intra-CU mobility because the UE is moving cells within a single CU. However, this is also inter-DU mobility because the UE moves between different DUs.

[0070] Figure 6 An embodiment of inter-CU mobility of a user equipment (UE) is shown. In this embodiment, the base station may include multiple CUs (CU_1 and CU_2). Each CU may include multiple DUs, but in this example, each CU is shown as having a corresponding DU (CU_1 has DU_1 and CU_2 has DU_2). Each DU is shown as having multiple cells. In this example, the UE trajectory of UE 602 is from Cell_2 through Cell_3, to inter-CU position 604 (between CU_1 and CU_2), and then to Cell_5 and Cell_6. When the UE moves, the mobility can change cells as shown and can be transferred between several cells. Because UE602 (at inter-CU position 604) switches the cell from CU_1 to CU_2, the transfer is called inter-CU mobility.

[0071] Network-triggered L1 / L2 mobility

[0072] The inter-cell mobility may be triggered by the network (eg, base station) or the UE. As described, L1 / L2 signaling is used to improve inter-cell mobility. The examples described throughout may be triggered by the network or by the UE, and Figure 7-Figure 8 The embodiments shown in may be applicable to other embodiments.

[0073] Figure 7An embodiment of network-triggered inter-cell mobility is shown. This embodiment illustrates the communication or signaling between the UE, the source cell, and the target cell. The communication shows how the UE can move from the source cell to the target cell and the L1 / L2 signaling used as part of the transfer. In box 702, the network ("NW") pre-configures one or more candidate / neighboring cells for inter-cell mobility via RRC signaling (e.g., RRC reconfiguration (RRCReconfiguration) message). The candidate cell configuration may include multiple candidates that serve as target cells. Further embodiments and examples about candidate lists and about what the configuration may include are described below. In box 704, the UE responds to the RRC message with a confirmation / completion message to the network at the source cell. In one embodiment, the message may be an RRC reconfiguration complete (RRCReconfigurationComplete). In box 706, the UE reports L1 and / or L3 measurements related to neighboring cells (i.e., potential candidate cells) to the network. Further embodiments and examples about measurements and neighbors / candidates are described below.

[0074] In one embodiment, the source cell of the network determines at least one of the candidate cells to be activated based on the measurement in box 708. The candidate cell to be activated may also be referred to as an identified cell or an identified candidate cell. The identification process is further described below. Based on the identification of at least one target cell, the source cell sends a trigger command including the identification of at least one target cell to the UE in box 710. The trigger command is an L1 / L2 command. Based on the reception of the L1 / L2 command, the UE switches to the target cell in box 712 and communicates with the target cell in box 714. The communication between the UE and the target cell is through L1 / L2 signaling. As described, cell mobility using L1 / L2 signaling can provide several advantages. In some embodiments, configuration details of neighbor / candidate cells (including target cells) can be provided for identifying or determining the target cell. In box 714, the information can be further used to establish L1 / L2 communication after being identified by the UE.

[0075] UE-triggered L1 / L2 mobility

[0076] Inter-cell mobility may be triggered by the network (eg, a base station) or by the UE. As described, L1 / L2 signaling is used to improve inter-cell mobility. The examples described throughout may be triggered by the network or by the UE, and Figure 7-Figure 8 The embodiments shown in may be applicable to other embodiments.

[0077] Figure 8An embodiment of inter-cell mobility triggered by a user equipment (UE) is shown. The embodiment illustrates the communication or signaling between the UE, the source cell, and the target cell. The communication shows how the UE can move from the source cell to the target cell and the L1 / L2 signaling used as part of the transfer. In box 802, the network ("NW") pre-configures one or more candidate / neighboring cells for inter-cell mobility via RRC signaling (e.g., an RRC reconfiguration message). The candidate cell configuration may include multiple candidates that act as target cells. In addition, the configuration message includes a trigger condition used by the UE for triggering mobility based also on the configuration for the candidate cell. Additional embodiments and examples regarding candidate lists, configurations, and trigger conditions are described below. In box 804, the UE responds to the RRC message with a confirmation / completion message to the network at the source cell. In one embodiment, the message may be an RRC reconfiguration completion.

[0078] For the example of UE triggering, in box 806, the UE evaluates the triggering condition. In box 808, the evaluation of the triggering condition is used to identify the target cell from the candidate cells. The triggering condition may also be referred to as an execution condition. Specifically, if at least one candidate cell satisfies the triggering condition, the UE may switch to the candidate cell. In other words, if the candidate cell does not meet the triggering condition, the UE may not switch to the candidate cell. The identification in box 808 may also include activating or switching to the target cell, and the UE may communicate with the target cell in box 810. The communication between the UE and the target cell is carried out through L1 / L2 signaling. As described, cell mobility using L1 / L2 signaling can provide several advantages. In some embodiments, configuration details of neighbors / candidate cells (including target cells) may be provided for identifying or determining the target cell. In box 810, the information may be further used to establish L1 / L2 communication after being identified by the UE.

[0079] Candidate cell configuration

[0080] As about Figure 7-Figure 8 As described, the candidate cell may include a configuration that is sent. The configuration may include configuration parameters provided to identify the candidate cell (e.g., the target cell). The candidate cell configuration may include a lower layer configuration (e.g., an RLC layer configuration, a MAC layer configuration, or / and a physical layer configuration). In some embodiments, the candidate cell configuration may include at least one of the following information elements (IE): cell group configuration (CellGroupConfig), SpCell configuration (SpCellConfig), serving cell configuration common (ServingCellConfigCommon) and / or serving cell configuration (ServingCellConfig).

[0081] The candidate cell configurations may be provided via different options. In one embodiment, each candidate cell configuration may be included in an RRC container and linked to the cell identification (ID) information (e.g., like a CHO / HO based solution). In other embodiments, the candidate cell configurations may be included in an RRC message as a cell list, and each cell configuration may be linked to the cell identification information (e.g., like a cell activation / deactivation based solution).

[0082] The cell ID information used for configuration and maintenance of candidate cells may include a candidate cell configuration index (e.g., candidate configuration Id (CandReconfigId)), a candidate / serving cell ID (e.g., a serving cell index (ServCellIndex)), a physical cell ID (PCI), PCI+frequency, or a reference signal (RS) ID associated with the candidate cell (e.g., an RS ID linked to the candidate cell via the PCI, which has been configured as part of the current serving cell configuration). The RS may be at least one of a synchronization signal block (SSB), a channel state information (CSI) reference signal (CSI-RS), and a temporary / tracking reference signal (TRS). In other embodiments, a transmit configuration indication (TCI) state ID associated with the candidate cell may also be used. The TCI state may be linked to the candidate cell (e.g., via the PCI) and has been configured as part of the current serving cell configuration.

[0083] The stored candidate cells may be activated as SpCells or SCells. In some embodiments, the cells may be activated as both. Examples when activated as SpCells, SCells, or both are described below.

[0084] In one embodiment for identifying candidate cells, there may be separate structures / lists for candidate SCells (i.e., PCell, PSCell) and candidate SCells, for example, a candidate SCell list (e.g., candidateSpCellToAddModList, candidateSpCellToReleaseList) and a candidate SCell list (e.g., candidateSCellToAddModList, candidateSCellToReleaseList).

[0085] In another embodiment for identifying candidate cells, there may be a common structure / list for candidate cells (e.g., candidateCellToAddModList, candidateCellToReleaseList), and each entry may be configured as a candidate SpCell or a candidate SCell. In this example, there may be an indicator / flag used to indicate whether a cell can be a candidate SpCell or a candidate SCell (e.g., candidateCellType, candidateSpCell, or candidateSCell). In another alternative to this example, different cell ID ranges may be assigned to candidate SpCells and candidate SCells (e.g., assigning values ​​0 to X to candidate SCells and values ​​X+1 to N to candidate SCells). In another alternative to this example, there may be a bitmap used to indicate which cells can be activated as SpCells (e.g., a bit set to 1 in the bitmap indicates that the cell can be activated as a SpCell). In another alternative to this example, there may be a SpCell-specific configuration (e.g., SpCellConfig, reconfigurationWithSync, PUCCH-Config) in the candidate cell configuration, which may be used to distinguish whether the candidate cell can be activated as a SpCell or an SCell. For example, if the candidate cell configuration includes a SpCell-specific command, the candidate cell is used as a candidate SpCell. Otherwise, it is used as a candidate SCell.

[0086] In another embodiment for identifying candidate cells, there may be a common structure / list for candidate cells (e.g., candidateCellToAddModList, candidateCellToReleaseList), and each entry may be configured as a candidate cell for both SpCell and SCell. In an alternative example of this embodiment, for an entry including (e.g., (multiple) SpCell-specific configurations (e.g., SpCellConfig, reconfigurationWithSync, PUCCH-Config)), the associated candidate cell may be used as both a candidate SpCell and a candidate SCell. Otherwise, the entry may be used as a candidate SCell. In another alternative example of this embodiment, the entry includes two sub-entries, one sub-entry containing a configuration used for a candidate SpCell (e.g., including (multiple) SpCell-specific configurations), and the other sub-entry containing a configuration used for a candidate SCell (e.g., without (multiple) SpCell-specific configurations). How a candidate cell is used as a SpCell or a SCell may be determined depending on the network ("NW").

[0087] In another embodiment, the indicator or flag triggering mobility in the L1 / L2 command may also indicate whether the cell is activated as a SpCell. When the cell is activated as a SpCell, the SpCell specific configuration may be used / applied by the UE.

[0088] In some embodiments, the NW may also provide information about which cells can be activated simultaneously. Candidate cell mapping / combination information may be provided via several different methods. In one example, there may be a cell combination list (e.g., a candidate cell combination list (candidateCellCombinationList)) to indicate which candidate cells can be activated simultaneously. Each item in the list may include a cell combination ID (to identify any potential cell combination) and / or a cell combination containing multiple candidate cell IDs. In another example, there may be a bitmap (e.g., a bitmap size of N bits to indicate N candidate cells) for indicating which candidate cells can be activated simultaneously. A bit set to 1 in the bitmap indicates that the cell can be activated simultaneously, or a bit set to 0 indicates that the cell cannot be activated simultaneously.

[0089] Community_1 Community_2 Community_3 Community_4 1 1 1 0 1 0 1 1 1 1 0 1

[0090] Table 1: Bitmap of whether candidate cells can be activated simultaneously.

[0091] In this example, the NW pre-configures 4 candidate cells, and only 1+2+3, 1+3+4, and 1+2+4 are allowed to be activated simultaneously. The NW can provide the above bitmap table as part of the configuration. Alternatively, the NW can provide a list of candidate cell ID combinations, such as {cell_1, cell_2, cell_3}, {cell_1, cell_3, cell_4}, {cell_1, cell_2, cell_4}.

[0092] There may be various embodiments to reduce the signaling overhead for candidate cell configuration. In one embodiment, one or more separate common sets / templates are defined as a baseline for the candidate cell configuration, and (multiple) candidate cells are configured based on the baseline configuration and the incremental configuration added to the baseline configuration. In another embodiment, one or more serving / candidate cells are identified as (multiple) reference cells in the candidate cell configuration entry in the candidate cell list (e.g., including a reference ID for the current serving cell ID or other candidate cell IDs), and (multiple) candidate cells are configured based on the configuration of the reference cell and the incremental configuration of the reference cell configuration. This embodiment may also be considered for reusing a serving cell as a candidate cell, or vice versa. Specifically, a reference cell indicator (e.g., referenceCell) is included in the candidate cell configuration or the serving cell configuration. For example, for a candidate cell entry, a serving cell ID (e.g., SCellIndex or ServCellIndex) may be included to indicate that the referenced serving cell is also considered a candidate cell for L1 / L2 mobility. The candidate cell ID may be indicated in the current serving cell configuration (eg, SpCellConfig or SCellConfig) to indicate that the candidate cell is added as a serving cell (eg, via an RRC reconfiguration message).

[0093] L1 / L3 Measurement

[0094] Figure 7 The diagram illustrates L1 / L3 measurements used for measurement reporting that helps determine / identify a target cell from candidate cells. In some embodiments, the L1 / L3 measurement configuration may be provided to the UE by the network.

[0095] The NW may provide the L1 measurement configuration of a candidate cell or a neighboring cell to the UE via at least one of the following alternatives: 1) configuring / adding L1 measurement for the candidate cell in the current L1 measurement configuration (e.g., channel state information measurement configuration CSI-MeasConfig) on ​​the serving cell; 2) configuring or reusing L1 measurement for the candidate cell in the RRM measurement configuration (e.g., MeasConfig); 3) defining a separate structure to provide L1 measurement for the candidate cell; or 4) the L1 measurement configuration for the candidate cell is configured or included in each candidate cell configuration.

[0096] The L1 measurement configuration may include at least one of the following: an addition / modification list for L1 measurement objects / resources; a removal list for L1 measurement objects / resources; an addition / modification list for L1 measurement IDs (measurement IDs are links between measurement objects / resources and reporting configurations); a removal list for L1 measurement IDs; an addition / modification list for L1 reporting configurations; a removal list for L1 reporting configurations; a measurement gap configuration for L1 measurements; or a threshold for SpCell / serving cell RSRP measurement control when the UE is required to perform L1 measurements on non-serving / candidate cells (e.g., L1 SSB RSRP threshold or L1 CSI-RS RSRP threshold). When the serving cell becomes worse than the threshold, the UE may be required to perform L1 measurements on non-serving / candidate / neighboring cells. These measurements are then used to select / identify the target cell from among the candidate cells.

[0097] L1 measurement may be provided or activated in different embodiments. The measurement may be referred to as an object / resource (e.g., a reference signal resource used for L1 measurement). It may be provided in the following alternative ways: 1) configuring or adding reference signal (RS) resources related to candidate / neighboring cells in the L1 measurement configuration (e.g., CSI-ResourceConfig) for the current serving cell; 2) reusing RS resources related to candidate / neighboring cells in L3 / RRM measurements, or configuring / adding additional RS resources related to candidate / neighboring cells in the L3 / RRM measurement configuration (e.g., CSI-RS-ResourceConfigMobility); 3) defining a separate structure to provide RS resources for candidate / neighboring cells; or 4) RS resources for candidate cells are configured / included in each candidate cell configuration. The RS type may include at least one of SSB, CSI-RS, TRS. In some embodiments, the RS resources may include at least one of the following: 1) RS resource ID; 2) frequency domain resources of RS; 3) time domain resources of RS; or 4) resource type (e.g., non-periodic, semi-persistent, or periodic). For configured RS measurement resource activation, when it is configured, the RS / measurement resource can be considered to be activated (e.g., can be detected or measured by the UE), or when it is configured, the RS / measurement resource can be considered to be deactivated (e.g., cannot be detected or measured by the UE). The NW can explicitly indicate which RS resources related to the neighboring / candidate cells (e.g., indicating RS resource ID, candidate cell ID) will be activated (e.g., via L1 / L2 commands or RRC signaling). When the RS resources related to the neighboring / candidate cells are activated, the UE may be required to perform L1 measurements on the RS resources related to the neighboring / candidate cells. When the RS resources related to the neighboring / candidate cells are deactivated, the UE is not required to perform L1 measurements on the RS resources related to the neighboring / candidate cells.

[0098] The L1 measurement report can be configured in different ways. The L1 measurement report configuration (e.g., CSI-ReportConfig) can be used to configure the L1 measurement report on the current serving cell. It may include at least one of a report configuration ID or a report type (e.g., aperiodic, semi-persistent, periodic, or event-triggered). For the event trigger type, the trigger event can be established as a new event based on the L1 measurement. For example, the L1 measurement of the neighboring cell becomes better than a threshold (e.g., A4 event, RSRP, RSRQ, and / or SINR value). In another example, the L1 measurement of the neighboring cell becomes better than the L1 measurement of the SpCell / serving cell (e.g., A3 event). In another example, the L1 measurement of the SpCell / serving cell becomes worse than a first threshold, and the L1 measurement of the neighboring cell becomes better than a second threshold (e.g., A5 event). The L1 measurement report can be further configured by reusing L3-based measurement events (e.g., events A3 / A4 / A5), but configured with additional parameter values ​​for L1 / L2 mobility (e.g., additional hysteresis, trigger time (timeToTrigger), threshold). More flexible values ​​can make L1 / L2 mobility easier to trigger. L1 measurement reporting can be further configured through new events based on L1 measurements on the serving cell and L3 measurements on candidate / neighboring cells. For example, the L1 measurement of the SpCell / serving cell becomes worse than a first threshold, while the L3 measurement of the neighboring cell becomes better than a second threshold (e.g., A5 type event).

[0099] The L1 measurement gap may be configured to specify a window in which the UE may perform inter-frequency and / or intra-frequency L1 measurements. The measurement gap may be provided by reusing a measurement gap configuration (e.g., MeasGapConfig) for L3 / RRM measurements. Additional parameter values ​​(e.g., additional gapOffset, mgl, mgrp, mgta, etc.) may be configured for L1 measurements. The offset value may be based on the parameter value for L3 measurements (e.g., offset value for gapOffset, mgl, mgrp, mgta, etc.). The L1 measurement gap may be configured to define a separate measurement gap configuration (e.g., L1MeasGapConfig) for L1 measurements. The L1 measurement gap configuration may include at least one of the following:

[0100] ● Gap type (e.g., per FR1 gap, per FR2 gap, per UE gap);

[0101] ● Gap offset;

[0102] ●Measurement gap repetition period;

[0103] ●Measure the gap length;

[0104] ● The measurement gap timing is advanced; or

[0105] - Reference serving cell, whose SFN and subframe are used for gap calculation for this gap pattern.

[0106] exist Figure 8 In the embodiment, the triggering condition is provided to the UE. The triggering condition may also be referred to as an execution condition and establishes a condition or threshold by which mobility may be triggered. In one embodiment, the triggering condition comprises a list of measurement identifiers measId, which may be linked to the L1 / L3 measurement objects / resources and reporting configurations as described above. In another embodiment, the triggering condition comprises any of the measurement events listed above.

[0107] A candidate cell may be linked to a trigger condition. Specifically, one or more execution conditions are linked to a candidate cell. In another embodiment, one or more execution conditions are linked to multiple candidate cells (e.g., one or more conditions for a candidate cell combination including an SpCell and an associated SCell). If multiple conditions are linked to a candidate cell / cell combination, the UE may consider the condition to be met when all conditions are met (e.g., each condition relationship is "AND") or when one of the conditions is met (e.g., each condition relationship is "OR") .

[0108] The configured radio resource management (RRM) measurements may be affected by the execution of L1 / L2 mobility (e.g., the change between inter-frequency measurements and intra-frequency measurements). Triggering events on the UE side (e.g., for other candidate cells or CHO, if coexistence with CHO is allowed) should be taken into account to ensure that the events are still valid after the execution of L1 / L2 mobility. The updated RRM measurement configuration (e.g., measurement object configuration, measurement report configuration, measurement gap configuration) may be provided differently in various embodiments. In one embodiment, the NW pre-configures the UE with the updated measurement configuration associated with each candidate cell. For example, the measurement configuration is included in each candidate cell configuration, or a separate structure for measurement configuration update is defined (e.g., a measurement configuration list, each measurement configuration is linked to a candidate cell ID). After triggering L1 / L2-based mobility, the UE applies the corresponding measurement configuration of the target cell. In another embodiment, after triggering L1 / L2-based mobility, or after successfully completing mobility, the UE automatically triggers a measurement configuration switch (e.g., measId is associated with a measObjectId value corresponding to the source frequency, linked to a measObjectId value corresponding to the target frequency). In another embodiment combined with the above embodiment, the NW pre-configures the UE with a portion of the updated measurement configuration (e.g., gap configuration, reporting configuration) associated with each candidate cell. After triggering L1 / L2-based mobility, the UE performs an automatic mobility switch and applies the corresponding measurement configuration of the target cell based on the baseline / source measurement configuration.

[0109] For reporting configuration (e.g., including triggering / execution conditions) updates, the source configuration may be stored as a template / baseline, or the NW provides a set of separate reporting configurations as templates / baselines. The NW provides a set of incremental configurations for each candidate cell, which can be applied based on the template / baseline when L1 / L2 mobility is triggered. The incremental configuration may include a list of cell-based offset values ​​(e.g., RSRP, RSRQ, SINR values), each offset value being associated with each candidate cell. When a candidate cell is selected / indicated to be activated / switched as a target cell, the UE adds the cell-based offset value associated with the cell to the threshold / offset value within the template / baseline configuration to generate a new reporting configuration for the target cell. An example signaling structure is shown in Table 2 below:

[0110]

[0111] Table 2: Signaling structure including incremental configuration of cell-based offset value.

[0112] In Table 2, the measurement information for the incremental configuration includes a list of candidate cell IDs and associated cell base offset values. The incremental configuration may also include a set of frequency / MO base offset values ​​(e.g., RSRP, RSRQ, SINR values) for each candidate cell. When a candidate cell is selected / indicated to be activated / switched as a target cell, the UE adds the frequency base offset value associated with the cell to the threshold / offset value linked to the corresponding frequency in the template / baseline configuration. An example signaling structure is shown in Table 3 below:

[0113]

[0114] Table 3: Signalling structure including incremental configuration of frequency / MO base offset values.

[0115] In Table 3, the measurement information for incremental configuration includes a list of candidate cell IDs and an associated list of measurement object / frequency information. Each measurement object / frequency information includes a list of measurement object IDs or frequencies and associated measurement object / frequency values.

[0116] To provide measurement gap configuration updates, there may be a list of measurement gap configurations (e.g., measGapConfigList), each measurement gap configuration being linked to a set of candidate cells, such as a candidate cell list within GapConfig. In another embodiment of providing measurement gap configuration updates, there may be a list of candidate cells, each candidate cell being linked to one or a set of measurement gap configurations. In another embodiment of providing measurement gap configuration updates, there may be a template / baseline measurement gap configuration (e.g., source measurement gap configuration), the list of updated measurement configurations being a delta configuration based on the template / baseline. When a candidate cell is activated, the UE autonomously applies / activates the associated measurement gap configuration.

[0117] L1 / L2 mobility triggered by the network

[0118] Return to reference Figure 7, L1 / L2 mobility can be triggered by the network. In box 706, the UE reports L1 / L3 measurements related to neighboring cells (including candidate cells) to the NW. The NW selects a target candidate cell based on the measurement report in box 708, and sends a trigger command (e.g., an L1 / L2 command) in box 710 to instruct the UE to select the indicated cell to perform inter-cell mobility. Another example of triggering of L1 / L3 measurement reporting is described below. After the conditions / events of the configured reporting type (e.g., non-periodic, semi-persistent, periodic, or event-triggered) are met, the UE can trigger the L1 / L3 measurement report. For the non-periodic type, after receiving a DCI trigger for an L1 measurement report request, the UE should send a non-periodic L1 measurement report (e.g., a CSI report) on the PUSCH. For the semi-persistent type, after receiving a DCI trigger for an L1 measurement report request, the UE can send a semi-persistent L1 measurement report (e.g., a CSI report) on the PUSCH. For the semi-persistent type, upon receiving a MAC CE for an L1 measurement report request, the UE shall send a semi-persistent L1 measurement report (e.g., CSI report) on the PUCCH. For the periodic type, the UE shall send a periodic L1 measurement report (e.g., CSI report) on the PUCCH according to the configured / defined periodicity. For the event-triggered type, upon determining / detecting an L1 measurement that satisfies a configured condition / event, the UE shall send an L1 measurement report (e.g., via a CSI report or MAC CE).

[0119] In an alternative embodiment, the UE may trigger an L1 / L3 measurement report after detecting N consecutive L1 measurements that satisfy the conditions (e.g., for the event trigger type above). In an alternative embodiment, the UE may trigger an L1 / L3 measurement report after detecting N consecutive "out-of-sync" indications for the SpCell / serving cell from the lower layers (i.e., a physical layer problem is detected). In an alternative embodiment, the UE may trigger an L1 / L3 measurement report after detecting a radio link failure (RLF) or beam failure recovery (BFR) on the SpCell / serving cell (e.g., T310 expiration, T312 expiration, random access problem, reaching the maximum number of retransmissions, listen-before-talk (LBT) failure).

[0120] The measurement report may be sent via L1 signaling (e.g., via CSI report) or via MAC CE. The measurement report may include at least one of the following: L1 SSB RSRP, L1 SSB RSRQ, L1SSB SINR, L1 CSI-RS RSRP, L1 CSI-RS RSRQ, L1 CSI-RS SINR for neighboring / candidate cells or / and serving cells. For example, via L1 / L2 commands (downlink control information (DCI), MAC control element (MAC CE)), the NW may also indicate which measurements related to neighboring / candidate cells are requested to be reported (e.g., via RS resource ID, candidate cell ID). The UE may send a measurement report that includes only measurement results for the indicated neighboring / candidate cells.

[0121] The trigger command may be at least one of a physical layer DCI, a MAC CE, or an RRC signaling. The trigger command may include at least one of the following information of one or more selected cells to instruct the UE to activate or switch to the indicated (multiple) cells:

[0122] ● Candidate cell configuration index (such as CandReconfigId);

[0123] ● Candidate / serving cell ID (such as, for example, ServCellIndex);

[0124] PCI or PCI+ frequency;

[0125] ● Reference signal (RS) ID associated with the candidate cell, for example: the RS ID linked to the candidate cell (e.g., via the physical cell ID (PCI)) has been configured as part of the current serving cell configuration. The RS can be at least one of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), and a tracking / temporary reference signal (TRS);

[0126] ● a transmission configuration indication (TCI) state ID associated with the candidate cell (e.g., a TCI state linked to the candidate cell via a PCI) has been configured as part of the current serving cell configuration; or

[0127] • Candidate cell combination ID (eg, indicating which candidate cells can be activated simultaneously).

[0128] The trigger command may also include at least one of the following information:

[0129] =Timing Advance (TA) value or compensated TA value of the selected / indicated candidate cell(s);

[0130] - the Cell Radio Network Temporary Identifier (C-RNTI) of the selected / indicated candidate cell(s);

[0131] • The activated DL / UL BWPID of the selected / indicated candidate cell(s);

[0132] An indication / flag to indicate whether the UE can maintain connection with the source / current SpCell / serving cell during L1 / L2 based inter-cell mobility (i.e. like DAPS HO);

[0133] An indication or flag to indicate whether a RACH procedure for the selected / indicated candidate cell(s) is required / skipped or whether a no RACH procedure is allowed;

[0134] The initial TCI state(s) of the selected / indicated candidate cell(s);

[0135] ● the serving cell ID(s) of the selected / indicated candidate cell(s);

[0136] ●PDCP replication activation / deactivation indication, used to indicate whether to activate / maintain / deactivate PDCP replication after L1 / L2 based inter-cell mobility is completed; or

[0137] ● An indication or flag used to indicate whether the selected / indicated candidate cell(s) are activated as SpCells.

[0138] L1 / L2 mobility triggered by UE

[0139] Return to reference Figure 8 , L1 / L2 mobility may be triggered by a user equipment (UE). In block 806, the UE begins evaluating (multiple) execution / triggering conditions for candidate cells. If at least one candidate cell satisfies the corresponding (multiple) execution conditions, then in block 808, the UE connects to the target candidate cell based on the stored cell configuration. L1 / L2 mobility execution may be triggered when at least one of the following conditions is met:

[0140] ●After at least one candidate cell / cell combination satisfies the corresponding (multiple) execution conditions;

[0141] ● After at least one candidate cell / cell combination N continuously satisfies the corresponding execution condition(s);

[0142] ● After N consecutive "out of sync" indications for the SpCell / serving cell are detected from lower layers (i.e. a physical layer problem is detected); or

[0143] ●After a radio link failure (RLF) or beam failure recovery (BFR) is detected on the SpCell / serving cell (e.g., T310 expiration, T312 expiration, random access problem, reaching the maximum number of RLC retransmissions, or LBT failure).

[0144] UE behavior after triggering

[0145] The examples discussed above are for UE triggering, but the following discussion of UE behavior for triggering L1 / L2-based inter-cell mobility can also be applied to UE-triggered mobility and NW-triggered mobility. After triggering L1 / L2-based inter-cell mobility (e.g., after receiving an L1 / L2 trigger command or after detecting that (multiple) execution conditions are met), the UE may perform at least one of the following operations:

[0146] ● Applying / activating the stored cell configuration of the indicated / selected candidate / target cell;

[0147] When a cell is indicated by the NW to be activated as a SpCell (e.g., via an indication in a trigger command), applying / activating the stored SpCell configuration (i.e., the configuration including the SpCell specific configuration(s)) of the indicated / selected candidate / target cell;

[0148] If indicated by the NW (e.g., via an indication in a trigger command), apply a new TA value for the indicated / selected candidate / target cell(s) or apply a compensated TA value based on the current TA value;

[0149] If indicated by the NW (e.g., via an indication in a trigger command), apply the C-RNTI and / or serving cell ID(s) for the indicated / selected candidate / target cell(s);

[0150] • If indicated by the NW (e.g., via an indication in a trigger command), switch to / activate an uplink (UP) / downlink (DL) / bandwidth part (BWP) according to the activated DL / UL BWP identifier (ID);

[0151] ● Start a timer for L1 / L2 mobility (e.g., a MAC layer timer or an RRC layer timer, such as T304);

[0152] ● Disengage from the source / current SpCell / serving cell, synchronize and connect to the indicated / selected candidate / target cell(s); or

[0153] - If instructed by the NW (eg, via an indication in a trigger command), maintain connection to the source / current SpCell / serving cell, synchronize and connect to the indicated / selected candidate / target cell(s).

[0154] For the connection to the target cell, the UE may perform the following process. In one embodiment, if no RACH is configured / allowed, the UE accesses the target cell via a RACH process (e.g., CBRA, CFRA, two-step RA) and completes the L1 / L2-based inter-cell mobility process by sending L1 / L2 signaling to the target cell. In an alternative embodiment, when no RACH is configured / allowed (e.g., via an indication in a trigger command), the UE sends L1 / L2 signaling to the target cell via a pre-allocated uplink grant. In another embodiment, the UE monitors the physical downlink control channel (PDCCH) of the target cell to receive an uplink grant, and the UE sends L1 / L2 signaling to the target cell via the received uplink grant. In another embodiment, the UE sends a scheduling request (SR) to the target cell and starts monitoring the PDCCH of the target cell to receive an uplink grant, and the UE sends L1 / L2 signaling to the target cell via the received uplink grant. In another embodiment, the UE monitors the PDCCH of the target cell with the TCI state indicated in the received L1 / L2 trigger command to receive an uplink grant, and the UE sends L1 / L2 signaling to the target cell via the received uplink grant. In another embodiment, the UE sends an SR to the target cell and starts monitoring the PDCCH of the target cell with the TCI state indicated in the received L1 / L2 trigger command to receive an uplink grant, and the UE sends L1 / L2 signaling to the target cell via the received uplink grant.

[0155] The L1 / L2 signaling may be at least one of physical layer uplink control information (UCI), ACK or MAC CE. The L1 / L2 signaling may also include activated / selected (multiple) candidate / target cell IDs or activated / selected candidate cell combination IDs to the NW.

[0156] In order to switch between the current / source serving cell and the target cell, switching is performed between the candidate cell ID and the serving cell ID. After triggering L1 / L2-based inter-cell mobility, if the NW does not explicitly provide (multiple) serving cell IDs (e.g., not pre-configured with the candidate cell configuration or / and not indicated in the triggering command), the UE can automatically perform switching between the candidate cell ID (which is used for configuration and maintenance of the candidate cell) and the serving cell ID (which is used for subsequent cell operations, such as in SCell activation / deactivation MAC CE). For each candidate cell, if the candidate cell is activated as a PCell, the UE sets the serving cell ID for the cell to 0 (i.e., ServCellIndex=0), but if the candidate cell is activated as an SCell or PSCell, the UE uses the candidate cell ID that has been previously assigned to the candidate cell (e.g., the candidate cell ID included in the RRC message with the candidate cell configuration) as the serving cell ID (i.e., ServCellIndex=candidate cell ID).

[0157] L1 / L2 mobility failure detection / handling

[0158] A new timer may be used for L1 / L2 based inter-cell mobility (e.g., a timer similar to T304). The timer may be an RRC layer timer or a MAC layer timer. In one embodiment, the timer is started after triggering L1 / L2 based inter-cell mobility (e.g., receiving an L1 / L2 command, or after executing UE triggered L1 / L2 mobility (i.e., when applying a stored candidate cell configuration or after detecting that an execution condition is met)). The timer is stopped when at least one of the following conditions is met:

[0159] ● After successful completion of L1 / L2-based inter-cell mobility, such as successful completion of random access on the corresponding candidate cell or sending an L1 / L2 indication (such as UCI, ACK, MAC CE) to the corresponding candidate / target cell;

[0160] ●After RLF / BFR is detected on the current / source serving cell;

[0161] ●After the candidate cell configuration is released;

[0162] ● When the timer is set as a MAC layer timer, when the RRC layer notifies the MAC layer to stop the timer; or

[0163] ●When the timer is an RRC layer timer, when the MAC layer notifies the RRC layer that the L1 / L2-based inter-cell mobility is successfully completed.

[0164] When the timer is a MAC layer timer and the timer expires, the UE may trigger / send a MAC CE to report a L1 / L2 mobility failure. In another embodiment, when the timer is a MAC layer timer and the timer expires, the UE may notify an upper layer (e.g., an RRC layer) of the detection of a L1 / L2 mobility failure. The RRC layer may then trigger an RRC reestablishment procedure, report the L1 / L2 mobility failure to the NW, or select another candidate cell among the stored candidate cells to perform a second L1 / L2 inter-cell mobility (e.g., activate or switch to a different candidate cell).

[0165] When the timer is an RRC layer timer and the timer expires, the UE may trigger an RRC reestablishment procedure. In another embodiment, when the timer is an RRC layer timer and the timer expires, the UE may report an L1 / L2 mobility failure to the NW. In another embodiment, when the timer is an RRC layer timer and the timer expires, the UE may select another candidate cell among the stored candidate cells to perform a second L1 / L2 inter-cell mobility (e.g., activate or switch to a different candidate cell).

[0166] The above-mentioned L1 / L2 mobility failure report can be sent to the NW via L1 / L2 signaling (e.g., UCI, MAC CE) or via RRC signaling (e.g., reusing existing RRC messages including FailureInformation messages, MCGFailureInformation messages, or SCGFailureInformation messages) or by defining new RRC messages. The failure report may include the failure type (e.g., L1 / L2 mobility failure) and / or (multiple) failed candidate cell IDs or failed candidate cell combination ID information.

[0167] In one embodiment, there may be a CHO-based recovery solution. If the UE fails to access a candidate cell and detects that at least one of the other candidate cells meets the corresponding trigger condition or a separate condition / threshold set by the NW (e.g., a condition / threshold used only for cell selection during failure recovery), the UE may automatically trigger a second L1 / L2 mobility to the selected candidate cell. If the failed cell is a candidate PCell and the source cell connection is maintained during L1 / L2 mobility (e.g., like DAPS), the UE may fall back to the source cell and report the L1 / L2 mobility failure to the source cell. If the failed cell is a candidate PSCell or a candidate SCell, the UE reports the failure information to the NW via RRC signaling (e.g., FailureInformation message, or SCGFailureInformation message) or MAC CE (e.g., a new failure report MAC CE).

[0168] When Packet Data Convergence Protocol (PDCP) replication is configured for a UE, several alternatives may be considered for handling PDCP replication after triggering L1 / L2-based inter-cell mobility or completing L1 / L2-based inter-cell mobility. In one embodiment, the UE autonomously deactivates PDCP replication after triggering L1 / L2 mobility. In another embodiment, the NW explicitly indicates whether to activate / deactivate / maintain PDCP replication (e.g., via an L1 / L2 mobility trigger command). In another embodiment, if the previous LCH is removed after performing / completing L1 / L2 mobility (e.g., no serving cell is linked to the previous LCH), the UE autonomously switches the primary path to reference another logical channel (LCH) (e.g., an LCH linked to an activated candidate cell).

[0169] CU / DU Coordination

[0170] As mentioned above Figure 3 As described, the network (NW) or base station may include a central unit (CU) and a distributed unit (DU). In general, the CU may provide support for higher layers of the protocol stack (such as SDAP, PDCP, and RRC), while the DU may provide support for lower layers of the protocol stack (such as RLC, MAC, and physical layers). In addition to those functions specifically assigned to the DU, the CU may include operations for forwarding user data, mobility control, radio access network sharing, session management, and the like. A single DU may support one or more cells. However, each cell is supported only by a single DU. Cell mobility between cells may come from different CUs or DUs or may be within a CU and / or DU.

[0171] Existence Figure 4-Figure 6 A few examples are shown in . Figure 4 An embodiment of intra-DU mobility is shown. Figure 5 Embodiments of intra-CU and inter-DU mobility are shown. Figure 6 1 and 2 show embodiments of inter-CU mobility. In these examples, mobility can be triggered by the network, such as Figure 7 As shown in , or can be triggered by a user equipment (UE), such as Figure 8 As shown in . Figure 7 The NW triggered mobility may be further modified depending on whether it is DU triggered mobility or CU triggered mobility.

[0172] Specifically, the CU and DU coordinate adding / modifying / releasing candidate cell configurations and triggering events. There are at least four embodiments for coordinating the initiation / preparation of candidate cell configurations. In embodiment 1, the CU determines a recommended candidate cell and the CU determines a triggering event. In embodiment 2, the CU determines a recommended candidate cell and the DU determines a triggering event. In embodiment 3, the DU determines a recommended candidate cell and the DU determines a triggering event. In embodiment 4, the DU determines a recommended candidate cell and the CU determines a triggering event.

[0173]

[0174]

[0175] Table 5: Summary of four embodiments of CU / DU initiation (candidate cell proposal) and CU / DU triggering (event determination).

[0176] For embodiments 1 and 2 in which the CU determines recommended candidate cells, the CU sends a list of recommended candidate cells to the DU via an F1 message (e.g., a UE CONTEXT MODIFICATION REQUEST message or other message) to request the DU to establish or configure. The message may also include an indication for indicating that the process is used for L1 / L2 mobility and / or an indication for indicating which type of L1 / L2 mobility the process is used for (e.g., "UE-triggered L1 / L2 mobility", "NW-triggered L1 / L2 mobility", "CU-triggered L1 / L2 mobility", or "DU-triggered L1 / L2 mobility"). For embodiment 1, the CU may also send a triggering event to the DU (e.g., for DU-triggered mobility).

[0177] For embodiments 1 and 2 in which the CU determines the recommended candidate cells, the DU sends a list of accepted or failed / rejected candidate cells and / or a candidate cell configuration for each accepted candidate cell to the CU via an F1 message (e.g., a UE CONTEXT MODIFICATION RESPONSE message or other message). If the DU accepts all recommended candidate cells, a list of accepted or failed / rejected candidate cells is not provided. If the DU fails to establish or configure some candidate cells, a list of failed / rejected candidate cells (including failed candidate cells) or a list of accepted candidate cells (including accepted candidate cells) is provided. The candidate cell configuration may be encapsulated in an RRC container (e.g., a HandoverPreparationInformation, CG-Config, or CG-ConfigInfo message). For embodiment 2, the DU may also send a trigger event (e.g., for UE-triggered mobility or CU-triggered mobility) to the CU.

[0178] For embodiments 3 and 4 in which the DU determines the recommended candidate cells, the DU sends a request for a candidate cell list to the CU via an F1 message (e.g., a UE CONTEXT MODIFICATION REQUIRED message or other message) to request the CU to allow the DU to establish. The message may also include an indication for indicating that the process is used for L1 / L2 mobility and / or an indication for indicating which type of L1 / L2 mobility the process is used for (e.g., "UE-triggered L1 / L2 mobility", "NW-triggered L1 / L2 mobility", "CU-triggered L1 / L2 mobility", or "DU-triggered L1 / L2 mobility"). The DU may also provide a candidate cell configuration for each requested candidate cell. The candidate cell configuration may be encapsulated in an RRC container (e.g., a HandoverPreparationInformation, CG-Config, or CG-ConfigInfo message). For embodiment 3, the DU may also send a trigger event to the CU (e.g., for UE-triggered mobility or CU-triggered mobility).

[0179] For embodiments 3 and 4 in which the DU determines the recommended candidate cells, the CU sends a list of accepted or failed / rejected candidate cells to the DU via an F1 message (e.g., a UE CONTEXT MODIFICATION CONFIRM message). If the CU accepts all requested candidate cells, a list of accepted or failed / rejected candidate cells is not provided. If the CU rejects some candidate cells, a list of failed / rejected candidate cells (including failed / rejected candidate cells) or a list of accepted candidate cells (including accepted candidate cells) is provided. For embodiment 4, the CU may also send a triggering event (e.g., for DU triggered mobility) to the DU.

[0180] The triggering event may include an event based on L1 measurement. For example, when the L1 measurement of a neighboring cell becomes better than a threshold (e.g., RSRP, RSRQ, or / and SINR value for an event similar to A4). In another example, when the L1 measurement of a neighboring cell becomes better than the L1 measurement of the SpCell / serving cell (e.g., an event similar to A3). In another example, when the L1 measurement of the SpCell / serving cell becomes worse than a first threshold and the L1 measurement of the neighboring cell becomes better than a second threshold (e.g., an event similar to A5). In an alternative, the triggering event may include an event based on the L1 measurement on the serving cell and the L3 measurement on the candidate / neighboring cell, such as when the L1 measurement of the SpCell / serving cell becomes worse than a first threshold and the L3 measurement of the neighboring cell becomes better than a second threshold (e.g., an event similar to A5). In another alternative, the triggering event may include a list of (multiple) measIds, which are linked to the L1 / L3 measurement objects / resources and reporting configurations.

[0181] In an embodiment where information (e.g., trigger event(s), indication for L1 / L2 mobility) is provided, the information may be forwarded to the CU or DU via the message directly in an F1 message (e.g., UE context modification request / response, UE context modification required / confirmation message). In another embodiment, the information (e.g., trigger event(s), indication for L1 / L2 mobility) may be provided in an RRC message (e.g., HandoverPreparationInformation, CG-Config, or CG-ConfigInfo message). The RRC message may be included in the F1 message as an information element (IE).

[0182] Fig. 9 An embodiment of intra-DU mobility based on CU-initiated candidate cell preparation is shown. Fig. 9Applicable to Embodiment 1 and Embodiment 2 from Table 5. A user equipment (UE) communicates with a base station distributed unit (DU) and a base station centralized unit (CU). Figure 4 The diagram shows the mobility within the DU, and Fig. 9 Intra-DU mobility based on CU-initiated candidate cell preparation is shown. In block 902, the CU determines (e.g., based on RRM measurements) a proposed candidate cell. The CU sends a list of proposed candidate cells to the DU via an F1 message (e.g., a UE context modification request message or other message) to request the DU to establish or configure the candidate cells. The message may also include an indication indicating that the procedure is for L1 / L2 mobility, and / or an indication indicating which type of L1 / L2 mobility the procedure is for.

[0183] In block 904, the DU determines whether to establish or configure the candidate cells as recommended, and sends the generated candidate cell configuration (e.g., CellGroupConfig) to the CU (e.g., via a UE context modification response message). If the DU fails to establish or configure some candidate cells, the DU may also include an accepted cell list (e.g., a list including cells that have been successfully established) or a failed / rejected cell list (e.g., a list including cells that have not been established) in the message. The DU may also include the generated trigger event / execution condition (e.g., for UE or CU triggered mobility) in the message.

[0184] In block 906, the CU sends the generated RRC reconfiguration message to the DU (e.g., via a DL RRC MESSAGE TRANSFER message). The RRC message includes the candidate cell configuration and may also include a triggering event / condition associated with the candidate cell(s) (e.g., for UE triggered mobility). In block 908, the DU forwards the received RRC reconfiguration message to the UE. In block 910, the UE responds to the DU with an RRC reconfiguration complete message, which the DU then forwards to the CU in block 912 (e.g., via an UL RRC MESSAGE TRANSFER message). In some embodiments, in block 906 the CU sends the generated triggering event to the DU. In an alternative embodiment, blocks 906 and 912 may include a UE context modification request message and a UE context modification response message.

[0185] Fig.10 An embodiment of intra-DU mobility based on DU-initiated candidate cell preparation is shown. Fig.10 Applicable to Examples 3 and 4 from Table 5. Figure 4 The diagram shows the mobility within the DU, and Fig.10Intra-DU mobility based on DU-initiated candidate cell preparation is shown. In box 1002, the DU determines (e.g., based on L1 measurements) recommended candidate cells. The DU sends a requested candidate cell list to the CU via an F1 message (e.g., a UE context modification required message or other message) to request the CU to establish or configure the candidate cells. The DU may also include the generated candidate cell configuration (e.g., CellGroupConfig) and / or triggering event (e.g., for CU or UE triggered mobility) in the message. The message may also include an indication indicating that the process is for L1 / L2 mobility, and / or an indication indicating which type of L1 / L2 mobility the process is for.

[0186] In block 1004, the CU determines whether to accept the requested candidate cells. If the CU rejects some candidate cells, the CU may also include a list of accepted cells (e.g., a list including accepted cell IDs) or a list of failed / rejected cells (e.g., a list including rejected cell IDs) in the message. The CU generates an RRC reconfiguration message including a candidate cell configuration for each accepted cell, and may also include the generated trigger event / execution condition (e.g., for UE triggered mobility) in the message, and sends the RRC message to the DU via an F1 message (e.g., a UE context modification confirmation message or other message). The F1 message may also include a trigger event for the DU (e.g., for DU triggered mobility).

[0187] In block 1006, the DU forwards the received RRC reconfiguration message to the UE. In block 1008, the UE responds to the DU with an RRC reconfiguration complete message, which the DU forwards to the CU in block 1010 (e.g., via an UL RRC MESSAGE TRANSFER message). In some embodiments, the DU may generate a trigger event after the CU accepts the desired candidate cell (e.g., after block 1004), and send the generated trigger event to the CU via a UE CONTEXT MODIFICATION REQUEST message. The CU then generates an RRC reconfiguration message and sends it to the UE via the DU (e.g., the generated RRC reconfiguration message is sent to the DU via a DL RRC MESSAGE TRANSFER message), and the DU forwards the received RRC reconfiguration message to the UE.

[0188] Fig.11 An embodiment of inter-DU mobility based on CU-initiated candidate cell preparation is shown. Fig.11 Applicable to Example 1 and Example 2 from Table 5. Figure 5 The diagram shows inter-DU mobility, and Fig.11Inter-DU mobility based on candidate cell preparation initiated by a CU is shown. There may be a source DU from which the UE is transferred to the candidate DU (also called target DU). In this example, the CU does not change because this is intra-CU inter-DU mobility.

[0189] In box 1102, the CU determines (e.g., based on RRM measurements) recommended candidate cells. The CU sends a list of recommended candidate cells to the candidate DU via an F1 message (e.g., a UE context setup request message or other message) to request the candidate DU to establish or configure the candidate cells. The message may also include an indication for indicating that the process is for L1 / L2 mobility, and / or an indication for indicating which type of L1 / L2 mobility the process is for. Prior to box 1102, in some embodiments, the CU may send a UE context modification request message to the source DU to query the latest configuration. The source DU responds with a UE context modification response message including complete configuration information.

[0190] In box 1104, the target DU determines whether to establish or configure the candidate cell as recommended, and sends the generated candidate cell configuration (e.g., CellGroupConfig) to the CU (e.g., via a UE context establishment response message). If the target DU fails to establish some candidate cells, the DU may also include a list of accepted cells (e.g., a list of successfully established cells) or a list of failed / rejected cells (e.g., a list of unestablished cells) in the message. In box 1106, the CU may send the configured candidate cell list to the source DU via an F1 message (e.g., a UE context modification request message). The message may also include a trigger event / execution condition generated by the CU (e.g., for DU triggered mobility). In box 1108, the source DU responds with a UE context modification response message. The message may also include a trigger event / execution condition generated by the DU (e.g., for UE triggered mobility or CU triggered mobility).

[0191] In box 1110, the CU sends the generated RRC reconfiguration message to the DU (e.g., forwarding the message via a DL RRC message). The RRC message includes the candidate cell configuration and may also include triggering events / conditions associated with the (multiple) candidate cells (e.g., for UE-triggered mobility). In box 1112, the DU forwards the received RRC reconfiguration message to the UE. In box 1114, the UE responds to the DU with an RRC reconfiguration complete message, which the DU forwards to the CU in box 1116 (e.g., forwarding the message via an UL RRC message). In some embodiments, boxes 1106 and 1108 may be skipped. After box 1104, the CU may send the generated RRC reconfiguration message to the source DU (e.g., via a UE context modification request message). The message may also include a configured candidate cell list and / or a triggering event / execution condition generated by the CU (e.g., for DU-triggered mobility).

[0192] Fig.12 An embodiment of inter-DU mobility based on DU-initiated candidate cell preparation is shown. Fig.12 Applicable to Examples 3 and 4 from Table 5. Figure 5 The diagram shows inter-DU mobility, and Fig.12 Inter-DU mobility based on DU-initiated candidate cell preparation is shown. In block 1202, the source DU determines a candidate cell (e.g., based on L1 measurements). The DU sends a suggested candidate cell list or / and (multiple) candidate DUIDs to the CU via an F1 message (e.g., a UE context modification required message or other message) to request the establishment of a candidate cell. The message may also include an indication indicating that the process is for L1 / L2 mobility, and / or an indication indicating which type of L1 / L2 mobility the process is for.

[0193] In block 1204, the CU sends a list of suggested candidate cells to the candidate DU via an F1 message (e.g., a UE context setup request message or other message) to request the candidate DU to establish the candidate cell. The message may also include an indication that the process is for L1 / L2 mobility, for example, an "L1 / L2 mobility" indicator. In some embodiments, prior to block 1204, the CU may send a UE context modification request message to the source DU to query the latest configuration, and the source DU responds with a UE context modification response message including complete configuration information.

[0194] In box 1206, the target DU determines whether to establish the candidate cell as recommended, and sends the generated candidate cell configuration (e.g., CellGroupConfig) to the CU (e.g., via a UE context setup response message). If the target DU fails to establish some candidate cells, the DU may also include an accepted cell list (e.g., a list of successfully established cells) or a failed / rejected cell list (e.g., a list of unestablished cells) in the message. In box 1208, the CU sends the generated RRC reconfiguration message to the DU via an F1 message (e.g., a UE context modification confirmation message). The RRC message includes the candidate cell configuration and may also include triggering events / execution conditions associated with (multiple) candidate cells (e.g., for UE triggered mobility). The F1 message may also include a configured candidate cell list and / or triggering events / conditions (e.g., for DU triggered mobility). In box 1210, the DU forwards the received RRC reconfiguration message to the UE. In block 1212, the UE responds to the DU with an RRC Reconfiguration Complete message, which the DU forwards to the CU in block 1214 (eg, via a UL RRC Messaging message).

[0195] In some embodiments, after block 1206, the CU may send a UE Context Modification Request message to the source DU to notify the configured / accepted candidate cell list. The message may also include a triggering event / execution condition generated by the CU (e.g., for DU triggered mobility), and the source DU responds to the CU with a UE Context Modification Response message. The message may include a triggering event / execution condition generated by the DU (e.g., for UE triggered mobility or DU triggered mobility), and then the CU sends the generated RRC reconfiguration message to the source DU via an F1 message (e.g., a DL RRC message forwarding message).

[0196] Figure 9-12 can be considered as part of the candidate cell configuration initiation / preparation phase, while Figure 13-Figure 18It is part of the L1 / L2 mobility triggering phase. The overall process of L1 / L2 mobility can be any combination of part of the initiation / preparation phase for candidate cell configuration and part of the L1 / L2 mobility triggering phase. There are several options for triggering L1 / L2 mobility. As discussed above, there can be NW-triggered mobility or UE-triggered mobility. For NW-triggered mobility, it can be triggered by CU or DU. For CU-triggered mobility, the CU sends the (multiple) candidate cells to be activated / switched to the DU, and the DU sends an L1 / L2 command to indicate the (multiple) candidate cells to be activated / switched to the UE. For DU-triggered mobility, the DU sends an L1 / L2 command to indicate the (multiple) candidate cells to be activated / switched to the UE, and after the L1 / L2 mobility is completed (for example, the RA for the DU is successfully completed, or the L1 / L2 signaling from the UE is successfully received at the DU), then the DU can notify the CU of the activation / target cell. In one embodiment, the DU only notifies the CU of the activated / target SpCell, but not the activated / target SCell. If all candidate cells are activated as SCells (i.e., L1 / L2 mobility is triggered for SCell addition / change), the DU may not notify the CU. In another embodiment, the DU notifies all activated candidate cell(s), including both SpCells and SCell(s).

[0197] For UE-triggered mobility, the UE directly triggers L1 / L2 mobility when at least one execution condition is met. After completing L1 / L2 mobility (e.g., successfully completing RA for DU, or successfully receiving L1 / L2 signaling from UE at DU), the DU may notify the CU of the activated / target cell. In one embodiment, the DU only notifies the CU of the activated / target SpCell, but does not notify the CU of the activated / target SCell. If all candidate cells are activated as SCells (i.e., L1 / L2 mobility is triggered for SCell addition / change), the DU may not notify the CU. In another embodiment, the DU notifies all activated (multiple) candidate cells, including both SpCells and (multiple) SCells.

[0198] Fig.13 An embodiment of intra-DU mobility based on CU trigger determination is shown. Fig.13 Applicable to Example 1 and Example 4 from Table 5. Figure 4 The diagram shows the mobility within the DU, and Fig.13Intra-DU mobility based on CU trigger determination is shown. In block 1302, L1 / L3 measurement reports are provided from the UE to the DU and forwarded to the CU in block 1304. The measurement reports are used to determine candidate cells in block 1306. Blocks 1302-1306 are discussed in other embodiments.

[0199] In box 1308, after the CU determines the (multiple) candidate cells to be activated / switched to, for example, based on L1 or / and L3 measurement reports or load balancing, the CU sends the (multiple) candidate cells to be activated / switched to the DU via an F1 message (e.g., a UE context modification request message or other message). In box 1310, the DU sends an L1 / L2 command to the UE to indicate the (multiple) candidate cells to be activated / switched. In box 1312, the UE activates / accesses the target cell (e.g., via a random access procedure), and in box 1314, L1 / L2 signaling is sent to the DU (e.g., via ACK, UCI, MAC CE) to complete the L1 / L2 mobility procedure. In box 1316, the DU responds to the CU (e.g., via a UE context modification response message or other message). The message may include (multiple) activation / target cell IDs.

[0200] Fig.14 An embodiment of intra-DU mobility based on DU trigger determination is shown. Fig.14 Applicable to Examples 2 and 3 from Table 5. Figure 4 The diagram shows the mobility within the DU, and Fig.14 Intra-DU mobility determined based on DU triggering is shown. In box 1402, an L1 measurement report is provided from the UE to the DU. In box 1404, the DU determines (multiple) candidate cells to be activated based on the measurement. In box 1406, after the DU determines the (multiple) candidate cells to be activated / switched to, the DU sends an L1 / L2 command to the UE to indicate the (multiple) candidate cells to be activated / switched to. In box 1408, the UE activates / accesses the target cell (e.g., via a random access procedure), and in box 1410, L1 / L2 signaling is sent to the DU to complete the L1 / L2 mobility procedure. In box 1412, the DU can notify the CU of the (multiple) activated / target cells (e.g., via an ACCESS SUCCESS message).

[0201] Fig.15 An embodiment of intra-DU mobility based on UE triggered determination is shown. Figure 4 The diagram shows the mobility within the DU, and Fig.15Intra-DU mobility determined based on UE triggering is shown. In box 1502, the UE evaluates (multiple) execution conditions for candidate cells. If at least one candidate cell satisfies the (multiple) corresponding execution conditions, the UE applies / activates the corresponding candidate cell configuration. In box 1504, the UE activates / accesses the target cell (e.g., via a random access procedure), and in box 1506, L1 / L2 signaling is sent to the DU (e.g., via ACK, UCI, MAC CE) to complete the L1 / L2 mobility process. In box 1508, the DU notifies the CU of the successful completion of the L1 / L2 mobility (e.g., via an access success message or other message). The message may include (multiple) activation / target cell IDs.

[0202] Fig.16 An embodiment of inter-DU mobility based on CU trigger determination is shown. Fig.16 Applicable to Example 1 and Example 4 from Table 5. Figure 5 The diagram shows inter-DU mobility, and Fig.16 Inter-DU mobility determined based on CU triggering is shown. In box 1602, L1 / L3 measurement reports are provided from the UE to the source DU and forwarded to the CU in box 1604. In box 1606, the measurement reports are used to determine candidate cells. Boxes 1602-1606 have been discussed in other embodiments. In box 1608, the CU determines the (multiple) candidate cells to be activated / switched to (e.g., based on L1 or / and L3 measurement reports, or / and load conditions), and the CU sends the (multiple) candidate cells to be activated / switched to the source DU via an F1 message (e.g., a UE context modification request message or other message). In box 1610, the source DU sends an L1 / L2 command to the UE to indicate the candidate cells to be activated / switched. The source DU may also send a downlink data delivery status frame in box 1612 to notify the CU of downlink data that was not successfully sent to the UE. In box 1614, the source DU responds to the CU (e.g., via a UE context modification response message or other message). In block 1616, the UE activates / accesses the target cell (e.g., via a random access procedure), and sends L1 / L2 signaling to the DU in block 1622 to complete the L1 / L2 mobility procedure. After block 1616, the target DU may send a downlink data delivery status frame in block 1618 to notify the CU. The downlink packet may include a PDCP PDU that was not successfully transmitted in the source DU, which is sent from the CU to the target DU. In block 1620, the target DU may also notify the CU of the successful completion of the L1 / L2 mobility (e.g., via an access success message). The message may also include (multiple) activated / target cells.

[0203] Fig.17 An embodiment of inter-DU mobility based on DU trigger determination is shown. Fig.17 Applicable to Examples 2 and 3 from Table 5. Figure 5 The diagram shows inter-DU mobility, and Fig.17 Inter-DU mobility determined based on DU triggering is shown. In box 1702, an L1 measurement report is provided from the UE to the source DU. In box 1704, the source DU determines the (multiple) candidate cells to be activated based on the measurement. In box 1706, after the source DU determines the (multiple) candidate cells to be activated / switched to, the source DU sends an L1 / L2 command to the UE to indicate the (multiple) candidate cells to be activated / switched to. The source DU determines (for example, based on the L1 measurement report) the (multiple) candidate cells to be activated / switched to, and the source DU sends an L1 / L2 command to the UE to indicate the (multiple) candidate cells to be activated / switched to. The source DU may also send a downlink data delivery status frame in box 1708 to notify the CU of downlink data that was not successfully sent to the UE. In box 1710, the UE activates / accesses the target cell (for example, via a random access process), and sends L1 / L2 signaling to the DU in box 1716 to complete the L1 / L2 mobility process. After block 1710, the target DU may send a downlink data delivery status frame in block 1712 to notify the CU. The downlink packet may include a PDCP PDU that was not successfully transmitted in the source DU, which is sent from the CU to the target DU. In block 1714, the target DU may also notify the CU (e.g., via an access success message) of the successful completion of the L1 / L2 mobility. The message may also include (multiple) activated / target cells.

[0204] Fig.18 An embodiment of inter-DU mobility based on UE-triggered determination is shown. Figure 5 The diagram shows inter-DU mobility, and Fig.18 Inter-DU mobility determined based on UE triggering is shown. In box 1802, the UE evaluates (multiple) execution conditions for candidate cells. If at least one candidate cell satisfies (multiple) corresponding execution conditions, the UE applies / activates the corresponding candidate cell configuration. In box 1804, the UE activates / accesses the target cell (e.g., via a random access process), and sends L1 / L2 signaling to the DU in box 1810 to complete the L1 / L2 mobility process. After box 1804, the target DU may send a downlink data delivery status frame in box 1806 to notify the CU. The downlink packet may include a PDCP PDU that was not successfully transmitted in the source DU, which is sent from the CU to the target DU. In box 1808, the target DU may also notify the CU of the successful completion of the L1 / L2 mobility (e.g., via an access success message). The message may also include (multiple) activation / target cells.

[0205] In box 1812, the CU may also initiate a UE context modification process to the source DU to stop data transmission for the UE. The CU sends a UE context modification request message to the source DU and instructs to stop data transmission for the UE. In box 1814, the source DU also sends a downlink data delivery status frame to notify the CU of the downlink data that was not successfully sent to the UE. In box 1822, the source DU responds to the CU with a UE context modification response message. In some embodiments, in box 1816, the downlink user data is provided by the CU to the candidate DU, and then the downlink user data is provided to the UE in box 1818. In box 1820, uplink user data is provided from the UE to the source DU.

[0206] Control of L1 / L2 mobility triggers

[0207] The CU can control whether the DU is allowed to trigger L1 / L2 mobility (i.e., send an L1 / L2 mobility trigger command to the UE). If the CU determines to stop / suspend the L1 / L2 mobility trigger (for example, when the CU determines to trigger L3 mobility via legacy HO (i.e., PCell change), DAPSHO, legacy PSCell addition / change, etc.), the CU sends an indication (e.g., "L / L2 mobility trigger indicator", which is set to "Stop / Suspend") via an F1 message (e.g., a UE context modification request message or other message) to instruct the DU to stop / suspend the L1 / L2 mobility trigger. After / after receiving the indication, the DU should not send an L1 / L2 mobility trigger command to the UE. If the CU determines to resume / restart the L1 / L2 mobility trigger (e.g., when the L3 mobility is completed), the CU sends an indication (e.g., "L / L2 mobility trigger indicator", which is set to "Restart / Resume") via an F1 message (e.g., a UE context modification request message or other message) to instruct the DU to resume / restart the L1 / L2 mobility trigger. After / after receiving the indication, the DU may restart sending the L1 / L2 mobility trigger command to the UE, for example, when it is determined that the trigger event(s) are met.

[0208] For example, when it is determined that (multiple) triggering events are met, the DU may request to restart / resume the L1 / L2 mobility trigger. The DU sends an indication (e.g., "L / L2 mobility trigger request indicator") via an F1 message (e.g., a UE context modification required message or other message) to request the CU to allow the restart of the L1 / L2 mobility trigger. The CU determines whether to accept the request and sends a response to the DU via an F1 message (e.g., a UE context modification confirmation or a UE context modification rejection (UE CONTEXT MODIFICATION REFUSE) message). If the CU rejects the request, it may also include a reason (e.g., L3 mobility trigger) in the response message.

[0209] Mobility Interaction

[0210] In alternative embodiments, L1 / L2 mobility may interact with other functions, such as handover (HO), conditional handover (CHO), conditional PSCell addition / change (CPAC), dual active protocol stack (DAPS), or other functions. In one embodiment, the L1 / L2 mobility configuration may include those other functions. L1 / L2 mobility may be combined with CHO / CPAC (i.e., UE-triggered L1 / L2 mobility), where the UE automatically triggers L1 / L2 mobility based on pre-configured execution conditions and stored candidate cell configurations. In another example, L1 / L2 mobility may be combined with DAPS so that the UE maintains a source cell connection when triggering L1 / L2 mobility to a target candidate cell.

[0211] In an alternative embodiment, those other functions may be modified to include L1 / L2 mobility configuration. For example, legacy HO, legacy PSCell addition / change, CHO, CPAC, DAPS, or HO configuration may be modified to include candidate cell configuration for L1 / L2 mobility. In other words, L1 / L2 mobility configuration is based on the target cell configuration, and L1 / L2 mobility (if triggered) may be performed after other functions are completed. Alternatively, L1 / L2 mobility and other functions may be configured to the UE independently.

[0212] When L1 / L2 mobility has been configured (i.e., the UE has stored the candidate cell configuration), the source cell / node may want to initiate or prepare an L3 PCell change (e.g., traditional HO, CHO, DAPS, etc.) and / or an L3 PSCell addition / change (e.g., traditional PSCell addition / change, CPAC, etc.). The source cell / node may send information to the target cell / node to forward / maintain / remove the candidate cell configuration. In one embodiment, the information may include (multiple) candidate cell configurations, such as candidate cell IDs and each cell configuration. In some embodiments, there may be a list of candidate cells that should be maintained / removed. In another embodiment, the information may include an indication of whether to maintain / remove (multiple) candidate cell configurations in the configuration of other functions. For example, the indication may indicate whether to maintain / remove a candidate PCell configuration, a candidate PSCell configuration, a candidate SpCell configuration, and / or a candidate SCell configuration (e.g., "maintainCandidatePCell", "maintainCandidatePSCell", "maintainCandidateSpCell", "maintainCandidateSCell"). In another embodiment, the information may include an indication of which candidate cell's configuration may be considered as a baseline / reference for the incremental configuration of the target cell configuration in the configuration of other functions (e.g., the indication indicates one or more candidate cell IDs as (multiple) baseline cells). For example, the indication may indicate which candidate cell's configuration may be considered as a baseline / reference for the incremental configuration of the target PCell, target PSCell, target SpCell, or / and target SCell (e.g., "baselineForPCell", "baselineForPSCell", "baselineForSpCell", "SCell baseline"). Other functions may have different configurations (e.g., legacy HO / legacy PSCell addition / change / CHO / CPAC / DAPS HO configurations).

[0213] In an embodiment where the information is provided, the above information may be forwarded to the target cell / node, and the information may be directly included in an Xn / X2 message (e.g., a HO request message, an SN add request message, or an SN change required message). In another embodiment, the information may be provided in an RRC message (e.g., a HandoverPreparationInformation, a CG-Config, or a CG-ConfigInfo message). The RRC message may be included in the Xn / X2 message as an information element.

[0214] If other functions are triggered or executed first, there may be alternative solutions for processing the stored L1 / L2 mobility configuration. In one embodiment, the UE may remove the stored L1 / L2 mobility configuration (e.g., candidate cell configuration). For example, the UE may remove the stored L1 / L2 mobility configuration based on an explicit indication from a source cell, where the source cell explicitly releases the candidate cell configuration via an RRC message (e.g., an RRC reconfiguration message) before sending a HO / PSCell add / change command to the UE. In an alternative embodiment, the UE may remove the stored L1 / L2 mobility configuration based on an explicit indication from a target cell. For example, the target cell explicitly releases the candidate cell configuration in the command of other functions (e.g., including an indication in the RRC reconfiguration message indicating the removal of the stored candidate cell configuration). In another example, the target cell may explicitly indicate which candidate cell configuration should be released in the command of other functions (e.g., including a list of released candidate cells in the RRC reconfiguration message). In another example, after triggering the execution of other functions, such as receiving an L3 mobility command (e.g., an RRC reconfiguration message for HO or / and PSCell addition / change) or triggering the execution of conditional L3 mobility (e.g., satisfying the execution conditions for CHO / CPAC), the UE autonomously removes the stored L1 / L2 mobility configuration. In another example, after completing the execution of other functions, such as completing the RA to the target cell, the UE autonomously removes the stored L1 / L2 mobility configuration.

[0215] In another embodiment where other functions are triggered or executed first, the L1 / L2 mobility configuration may be maintained by the UE through the stored L1 / L2 mobility configuration. For example, the UE maintains the stored L1 / L2 mobility configuration according to an explicit indication from the target cell. The explicit indication may come from the target cell, which explicitly indicates the maintenance of the candidate cell configuration in the command of the other function (e.g., including an indication to maintain the stored candidate cell configuration in the RRC reconfiguration message). In another example, the target cell explicitly indicates which candidate cell configurations should be maintained in the command of the other function (e.g., including a list of released / maintained candidate cells in the RRC reconfiguration message).

[0216] In another embodiment, the UE may maintain the stored L1 / L2 mobility configuration without explicit indication. If the L1 / L2 mobility configuration is maintained, other functions may be triggered / executed first, as described above. The processing of the execution condition evaluation (i.e., the L1 / L2 mobility triggered for the UE) may be processed after the execution of other functions is triggered. For example, the UE automatically stops evaluating the execution conditions (e.g., for all candidate cells, only for L1 / L2 mobility candidate cells within the MCG, or only for L1 / L2 mobility candidate cells within the SCG). Alternatively, the UE may stop evaluating the execution conditions based on an explicit indication from the network (e.g., the target cell), which may explicitly indicate in an RRC message (e.g., an RRC reconfiguration message) or a MAC CE to stop evaluating the execution conditions of the candidate cells (e.g., for all candidate cells, only for L1 / L2 mobility candidate cells within the MCG, or only for L1 / L2 mobility candidate cells within the SCG).

[0217] When the UE successfully completes the execution of other functions (e.g., completes RA to the target cell), the UE may remove the stored L1 / L2 mobility configuration. Alternatively, the UE may restart the evaluation of the execution conditions for UE-triggered L1 / L2 mobility (e.g., for all candidate cells, only for L1 / L2 mobility candidate cells within the MCG, or only for L1 / L2 mobility candidate cells within the SCG).

[0218] In some embodiments, the removal of stored L1 / L2 mobility configurations may depend on which type of function is being performed. For example, if the function is related to MCG (e.g., HO / CHO / DAPS), the UE may remove only the L1 / L2 mobility configuration within the MCG, only the L1 / L2 mobility configuration within the SCG, or only the L1 / L2 mobility configuration within both the MCG and the SCG (i.e., all candidate cell configurations). In another example, if the function is related to SCG (e.g., PSCell addition / change / CPACS), the UE may remove only the L1 / L2 mobility configuration within the MCG, only the L1 / L2 mobility configuration within the SCG, or only the L1 / L2 mobility configuration within both the MCG and the SCG (i.e., all candidate cell configurations).

[0219] The above embodiments involve triggering L1 / L2 mobility first. In alternative embodiments, other functions may be triggered or executed first. When other functions are triggered first, there may be different alternatives, such as when CHO / CPAC and L1 / L2 mobility are configured independently for the UE (for example, the UE stores both the CHO / CPAC candidate cell configuration and the L1 / L2 mobility candidate cell configuration) or when the UE triggers L1 / L2 mobility (for example, receiving an NW-triggered L1 / L2 command or triggering the execution of UE-triggered L1 / L2 mobility). Alternatives include whether the UE removes the stored CHO / CPAC configuration or whether the UE maintains the stored CHO / CPAC configuration but stops the evaluation of CHO / CPAC. When the UE successfully completes L1 / L2 mobility (for example, completes RA to the target cell or sends L1 / L2 signaling to the target cell), the UE can remove the stored CHO / CPAC configuration. Alternatively, the UE can restart the evaluation of CHO / CPAC. In some embodiments, the removal of the stored CHO / CPAC configuration may depend on which type of L1 / L2 mobility is performed. For example, if the L1 / L2 mobility is for a cell change within an MCG (e.g., PCell change, MCG SCell add / change), the UE may remove only the CHO configuration, only the CPAC configuration, or both the CHO and CPAC configurations. In another example, if the L1 / L2 mobility is for a cell change within an SCG (e.g., PSCell add / change, SCG SCell add / change), the UE may remove only the CPAC configuration, or both the CHO and CPAC configurations.

[0220] The above embodiments involve triggering L1 / L2 mobility first, or triggering other functions first. However, there are also embodiments for triggering other functions and L1 / L2 mobility processing simultaneously or substantially simultaneously. When the trigger conditions of CHO / CPAC and L1 / L2 mobility are met at the same time (for example, the UE detects that the CHO / CPAC execution condition is met, and the L1 / L2 mobility execution condition is met or the L1 / L2 mobility command is received from the NW), the UE can first perform one function according to the following alternative schemes on priority:

[0221] ●CHO>L1 / L2 mobility for PCell changes>CPAC>L1 / L2 mobility for PSCell changes>L1 / L2 mobility for SCell changes

[0222] ●L1 / L2 mobility for PCell changes>CHO>L1 / L2 mobility for PSCell changes>CPAC>L1 / L2 mobility for SCell changes

[0223] Failure handling for mobility interactions

[0224] If conditional L3 mobility (e.g., CHO, CPAC) and L1 / L2 mobility are configured simultaneously, after detecting L1 / L2 mobility failure, the UE may continue conditional L3 mobility evaluation, and select a conditional L3 mobility candidate cell to perform conditional L3 mobility when an execution condition (e.g., conditional L3 mobility execution condition or an additional preconfigured threshold for failure recovery) is met. In one embodiment, after detecting L1 / L2 mobility for PCell change failure, the UE continues CHO evaluation, and selects a CHO candidate cell to perform CHO when an execution condition (e.g., CHO execution condition or an additional preconfigured threshold for failure recovery) is met. In one embodiment, after detecting L1 / L2 mobility for PSCell change failure, the UE continues CPAC evaluation, and selects a CPAC candidate cell to perform CPAC when an execution condition (e.g., CPAC execution condition or an additional preconfigured threshold for failure recovery) is met.

[0225] Measurement processing for conditional mobility

[0226] In conditional mobility (e.g., CHO, CPAC, UE-triggered L1 / L2 mobility), the NW (e.g., MN, SN) may generate / configure a separate measurement gap for the UE and send it to the UE via RRC signaling (e.g., RRCReconfiguration message with conditional mobility configuration). For example, conditional reconfiguration-related measurement gaps (e.g., conditionalReconfigurationGap) are introduced within the existing conditionalReconfigurationIE. The conditional reconfiguration-related measurement gaps are only used by the UE during conditional mobility evaluation. During conditional mobility preparation, the source node (e.g., source SN, source MN) may send the original / source measurement gap configuration to the target node (e.g., target SN, target MN). The target node generates a measurement gap for a candidate cell (i.e., the measurement gap configuration included in the candidate cell configuration) based on the original / source measurement gap configuration.

[0227] When the UE receives a measurement gap associated with conditional reconfiguration, the UE may ignore the original / source measurement gap, but store two sets of measurement gap configurations (i.e., the original measurement gap configuration and the measurement gap associated with conditional reconfiguration). After triggering the execution of conditional mobility, the UE applies the measurement gap configuration for the candidate cell based on the original / source measurement gap configuration. After successfully completing conditional mobility or triggering the execution of conditional mobility, the UE may then remove the measurement gap associated with conditional reconfiguration.

[0228] Mobility interactions in idle / inactive states

[0229] When the UE enters the RRC_INACTIVE / IDLE (RRC_inactive / idle) state, there are several alternative embodiments for processing L1 / L2 mobility configuration (e.g., candidate cell configuration). In a first embodiment, when the UE enters the RRC_INACTIVE / IDLE state, the NW explicitly indicates via RRC signaling whether to store / maintain / retain or remove the candidate cell configuration (e.g., including an indicator in the RRCRelease message). The UE stores / maintains / retains or removes the stored candidate cell configuration based on explicit indication after entering the RRC_INACTIVE / IDLE state. In a second embodiment, when the UE enters the RRC_INACTIVE / IDLE state, the NW explicitly indicates via RRC signaling which candidate cell configuration can be stored / maintained / retained or removed (e.g., including a list of maintained cell IDs or a list of removed cell IDs in the RRCRelease message). The UE stores / maintains / retains or removes the indicated candidate cell configuration based on explicit indication after entering the RRC_INACTIVE / IDLE state. In a third embodiment, the UE autonomously removes the stored candidate cell configuration after entering the RRC_INACTIVE / IDLE state (eg, when receiving a RRCRelease message including / not including suspendConfig). In a fourth embodiment, the UE maintains the stored candidate cell configuration after entering the RRC_INACTIVE / IDLE state.

[0230] If the L1 / L2 mobility configuration is maintained during the RRC_INACTIVE state, there are several alternative embodiments for processing the stored configuration after the RRC connection is restored (e.g., a transition from the RRC_INACTIVE state to the RRC_CONNECTED state). In a first embodiment, the NW explicitly instructs the UE to restore / activate one or more candidate cells via RRC signaling (e.g., one or more candidate cell IDs to be restored / activated are included in the RRRCResume message). The UE restores / activates the indicated (multiple) candidate cells based on the explicit indication after receiving the RRC signaling. In a second embodiment, the NW explicitly instructs the UE to restore one or more candidate cell configurations, which can serve as a baseline for subsequent incremental configurations for adding / modifying serving cells (e.g., one or more candidate cell IDs to be restored are included in the RRRCResume message), and may also include incremental configurations based on the cell configuration indicated via RRC signaling. The UE restores the indicated (multiple) candidate cell configurations based on the explicit indication after receiving the RRC signaling. The UE may apply the received incremental configuration based on the indicated cell configuration (if any).

[0231] Multi-connectivity

[0232] The L1 / L2-based inter-cell mobility mechanism can also be used in a multi-connectivity architecture (i.e., the multi-cell group configuration can be pre-configured by the NW). Multi-connectivity can be referred to as multi-radio dual connectivity (MR-DC). The embodiments discussed throughout the text can be applied to any multi-connectivity / MR-DC environment or architecture, where the "candidate cell" can be referred to as a "candidate cell group" (e.g., MCG, SCG) for multi-connectivity / MR-DC. Dynamic cell group activation / switching can be triggered by the NW via RRC signaling (e.g., RRC reconfiguration message) or L1 / L2 commands (e.g., DCI, MAC CE). The UE can also trigger cell group activation / switching based on pre-configured execution conditions and candidate cell group configurations. Applying the embodiments to multi-connectivity / MR-DC may include selective activation / switching, where the "candidate cell" can be referred to as a "candidate cell group" (e.g., MCG, SCG) for multi-connectivity / MR-DC.

[0233] The above systems and processes may be encoded in a signal bearing medium, a computer readable medium such as a memory, programmed in a device such as one or more integrated circuits, one or more processors, or processed by a controller or computer. The data may be analyzed in a computer system and used to generate a spectrum. If the method is performed by software, the software may reside in a memory, a synchronizer, a communication interface, or a non-volatile or volatile memory that is resident in or interfaced to a storage device, or communicates with a transmitter. The circuit or electronic device is designed to send data to another location. The memory may include an ordered list of executable instructions for implementing a logical function. The described logical function or any system element may be implemented by an optical circuit, a digital circuit, by source code, by an analog circuit, by an analog source such as an analog electrical signal, an audio signal, or a video signal, or a combination thereof. The software may be embodied in any computer readable or signal bearing medium for use by or in conjunction with an instruction executable system, device, or device. Such a system may include a computer-based system, a system containing a processor, or another system that can selectively obtain instructions from an instruction executable system, device, or device that can also execute instructions.

[0234] "Computer readable medium", "machine readable medium", "propagated signal" medium and / or "signal bearing medium" may include any device that includes storage, communication, propagation or transmission of software for use by or in conjunction with a computer executable system, device or apparatus. Machine readable medium may selectively be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, apparatus, device or propagation medium. A non-exhaustive list of examples of machine readable medium would include: an electrically connected "electronic device" having one or more wires, a portable magnetic or optical disk, a volatile memory such as a random access memory "RAM", a read-only memory "ROM", an erasable programmable read-only memory (EPROM or flash memory), or an optical fiber. Machine readable medium may also include a tangible medium on which the software is printed, as the software may be stored electronically as an image or in another format (e.g., by optical scanning) and then compiled and / or interpreted or otherwise processed. The processed medium may then be stored in a computer and / or machine memory.

[0235] The illustrations of the embodiments described herein are intended to provide a general understanding of the structures of the various embodiments. The illustrations are not intended to be used as a complete description of all elements and features of the devices and systems utilizing the structures or methods described herein. After reading this disclosure, many other embodiments will be apparent to those skilled in the art. Other embodiments may be utilized and derived from this disclosure, so that structural and logical replacements and changes may be made without departing from the scope of this disclosure. In addition, the illustrations are merely representative and may not be drawn to scale. Certain proportions in the illustrations may be exaggerated, while other proportions may be minimized. Therefore, this disclosure and the accompanying drawings should be considered illustrative rather than restrictive.

[0236] One or more embodiments of the present disclosure may be referred to herein individually and / or collectively by the term "invention", which is merely for convenience and is not intended to limit the scope of the present application to any particular invention or inventive concept. In addition, although specific embodiments have been illustrated and described herein, it should be understood that any subsequent arrangements designed to achieve the same or similar purposes may replace the specific embodiments shown. The present disclosure is intended to cover any and all subsequent modifications or variations of the various embodiments. Those skilled in the art will understand the combination of the above-mentioned embodiments and other embodiments not specifically described herein after reading the description.

[0237] The phrase "coupled to" is defined to mean directly connected or indirectly connected through one or more intermediate components. Such intermediate components may include hardware and software based components. The arrangement and type of components may be changed without departing from the spirit or scope of the claims set forth herein. More, different or fewer components may be provided.

[0238] The above disclosed subject matter is considered to be illustrative rather than restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments that fall within the true spirit and scope of the present invention. Therefore, to the maximum extent permitted by law, the scope of the present invention is determined by the most widely permitted interpretation of the appended claims and their equivalents, and should not be restricted or limited by the foregoing detailed description. Although various embodiments of the present invention have been described, it is apparent to those of ordinary skill in the art that more embodiments and implementations within the scope of the present invention are possible. Therefore, the present invention is not limited except according to the appended claims and their equivalents.

Claims

1. A method for wireless communication, comprising: Receiving, by a user equipment UE, a configuration message from a base station, the configuration message including a list of candidate cells, each candidate cell in the list of candidate cells having a configuration and a candidate cell configuration index corresponding to the configuration; sending a measurement report to the base station, the measurement report comprising layer 1 L1 measurement for at least one candidate cell in the list of candidate cells; receiving a media access control (MAC) control element (CE) command from the base station, wherein the MAC CE command includes a candidate cell configuration index of a target cell in the list of candidate cells and a transmission configuration indicator (TCI) state of the target cell; as well as Based on the MAC CE command and the configuration of the target cell, a communication is sent to the target cell.

2. The method according to claim 1, wherein the MAC CE command further includes at least one of the following: a timing advance TA value or a synchronization signal block SSB identifier ID related to the target cell.

3. The method according to claim 1, wherein the configuration message includes at least one of the following: a physical cell identifier PCI, a reference signal RS ID related to a candidate cell, or a TCI state ID related to the candidate cell.

4. The method according to claim 1, further comprising at least one of the following: Applying the stored cell configuration of the target cell; performing mobility from a current serving cell to the target cell; or After the inter-cell mobility based on layer 1 L1 / layer 2 L2 is triggered, a timer for the mobility is started, wherein the timer is a radio resource control RRC layer timer T304. 5 . The method according to claim 4 , wherein the timer is stopped in a case where the L1 / L2 based inter-cell mobility is notified as being completed successfully.

6. The method according to claim 4, further comprising at least one of the following: determining a failure for the mobility based on expiration of the timer; or Another cell among the candidate cells is selected to perform mobility to the selected another cell.

7. The method according to claim 1, further comprising: Upon entering the IDLE state or upon receiving an RRC release message including an indication to suspend the RRC connection, the stored candidate cell configuration is removed.

8. A method for wireless communication, comprising: A base station sends a configuration message to a user equipment UE, where the configuration message includes a list of candidate cells, each candidate cell in the list of candidate cells has a configuration and a candidate cell configuration index corresponding to the configuration; receiving a measurement report from the UE, the measurement report comprising layer 1 L1 measurements for at least one candidate cell in the list of candidate cells; Sending a media access control (MAC) control unit (CE) command to the UE, where the MAC CE command includes a candidate cell configuration index of a target cell in the list of candidate cells and a transmission configuration indicator (TCI) state of the target cell; as well as Communications are received at the target cell based on the MAC CE command and the configuration of the target cell.

9. The method according to claim 8, wherein the MAC CE command further includes at least one of the following: a timing advance TA value or a synchronization signal block SSB identifier ID related to the target cell.

10. The method according to claim 8, wherein the configuration message comprises at least one of the following: a physical cell identity (PCI), a reference signal (RS) ID related to a candidate cell, or a TCI state ID related to the candidate cell.

11. A first wireless communication device, comprising a processor and a memory, wherein the processor is configured to read a code from the memory and implement: receiving a configuration message from a base station, the configuration message including a list of candidate cells, each candidate cell in the list of candidate cells having a configuration and a candidate cell configuration index corresponding to the configuration; sending a measurement report to the base station, the measurement report comprising layer 1 L1 measurement for at least one candidate cell in the list of candidate cells; receiving a media access control (MAC) control element (CE) command from the base station, wherein the MAC CE command includes a candidate cell configuration index of a target cell in the list of candidate cells and a transmission configuration indicator (TCI) state of the target cell; as well as Based on the MAC CE command and the configuration of the target cell, a communication is sent to the target cell.

12. The first wireless communication device according to claim 11, wherein the MAC CE command further includes at least one of the following: a timing advance TA value or a synchronization signal block SSB identifier ID related to the target cell.

13. The first wireless communication device according to claim 11, wherein the configuration message comprises at least one of the following: a physical cell identifier (PCI), a reference signal (RSID) related to a candidate cell, or a transmission configuration indicator (TCI) state ID related to the candidate cell.

14. The first wireless communication device according to claim 11, further comprising at least one of the following: Applying the stored cell configuration of the target cell; performing mobility from a current serving cell to the target cell; or After the inter-cell mobility based on layer 1 L1 / layer 2 L2 is triggered, a timer for the mobility is started, wherein the timer is a radio resource control RRC layer timer T304. 15 . The first wireless communication apparatus according to claim 14 , wherein the timer is stopped in a case where the L1 / L2-based inter-cell mobility is notified as being successfully completed.

16. The first wireless communication device according to claim 14, further comprising at least one of the following: determining a failure for the mobility based on expiration of the timer; or Another cell among the candidate cells is selected to perform mobility to the selected another cell.

17. The first wireless communication device according to claim 11, further comprising: Upon entering the IDLE state or upon receiving an RRC release message including an indication to suspend the RRC connection, the stored candidate cell configuration is removed.

18. A second wireless communication device, the second wireless communication device comprising a processor and a memory, wherein the processor is configured to read a code from the memory and implement: Sending a configuration message to a user equipment UE, the configuration message including a list of candidate cells, each candidate cell in the list of candidate cells having a configuration and a candidate cell configuration index corresponding to the configuration; receiving a measurement report from the UE, the measurement report comprising layer 1 L1 measurements for at least one candidate cell in the list of candidate cells; Sending a media access control (MAC) control unit (CE) command to the UE, where the MAC CE command includes the candidate cell configuration index of the target cell in the list of candidate cells and a transmission configuration indicator (TCI) state of the target cell; as well as Communications are received at the target cell based on the MAC CE command and the configuration of the target cell.

19. The second wireless communication device according to claim 18, wherein the MAC CE command further includes at least one of the following: a timing advance TA value or a synchronization signal block SSB identifier ID related to the target cell.

20. The second wireless communication device according to claim 18, wherein the configuration message comprises at least one of the following: a physical cell identifier (PCI), a reference signal (RSID) related to a candidate cell, or a TCI state ID related to the candidate cell.

21. A computer program product comprising computer readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the method according to any one of claims 1 to 7 or claims 8 to 10.

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