CN114641082A

CN114641082A - Cell change method and user equipment

Info

Publication number: CN114641082A
Application number: CN202011489877.3A
Authority: CN
Inventors: 常宁娟; 刘仁茂
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2022-06-17
Also published as: WO2022127731A1

Abstract

The invention provides a cell change method and user equipment. The cell change method includes: under the condition that a random access process is not triggered, User Equipment (UE) executes a primary cell PSCell change process for an auxiliary cell group (SCG); the UE applying the configuration in the RRC reconfiguration message for SCG; the UE sets the content in the RRC reconfiguration complete message as a response message and submits the RRC reconfiguration complete message to a lower layer for sending; and when the RRC reconfiguration completion message is submitted to a lower layer for transmission or the UE receives a confirmation instruction from a network side, the UE considers that the PSCell change is successfully completed and executes the UE operation after the PSCell change is completed.

Description

Cell change method and user equipment

Technical Field

The present disclosure relates to the field of wireless communication technologies, and in particular, to a method for cell change and a corresponding user equipment.

Background

The 3GPP RAN working group is currently conducting a release 17 research project (see 3GPP document RP-193249(New WID on flame enhancements on Multi-Radio Dual-Connectivity)). Among them, in order to further reduce the power consumption of the UE in the dual-connection DC case, one of the research objectives is to implement a dynamic Secondary Cell Group (SCG) activation/deactivation mechanism. In the SCG deactivated state, the UE may not need to perform downlink physical channel monitoring on the serving cell associated in the SCG, nor perform related link state detection or link state report, thereby achieving the purpose of power saving. In the current conclusion, the UE in SCG deactivation state can perform SCG related mobility, including performing Radio Resource Management (RRM) measurement for SCG mobility, and receiving and performing Radio Resource Control (RRC) reconfiguration message containing synchronous reconfiguration from the network side.

The present disclosure proposes a solution to the problem of how to perform SCG mobility with the introduction of SCG activation/deactivation mechanisms in NR systems.

Disclosure of Invention

An object of the disclosed embodiments is to propose a solution to the problem of how to perform SCG mobility, i.e. SCG change, under introduction of SCG activation/deactivation mechanism in NR systems. The embodiment of the disclosure provides a cell change method executed in user equipment and corresponding user equipment.

According to a first aspect of the present disclosure, a cell change method is provided, including: under the condition that a random access process is not triggered, User Equipment (UE) executes a primary cell PSCell change process for an auxiliary cell group (SCG); the UE applying the configuration in the RRC reconfiguration message for SCG; the UE sets the content in the RRC reconfiguration complete message as a response message and submits the RRC reconfiguration complete message to a lower layer for sending; and when the RRC reconfiguration complete message is delivered to a lower layer for transmission or the UE receives a confirmation instruction from a network side, the UE considers that the PSCell change is successfully completed and executes the UE operation after the PSCell change is completed.

In the cell change method of the first aspect, the RRC reconfiguration message may include a synchronization reconfiguration information element.

In the cell change method according to the first aspect, the UE may consider that the PSCell change is successfully completed when the RRC reconfiguration complete message is delivered to a lower layer and the SCG is in a deactivated state.

In the cell change method according to the first aspect, the acknowledgement indication may be used to inform the UE that the PSCell change is completed or inform the UE that the network side successfully receives the RRC reconfiguration complete message.

In the cell change method according to the first aspect, the UE may execute the PSCell change procedure when receiving an RRC message including a PSCell change command from a network side.

In the cell change method according to the first aspect, the UE operation may include at least one of: (1) stopping a T304 timer corresponding to the SCG; (2) stopping a timer T310 for radio link failure monitoring corresponding to the source PSCell; (3) applying a configuration that does not require the UE to know a System Frame Number (SFN) of a target PSCell; (4) after obtaining the SFN of the target PSCell, the UE needs to know the measurement and radio resource configuration part of the SFN of the target PSCell; (5) performing an operation related to removing the saved conditional reconfiguration if the UE is configured with a conditional reconfiguration for SCG; (6) if the UE sends UE auxiliary information RRC message UEAssistant information to the source SCG within the last 1 second and the UE is still configured in the target SCG to provide the related UE auxiliary information, initiating the sending of the UE auxiliary information RRC message of the cell group to provide the related UE auxiliary information to the target PSCell; (7) ending the RRC reconfiguration process.

Further, according to a second aspect of the present disclosure, there is provided a cell change method including: user Equipment (UE) executes condition primary and secondary cell PSCell change CPC evaluation, and confirms whether the execution condition corresponding to the stored CPC candidate cell is satisfied; the UE selects a target PSCell from the trigger cells meeting the execution condition; the UE performing CPC configuration of the target PSCell; and the UE sets the content of the RRC reconfiguration complete message as a response message, generates the RRC reconfiguration complete message, embeds the RRC reconfiguration complete message in an outer layer message and delivers the message to a bottom layer through SRB1 to send the message under the condition that the secondary cell group SCG is in a deactivated state.

In the cell change method of the second aspect, the outer layer message may be a ULInformationTransferMRDC message.

According to a third aspect of the present disclosure, there is provided a user equipment comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the cell change method as described above and below.

Drawings

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

fig. 1 is a flowchart showing an example of a cell change method according to the present invention.

Fig. 2 is a flowchart illustrating a cell change method according to an example of embodiment 3.

FIG. 3 is a block diagram illustrating a user equipment UE according to the present invention

In the drawings, the same or similar structures are identified by the same or similar reference numerals.

Detailed Description

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the disclosure.

In the present disclosure, the terms "include" and "contain," as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or.

In this specification, the various embodiments described below which are used to describe the principles of the present disclosure are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the present disclosure as defined by the claims and their equivalents. The following description includes numerous specific details to aid understanding, but such details are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Moreover, descriptions of well-known functions and constructions are omitted for clarity and conciseness. Moreover, throughout the drawings, the same reference numerals are used for similar functions and operations. Unless otherwise specified, the terms, definitions and methods may be used in common before the embodiments, and the embodiments may work in conjunction before the embodiments.

Hereinafter, a Long Term Evolution (LTE)/NR mobile communication system and its subsequent Evolution are taken as an example application environment, and a plurality of embodiments according to the present disclosure are specifically described. However, it is to be noted that the present disclosure is not limited to the following embodiments, but is applicable to more other wireless communication systems. Unless otherwise specified, the concepts of cell and base station may be interchanged in this disclosure; primary and Secondary Cell Group Cell/Primary and Secondary Cell (PSCell) change means that a PSCell of a UE is changed from a source PSCell to a target PSCell, where the source PSCell and the target PSCell may be the same Cell or different cells. The source PSCell may also be referred to as a source base station, a source beam (beam), a source Transmission point (TRP), and a source Slave Cell Group (SCG), and the target PSCell may also be referred to as a target base station, a target beam, a target Transmission point, and a target SCG. In the NR system, the PSCell change command is an RRC reconfiguration message including a synchronization reconfiguration (reconfiguration with sync) information element in the SCG configuration, which is also referred to as a synchronization reconfiguration of the SCG. In the LTE system, the RRC connection reconfiguration message refers to an RRC connection reconfiguration message in which the SCG configuration includes a mobile control information (mobility control infoscg) information element. Wherein the synchronization reconfiguration information element or the mobile control information element includes one or more configuration information of the target cell, such as a target cell identifier, a target cell frequency, a common configuration of the target cell, such as system information, a random access configuration used by the UE to access the target cell, a security parameter configuration of the UE in the target cell, a radio bearer configuration of the UE in the target cell, and the like. Cancellation, release, deletion, cleanup, and the like may be substituted. Execution, use, and application are alternatives. Configuration and reconfiguration may be alternative. Links and connections may be replaced. Monitoring (monitor) and detection (detect) may be replaced.

The following presents a simplified summary of the prior art to which embodiments of the present disclosure relate.

Dual Connectivity (DC):

in order to improve the data transmission efficiency of the UE, the UE establishes links with two base stations at the same time, that is, the radio resources used by the UE are provided by different schedulers located at the two base stations. The Radio Access between the two base stations and the UE may be of the same or different Standards (RATs), such as NR, or one NR, and one LTE is also called Evolved Universal Terrestrial Radio Access (E-UTRA). One of the two base stations is called a Master Node (MN) or MgNB, MeNB, and a Group of serving cells under the Master Node is called a Master Cell Group (MCG); the other is called a Secondary base Station (SN) or SgNB, SeNB, and the serving Cell Group under the Secondary base station is called a Secondary Cell Group (SCG). The MCG comprises a Primary Cell (PCeH) and optionally one or more Secondary cells (scells). The PCell works on the main frequency, and the UE executes an initial connection establishment process or a connection reestablishment process through the main frequency. The SCG contains one PSCell and optionally one or more scells. The PSCell refers to an SCG cell in which the UE performs random access when performing a synchronization reconfiguration procedure or an SCG addition procedure. PCell and PSCell are also collectively referred to as special cell SpCell. In the present disclosure, the SCG is exemplified by an SCG under dual-connection DC, but the SCG only under dual-connection DC is not limited, for example, more than two SCGs, that is, a plurality of SCGs in a case where a UE is connected to more than two base stations may be used, and in this case, the operation described in the embodiment is performed on a corresponding SCG.

PSCell change procedure in existing mechanisms

As mentioned above, taking NR system as an example, the PSCell change procedure is triggered by the RRC reconfiguration message for SCG containing a synchronization reconfiguration information element to be performed by the UE. The PSCell change procedure may be initiated by the MN or by the SN. When a Signaling Radio Bearer (SRB) 3 is configured, the SN may autonomously initiate a PSCell change process without participation of the MN, and at this time, the SN sends a PSCell change command for SCG to the UE on the SRB 3. Generally, PSCell changes initiated autonomously by SN of SRB3 are Intra-SN, i.e., PSCell changes within the same secondary base station. When SRB3 is not configured, PSCell change procedures, whether SN or MN initiated, send PSCell change commands to UEs, including intra-SN or inter-SN PSCell changes, on SRB 1. The RRC reconfiguration message for the PSCell change command of the SN is contained in an NR-SecondaryCellGroup config information element (when the E-UTRAN is MN) or an mrdc-SecondaryCellGroup information element (when the NR is MN) of its outer RRC message. The outer layer message is typically an RRC (connection) reconfiguration message or a dlinformation transfermrdc message. The UE receiving the PSCell change command executes the change process of the PSCell, starts a timer T304 for monitoring the process, starts downlink synchronization to the target PSCell, applies configuration of an RRC reconfiguration message containing the synchronous reconfiguration of the SCG, and sends an RRC reconfiguration completion message to the network side. According to the outer layer message of the received PSCell change command, the RRC reconfiguration complete message may also be embedded in an outer layer RRC message, such as an RRC (connection) reconfiguration complete message or a ULInformationTransferMRDC message. At the same time, the UE also triggers the MAC layer to perform a random access procedure to the target PSCell. When the MAC layer successfully completes the triggered random access procedure, the UE performs one or more of the following procedures: (1) stopping a T304 timer corresponding to the SCG; (2) stopping a timer T310 for radio link failure monitoring corresponding to the source PSCell; (3) applying the configuration of the system frame number SFN without the UE knowing the target PSCell, including Channel State Information (CSI) report configuration, scheduling request configuration, sounding reference signal configuration and the like; (4) after obtaining the SFN of the target PSCell, applying a part which needs the UE to know the SFN measurement and radio resource allocation of the target PSCell; (5) if the UE is configured with a Conditional reconfiguration (Conditional reconfiguration) (also called a Conditional PSCell Change (CPC) configuration) or a Conditional PSCell Add Change (CPAC) configuration) for the SCG, removing all the saved Conditional reconfigurations (all entries in the UE variable varconditional reconfiguration), and for each measurement identifier in the source PSCell configuration, removing, for each reporting type (reportType) of its associated reporting configuration (reportConfig) set to a Conditional trigger configuration (condterconfig), an entry corresponding to a reporting configuration identifier reportConfigId that matches the reporting configuration identifier from a reporting configuration list in the UE variable VarMeasConfig for saving the UE measurement configuration, for each reporting configuration identifier (reportConfigId); if the associated measurement object identifier measObjectId is associated with only one reporting configuration reportConfig whose reporting type reportType is set as condition trigger configuration condterconfig, removing the entry of the matched measurement object identifier measObjectId from the measurement object list measObjectList in the UE variable VarMeasConfig; the entry of the matching measurement identity measId is removed from the measurement identity list measIdList in the UE variable VarMeasConfig. (6) If the UE sent the UE assistance information RRC message ueassistance information for the source SCG within the last 1 second and the UE is still configured to provide relevant UE assistance information in the target SCG, then sending a UE assistance information RRC message for the cell group is initiated to provide relevant UE assistance information to the target PSCell. (7) The RRC reconfiguration procedure is ended.

Cell change procedure without random access in existing mechanisms

In the LTE system, in order to reduce the interruption caused by cell change, in some scenarios, for example, the fixed value of the timing advance of the source cell and the target cell to their group or target cell at the same time is always 0, and in the process of cell change, the network side may configure the UE not to perform the random access process. For SCG, the rach-skipccg information element is carried in the RRC message for PSCell change tells the UE that random access need not be performed. And the configuration lower layer applies the configuration of the rach-skip in the process of executing the PSCell change by the UE. Based on the configuration, the MAC layer applies the time advance TA configuration indicated in the configuration, and starts the corresponding time to timer TAT. And in the PSCell changing process, the UE generates an RRC connection reconfiguration completion message and feeds back the RRC connection reconfiguration completion message to the network side for responding to the RRC message of the PSCell changing command. Under the mechanism, the MAC layer of the UE monitors the PDCCH for the target PSCell, and when a UE contention resolution identity MAC Control element is received on a Physical Downlink Shared Channel (PDSCH) indicated by a Physical Downlink Control Channel (PDCCH) of the PSCell addressed by a Cell-Radio Network Temporary identity (C-RNTI), the MAC layer indicates to the RRC layer that the UE successfully receives a PDCCH transmission addressed by the C-RNTI. For the RRC layer, when the MAC layer indicates successful reception of a PDCCH transmission addressed with the C-RNTI when the rach-skiPSCG is configured, the UE performs the following operations: (1) stopping a T307 timer corresponding to the SCG; (2) releasing the rach-skipccg configuration; (3) applying the configuration of the system frame number SFN without the UE knowing the target PSCell, including Channel State Information (CSI) report configuration, scheduling request configuration, sounding reference signal configuration and the like; (4) after acquiring the SFN of the target PSCell, the measurement and radio resource configuration part that requires the UE to know the SFN of the target PSCell is applied.

Conditional reconfiguration for SCG

Condition-based cell change:

among the technical requirements of release 16, it is required to satisfy "0 ms" data interruption delay as much as possible in the cell change process, and to improve the robustness of the cell change to meet the mobility requirement of the seamless cell change in NR. In the current cell change process, one reason for causing the cell change failure and causing the interruption of data transmission for a long time is that the cell change command fails to be received due to untimely issuing of the cell change command. For the problem, a feasible method is to set a relatively conservative measurement report threshold in condition switching based on condition cell change (referred to as condition switching for short), so that the base station obtains the measurement result in advance, and performs cell change preparation in advance according to the measurement result and the selected target base station, so that the base station can issue a cell change command including a cell change candidate cell and a cell change execution condition to the UE in advance before the true cell change condition (corresponding to the conservative measurement report threshold) is met, wherein the cell change command carries the condition that the UE executes the cell change. Different from the existing cell change mechanism, after receiving the conditional cell change command, the UE does not immediately perform the cell change, but stores the received configuration of the cell change command, and starts to monitor the link quality of the source cell or the link quality of the target cell according to the cell change execution condition carried in the cell change command message to evaluate whether the cell change execution condition is satisfied. And only when the configured cell change execution condition is monitored to be met, the UE starts to execute the stored cell change command and accesses the target cell. In summary, a conditional cell change refers to a cell change procedure that is performed only when one or more configured cell change execution conditions are satisfied. For the cell change performing condition, for example, the cell change performing condition is a measurement event, such as the condition is a conditional reconfiguration measurement event a3 (neighbor cell signal quality is better than serving cell signal quality by an offset for a period of time). The neighboring cell corresponds to a target cell of cell change. The condition-based cell change may be applied to a PCell change, which may be referred to as a condition handover, or to a PSCell change, which may be referred to as a CPC. Since the cell change command is included in the RRC reconfiguration message, the conditional cell change CHO is also called a conditional reconfiguration (conditional reconfiguration). In the present disclosure, the conditional reconfiguration for SCG, and CPC/CPAC may be replaced.

The UE energy saving mechanism of cell granularity in the existing mechanism:

in the NR system of release 16, power consumption of the UE on one SCell may be reduced by a method of deactivating the SCell or changing a Bandwidth Part (BWP) in which the SCell operates to a dormant BWP, in consideration of a traffic change of the UE.

In the SCell activation and deactivation mechanism, one or more scells are activated or deactivated mainly through Medium Access Control (MAC) Control Element (CE) or Radio Resource Control (Radio Resource Control) signaling. In addition, when the SCell deactivation timer associated with the SCell operating on the UE times out or stops, the UE deactivates the corresponding SCell. When the UE receives activation and deactivation of the MAC CE by one SCell, if a bit corresponding to one SCell in the MAC CE is set to be 1 (namely, the SCell is indicated to be activated), the UE activates the SCell; if set to "0" (i.e., indicating activation of the SCell), the UE deactivates the SCell. In addition, if the information element (sCellState) of the SCell for indicating the SCell activation/deactivation status in the RRC message received by the UE is set to "activated". The UE activates the SCell; otherwise, if the sCellState of the SCell in the RRC message received by the UE is not set to activated or set to deactivated. The UE deactivates the SCell. When one SCell is in an active state, the UE performs normal operations on the SCell, including as follows: the SCell normally transmits Uplink and Downlink data, transmits a Sounding Reference Signal (SRS) on the SCell, reports a Channel State Indication (CSI) for the SCell, performs Physical Downlink Control Channel (PDCCH) monitoring on the SCell, performs PDCCH monitoring for the SCell, and transmits a Physical Uplink Control Channel (PUCCH) on the SCell. When an SCell is deactivated, the UE stops a timer associated with the SCell, deactivates an activation BWP associated with the SCell, clears a Configured downlink allocation (downlink assignment) or a type 2 Configured uplink Grant (CG) associated with the SCell, suspends an uplink Grant Configured with type 1, clears a hybrid automatic repeat request (HARQ) buffer associated with the SCell, and so on. For an SCell in a deactivated state, the UE does not perform normal operation on the SCell, including one or more of: the method comprises the steps of not sending Sounding Reference Signals (SRS) on the SCell, not carrying out Channel State Indication (CSI) reporting for the SCell, not carrying out Physical Downlink Control Channel (PDCCH) monitoring on the SCell, not carrying out PDCCH monitoring for the SCell, not carrying out PUCCH sending on the SCell, and not sending an Uplink Shared Channel (UL-SCH) and a Random Access Channel (RACH) on the SCell.

In the SCell dormancy mechanism, further power savings are achieved by operating the SCell in active state on one configured dormant BWP. The base station configures the dormant BWP identification of one SCell for the UE through RRC signaling. When the active BWP of an SCell is a dormant BWP, the BWP or the SCell may be considered to be in a dormant state. The base station informs the UE to operate on the dormant BWP through RRC signaling or Downlink Control Information (DCI) for BWP change. For a dormant BWP, the operation of the UE may include one or more of: not monitor the PDCCH on the BWP, not monitor the PDCCH for the BWP, not receive the Downlink Shared Channel (DL-SCH) on the BWP, not perform CSI measurement for the BWP, stop all uplink activities associated with the SCell, etc.

However, the above-mentioned energy saving mechanism for SCell is not applicable to PSCell, that is, the SCell in release 16 including PCell and PSCell is always in an active state. As mentioned above, in the current release 17, it is expected to further save the power overhead caused by unnecessary uplink and downlink transmission or link monitoring when the UE traffic is low. One way is to introduce an activation and deactivation mechanism of SCG, where the entire SCG cell group is quickly activated and deactivated to use dynamically changing UE traffic/service rate, and the deactivation of SCG includes suspending a related Radio Bearer (RB), not monitoring a PDCCH channel corresponding to SCG, and so on, thereby improving power utilization. In the current 3GPP conclusions, the UE may perform PSCell mobility in SCG deactivation state, including receiving RRC messages of PSCell change commands from SRB1 of the MCG, applying the RRC messages, and accessing to the target PSCell. In one possible approach, considering that the SCG is in the deactivated state at this time, the UE may be allowed to perform no random access procedure when performing the PSCell change for further energy saving. However, in the existing mechanism, a random access process in the PSCell change process is necessary, and the PSCell change process without the random access process will inevitably affect the PSCell change process, for example, the UE cannot determine when to stop the T304 timer properly, when to apply CSI configuration, and the like. Further, when the UE is configured with CPC, for the CPC procedure in SCG deactivated state, the UE cannot transmit RRC message for responding to CPC execution because SRB3 on SCG is suspended. Based on this, the content and embodiments described in the present disclosure focus on the issue of how to perform a PSCell change under the SCG activation deactivation mechanism. By the method, the UE can correctly transmit the RRC message, namely the RRC reconfiguration complete message, for responding to the PSCell change command, and determine when the PSCell change process is finished when the random access process is not executed, so that other UE operations after the PSCell change is executed, and the RRC reconfiguration process is finished. The activation/deactivation of the SCG, the resume/suspend (resume) of the SCG, and the activation/deactivation of the PSCell may be alternated. The SCG activation deactivation command is a generic name for the SCG activation command and the SCG deactivation command.

Hereinafter, a cell change method according to the present invention will be described in detail as an example. Fig. 1 is a flowchart showing an example of a cell change method according to the present invention.

As shown in fig. 1, in step S101, the user equipment UE performs a primary and secondary cell PSCell change procedure for the secondary cell group SCG without triggering a random access procedure.

Further, in step S102, the UE applies the configuration in the RRC reconfiguration message for SCG.

In step S103, the UE sets the content of the RRC reconfiguration complete message as a response message, and delivers the RRC reconfiguration complete message to the lower layer to transmit the RRC reconfiguration complete message.

In step S104, when the RRC reconfiguration complete message is delivered to the lower layer for transmission, or when the UE receives an acknowledgement from the network side, the UE considers that the PSCell change is successfully completed, and performs the UE operation after the PSCell change is completed.

In addition, with regard to specific contents of the UE operation, reference may be made to examples in the following respective embodiments.

Hereinafter, several examples of the present invention will be described, which are merely examples for understanding the present invention and are not to be construed as limiting the present invention in any way.

Example 1

This embodiment proposes a method of PSCell-sync reconfiguration procedure that does not perform a random access procedure. By the method, the UE can determine the time for successfully completing the PSCell changing process and continue the subsequent related UE operation in the PSCell changing process without executing the random access process.

Step 1: the UE performs a PSCell change procedure for the SCG, and in the procedure, the UE does not trigger a random access procedure to the PSCell.

Preferably, the UE does not trigger the random access procedure to the PSCell is decided by the UE according to the state in which the UE is located. For example, when receiving an RRC message of the PSCell change command or initiating a PSCell change procedure, the SCG of the UE is in a deactivated state. Alternatively, the random access procedure that the UE does not trigger to the PSCell is configured by the network side, for example, the network side includes an indication information for indicating no random access procedure in an RRC message of a PSCell change command sent to the UE.

As mentioned above, the PSCell change procedure is an RRC reconfiguration procedure for the SCG performed by a UE, wherein the RRC reconfiguration procedure includes a synchronization reconfiguration, and the RRC message of the PSCell change command refers to an RRC reconfiguration message for the SCG, which includes a synchronization reconfiguration information element.

Step 2: the UE applies the configuration in the RRC reconfiguration message, including the configuration in the synchronization reconfiguration information element.

And step 3: and the UE sets the content in the response message RRC reconfiguration complete message and delivers the RRC reconfiguration complete message to the lower layer for sending. Preferably, the RRC reconfiguration complete message is sent through SRB 1.

And 4, step 4: and when the RRC reconfiguration complete message is delivered to the lower layer for transmission, the UE considers that the PSCell change is successfully completed and executes the UE operation after the PSCell change is completed. Including one or more of the following: (1) stopping a T304 timer corresponding to the SCG; (2) stopping a timer T310 for radio link failure monitoring corresponding to the source PSCell; (3) applying the configuration of the system frame number SFN without the UE knowing the target PSCell, including Channel State Information (CSI) report configuration, scheduling request configuration, sounding reference signal configuration and the like; (4) after obtaining the SFN of the target PSCell, applying a part which needs the UE to know the SFN measurement and radio resource allocation of the target PSCell; (5) if the UE is configured with a Conditional reconfiguration (Conditional reconfiguration) (also called a Conditional PSCell Change (CPC) configuration) or a Conditional PSCell Add Change (CPAC) configuration) for the SCG, removing all the saved Conditional reconfigurations (all entries in the UE variable varconditional reconfiguration), and for each measurement identifier in the source PSCell configuration, removing, for each reporting type (reportType) of its associated reporting configuration (reportConfig) set to a Conditional trigger configuration (condterconfig), an entry corresponding to a reporting configuration identifier reportConfigId that matches the reporting configuration identifier from a reporting configuration list in the UE variable VarMeasConfig for saving the UE measurement configuration, for each reporting configuration identifier (reportConfigId); if the associated measurement object identifier measObjectId is associated with only one reporting configuration reportConfig whose reporting type reportType is set as condition trigger configuration condterconfig, removing the entry of the matched measurement object identifier measObjectId from the measurement object list measObjectList in the UE variable VarMeasConfig; the entry of the matching measurement identity measId is removed from the measurement identity list measIdList in the UE variable VarMeasConfig. (6) If the UE sent the UE assistance information RRC message ueassistance information for the source SCG within the last 1 second and the UE is still configured to provide relevant UE assistance information in the target SCG, then sending a UE assistance information RRC message for the cell group is initiated to provide relevant UE assistance information to the target PSCell. (7) The RRC reconfiguration procedure is ended.

Preferably, when the RRC reconfiguration complete message is delivered to the lower layer for transmission and the SCG is in a deactivated state, the UE considers that the PSCell change is successfully completed. Alternatively, the RRC reconfiguration complete message is delivered to the lower layer, which may be that the RRC reconfiguration complete message has been sent or has been successfully sent. Optionally, the successfully transmitted is a transmission success acknowledgement indication from a bottom layer, such as a Radio Link Control (RLC) layer or a MAC layer.

It is to be noted that although the embodiment is described based on the change of the PSCell, the embodiment is also applicable to a PCell change procedure, which is a handover procedure not performing random access.

The above method is also applicable to the LTE system, and at this time, the RRC reconfiguration message for SCG that includes the synchronization reconfiguration is an RRC connection reconfiguration message that includes SCG mobility control information (MobilityControlInfoSCG), and the timer T304 is a T307 timer.

Before step 1, the UE may further receive an RRC message of the PSCell change command from the network side.

Example 2

This embodiment proposes another method of PSCell-sync reconfiguration procedure that does not perform a random access procedure. By the method, the UE can determine the time for successfully completing the PSCell changing process and continue the subsequent related UE operation in the PSCell changing process without executing the random access process.

Step 1: the UE performs a PSCell change procedure for SCG, and in the procedure, the UE does not trigger a random access procedure to the PSCell.

Preferably, the UE does not trigger the random access procedure to the PSCell is decided by the UE according to the state in which the UE is located. Such as when receiving an RRC message of a PSCell change command or initiating a PSCell change procedure, the SCG of the UE is in a deactivated state. Alternatively, the UE does not trigger the random access procedure to the PSCell is configured by the network side, for example, the network side includes an indication message indicating no random access procedure in an RRC message of a PSCell change command sent to the UE.

As mentioned above, the PSCell change procedure is an RRC reconfiguration procedure for the SCG performed by a UE and includes a synchronization reconfiguration, and the RRC message of the PSCell change command refers to an RRC reconfiguration message for the SCG and includes a synchronization reconfiguration information element.

And 4, step 4: the UE receives an acknowledgement indication from the network side. The acknowledgement indication is used to inform the UE that the PSCell change is completed or inform the UE that the network side successfully receives the RRC reconfiguration complete message in step 3. Preferably, the indication is an RRC message, alternatively, the indication is a MAC control element or L1 signaling. And when the UE receives the confirmation indication, the UE considers that the PSCell change is successfully completed, and executes the UE operation after the PSCell change is completed. Including one or more of the following: (1) stopping a T304 timer corresponding to the SCG; (2) stopping a timer T310 for radio link failure monitoring corresponding to the source PSCell; (3) applying the configuration of the system frame number SFN without the UE knowing the target PSCell, including Channel State Information (CSI) report configuration, scheduling request configuration, sounding reference signal configuration and the like; (4) after obtaining the SFN of the target PSCell, applying a part which needs the UE to know the SFN measurement and radio resource allocation of the target PSCell; (5) if the UE is configured with a Conditional reconfiguration (Conditional reconfiguration) (also called a Conditional PSCell Change (CPC) configuration) or a Conditional PSCell Add Change (CPAC) configuration) for the SCG, removing all the saved Conditional reconfigurations (all entries in the UE variable varconditional reconfiguration), and for each measurement identifier in the source PSCell configuration, removing, for each reporting type (reportType) of its associated reporting configuration (reportConfig) set to a Conditional trigger configuration (condterconfig), an entry corresponding to a reporting configuration identifier reportConfigId that matches the reporting configuration identifier from a reporting configuration list in the UE variable VarMeasConfig for saving the UE measurement configuration, for each reporting configuration identifier (reportConfigId); if the associated measurement object identifier measObjectId is associated with only one reporting configuration reportConfig whose reporting type reportType is set as condition trigger configuration condterconfig, removing the entry of the matched measurement object identifier measObjectId from the measurement object list measobjectlist in the UE variable VarMeasConfig; the entry of the matching measurement identity measId is removed from the measurement identity list measIdList in the UE variable VarMeasConfig. (6) If the UE sent the UE assistance information RRC message ueassistance information for the source SCG within the last 1 second and the UE is still configured to provide relevant UE assistance information in the target SCG, then sending a UE assistance information RRC message for the cell group is initiated to provide relevant UE assistance information to the target PSCell. (7) The RRC reconfiguration procedure is ended.

Preferably, when the UE receives the confirmation indication and the SCG is in the deactivated state, the UE considers that the PSCell change is successfully completed. Preferably, said confirmation indication is sent by the master base station MN to the UE. Alternatively, the acknowledgement indication is generated by the secondary base station SN and sent to the UE via the primary base station MN link.

Example 3

This embodiment presents a CPC execution method executed in the SCG deactivated state. In the existing mechanism, if the CPC configuration is received through SRB3, when the CPC execution condition is satisfied, the UE executes CPC and sends a feedback message RRC reconfiguration complete message to the network side on SRB 3; if the CPC configuration is received through the SRB1, when the CPC execution condition is satisfied, the UE executes CPC and sends a feedback message RRC reconfiguration complete message to the network side on the SRB 1. And when the SCG is in the deactivated state, the SRB associated with the SCG is suspended, and the UE does not monitor the PDCCH related to the SCG. When the CPC condition is satisfied, the CPC configuration is executed and the CPC configuration is received through SRB3, and at this time, the RRC reconfiguration complete message generated by the UE executing the CPC procedure is stuck on the UE and cannot be sent out. By the method of the embodiment, the UE sends the RRC reconfiguration complete message for responding to the completion of CPC execution to the SN through the SRB1 via the MN, thereby avoiding the problem that the RRC reconfiguration complete message on the UE is cached at the UE side and cannot be sent to the network side.

Fig. 2 is a flowchart showing a cell change method according to an example of embodiment 3, and specifically, as shown in fig. 2.

Step 201: and the UE performs CPC evaluation and confirms that all execution conditions corresponding to the saved one or more CPC candidate cells are satisfied. The UE selects one of the one or more trigger cells satisfying the execution condition as a target PSCell (selected cell for which conditional reconfiguration is executed).

Step 202: the UE performs CPC configuration for the target PSCell. Namely, the UE applies the corresponding stored conditional reconfiguration (condRRCReconfig) to the selected cell, and executes the process of applying the RRC reconfiguration message included in the conditional reconfiguration. The CPC condition reconfiguration for the target PSCell is received over SRB 3.

Step 203: the UE sets the content of the response message RRC reconfiguration complete message, generates the message, and if the SCG is in a deactivation state at the moment, the UE embeds the RRC reconfiguration complete message in an outer layer message and transmits the message to the bottom layer through SRBl delivery. Preferably, the outer RRC message is a ULInformationTransferMRDC message.

In conjunction with the foregoing steps, the operation may be described as: if the RRC reconfiguration message is received through SRB3, and if the application of RRC reconfiguration is due to conditional reconfiguration execution for SCG and SCG is in a deactivated state, the UE embeds the RRC reconfiguration complete message in an outer RRC message and sends it through SRB1 delivery to the bottom layer. Optionally, this step is performed under the following conditions: when the RRC reconfiguration message is not received in an outer layer RRC message (dlinformation transfermrdc). If the above condition is not satisfied, the UE delivers an RRC reconfiguration complete message to the lower layer and transmits it through the SRB 3.

Optionally, the SCG may be deactivated instead of the SRB3 being suspended.

Example 4

This embodiment proposes a method of performing a PSCell change in an SCG deactivated state.

As described above, in order to reduce the overhead of the UE and achieve the purpose of further saving energy, when the UE executes the PSCell change procedure in the SCG deactivation state, the UE may not trigger the random access procedure. In this embodiment, continuing the above method, the UE does not trigger the random access procedure in performing the PSCell change procedure, but when the subsequent SCG is activated, the UE triggers the random access procedure to the SCG/PSCell, having achieved uplink synchronization to the PSCell.

That is, when the UE executes SCG activation, if the UE executes the PSCell change process in the SCG deactivation state before SCG activation and does not execute the random access process, the UE initiates the random access process to the PSCell to acquire uplink synchronization.

The UE performs SCG activation, where the UE receives an indication from the network side to activate SCG, or the UE autonomously determines to activate SCG, for example, when uplink data associated with SCG arrives on the UE, the UE needs to activate SCG to transmit data. The indication on the network side for activating SCG may be RRC signaling, MAC control element or L1 signaling. Preferably, the uplink data arrival associated with the SCG means that the PDCP anchor of the RB associated with the uplink data is in the SCG.

In current 3GPP evolution, the UE behavior at SCG activation deactivation is not yet certain. In the present disclosure, the specific behavior of the UE when in the SCG activated state and the SCG deactivated state is also not limited.

As an example, when the UE changes one SCG from a deactivated state to an activated state, the UE performs one or more of the following operations:

operation 1: activating all SCells in the SCG, and executing in an MAC layer or an RRC layer;

operation 2: activating the PSCell corresponding to the SCG, and executing the PSCell in an MAC layer or an RRC layer;

operation 3: activating a downlink BWP and an uplink BWP respectively indicated by a firstActiveDownlinkBWP-Id information element and/or a firstActiveDownlinkBWP-Id information element; wherein, the firstActiveDownlinkBWP-Id information element and the firstActiveDownlinkBWP-Id information element are configured by the network side through RRC signaling (such as RRC reconfiguration message), which is used for indicating the activated downlink/uplink BWP identification when the configuration of the RRC signaling is executed or the downlink/uplink BWP identification used when the MAC layer activates one SCell or PSCell, and executed at the MAC layer;

and operation 4: starting or restarting an sCellDeactivationTimer associated with the Scell or PSCell; the sCellDeactivationTimer is used for controlling the activation and deactivation states of the SCell or PSCell, when the SCell or PSCell times out, the UE considers that the associated cell is in the deactivation state, and when the SCell or PSCell runs, the UE considers that the associated cell is in the activation state. Performed at the UE MAC layer. In another mode, the operation includes starting a scgdeactivetimer timer associated with the SCG, where the scelldeactivatationtimer is used for activation and deactivation state control of the SCG, and when the scgdeactivetimer expires, the UE considers that the associated SCG is in a deactivated state, and when the scgdeactivetizer runs, the UE considers that the associated SCG is in an activated state. In yet another mode, the operation includes stopping an SCG activation deactivation timer, where the SCG activation deactivation timer is used for SCG activation/deactivation state control, and when the SCG activation/deactivation timer times out, the UE considers that the associated SCG is in an activated state, and the UE performs a state change operation from the SCG deactivated state to the activated state in this embodiment; when it is running, the UE considers the associated SCG to be in a deactivated state.

Operation 5: initializing or re-initializing an uplink grant of a suspended type 1 configuration associated with the SCell or PSCell; performing at the UE MAC layer

Preferably, the above-mentioned operations 3 to 5 are performed when the firstActiveDownlinkBWP-Id is not set to the sleep BWP. Optionally, when the SCG activation command is MAC CE or RRC signaling, the SCG activation command separately indicates that the activation state of each SCG SCell is activated or deactivated in addition to indicating that the state of PSCell/SCG is activated. In this case, the scells in operation 1 refer to all scells whose activation states are indicated as activated, and the above-described operations 3 to 5 are also performed for all scells whose activation states are indicated as activated.

Operation 6: all DRBs and SRBs associated with the SCG are restored. Including splitting the SCG portion of the bearer. Performing at RRC layer of UE

Operation 7: starting or restarting an uplink time alignment timer (TimeAlignimentTimer) for uplink time alignment associated with the uplink Time Advance Group (TAG) for the SCG/PSCell or the PSCell; performing at the MAC layer of the UE

Operation 8: performing an operation of resetting the MAC entity; preferably, the operation of resetting the MAC entity does not include canceling a triggered Buffer Status Report (BSR) procedure. Performed at the MAC layer of the UE.

Operation 9: triggering the random access procedure of the PSCell. Optionally, the UE determines whether to perform the random access procedure based on the random access indication information in the SCG activation command. When the random access indication information in the SCG activation command exists or is set to TRUE or 1, or the random access parameter in the SCG activation command is configured in the SCG activation command, the UE performs the random access procedure of the PSCell. The random access parameter (RACH-configured Received Information element identifier) refers to a PRACH time frequency resource of a physical random access Channel performing the RACH procedure, a Reference Signal Received Power (RSRP) threshold configuration of a Synchronization Signal Block (SSB)/Channel State Information Reference Signal (CSIRS), a priority parameter (e.g., ra-priority Information element), and the like. Optionally, if the uplink time alignment timer associated with the PSCell is in a non-running state, the UE performs random access, otherwise the UE does not perform random access.

Operation 10: if the SCG activation command is obtained through the received MAC CE, or the SCG activation decision is determined by the MAC entity, for example, when BSR is triggered or a random access procedure is triggered, the MAC entity indicates the SCG activation information to an upper layer (e.g., RRC layer).

Operation 11: if the SCG activation command is obtained by physical layer signaling DCI, if the SCG activation field included in the DCI indicates SCG activation or the BWP identifier included in the DCI indicates that the BWP is not a dormant BWP, the physical layer indicates, to an upper layer (e.g., a MAC layer or an RRC layer), the SCG activation information or the PSCell activation information or the BWP change information. Preferably, the DCI refers to DCI for a PSCell or SCell of the SCG, and the BWP refers to a BWP configured by the PSCell or SCell.

Operation 12: if the SCG activation command is obtained through the received RRC signaling or the SCG activation decision is determined by RRC, for example, when the CPC execution procedure is triggered, the RRC layer indicates the SCG activation information to a lower layer (e.g., MAC layer). The SCG activation information may also be expressed as PSCell activation information.

And the UE executes the operation from the SCG deactivation state to the SCG activation state when receiving the SCG activation command, or the MAC layer or the RRC layer of the UE executes the relevant operation when receiving the inter-layer interaction indication information of the operation 10-12, such as the information indicating the SCG activation.

Operation 13: starting Radio Link Monitor (RLM) for the SCG Link;

operation 14: moving from Radio Resource Management (RRM) measurements for relaxed requirements to RRM measurements for performing normal SCG.

Operation 15: beam failure monitoring and possible beam failure recovery for the SCG link is started.

Operation 16: transmission of an uplink Reference Signal (SRS) is started.

As an example, when the UE changes one SCG from active state to active state, the UE performs one or more of the following operations:

operation 1: deactivating all SCells in the SCG, and executing in an MAC layer or an RRC layer;

operation 2: deactivating the PSCell corresponding to the SCG, and executing in an MAC layer or an RRC layer;

operation 3: deactivating all BWPs of the SCG PSCell or SCell, and executing in an MAC layer;

and operation 4: stopping the sCellDeactivationtimer timer associated with the Scell, the PSCell or the SCG; the sCellDeactivationTimer is used for activation and deactivation state control of the SCell, PSCell, or SCG, and when the SCell, PSCell, or SCG times out, the UE considers that the associated cell or SCG is in a deactivation state. Performed at the UE MAC layer. In one mode, the operation includes starting an SCG activation and deactivation timer, where the SCG activation and deactivation timer is used for SCG activation and deactivation state control, and when the SCG activation and deactivation timer times out, the UE considers that the associated SCG is in an activated state, and the UE performs a state change operation from the SCG deactivated state to the activated state in this embodiment; when it is running, the UE considers the associated SCG to be in a deactivated state.

Operation 5: suspending uplink grant and/or downlink allocation of the suspended type 1 configuration associated with the SCell or PSCell, and clearing the uplink grant of the type 2 configuration in response; performed at the UE MAC layer.

Operation 6: the DRBs and SRBs associated with all SCGs are suspended. Including splitting the SCG portion of the bearer. Is performed in the RRC layer of the UE.

Operation 7: stopping an uplink time alignment timer for uplink time alignment associated with the SCG; performed at the MAC layer of the UE. In another manner, the operations may also be performed to apply an SCG deactivation associated timer value to the uplink time alignment timer. The value of the timer refers to a value for configuring a timer duration (configured in a timeAlignmentTimer information element in a TAG-Config information element); the timer refers to a timer corresponding to a PSCell of the SCG or a TAG associated with the SCell. The SCG deactivates the associated timer value, meaning that the timer duration value is configured differently in the SCG deactivated state than the timer duration value used in the SCG activated state.

Operation 8: performing an operation of resetting the MAC entity; performed at the MAC layer of the UE.

Operation 9: if the SCG deactivation command is obtained through the received MAC CE, or the SCG deactivation decision is determined by the MAC entity, for example, when a deactivation timer associated with the PSCell expires or a timer associated with SCG deactivation expires, the MAC entity indicates information of SCG deactivation to an upper layer (e.g., RRC layer).

Operation 10: if the SCG deactivation command is obtained by physical layer signaling DCI, if the SCG deactivation field included in the DCI indicates SCG deactivation or the BWP identifier included in the DCI indicates that the BWP is a dormant BWP, the physical layer indicates, to an upper layer (such as a MAC layer or an RRC layer), information of SCG deactivation or information of PSCell deactivation or information of BWP change. Preferably, the DCI refers to DCI for a PSCell or SCell of the SCG, and the BWP refers to a BWP configured by the PSCell or SCell. .

Operation 11: if the SCG deactivation command is obtained through the received RRC signaling or the SCG deactivation decision is determined by RRC, for example, when the CPC execution procedure is triggered, the RRC layer indicates the SCG deactivation information to a lower layer (e.g., MAC layer). The SCG deactivation information may also be expressed as PSCell deactivation information.

Operation 12: if a DRB or SRB is configured as a split bearer, if its primary path information element primaryPath is set to SCG, then the primary path or primaryPath information element is set to MCG. Preferably, this operation is performed when the RB is not configured for PDCP repetition (indicated by the PDCP-Duplication information element). Wherein the primarypath information element is used to indicate a logical channel identity and a cell group identity of a primary RLC entity for uplink transmission when a PDCP entity of one bearer is associated with more than one RLC entity.

Operation 13: changing the currently activated working BWP of the SCG's PSCell and/or SCell to the dormant BWP.

The UE executes the operation from the SCG activated state to the SCG deactivated state when receiving the SCG deactivation command or when the UE determines that the SCG is deactivated (e.g., the corresponding deactivation timer is timed out), or executes the related operation when the MAC layer or the RRC layer of the UE receives the inter-layer interaction indication information of operations 9 to 11, such as the information indicating the SCG deactivation.

The SCG activation/deactivation command may be contained in RRC signaling, MAC CE, or physical layer L1 signaling DCI. In one approach, the SCG deactivation command may indicate the status of the PSCell or each SCell, such as indicating that the cell is in a deactivated state, or indicating that the active BWP of the cell change activation is a dormant BWP.

Operation 14: stopping Radio Link Monitor (RLM) for the SCG Link;

operation 15: from the normal RRM measurements of SCG, to Radio Resource Management (RRM) measurements that perform relaxed requirements.

Operation 16: the beam failure monitoring and possible beam failure recovery for the SCG link is stopped.

Operation 17: the transmission of the uplink Reference Signal (SRS) is stopped.

As an example, UE operation in SCG deactivation state includes one or more of:

not sending SRS on PSCell and SCell of SCG;

not reporting CSI of PSCell and SCell for SCG;

not transmitting UL-SCH on PSCell and SCell of SCG;

not transmitting RACH on PSCell and SCell of SCG;

not monitoring PDCCH on PSCell and SCell of SCG;

not monitoring the PDCCHs of the PSCell and SCell for SCG;

not transmitting PUCCH on PSCell and SCell of SCG;

not receiving UL-SCH on PSCell and SCell of SCG;

not performing a beam failure detection and beam failure recovery procedure for the PSCell and/or SCell of the SCG;

DRB or SRB associated with SCG is in suspend state;

no BSR is triggered;

not triggering a PHR procedure for power headroom reporting;

the PSCell and SCell of the SCG operate on the dormant BWP corresponding to the cell.

The radio link of the SCG link is not monitored for RLM;

the normal SCG RRM measurements are not performed but the relaxed requirement RRM measurements are performed.

Beam failure monitoring and possible beam failure recovery for the SCG link are not performed.

The transmission of the uplink Sounding Signal (SRS) is not performed.

As an example, a UE in SCG active state performs communication operations of the PSCell and SCell of a normal SCG, including one or more of:

sending SRS on the PSCell and SCell of the SCG;

reporting CSI of a PSCell and an SCell for SCG;

transmitting UL-SCH on PSCell and SCell of SCG;

sending RACH on PSCell and SCell of SCG;

monitoring a PDCCH on a PSCell and an SCell of the SCG;

monitoring PDCCHs of a PSCell and an SCell for SCG;

transmitting PUCCH on PSCell and SCell of SCG;

receiving an UL-SCH on a PSCell and an SCell of an SCG;

performing a beam failure detection and beam failure recovery procedure for the PSCell and/or SCell of the SCG;

DRB or SRB associated with SCG is in non-suspended state;

the PSCell and SCell of the SCG do not operate on the dormant BWP corresponding to the cell.

Furthermore, it is only defined that PSCell is in active state or PSCell does not operate on dormant BWP when SCG is in active state, and one or more scells are allowed to be in deactivated state or operate on dormant BWP when one or more of the above operations are for PSCell and SCell in active state or SCell operating on non-dormant BWP.

Performing Radio Link Monitoring (RLM) on the SCG link;

RRM measurements of normal SCG are performed.

Beam failure monitoring and possible beam failure recovery are performed on the SCG link.

Transmission of an uplink Sounding Signal (SRS) is performed.

Example 5

This embodiment explains the user equipment UE of the present disclosure. Fig. 3 is a block diagram showing a user equipment UE according to the present invention. As shown in fig. 3, the user equipment UE30 includes a processor 301 and a memory 302. The processor 301 may include, for example, a microprocessor, a microcontroller, an embedded processor, or the like. The memory 302 may include, for example, volatile memory (e.g., random access memory RAM), a Hard Disk Drive (HDD), non-volatile memory (e.g., flash memory), or other memory, among others. The memory 302 has stored thereon program instructions. The instructions, when executed by the processor 301, may perform various methods such as the above-described movement information reporting method described in detail in the present invention.

In the present disclosure, a "base station" refers to a mobile communication data and control switching center having a large transmission power and a wide coverage area, and includes functions of resource allocation scheduling, data reception and transmission, and the like. "user equipment" refers to a user mobile terminal, and includes, for example, a mobile phone, a notebook, and other terminal equipment that can wirelessly communicate with a base station or a micro base station.

The method of the present disclosure and the related apparatus have been described above in connection with preferred embodiments. Those skilled in the art will appreciate that the methods illustrated above are exemplary only. The methods of the present disclosure are not limited to the steps or sequences shown above. The base station and the user equipment shown above may comprise further modules, for example, modules that may be developed or that may be developed in the future for a base station, MME, or UE, etc. The various identifiers shown above are merely exemplary and not limiting, and the present disclosure is not limited to the specific information elements that are examples of these identifiers. Many variations and modifications may occur to those skilled in the art in light of the teachings of the illustrated embodiments.

The program running on the apparatus according to the present disclosure may be a program that causes a computer to realize the functions of the embodiments of the present disclosure by controlling a Central Processing Unit (CPU). The program or information processed by the program may be temporarily stored in a volatile memory (such as a random access memory RAM), a Hard Disk Drive (HDD), a nonvolatile memory (such as a flash memory), or other memory system.

A program for implementing the functions of the embodiments of the present disclosure may be recorded on a computer-readable recording medium. The corresponding functions can be realized by causing a computer system to read the programs recorded on the recording medium and execute the programs. The term "computer system" as used herein may be a computer system embedded in the device and may include an operating system or hardware (e.g., peripheral devices). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium that stores a program for short-term dynamics, or any other recording medium that is readable by a computer.

The various features or functional blocks of the devices used in the above embodiments may be implemented or performed by circuitry (e.g., a single or multi-chip integrated circuit). Circuitry designed to perform the functions described herein may include a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The circuit may be a digital circuit or an analog circuit. Where new integrated circuit technology has emerged as a replacement for existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present disclosure may also be implemented using such new integrated circuit technology.

Further, the present disclosure is not limited to the above-described embodiments. While various examples of the embodiments have been described, the disclosure is not so limited. Fixed or non-mobile electronic devices installed indoors or outdoors may be used as terminal devices or communication devices, such as AV devices, kitchen devices, cleaning devices, air conditioners, office devices, vending machines, and other home appliances.

As above, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. However, the specific configuration is not limited to the above embodiment, and the present disclosure also includes any design modification without departing from the gist of the present disclosure. In addition, various modifications can be made to the present disclosure within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Further, components having the same effects described in the above embodiments may be substituted for each other.

Claims

1. A method of cell change, comprising:

under the condition that a random access process is not triggered, User Equipment (UE) executes a primary cell PSCell change process for an auxiliary cell group (SCG);

the UE applying the configuration in the RRC reconfiguration message for SCG;

the UE sets the content in the RRC reconfiguration complete message as a response message and submits the RRC reconfiguration complete message to a lower layer for sending; and

and when the RRC reconfiguration complete message is delivered to a lower layer for transmission or the UE receives a confirmation instruction from a network side, the UE considers that the PSCell change is successfully completed and executes the UE operation after the PSCell change is completed.

2. The cell change method according to claim 1,

the RRC reconfiguration message includes a synchronization reconfiguration information element.

3. The cell change method according to claim 1 or 2,

and when the RRC reconfiguration complete message is submitted to a lower layer for transmission and the SCG is in a deactivation state, the UE considers that the PSCell change is successfully completed.

4. The cell change method according to claim 1 or 2,

the acknowledgement indication is used for informing the UE that the PSCell change is completed or informing the UE that the network side successfully receives the RRC reconfiguration complete message.

5. The cell change method according to claim 1 or 2,

and the UE executes the PSCell change process when receiving an RRC message containing a PSCell change command from a network side.

6. The cell change method according to claim 1 or 2,

the UE operation includes at least one of:

(1) stopping a T304 timer corresponding to the SCG;

(2) stopping a timer T310 for radio link failure monitoring corresponding to the source PSCell;

(3) applying a configuration that does not require the UE to know a System Frame Number (SFN) of a target PSCell;

(4) after obtaining the SFN of the target PSCell, the UE needs to know the measurement and radio resource configuration part of the SFN of the target PSCell;

(5) if the UE is configured with the conditional reconfiguration for SCG, performing the operation related to the removal of the saved conditional reconfiguration;

(6) if the UE sends UE auxiliary information RRC message UEAssistant information to the source SCG within the last 1 second and the UE is still configured in the target SCG to provide the related UE auxiliary information, initiating the sending of the UE auxiliary information RRC message of the cell group to provide the related UE auxiliary information to the target PSCell;

(7) ending the RRC reconfiguration process.

7. A method of cell change, comprising:

user Equipment (UE) executes condition primary and secondary cell PSCell change CPC evaluation, and confirms whether the execution condition corresponding to the stored CPC candidate cell is satisfied;

the UE selects a target PSCell from the trigger cells meeting the execution condition;

the UE performing CPC configuration of the target PSCell; and

the UE sets contents of an RRC reconfiguration complete message as a response message and generates the RRC reconfiguration complete message,

and under the condition that the secondary cell group SCG is in a deactivated state, the UE embeds the RRC reconfiguration complete message in an outer layer message and sends the RRC reconfiguration complete message through SRB1 delivered to an underlying layer.

8. The cell change method according to claim 7,

the outer layer message is a ULInformationTransferMRDC message.

9. A user equipment, UE, comprising:

a processor; and

a memory storing instructions;

wherein the instructions, when executed by the processor, perform the cell change method of any one of claims 1 to 8.