Inter-cell mobility triggered by the network

Abstract

In wireless communications, for inter-cell mobility, a device can change, add, or switch between cells accessed by the network. This can include layer 1 and / or layer 2 (L1 / L2) signaling for user equipment (UE) moving between cells in the network. This signaling can reduce mobility interruption time and improve the robustness of handovers. 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 centralized units (CU) and distributed units (DU). These processes can reduce interruption time and improve reliability.

Description

[0001] This application is a divisional application of the invention patent application with the application date of January 21, 2022, application number 202280089631.8, and invention name “Inter-cell mobility triggered by 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 technologies are driving the world toward an increasingly interconnected and networked society. Wireless communications rely on efficient network resource management and allocation between user mobile stations and radio access network nodes (including but not limited to wireless base stations). Next-generation networks are expected to provide high-speed, low-latency, and ultra-reliable communication capabilities, meeting the needs of diverse industries and users. User mobile stations, or user equipment (UE), are becoming increasingly complex and the amount of data they transmit is increasing. To improve communications, meet the reliability requirements of vertical industries, and support next-generation network services, communication advancements 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 for user equipment (UE) moving between cells in a network. This signaling can reduce mobility interruption time and improve handover robustness. 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 including a plurality of candidate cells, the plurality of candidate cells having a configuration and cell identification ("ID") information for each candidate cell; sending a 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 a configuration message and command 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 acknowledgement ("ACK") signaling, and further, wherein the L2 signaling includes a media access control element ("MAC CE"). The command includes cell ID information of the identified candidate cell, wherein 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 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 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 desynchronization 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 to indicate whether to skip the RACH process for the identified candidate cell, an indication to indicate whether the UE maintains connection with the current serving cell; an indication to indicate whether the identified candidate cell is activated as a special cell ("SpCell"); an indication to indicate whether to activate PDCP replication after accessing the identified candidate cell.

[0007] The method also includes: activating the stored cell configuration of the identified candidate cell; applying the stored cell configuration of the identified candidate cell; or performing mobility 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 communication to the identified candidate cell, failure of the current serving cell, or information from an upper layer indicating the stopping 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 the 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 the failure of activation or mobility; or selecting another cell among the candidate cells to perform another activation on 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; and removing the stored candidate cell configuration based on the receipt of the message. The method also includes: receiving a message from the 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 the suspension of 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. The candidate cells refer to a candidate cell group, wherein the candidate cell group (cell group) 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 including a plurality of candidate cells, the plurality of candidate cells having a configuration and cell identification ("ID") information for each candidate cell; receiving a 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 configuration message and the command are sent 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 downlink control information ("DCI"), uplink control information ("UCI"), and physical layer acknowledgement ("ACK") signaling, and wherein the L2 signaling includes a media access control element ("MAC CE"). The command includes cell ID information of the identified candidate cell, where 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 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"), where the identification is based on a separate list. The candidate cells include a list, where each cell can be configured as a special cell ("SpCell") or a secondary cell ("SCell"). The candidate cells include a list, where 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 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 the suspension of 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 configurations, 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 at least one identified 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 at least one identified 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"), and physical layer acknowledgement ("ACK") signaling, wherein the L2 signaling includes a media access control element ("MAC CE"). The evaluation includes comparing measurement results of the candidate cells with the execution conditions, wherein the at least one identified 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 the identified at least one 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 identity ("PCI"), a PCI and frequency, a reference signal ("RS") ID related to the candidate cell, or a transmission configuration indication ("TCI") state ID related to the candidate cell. Sending a communication to the identified at least one candidate cell is based on a condition that includes at least one of an out-of-sync indication from a serving cell or a special cell ("SpCell"), or a failure of the 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"), where the identification is based on the separate list. The candidate cells include a list where each candidate cell can be configured as a special cell ("SpCell") or a secondary cell ("SCell"). The candidate cells include a list where 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 the stored cell configuration of the at least one identified candidate cell; applying the stored cell configuration of the at least one identified candidate cell; or performing mobility from the current serving cell to the 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 the following: successful transmission of communication to the at least one identified candidate cell, failure of the current serving cell, or information from an upper layer indicating the stopping of the timer. The method also includes determining the failure of activation or mobility based on the expiration of the timer. The method also includes reporting the failure of activation or mobility to the base station, wherein the failure is reported via MAC CE or RRC signaling; notifying the upper layer of the failure of activation or mobility; or selecting another cell among the stored candidate cells to perform another activation on 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"), a 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; and removing a stored candidate cell configuration based on receiving the message. The method also includes: receiving a message from the 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 cells 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 the suspension of 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, the candidate cell group being 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 including a plurality of candidate cells having configurations, cell identification ("ID") information, and one or more execution conditions; and receiving a communication at an identified candidate cell among the candidate cells, the identified candidate cell being identified based on an evaluation of the candidate cells and their configurations. The configuration message is sent 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 downlink control information ("DCI"), uplink control information ("UCI"), and 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 conditional, the condition including at least one of: the identified candidate cell satisfying a triggering condition, an event triggered by an out-of-sync indication from a serving cell or 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 identity ("PCI"), a PCI and 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 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 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 the suspension of 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. 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").

[0014] In another embodiment, a wireless communication method includes: sending a request message including a plurality of 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 configured candidate cells. The request message includes at least one of the following: an indication that the procedure is initiated for L1 / L2 mobility, or an indication that the procedure is initiated for a type of L1 / L2 mobility. The type of L1 / L2 mobility includes at least one of network ("NW") triggered mobility, CU triggered mobility, DU triggered mobility, or user equipment ("UE") triggered mobility.

[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 a 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 the CU, at least one of the candidate cells from the DU 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 further wherein the UE is utilized to transmit the 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, at a distributed unit ("DU"), a request message including a plurality of candidate cells from a centralized unit ("CU"), requesting 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: an indication that the procedure is initiated for L1 / L2 mobility, or an indication that the procedure is initiated for a type of L1 / L2 mobility. The type of L1 / L2 mobility includes at least one of network ("NW") triggered mobility, CU triggered mobility, DU triggered mobility, or user equipment ("UE") triggered mobility.

[0018] The method also includes receiving one or more triggering events from the CU at the DU, through which the DU can trigger L1 / L2 mobility. The method also includes sending one or more triggering 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 a 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 an acknowledgment of the configuration message from the UE at the DU; and sending an acknowledgment of the configuration message from the DU to the CU. The method also includes receiving at least one 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 has 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 has 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 sending 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 wherein the L1 / L2 signaling is transmitted using the UE. 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 including a plurality of candidate cells and a configuration for each candidate cell and a measurement configuration for at least one candidate cell; and performing measurements on the at least one candidate cell based on the measurement configuration. The method also includes: receiving a command identifying at least one of the candidate cells based on the measurements; 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 an execution condition and the configuration of the identified candidate cell; wherein the execution condition is included in the configuration message for each candidate cell. Performing the measurements, evaluating the measurements, or triggering the L1 / L2 mobility is performed at a device ("UE"), and 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 L1 reference signal received power ("RSRP") measurement of the serving cell to control 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, performing L1 measurement for the candidate cell or neighboring cell by the UE.

[0021] The L1 measurement configuration includes a reporting configuration for triggering a measurement report based on an L1 measurement for a candidate cell or a neighboring cell, wherein the reporting configuration includes a reporting configuration identifier and a measurement report type. The measurement report type includes a type of report triggered based on a measurement reporting event, wherein the measurement reporting 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 measurements for at least one of the neighboring cell or the candidate cell meet at least one of the measurement reporting events. The method also includes receiving a second command that identifies at least one of at least one cell identifier or at least one RS resource identifier of the candidate cell or the neighboring cell. The method also includes: performing measurements based on the identified RS resource identifier or cell identifier of the candidate cell or the neighboring cell; or reporting measurements based on the identified RS resource identifier or 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 medium 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 the 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: transmitting a configuration message including a plurality of 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 the at least one candidate cell, the measurement report being based on the measurement configuration. The method also includes transmitting a command identifying 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 configuration message and command are transmitted 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 candidate cells or neighboring cells are configured within the RS resource set for the current serving cell or through a separate structure that lists the RS resources for candidate cells or neighboring cells. 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 reporting configuration for triggering a measurement report based on the L1 measurement for the candidate cell or neighboring cell. The reporting configuration includes a reporting 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 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, 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 the 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 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-described embodiments.

[0026] In some embodiments, there is a wireless communication device comprising 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 comprises a computer-readable program medium with 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 An embodiment of user equipment (UE) intra-CU and inter-DU mobility is 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] Figure 9 An embodiment of intra-DU mobility based on CU-initiated candidate cell preparation is shown.

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

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

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

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

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

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

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

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

[0044] Figure 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 hereinafter with reference to the accompanying drawings, which form a part hereof and show by way of illustration specific examples of embodiments. However, it should be 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 of the embodiments set forth below.

[0046] Throughout the specification and claims, terms may have nuanced meanings that are suggested or implied by the context beyond their explicitly stated meanings. 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 based on their 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. Typically, "or", if used to associate a list such as A, B or C, is intended to mean A, B and C (used here with an inclusive meaning) as well as A, B or C (used here 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 plural usage, depending at least in part on the context. In addition, the terms "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 for the presence of additional factors that are not necessarily explicitly described, also depending 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 may send data via a random access channel ("RACH") protocol scheme or a configured grant ("CG") scheme. The CG may be used to reduce the waste of periodically allocated resources by enabling multiple devices to share periodic resources. A base station or node may 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 possible. The wireless communication described herein may be via radio access.

[0049] As follows about Figures 1-6 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 the 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 Medium 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 handover or change / add operations may occur to improve network reliability for the UE as it moves. The movement may be from a source cell to a target cell based on a number of potential target cells, referred to as candidates. Movement between cells may also include a number of 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 can evaluate the execution condition(s) after receiving the CHO configuration and stop evaluating the execution condition(s) once the handover is triggered. The CHO configuration can 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 with 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. This consideration may be based on (multiple) configured conditions. A UE 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. Whereas, in the example of MR-DC, one node may provide New Radio ("NR") access while the other 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 1. The base station 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 an optical or wired interconnect, 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 the random access messaging environment, a UE 104 can 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, for example, via a system bus 210.

[0057] The mobile device 200 includes a communication interface 212, 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, using one or more system-on-chips (SoCs), 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 via 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 handles the transmission of signals via one or more antennas 232.

[0060] The communication interface 212 may include one or more transceivers. A transceiver may be a wireless transceiver that includes modulation / demodulation circuitry, a digital-to-analog converter (DAC), a shaping table, an analog-to-digital converter (ADC), filters, a waveform shaper, filters, a preamplifier, a power amplifier, 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 codings. 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, the IEEE, or other partners or standards bodies.

[0062] Multiple RAN nodes (e.g., eNBs, gNBs) of the same or different radio access technologies ("RATs") may be deployed in the same or different frequency carriers in certain geographic areas, and they may interoperate 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 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 The diagram shows a base station (labeled "gNB") communicating with the entire network (labeled "5GC"). The base stations can communicate with each other via a control plane interface ("Xn-C"). A base station is shown with one CU connected to two DUs via an F1 interface. This is just one example of a base station arrangement; in some embodiments, there can 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 the protocol stack (such as SDAP, PDCP, and RRC), while a DU can 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 of user data, mobility control, radio access network sharing, session management, etc. DU(s) are logical nodes with a subset of base station functionality and can be controlled by a CU.

[0065] The CU can be a logical node for the RRC, SDAP, and PDCP protocols of a hosting base station or the RRC and PDCP protocols of a 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 a 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 by only 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 within a 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, where the UE changes cells within a single DU. Examples of intra-DU mobility include: 1) PCell change within one DU (which may also include PCell change and SCell change); 2) PSCell change within one DU (which may also include PSCell change and SCell change); 3) PCell change within one DU and PSCell change within one DU (which may also include SCell change within a cell group). In another L1 / L2 mobility embodiment, there may be intra-CU and inter-DU mobility, where the UE changes cells between different DUs but within a single CU. Examples of intra-CU and inter-DU mobility include: 1) PCell change across DUs but within one CU (which may also include PCell change and SCell change); 2) PSCell change across DUs but within one CU (which may also include PSCell change and SCell change). In another mobility embodiment, there may be inter-CU mobility, where 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 this 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 , with a UE trajectory from cell 1 to cell 2. Mobility from a cell may occur when UE 402 is located between two cells and is making its way to a third location 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 The depicted example has a UE trajectory from cell 1 to cell 2, which also results in a transfer from DU_1 to DU_2. From-cell mobility can occur when UE 402 is located between two cells and is making its way to a third location within cell 2. This is intra-CU mobility, as the UE is moving cells within a single CU. However, this is also inter-DU mobility, as the UE is moving between different DUs.

[0070] Figure 6 An embodiment of user equipment (UE) inter-CU mobility 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 one 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 goes 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. As the UE moves, the mobility may change cells as shown and may transfer between several cells. Because UE 602 (at inter-CU position 604) switches cells from CU_1 to CU_2, the transfer is called inter-CU mobility.

[0071] Network-triggered L1 / L2 mobility

[0072] Inter-cell mobility can be triggered by the network (e.g., base station) or the UE. As mentioned, L1 / L2 signaling is used to improve inter-cell mobility. The examples described throughout can be triggered by the network or by the UE, and Figure 7-Figure 8 The embodiments shown in can be applied 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., an RRCReconfiguration message). The candidate cell configuration may include multiple candidates that act as target cells. Further embodiments and examples regarding the candidate list and what the configuration may include are described below. In box 704, the UE responds to the RRC message with an acknowledgment / completion message to the network at the source cell. In one embodiment, the message may be an 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 regarding 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 measurements in box 708. The candidate cells to be activated may also be referred to as identified cells or identified candidate cells. 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 via L1 / L2 signaling. As described, using L1 / L2 signaling for cell mobility can provide several advantages. In some embodiments, configuration details of neighbor / candidate cells (including the target cell) can be provided for identifying or determining the target cell. In box 714, this 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 can be triggered by the network (e.g., base station) or the UE. As mentioned, L1 / L2 signaling is used to improve inter-cell mobility. The examples described throughout can be triggered by the network or by the UE, and Figure 7-Figure 8 The embodiments shown in can be applied 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, a source cell and a 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 triggering conditions used by the UE to trigger mobility based also on the configuration for the candidate cells. Additional embodiments and examples regarding candidate lists, configurations and triggering conditions are described below. In box 804, the UE responds to the RRC message with an acknowledgment / completion message to the network at the source cell. In one embodiment, the message may be an RRC reconfiguration complete.

[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 meets 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 via L1 / L2 signaling. As described, using L1 / L2 signaling for cell mobility can provide several advantages. In some embodiments, configuration details of neighbor / candidate cells (including the target cell) may be provided for identifying or determining the target cell. In box 810, this information can 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 for identifying 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 (IEs): 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., such as a solution based on CHO / HO). 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., such as a solution based on cell activation / deactivation).

[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 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 PCI) and configured as part of the current serving cell configuration.

[0083] The stored candidate cells may be activated as either SpCells or SCells. In some embodiments, a cell may be activated as both. Examples of activation as either 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 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., values ​​0 to X are assigned to candidate SCells, while values ​​X+1 to N are assigned 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, an SpCell-specific configuration (e.g., SpCellConfig, reconfigurationWithSync, PUCCH-Config) may be present in the candidate cell configuration, which may be used to distinguish whether the candidate cell can be activated as an SpCell or an SCell. For example, if the candidate cell configuration includes an 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 that includes (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). It may depend on the network ("NW") to determine how a candidate cell is used as a SpCell or a SCell.

[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 in several different ways. 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 for indicating which candidate cells can be activated simultaneously (e.g., a bitmap of N bits in size to indicate N candidate cells). 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 four candidate cells, with only 1+2+3, 1+3+4, and 1+2+4 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}, or {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 measurements

[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 the candidate cell or 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 (a measurement ID is a link between a measurement object / resource and a reporting configuration); 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 (e.g., L1 SSB RSRP threshold or L1 CSI-RS RSRP threshold) when the UE is required to perform L1 measurements on non-serving / candidate cells. When the serving cell deteriorates below 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 a 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., aperiodic, 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 cell (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 cell are activated, the UE may be required to perform L1 measurements on the RS resources related to the neighboring / candidate cell. When the RS resources related to the neighboring / candidate cell are deactivated, the UE is not required to perform L1 measurements on the RS resources related to the neighboring / candidate cell.

[0098] L1 measurement reporting 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 can 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 more easily triggered. 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) used for L3 / RRM measurements. Additional parameter values ​​may be configured for L1 measurements (e.g., additional gapOffset, mgl, mgrp, mgta, etc.). The offset value may be based on the parameter values ​​for L3 measurements (e.g., offset values ​​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 example embodiment, the triggering conditions are provided to the UE. The triggering conditions may also be referred to as execution conditions and establish conditions or thresholds by which mobility can be triggered. In one embodiment, the triggering conditions include a list of measurement identifiers (measIds), which may be linked to the L1 / L3 measurement objects / resources and reporting configurations described above. In another embodiment, the triggering conditions include 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) can 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, upon triggering L1 / L2-based mobility or upon successful completion of mobility, the UE automatically triggers a measurement configuration switch (e.g., measId associated with the measObjectId value corresponding to the source frequency is linked to the 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. Upon 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 can 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 / handed over 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: Signaling structure for incremental configuration including frequency / MO basis offset values.

[0115] In Table 3, the measurement information for incremental configuration includes a list of candidate cell IDs and a list of associated 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 of which is linked to a set of candidate cells, such as the candidate cell list within GapConfig. In another embodiment of providing measurement gap configuration updates, there may be a list of candidate cells, each of which is 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., a source measurement gap configuration), with the list of updated measurement configurations being delta configurations 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., L1 / L2 command) in box 710 to instruct the UE to select the indicated cell to perform inter-cell mobility. Another example of triggering L1 / L3 measurement reporting is described below. After the conditions / events of the configured reporting type are met (e.g., aperiodic, semi-persistent, periodic, or event-triggered), the UE can trigger L1 / L3 measurement reporting. For the aperiodic type, after receiving a DCI trigger for an L1 measurement report request, the UE should send an aperiodic L1 measurement report (e.g., 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., 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., a CSI report) on the PUCCH. For the periodic type, the UE shall send a periodic L1 measurement report (e.g., a 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 meet 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 lower layers (i.e., detection of a physical layer problem). 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 reporting) or via MAC CE. The measurement report may include at least one of the following: L1 SSB RSRP, L1 SSB RSRQ, L1 SSB SINR, L1 CSI-RS RSRP, L1 CSI-RS RSRQ, and L1 CSI-RS SINR for neighboring / candidate cells and / or 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 physical layer DCI, MAC CE, or 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 cell(s):

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

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

[0124] PCI or PCI+ frequency;

[0125] A reference signal (RS) ID associated with the candidate cell, e.g., an RS ID linked to the candidate cell (e.g., via a physical cell ID (PCI)) that 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), or a tracking / temporary reference signal (TRS);

[0126] The Transmission Configuration Indication (TCI) state ID associated with the candidate cell (e.g., the TCI state linked to the candidate cell via the 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] The 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 BWPIDs 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 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 indicating 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 can 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 can be triggered when at least one of the following conditions is met:

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

[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 are detected from lower layers for the SpCell / serving cell (i.e., a physical layer problem is detected); or

[0143] ●After 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 or a compensated TA value based on the current TA value for the indicated / selected candidate / target cell(s);

[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 instructed 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] • Detaching from the source / current SpCell / serving cell, synchronizing and connecting 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 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 having the TCI state indicated in the received L1 / L2 triggering 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 having the TCI state indicated in the received L1 / L2 triggering 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 the activated / selected (multiple) candidate / target cell IDs or the 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., upon receiving an L1 / L2 command, or upon executing UE-triggered L1 / L2 mobility (i.e., upon applying a stored candidate cell configuration or upon 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 (e.g., 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 an L1 / L2 mobility failure. In another embodiment, when the timer is a MAC layer timer and the timer expires, the UE may notify the upper layer (e.g., the RRC layer) of the detection of the 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 from 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 the RRC reestablishment procedure. In another embodiment, when the timer is an RRC layer timer and the timer expires, the UE may report the 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 from 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 message, MCGFailureInformation message, or SCGFailureInformation message) or by defining a new RRC message. The failure report can 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 reporting 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., there is no serving cell 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 by only 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 example of intra-DU mobility is shown. Figure 5 An embodiment of intra-CU and inter-DU mobility is shown. Figure 6 In these examples, mobility can be triggered by the network, such as Figure 7 As shown in , or it can be triggered by user equipment (UE), 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 the recommended candidate cells and the CU determines the triggering event. In embodiment 2, the CU determines the recommended candidate cells and the DU determines the triggering event. In embodiment 3, the DU determines the recommended candidate cells and the DU determines the triggering event. In embodiment 4, the DU determines the recommended candidate cells and the CU determines the 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 the recommended candidate cells, the CU sends the recommended candidate cell list 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 procedure is for L1 / L2 mobility and / or an indication for indicating which type of L1 / L2 mobility the procedure is 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, no list of accepted or failed / rejected candidate cells is 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 triggering 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 triggering 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 proposed 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, no list of accepted or failed / rejected candidate cells is 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 the neighboring cell becomes better than a threshold (e.g., RSRP, RSRQ, or / and SINR value for an event like A4). In another example, when the L1 measurement of the neighboring cell becomes better than the L1 measurement of the SpCell / serving cell (e.g., an event like 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 like 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 like A5). In another alternative, the triggering event may include a list of (multiple) measIds that are linked to the L1 / L3 measurement objects / resources and reporting configuration.

[0181] In an embodiment where information (e.g., triggering event(s), indication for L1 / L2 mobility) is provided, the information may be forwarded to the CU or DU directly in an F1 message (e.g., UE Context Modification Request / Response, UE Context Modification Required / Confirm message). In another embodiment, the information (e.g., triggering 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] Figure 9 An embodiment of intra-DU mobility based on CU-initiated candidate cell preparation is shown. Figure 9Applicable to embodiment 1 and embodiment 2 from Table 5. 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 DU, while Figure 9 Intra-DU mobility based on CU-initiated candidate cell preparation is shown. In block 902, the CU determines suggested candidate cells (e.g., based on RRM measurements). The CU sends a list of suggested 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 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 of cells that have been successfully established) or a failed / rejected cell list (e.g., a list of 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 triggering events / conditions 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, the CU sends the generated triggering event to the DU in block 906. In alternative embodiments, blocks 906 and 912 may include a UE CONTEXT MODIFICATION REQUEST message and a UE CONTEXT MODIFICATION RESPONSE message.

[0185] Figure 10 An embodiment of intra-DU mobility based on DU-initiated candidate cell preparation is shown. Figure 10 Applicable to Examples 3 and 4 from Table 5. Figure 4 The diagram shows the mobility within DU, while Figure 10Intra-DU mobility based on DU-initiated candidate cell preparation is shown. In block 1002, the DU determines a recommended candidate cell (e.g., based on L1 measurements). 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 cell. 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 that includes a candidate cell configuration for each accepted cell and may also include the generated triggering 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 triggering 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., sending the generated RRC reconfiguration message to the DU via a DL RRC MESSAGE TRANSFER message), and the DU forwards the received RRC reconfiguration message to the UE.

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

[0189] In block 1102, the CU determines (e.g., based on RRM measurements) a list of 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 indicating that the procedure is for L1 / L2 mobility and / or an indication indicating which type of L1 / L2 mobility the procedure is for. Prior to block 1102, in some embodiments, the CU may send a UE Context Modify Request message to the source DU to query for the latest configuration. The source DU responds with a UE Context Modify Response message including complete configuration information.

[0190] In box 1104, the target 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 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 including successfully established cells) or a failed / rejected cell list (e.g., a list including 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 triggering 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 triggering 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., via a DL RRC message forwarding message). The RRC message includes the candidate cell configuration and may also include triggering events / conditions associated with the candidate cell(s) (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., via a UL RRC message forwarding 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 triggering events / execution conditions generated by the CU (e.g., for DU-triggered mobility).

[0192] Figure 12 An embodiment of inter-DU mobility based on DU-initiated candidate cell preparation is shown. Figure 12 Applicable to Examples 3 and 4 from Table 5. Figure 5 The diagram shows inter-DU mobility, and Figure 12 Inter-DU mobility based on DU-initiated candidate cell preparation is shown. In block 1202, the source DU determines candidate cells (e.g., based on L1 measurements). The DU sends a suggested candidate cell list and / or candidate DU ID(s) to the CU via an F1 message (e.g., a UE Context Modification Required message or other message) to request the establishment of 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.

[0193] In block 1204, the CU sends a suggested candidate cell list 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 a candidate cell. The message may also include an indication that the process is for L1 / L2 mobility, such as an "L1 / L2 mobility" indicator. In some embodiments, before block 1204, the CU may send a UE Context Modify Request message to the source DU to query the latest configuration, and the source DU responds with a UE Context Modify Response message including complete configuration information.

[0194] In box 1206, the target DU determines whether to establish the candidate cell as suggested 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 including successfully established cells) or a failed / rejected cell list (e.g., a list including 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 the (multiple) candidate cells (e.g., for UE triggered mobility). The F1 message may also include the 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 the CU then sends the generated RRC reconfiguration message to the source DU via an F1 message (e.g., a DL RRC message forwarding message).

[0196] Figures 9-12 can be considered as part of the candidate cell configuration initiation / preparation phase, while Figures 13-18It 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., successful completion of RA for the DU, or successful reception of L1 / L2 signaling from the UE at the 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 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).

[0198] Figure 13 An embodiment of intra-DU mobility based on CU triggering determination is shown. Figure 13 Applicable to Examples 1 and 4 from Table 5. Figure 4 The diagram shows the mobility within DU, while Figure 13Intra-DU mobility based on CU triggering 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 block 1308, after the CU determines the candidate cell(s) to be activated / handed over to, for example, based on L1 or / and L3 measurement reports or load balancing, the CU sends the candidate cell(s) to be activated / handed over to the DU via an F1 message (e.g., a UE Context Modification Request message or other message). In block 1310, the DU sends an L1 / L2 command to the UE to indicate the candidate cell(s) to be activated / handed over. In block 1312, the UE activates / accesses the target cell (e.g., via a random access procedure) and sends L1 / L2 signaling to the DU in block 1314 (e.g., via ACK, UCI, MAC CE) to complete the L1 / L2 mobility procedure. In block 1316, the DU responds to the CU (e.g., via a UE Context Modification Response message or other message). The message may include the activation / target cell ID(s).

[0200] Figure 14 An embodiment of intra-DU mobility based on DU trigger determination is shown. Figure 14 Applicable to Examples 2 and 3 from Table 5. Figure 4 The diagram shows the mobility within DU, while Figure 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 measurements. In box 1406, after the DU determines (multiple) candidate cells to be activated / handed over to, the DU sends an L1 / L2 command to the UE to indicate the (multiple) candidate cells to be activated / handed over 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 may notify the CU of the (multiple) activated / target cells (e.g., via an ACCESS SUCCESS message).

[0201] Figure 15 An embodiment of intra-DU mobility based on UE-triggered determination is shown. Figure 4 The diagram shows the mobility within DU, while Figure 15Intra-DU mobility based on UE-triggered determination is shown. In box 1502, 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 1504, the UE activates / accesses the target cell (e.g., via a random access procedure) and sends L1 / L2 signaling to the DU in box 1506 (e.g., via ACK, UCI, MAC CE) to complete the L1 / L2 mobility procedure. 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] Figure 16 An embodiment of inter-DU mobility based on CU triggering determination is shown. Figure 16 Applicable to Examples 1 and 4 from Table 5. Figure 5 The diagram shows inter-DU mobility, and Figure 16 Inter-DU mobility determined based on CU triggering is shown. In box 1602, an L1 / L3 measurement report is provided from the UE to the source DU and forwarded to the CU in box 1604. In box 1606, the measurement report is used to determine candidate cells. Boxes 1602-1606 are discussed in other embodiments. In box 1608, the CU determines the candidate cell(s) to be activated / switched to (e.g., based on the L1 or / and L3 measurement report, or / and load conditions), and the CU sends the candidate cell(s) 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. Following block 1616, the target DU may send a downlink data delivery status frame in block 1618 to notify the CU. Downlink packets may include PDCP PDUs that were not successfully transmitted in the source DU and are 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 the activated / target cell(s).

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

[0204] Figure 18 An embodiment of inter-DU mobility based on UE-triggered determination is shown. Figure 5 The diagram shows inter-DU mobility, and Figure 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 meets the (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 procedure) and sends L1 / L2 signaling to the DU in box 1810 to complete the L1 / L2 mobility procedure. 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) activated / target cells.

[0205] In block 1812, the CU may also initiate a UE context modification procedure 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 the source DU to stop data transmission for the UE. In block 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 block 1822, the source DU responds to the CU with a UE context modification response message. In some embodiments, in block 1816, downlink user data is provided by the CU to the candidate DU, and then the downlink user data is provided to the UE in block 1818. In block 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 L1 / L2 mobility triggering (e.g., 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" set to "Stop / Pause") via an F1 message (e.g., a UE Context Modification Request message or other message) to instruct the DU to stop / suspend L1 / L2 mobility triggering. After / after receiving this indication, the DU should not send an L1 / L2 mobility trigger command to the UE. If the CU determines to resume / restart L1 / L2 mobility triggering (e.g., when L3 mobility is completed), the CU sends an indication (e.g., "L / L2 Mobility Trigger Indicator" 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 L1 / L2 mobility triggering. After / after receiving the indication, the DU may restart sending the L1 / L2 mobility triggering command to the UE, for example, when it is determined that the triggering event(s) are met.

[0208] For example, upon determining that a triggering event(s) have been met, the DU may request to restart / resume L1 / L2 mobility triggering. The DU sends an indication (e.g., an "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 L1 / L2 mobility triggering to be restarted. 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 Confirm or a UE Context Modification Reject (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] Mobile Interaction

[0210] In alternative embodiments, L1 / L2 mobility may interact with other functionalities such as handover (HO), conditional handover (CHO), conditional PSCell add / change (CPAC), dual active protocol stack (DAPS), or other functionalities. In one embodiment, the L1 / L2 mobility configuration may include those other functionalities. 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 such that the UE maintains a source cell connection when triggering L1 / L2 mobility to a target candidate cell.

[0211] In alternative embodiments, those other functions can be modified to include L1 / L2 mobility configuration. For example, legacy HO, legacy PSCell add / change, CHO, CPAC, DAPS, or HO configuration can 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) can be performed after the other functions are completed. Alternatively, L1 / L2 mobility and other functions can be configured independently for the UE.

[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., legacy HO, CHO, DAPS, etc.) and / or an L3 PSCell addition / change (e.g., legacy 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 the candidate PCell configuration, candidate PSCell configuration, candidate SpCell configuration, and / or candidate SCell configuration (e.g., "maintainCandidatePCell", "maintainCandidatePSCell", "maintainCandidateSpCell", "maintainCandidateSCell"). In another embodiment, the information may include an indication of which candidate cell 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 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 add / change / CHO / CPAC / DAPS HO configurations).

[0213] In an embodiment where the information is provided, the information may be forwarded to the target cell / node and included directly 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 message, a CG-Config message, or a CG-ConfigInfo message). The RRC message may be included as an information element in the Xn / X2 message.

[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 the other function (e.g., includes 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 the other function (e.g., includes 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 RA to the target cell, the UE autonomously removes the stored L1 / L2 mobility configuration.

[0215] In another embodiment in which 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 instruction from the target cell. The explicit instruction 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 instruction 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., L1 / L2 mobility triggered for the UE) may be processed after the execution of the other functions is triggered. For example, the UE automatically stops evaluating the execution condition (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 condition 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 condition for the candidate cell (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 an MCG, or only for L1 / L2 mobility candidate cells within an 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 add / 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 performed 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, receives an NW-triggered L1 / L2 command or triggers 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 being 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 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 may first perform one function according to the following alternative schemes regarding 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 an L1 / L2 mobility failure, the UE may continue with the conditional L3 mobility evaluation and select a conditional L3 mobility candidate cell to perform conditional L3 mobility when an execution condition (e.g., a conditional L3 mobility execution condition or an additional pre-configured threshold for failure recovery) is met. In one embodiment, after detecting an L1 / L2 mobility failure for a PCell change, the UE continues with the CHO evaluation and selects a CHO candidate cell to perform CHO when an execution condition (e.g., a CHO execution condition or an additional pre-configured threshold for failure recovery) is met. In one embodiment, after detecting an L1 / L2 mobility failure for a PSCell change, the UE continues with the CPAC evaluation and selects a CPAC candidate cell to perform CPAC when an execution condition (e.g., a CPAC execution condition or an additional pre-configured 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) can 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, a conditional reconfiguration-related measurement gap (e.g., conditionalReconfigurationGap) is introduced within the existing conditionalReconfiguration IE. The conditional reconfiguration-related measurement gap is only used by the UE during conditional mobility evaluation. During conditional mobility preparation, the source node (e.g., source SN, source MN) can 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 the candidate cell (i.e., the measurement gap configuration included in the candidate cell configuration) based on the original / source measurement gap configuration.

[0227] When a 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 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 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 the 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 the 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 (e.g., when receiving an RRCRelease message including / excluding 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., including one or more candidate cell IDs to be restored / activated in the RRCResume 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 configuration for adding / modifying serving cells (e.g., including one or more candidate cell IDs to be restored in the RRCResume message), and can 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] L1 / L2 based inter-cell mobility mechanisms may also be used in a multi-connectivity architecture (i.e., the multi-cell group configuration may be pre-configured by the NW). Multi-connectivity may be referred to as multi-radio dual connectivity (MR-DC). The embodiments discussed throughout may be applied to any multi-connectivity / MR-DC environment or architecture, where "candidate cells" may be referred to as "candidate cell groups" (e.g., MCG, SCG) for multi-connectivity / MR-DC. Dynamic cell group activation / switching may be triggered by the NW via RRC signaling (e.g., RRC reconfiguration message) or L1 / L2 commands (e.g., DCI, MAC CE). The UE may also trigger cell group activation / switching based on pre-configured execution conditions and candidate cell group configuration. Applying the embodiments to multi-connectivity / MR-DC may include selective activation / switching, where "candidate cells" may be referred to as "candidate cell groups" (e.g., MCG, SCG) for multi-connectivity / MR-DC.

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

[0234] "Computer-readable medium," "machine-readable medium," "propagation signal" medium, and / or "signal-bearing medium" may include any device that stores, communicates, propagates, or transmits software for use by or in connection with a computer-executable system, apparatus, or device. A machine-readable medium may optionally 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 media would include: an electrically connected "electronic device" having one or more wires, a portable magnetic or optical disk, a volatile memory such as random access memory "RAM," read-only memory "ROM," an erasable programmable read-only memory (EPROM or flash memory), or optical fiber. A 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 apparatus 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 and not 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 this 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. This disclosure is intended to cover any and all subsequent modifications or variations of the various embodiments. The combination of the above-mentioned embodiments and other embodiments not specifically described herein will be clear to those skilled in the art 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-based and software-based components. The arrangement and types 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 subject matter disclosed above is considered to be illustrative and not 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 invention. Therefore, to the maximum extent permitted by law, the scope of the present invention is determined by the broadest permissible 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 will be apparent to those skilled 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 in accordance with 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 including 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, where the MAC CE command includes a candidate cell configuration index of a target cell in the candidate cell list 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. The method according to claim 4 , wherein the timer is stopped if 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, where 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 element (CE) command to the UE, where the MAC CE command includes a candidate cell configuration index of a target cell in the candidate cell list 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 includes 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 including 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, where the MAC CE command includes a candidate cell configuration index of a target cell in the candidate cell list 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 if L1 / L2-based inter-cell mobility is notified as 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, 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), where the configuration message includes a list of candidate cells, where 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 element (CE) command to the UE, where the MAC CE command includes the candidate cell configuration index of the target cell in the candidate cell list 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 apparatus 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 apparatus 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.

Images