Method for performing condition switching by user equipment and user equipment

Abstract

The invention provides a method for executing condition switching by user equipment and the user equipment. The method comprises the following steps: receiving an RRC (Radio Resource Control) reconfiguration message comprising condition switching configuration information from a network, and when judging that a first condition is satisfied based on the RRC reconfiguration message, executing NES condition switching evaluation for judging whether a candidate cell satisfies an NES condition switching execution condition for network energy saving NES, the first condition comprises at least one of the following items: the RRC reconfiguration message indicates to execute NES condition switching; the RRC reconfiguration message indicates that a source cell is in an NES mode; and when the candidate cell meeting the NES condition switching execution condition is judged to exist, executing an NES condition switching process of switching to the target cell by taking the candidate cell as the target cell.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more particularly to a method for executing conditional switching by a user equipment and a corresponding user equipment. Background Art

[0002] Network energy saving helps reduce environmental impact and save operator costs. By lengthening the time interval for the base station to continuously receive and send data and shutting down the transmission and reception of some symbols, the base station can be put into a sleep state, or the cell where it is located can be put into a network energy saving mode, thereby reducing the power consumption of the base station and achieving network energy saving. For the above reasons, in December 2022, at the RAN#98e plenary meeting of the 3rd Generation Partnership Project (3GPP), the NR network energy saving work item for version 18 (see non-patent literature: RP-223540 New WID: Network energy savings for NR) was approved. One of the goals of this work item is to enhance the conditional switching process for the NES mode.

[0003] The present invention discusses how the UE starts conditional switching evaluation and triggers conditional switching in a network energy-saving scenario, and how to report conditional switching information related to network energy-saving to the network. Summary of the invention

[0004] The object of the present invention is to provide a method capable of timely performing NES conditional switching and a user equipment for executing the method.

[0005] According to a method of the present invention, a method for performing conditional switching by a user equipment is provided, comprising: receiving an RRC reconfiguration message including conditional switching configuration information from a network, and when it is determined based on the RRC reconfiguration message that a first condition is met, performing an NES conditional switching evaluation to determine whether a candidate cell meets an NES conditional switching execution condition for network energy saving NES, wherein the first condition comprises at least one of the following: the RRC reconfiguration message indicates to perform NES conditional switching; the RRC reconfiguration message indicates that a source cell is in NES mode; and when it is determined that there is a candidate cell that meets the NES conditional switching execution condition, performing an NES conditional switching process of switching to the target cell with the candidate cell as the target cell.

[0006] According to another aspect of the present invention, a user equipment is provided, comprising: a processor; and a memory storing instructions, wherein the instructions execute the above method when executed by the processor.

[0007] According to the present invention, NES condition switching can be performed in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a flow chart of how a UE in RRC connected state changes a serving cell through a switching process.

[0009] Figure 2 This is a schematic diagram showing the flow of condition switching.

[0010] Figure 3 is a flowchart of a method for performing conditional switching by a user equipment according to an embodiment of the present invention.

[0011] Figure 4 A flowchart of a method for performing conditional switching by a user equipment according to another embodiment of the present invention.

[0012] Figure 5 The figure is a simplified structural block diagram of a user equipment UE involved in the present invention. DETAILED DESCRIPTION

[0013] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. In addition, for the sake of simplicity, detailed descriptions of known technologies that are not directly related to the present invention are omitted to prevent confusion in understanding the present invention.

[0014] The following describes some of the terms involved in the present invention. The specific meanings of the terms can be found in the latest 3GPP standard specifications.

[0015] UE:User Equipment

[0016] NR: New Radio, a new generation of wireless technology

[0017] MAC: Medium Access Control

[0018] MAC CE: MAC control element

[0019] RRC: Radio Resource Control

[0020] RRC CONNECTED: RRC connected state

[0021] RRC INACTIVE: RRC inactive state

[0022] RRC IDLE: RRC idle state

[0023] RAN: Radio Access Network, wireless access layer

[0024] PDCCH: Physical downlink control channel, physical downlink control channel

[0025] PUCCH: Physical Uplink Control Channel, physical uplink control channel

[0026] PUSCH: Physical Uplink Shared Channel, physical uplink shared channel

[0027] PBCH: Physical broadcast channel

[0028] SFN:System Frame Number system frame number

[0029] PDU: Protocol Data Unit

[0030] SSB: SS / PBCH block, synchronization signal / physical broadcast channel block

[0031] DCI: Downlink Control Information

[0032] C-RNTI: Cell Radio Network Temporary Identifier

[0033] RSRP: Reference Signal Received Power

[0034] RSRQ: Reference Signal Received Quality

[0035] SpCell: Special Cell, including PCell and PSCell

[0036] DC: Dual Connectivity

[0037] MCG: Master Cell Group

[0038] SCG: Secondary Cell Group

[0039] PCell: Primary Cell

[0040] PSCell: Primary SCG Cell

[0041] MIB: Master Information Block, main message block

[0042] SIB: System Information Block, system message block

[0043] NES: network energy saving

[0044] gNB: the next Generation Node B

[0045] RLF: Radio Link Failure, radio link failure

[0046] CN: Core Network

[0047] UL-SCH: Uplink Shared Channel, uplink shared channel

[0048] BWP: Bandwidth Part, bandwidth part

[0049] CHO: Conditional Handover

[0050] gNB: the next Generation Node B

[0051] RLF: Radio Link Failure, radio link failure

[0052] SN: Sequence Number

[0053] In the present invention, network (network or NW), base station (base station or gNB or eNB) and RAN can be used interchangeably. The network can be a long-term evolution LTE network, a new radio access technology (New RAT, NR) network, an enhanced long-term evolution eLTE network, or other networks defined in subsequent evolution versions of 3GPP.

[0054] In the present invention, the user equipment UE may refer to a device supporting network energy saving, may refer to a device supporting enhanced CHO or supporting NES CHO, may refer to other types of NR devices or LTE devices.

[0055] In the present invention, "feedback", "submit", "report", "send", "transmit or transport", "inform", "indicate", "provide" can be used interchangeably. "Use", "make available", "apply", "implement", "enable", "activate", "perform", "do" and the like can be used interchangeably.

[0056] In the present invention, "execution condition reconfiguration" and "execution condition switching" can be used interchangeably.

[0057] In the present invention, "associate", "correspond" and "map" can be used interchangeably.

[0058] In the present invention, the "physical layer" may also be referred to as "layer one (L1)" or "lower layer" and may be used interchangeably.

[0059] In the present invention, "handover" and "reconfiguration with sync" may be used interchangeably.

[0060] Handover refers to the change of the primary cell initiated by the network side, including the change of the primary cell between cells and the change of the primary cell within the cell, that is, the primary cell of the UE is changed from the source cell to the target cell, where the source cell and the target cell can be the same cell or different cells. In this process, the key or security algorithm used for access layer security can also be updated accordingly. The source cell is also called the source base station, or the source beam, the source transmission point (Transmission point, TRP), and the source master cell group (Master Cell Group, MCG). The target cell can also be called the target base station, or the target beam, the target transmission point or the target MCG. The source cell refers to the cell that serves the UE connected before the handover process is initiated, that is, the cell in which the UE receives the RRC message containing the handover command. The target cell refers to the cell that serves the UE to which the UE is connected after the handover process is successfully completed, or the cell indicated by the target cell identifier contained in the handover command, and the cell to which the UE accesses when it receives the handover execution. The handover command is used to trigger the UE to perform a handover, and in the NR system it is an RRC reconfiguration message containing a synchronous reconfiguration (Reconfiguration with sync) information element. Furthermore, for the handover of the master cell, it is an RRC reconfiguration message containing a synchronous reconfiguration (Reconfiguration with sync) information element for the master cell group (MCG). At this time, the handover can also be called the synchronous reconfiguration of the MCG. The synchronous reconfiguration information element includes the configuration information of the target cell, such as the target cell identifier, the target cell frequency, the public configuration of the target cell such as system information, the random access configuration used by the UE to access the target cell, the security parameter configuration of the UE in the target cell, and the radio bearer configuration of the UE in the target cell.

[0061] It should be noted that, in this specification, two things connected by "and", "or", or "and / or" may represent different ways of expressing the same meaning in different application scenarios. There may be a relationship of inclusion and being included between the two, and they do not necessarily refer to completely different contents.

[0062] Hereinafter, a description is given of related art of the present invention.

[0063] General Switch

[0064] The user mobility in the connected state is mainly achieved through a handover process, and the handover refers to the process of changing the serving cell of a UE in the RRC connected state. Figure 1 The flowchart shows that a UE in RRC connected state changes the serving cell through the handover process. Figure 1 As shown in FIG. 1 , the switching process generally includes the following stages:

[0065] Phase 1: Measurement phase. The base station sends a measurement configuration to the UE; the UE measures the radio link of the serving cell or neighboring cell based on the measurement configuration, and when the configured measurement reporting conditions are met, the UE sends a measurement report to the base station.

[0066] Phase 2: Handover preparation phase. The base station decides whether to trigger a handover for the UE based on the received measurement report and other factors such as the base station load. If it is determined that a handover is triggered for the UE, the source base station initiates the handover preparation process by sending a handover request message to the target base station. The target base station decides whether to accept the handover request for the UE based on factors such as the UE context in the handover request message and the available resources of the target base station. If yes, it replies to the source base station with a handover confirmation message, which contains an inter-node RRC message, namely the handover command.

[0067] Phase 3: Handover execution phase. The source base station sends the handover command to the UE and starts forwarding the UE's data to the target base station. The UE that receives the handover command immediately applies the configuration of the handover command to perform the handover, accesses the target base station through the random access process, and sends a confirmation message to the target base station. The random access process is not mandatory.

[0068] Phase 4: Handover completion phase. After the target base station confirms that the UE has successfully accessed, it sends a handover completion message to the source base station. The source base station can release the UE context stored thereon.

[0069] The UE detects the handover process through a timer T304. When the handover process is initiated, the UE starts the T304 timer; when the handover process is completed, the UE stops the timer T304; when T304 times out, the UE considers that the handover has failed.

[0070] Conditional Switching

[0071] In conditional switching, the base station obtains the measurement results in advance, and performs switching preparation in advance according to the measurement results and the selected target base station, so that the base station can send a switching command containing the switching candidate cell and the switching execution condition to the UE in advance before the actual switching condition is met, which carries the conditions for the UE to perform the switching. Different from the general switching mechanism, after receiving the conditional switching command, the UE does not perform the switching immediately, but saves the received switching command configuration, and starts to monitor the link quality of the source cell and / or the link quality of the target cell according to the switching execution condition carried in the switching command message to evaluate whether the switching execution condition is met. Only when it is monitored that the configured switching execution condition is met, the UE starts to execute the saved switching command and access the target cell. Conditional switching refers to a switching process that is performed only when one or more configured switching execution conditions are met. Because the switching command is included in the RRC reconfiguration message, conditional switching is also called conditional reconfiguration.

[0072] In the conditional switching process, the network sends the CHO configuration to the UE through the RRC message. After receiving the CHO configuration, the UE starts to evaluate the execution conditions. When the CHO execution conditions of a candidate cell are met, the UE executes the switching to the candidate cell according to the CHO switching command in the CHO configuration. Once the switching is executed, the evaluation of the CHO execution conditions is stopped.

[0073] The CHO configuration includes a CHO reconfiguration identifier for each candidate cell, a CHO execution condition (composed of one or two CHO trigger conditions, such as a measurement event) and a CHO switching command. The CHO switching command is to package the RRCReconfiguration message (with synchronous reconfiguration) as a container in the conditional RRC reconfiguration (condRRCReconfig) information element. The CHO trigger condition may include condition event T1 (CondEventT1) and condition event A3 / A4 / A5.

[0074] CondEventT1 contains an entry condition and an exit condition. Mt represents the UTC time on the UE side, Thresh1 represents the threshold parameter of the event, and Duration represents the interval parameter of the event. If Mt is greater than Thresh1, it is the entry condition of the event, and if Mt is greater than Thresh1+Duration, it is the exit condition of the event. The unit of all parameters is ms.

[0075] If the UE is configured with CHO and receives another general handover command from the gNB before the CHO execution conditions are met, the UE shall trigger a handover based on the received general handover command and will not wait for any CHO conditions to be met. The general handover command takes precedence over the CHO handover.

[0076] Figure 2 This is a schematic diagram showing the process of conditional switching. The basic process of conditional switching is as follows:

[0077] Step 1: The source base station configures the UE measurement process, and the UE reports the measurement report according to the measurement configuration.

[0078] Step 2: The source base station decides to handover the UE based on the measurement report.

[0079] Step 3: The source base station requests CHO for one or more candidate cells belonging to one or more candidate base stations, and sends a CHO request message for each candidate cell.

[0080] Step 4: Admission control may be performed by the target base station.

[0081] Step 5: The candidate base station sends a CHO response including the CHO candidate cell configuration, namely, a HO REQUEST ACKNOWLEDGE message to the source base station. The candidate base station sends a CHO response message for each candidate cell.

[0082] Step 6: The source base station sends an RRC reconfiguration message to the UE, including the configuration of the CHO candidate cell and the CHO execution condition.

[0083] Step 7: The UE sends an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source base station.

[0084] Step 8: After receiving the CHO configuration, the UE maintains the connection with the source base station and starts to evaluate the CHO execution conditions of the candidate cells. If at least one CHO candidate cell meets the corresponding CHO execution conditions, the UE detaches from the source base station, applies the stored corresponding configuration for the selected candidate cell, synchronizes to the candidate cell, and completes the RRC handover process by sending an RRCReconfigurationComplete message to the target base station. The UE releases the stored CHO configuration after successfully completing the RRC handover process.

[0085] Step 8a: The target base station sends a HANDOVER SUCCESS message to the source base station, notifying the UE that it has successfully accessed the target cell.

[0086] Step 8b: The source base station sends an SN status transfer (SN STATUS TRANSFER) message to the target base station.

[0087] Step 8c: The source base station sends a HANDOVERCANCEL message to other signaling connections or other candidate target base stations to cancel the CHO of the UE.

[0088] Radio link failure report

[0089] When RLF or handover failure occurs, the UE generates and saves a radio link failure report (RLF report), and saves the radio link failure information in the UE variable VarRLF-Report. After restoring the connection with the network side (such as through the RRC re-establishment process or the RRC establishment process for establishing a new connection), the UE can inform the network side through an RRC message that it has an available radio link failure report (indicated by the rlf-InfoAvailable information element). For example, the UE can inform the network side that the UE has a saved and available radio link failure report in the RRC connection re-establishment complete message (RRCReestablishmentComplete) during the RRC connection re-establishment process, the RRC connection reconfiguration complete message (RRCReconfigurationComplete) during the RRC connection reconfiguration process, the RRC connection setup complete message (RRCSetupComplete) during the RRC connection establishment process, or the RRC connection recovery complete message (RRCResumeComplete) during the RRC connection recovery process. After receiving the indication, the network side can request the UE to report its saved radio link failure report through an RRC message (RLF report request rlf-ReportReq information element in the UE information request UEInformationRequest message to indicate the request). The UE will report the saved radio link failure report (RLF report rlf-Report information element in the UE information response UEInformationResponse message) to the network side in the response RRC message. The radio link failure report obtained by the network side is used for network optimization, such as network coverage and mobility robustness optimization. The radio link failure report may include: the measurement results of the source cell and neighboring cells available when the link fails, location information, the main cell identifier where the link failure occurs, the link failure type (RLF or handover failure), the RLF cause, the time from connection failure to reporting the radio link failure, the time from the last receipt of the handover command to the connection failure (recorded as timeConnFailure information element), the cell identifier of the UE re-accessing the network, that is, the RRC re-established cell identifier, etc.

[0090] For each neighbor cell in the measurement results of the neighbor cells in the RLF report, if the UE supports RLF reporting for conditional switching when RLF is detected, and the neighbor cell is a candidate cell for conditional switching when failure is detected (the synchronization reconfiguration information element reconfigurationWithSync corresponding to the cell is included in the MasterCellGroup information element in the saved conditional reconfiguration variable), the UE sets the conditional switching configuration (choConfig) information element to the execution condition corresponding to each measurement identifier (measId) in the conditional trigger configuration (condTriggerConfig) information element associated with the neighbor cell in the conditional reconfiguration variable VarConditionalReconfig of the MCG.

[0091] Successful switch report

[0092] After the handover is successful, the UE saves the successful handover information in the UE variable VarSuccessHO-Report. After restoring the connection with the network side (such as through the RRC re-establishment process or the RRC establishment process for establishing a new connection), the UE can inform the network side through an RRC message that it has an available successful handover report (indicated by the successHO-InfoAvailable information element). For example, the UE can inform the network side that the UE has a saved and available successful handover report in the RRC connection reestablishment complete message (RRCReestablishmentComplete) during the RRC connection reestablishment process, the RRC connection reconfiguration complete message (RRCReconfigurationComplete) during the RRC connection reconfiguration process, the RRC connection establishment complete message (RRCSetupComplete) during the RRC connection establishment process, or the RRC connection recovery complete message (RRCResumeComplete) during the RRC connection recovery process. After receiving the indication, the network side can request the UE to report its saved successful handover report through an RRC message (the successful handover report request successHO-ReportReq information element in the UE information request UEInformationRequest message indicates the request). The UE will report the saved successful handover report (the successful handover report successHO-Report information element in the UE information response UEInformationResponse message) to the network side in the response RRC message. The successful handover report obtained by the network side is used for network optimization, such as network coverage and mobility robustness optimization.

[0093] When the UE determines the content of the success HO-Report information element in the UEInformationResponse message, for the target PCell indicated by the last RRCReconfiguration message with reconjigurationWithSync applied, if the last RRCReconfiguration message with reconfiguration WithSync applied is included in the saved condRRCReconfig, the UE sets the time since CHO reconfiguration (timeSinceCHO-Reconfig) information element to the time from the last time conditionalReconfiguration was received in the source PCell to the time when the target PCell initiated the conditional reconfiguration (the conditionalReconfiguration includes the condRRCReconfig for the target PCell).

[0094] RRC connection state measurement

[0095] In the RRC connected state, the base station can perform measurement configuration (measConfig) on ​​the UE through an RRC reconfiguration message (RRCReconfiguration). The UE measures the serving cell and the neighboring cell according to the measurement configuration.

[0096] The measurement configuration includes the measurement object (measObject) configuration, the measurement report configuration (reportConfig), the measurement identifier (measId) configuration, the quality configuration (quantityConfig), the measurement interval configuration (measGapConfig), etc.

[0097] - The measurement object configuration may include but is not limited to: time / frequency information to be measured and subcarrier spacing of reference signals to be measured, etc. Each measurement object may have one or more measurement report configurations.

[0098] -The measurement report configuration may include, but is not limited to: reporting criteria (i.e., criteria for triggering the UE to send a measurement report), reference signal type (e.g., based on SSB or CSI-RS), and report format. The reporting criteria may include a conditional reconfiguration trigger configuration (CondTriggerConfig), which is used to configure the conditional events that need to be evaluated for conditional switching. The type of triggered measurement report can be configured in the measurement report configuration, including periodic measurement reports and event measurement reports. For event measurement reports, the base station configures the triggering criteria for the measurement report, namely, various RSRP / RSRP and time thresholds. When the criteria are met, the UE can send a measurement report to the base station. After sending an event-triggered measurement report, the UE will periodically report the measurement report of the event to the base station before receiving a response from the base station.

[0099] -Each measurement identifier associates a measurement object with a measurement report configuration. By configuring multiple measurement identifiers, multiple measurement objects can be associated with one measurement report configuration, or one measurement object can be associated with multiple measurement report configurations. For conditional switching, one measurement identifier is associated with one conditional reconfiguration trigger configuration (CondTriggerConfig), and up to two measurement identifiers can be associated with one conditional reconfiguration execution condition, which means that whether the conditional switching execution condition is met can be determined based on up to two trigger events.

[0100] -Quality configuration defines layer 3 filtering parameters for event-triggered measurement reports and periodically triggered measurement reports.

[0101] - The measurement interval configuration indicates the periodicity that the UE may use to perform measurements.

[0102] NES conditional switching enhancement

[0103] When the network finds that the load on a certain cell is relatively light, in order to save network energy, the network can switch the UE in the RRC connected state on the cell to other cells to continue the service, and then the cell enters the network energy saving mode, which is referred to as NES mode in the present invention. The NES mode may include but is not limited to the following aspects: the cell does not continuously send downlink data to the UE, does not continuously receive uplink data sent by the UE, the SCell does not send SSB, reduces the number of antenna ports, reduces the number of activated transmission chains, adjusts the power offset, shuts down the cell, etc.

[0104] In order to switch the UE on the source cell to the neighboring cell before the source cell enters the NES mode, a possible implementation method is to use general switching, that is, the network sends a general switching command to each UE in the RRC connected state in the source cell, and the UE can switch to the neighboring cell after receiving the general switching command. However, this method requires sending an RRC message to each UE, which has a large signaling overhead and prolongs the switching time.

[0105] The use of NES conditional handover enhancement can save signaling and achieve the purpose of quickly handing over the UE to the neighboring cell. In order to enable the UE to switch to the neighboring cell faster, for network energy-saving scenarios, the network may configure more aggressive handover conditions for the UE (CHO configuration for NES), for example, the quality requirements for the neighboring cell may be reduced, so that the UE can switch to the neighboring cell as soon as possible.

[0106] The network can configure CHO configuration and NES CHO configuration for the UE at the same time. Under different conditions, the UE can determine which type of CHO configuration to use for evaluation and then perform conditional switching.

[0107] The present invention discusses how the UE starts the evaluation of conditional switching and triggers conditional switching for network energy saving scenarios, and how to report conditional switching information related to network energy saving to the network. Through the present invention, the UE can correctly and timely execute CHO when the NES mode changes in the source cell, thereby reducing the impact on the service, and can also enable the network to enter the NES mode in time to save energy; at the same time, the UE can also correctly report the RLF report and the successful switching report to the network for the CHO triggered by NES, so that the network can obtain more auxiliary information for network optimization.

[0108] Below, first refer to Figure 3 and Figure 4 The outline of the present invention will be described.

[0109] Figure 3 is a flowchart of a method for performing conditional switching by a user equipment according to an embodiment of the present invention.

[0110] like Figure 3 As shown, at 302, an RRC reconfiguration message including conditional handover configuration information is received from the network. Then, at 304, it is determined whether the RRC reconfiguration message satisfies a first condition. The first condition includes at least one of the following: the RRC reconfiguration message indicates that NES conditional handover is performed; the RRC reconfiguration message indicates that the source cell is in NES mode.

[0111] When at least one of the following is met, it can be judged that the RRC reconfiguration message indicates the execution of NES conditional switching. One situation is that the RRC reconfiguration message includes NES conditional switching configuration information for NES, that is, as long as the received RRC reconfiguration message is received, it is considered that the RRC reconfiguration message indicates the execution of NES conditional switching. Another situation is that the RRC reconfiguration message includes NES conditional switching evaluation indication information, that is, if the received RRC reconfiguration message includes NES conditional switching evaluation indication information, it is considered that the RRC reconfiguration message indicates the execution of NES conditional switching. Another situation is that the RRC reconfiguration message includes NES conditional switching evaluation indication information, and the NES conditional switching evaluation indication information indicates the execution of NES conditional switching.

[0112] It can be determined that the RRC reconfiguration message indicates that the source cell is in NES mode when at least one of the following is met. In one case, the RRC reconfiguration message includes NES conditional switching configuration information for NES, that is, as long as the received RRC reconfiguration message is received, it is considered that the RRC reconfiguration message indicates that the source cell processes the NES mode. In another case, the RRC reconfiguration message includes source cell NES state indication information, that is, if the received RRC reconfiguration message includes source cell NES state indication information, it is considered that the RRC reconfiguration message indicates that the source cell is in NES mode. In another case, the RRC reconfiguration message includes source cell NES state indication information, and the source cell NES state indication information indicates that the source cell is in NES mode.

[0113] When it is determined in 304 that the first condition is met, in 306, an NES conditional handover evaluation is performed to determine whether the candidate cell meets the NES conditional handover execution condition for the network energy saving NES. And in 308, it is determined whether there is a candidate cell that meets the NES conditional handover execution condition. In one example, when the first condition is met, the evaluation of the execution condition for the conditional handover of the non-NES may be stopped. Alternatively, when the first condition is not met, the evaluation of the execution condition for the conditional handover of the non-NES may be performed.

[0114] When it is determined in 308 that there is a candidate cell that satisfies the NES conditional handover execution condition, the NES conditional handover process of handing over to the target cell is executed with the candidate cell as the target cell.

[0115] The conditional switching configuration information may include NES conditional switching events for each candidate cell, NES conditional switching thresholds, and at least one of the switching conditions determined based on the NES conditional switching events and the NES conditional switching thresholds for each NES conditional switching event. The NES conditional switching event may be, for example, a measurement event. Accordingly, the NES conditional switching evaluation includes performing at least one of the following: performing an evaluation to determine whether the NES conditional switching event is satisfied; using the NES conditional switching threshold to evaluate the conditional switching execution condition; performing an evaluation to determine whether the switching condition is satisfied.

[0116] Figure 4 A flowchart of a method for performing conditional switching by a user equipment according to another embodiment of the present invention.

[0117] like Figure 4 As shown, at 402, DCI with NES indication information is monitored. The NES indication information is used to indicate at least one of the following: whether the source cell is in NES mode; whether to perform NES conditional handover.

[0118] At 404, it is determined whether the monitored NES indication information satisfies a condition. The condition may include that the NES indication information indicates that NES conditional switching is to be performed and / or the source cell is in NES mode.

[0119] In the case that the NES indication information indicates to perform NES conditional handover and / or the source cell is in NES mode, at 406 , it is determined whether NES conditional handover evaluation has been started when the DCI carrying the NES indication information is monitored.

[0120] If the NES conditional handover evaluation has already started when the DCI with NES indication information is monitored, then at 408, the NES conditional handover process of handing over to the target cell is executed.

[0121] Figure 4 The process can be Figure 3 In one example, it can be set that when one of the judgments in 308 and 406 is "yes", NES conditional switching is performed. In this case, if NES conditional switching is triggered due to receiving NES indication information, when NES conditional switching is performed, candidate cells that meet the NES conditional switching conditions may not be determined. At this time, the candidate cell with the best quality can be selected as the target cell.

[0122] In another example, even if the judgment is yes in 308, NES conditional switching is not performed, but NES conditional switching is performed only when NES indication information is received and the NES indication information meets the conditions. If a candidate cell that meets the NES conditional switching condition has been determined through NES conditional switching evaluation during the NES conditional switching process, the candidate cell is used as the target cell. If a candidate cell that meets the NES conditional switching condition has not been determined, the candidate cell with the best quality is selected as the target cell.

[0123] In the case where the handover is successfully executed, the user equipment may generate a successful handover report, which includes at least one of the following: information indicating that the handover corresponding to the successful handover report is triggered by receiving NES indication information; the time when the NES conditional handover is triggered by receiving the NES indication information; and the time interval from the start of the NES conditional handover evaluation to the handover to the target cell. In addition, in the case where a candidate cell that meets the NES conditional handover condition has been determined through the NES conditional handover evaluation when executing the NES conditional handover process, the successful handover report may also include the time interval from the determination that the NES conditional handover execution condition is met to the handover to the target cell due to the receipt of the NES indication message.

[0124] In the case of a handover failure, the user equipment may generate a radio link failure report, which includes at least one of the following: information indicating that the corresponding radio link failure is caused by a failure in the execution of a conditional handover, which is triggered by receiving an NES indication message related to NES; the time elapsed from the start of the NES conditional handover evaluation to the failure of the conditional handover. In addition, in the case that a candidate cell that meets the NES conditional handover condition has been determined through the NES conditional handover evaluation when executing the NES conditional handover process, the radio link failure report may also include the time elapsed from the determination that the NES conditional handover execution condition is met to the conditional handover failure triggered by the receipt of the NES indication message.

[0125] Hereinafter, several embodiments of the present invention for solving the above problems are described in detail.

[0126] In the following embodiments, "performing NES conditional switching" refers to the process of performing conditional reconfiguration. The UE performs switching to the candidate cell according to the conditional reconfiguration in the CHO configuration. When performing conditional reconfiguration to the candidate cell, "performing NES conditional switching" and "performing conditional switching" can be used interchangeably.

[0127] Example 1

[0128] This embodiment includes steps 101 and 103 .

[0129] Optionally, in step 101, the UE receives an RRC reconfiguration message sent by the network. Optionally, the RRC reconfiguration message includes a CHO configuration (referred to as conditional reconfiguration ConditionalReconfiguration), and / or a conditional reconfiguration trigger configuration (CondTriggerConfig), and / or a NES conditional switching configuration.

[0130] Optionally, the CHO configuration (i.e., conditional reconfiguration cell) may include: a conditional reconfiguration add modification list (condReconfigToAddModList). condReconfigToAddModList is used to add or modify a candidate SpCell. condReconfigToAddModList may include but is not limited to: a conditional reconfiguration identifier (condReconfigId), a conditional switching execution condition (condExecutionCond), and a conditional RRC reconfiguration (condRRCReconfig).

[0131] Optionally, the NES conditional switching configuration includes at least one of the following configurations:

[0132] -NES conditional switch execution condition (for example: NEScondExecutionCond);

[0133] -NES conditional switching events;

[0134] -NES conditional switching threshold;

[0135] -NES condition switching evaluation indication information;

[0136] -Source cell NES status indication information;

[0137] Optionally, the NES conditional switching execution condition may include one or more NES measurement identifiers (MeasId), and each MeasId may be associated with a CondTriggerConfig; or, the NES conditional switching execution condition may include one or more NES conditional switching events (or conditional switching event identifiers, such as condEventId), or one or more conditional switching events for NES conditional switching; or, the NES conditional switching execution condition may include one or more NES conditional switching thresholds; or, the NES conditional switching execution condition may include one or more NES conditional switching identifiers. Alternatively, the NES conditional switching execution condition may be determined based on the NES conditional switching events and / or the NES conditional switching thresholds.

[0138] Optionally, the NES conditional switching event may refer to one or more conditional switching events for NES (eg, NEScondEvent), or one or more conditional switching events with an NES identifier (eg, condEvent containing an NES identifier, i.e., indicating in condEvent whether a conditional event is NES).

[0139] Optionally, the NES conditional switching threshold value may refer to RSRP / RSRQ threshold values ​​(or RSRP / RSRQ offsets) of one or more serving cells or neighboring cells used for NES conditional switching.

[0140] Optionally, the NES conditional switching evaluation indication information is used to indicate whether the UE performs the NES conditional switching evaluation. A specific implementation method is, for example: the NES conditional switching evaluation indication information is set to a first value (e.g., TRUE, or 1, or nesCho), indicating that the UE needs to perform the NES conditional switching evaluation, otherwise (for example, the NES conditional switching evaluation indication information is set to a second value (e.g., FALSE, or 0, or cho), indicating that the UE does not need to perform the NES conditional switching evaluation, or the NES conditional switching evaluation can be delayed. Or, for example: when the NES conditional switching evaluation indication information is included in the RRC reconfiguration message (or NES conditional switching configuration), it indicates that the UE needs to perform the NES conditional switching evaluation.

[0141] Optionally, the source cell NES state indication information is used to indicate the current (or default, or initial) NES state of the UE source cell, that is, whether it is in NES mode or not in NES mode. For example: the source cell NES state indication information is set to a third value (for example, TRUE, or 1, or nes), indicating that the source cell is currently (or by default, or initially) in NES mode, and the source cell NES state indication information is set to a fourth value (for example, FALSE, or 0, or non-nes), indicating that the source cell is currently (or by default, or initially) not in NES mode. For another example: the source cell NES state indication information is included in the RRC reconfiguration message, indicating that the source cell is currently (or by default, or initially) in NES mode, otherwise it indicates that the source cell is currently (or by default, or initially) not in NES mode. Optionally, the source cell type indicated by the source cell NES state indication information is one of the following:

[0142] - source serving cell;

[0143] - Source PCell;

[0144] - source PSCell;

[0145] -SOURCESpCell.

[0146] Optionally, when at least one of the following first conditions is met, (optionally, when receiving the NES conditional switching configuration, or according to the NES conditional switching configuration) the UE performs the NES conditional switching evaluation:

[0147] -The NES conditional handover configuration is included in the RRC reconfiguration message;

[0148] -The NES conditional handover evaluation indication information is included in the RRC reconfiguration message or in the NES conditional handover configuration;

[0149] -The NES conditional handover evaluation indication information indicates that the UE needs to perform NES conditional handover;

[0150] - the NES conditional switching evaluation indication information is set to the first value;

[0151] - the source cell NES state indication information is included in the RRC reconfiguration message or in the NES conditional handover configuration;

[0152] -the source cell NES state indication information indicates that the source cell is currently (or by default, or initially) in NES mode;

[0153] -The source cell NES status indication information is set to the third value.

[0154] Optionally, "perform NES conditional switching evaluation" may refer to one of the following meanings: perform NES conditional switching event evaluation, perform NES conditional switching execution condition evaluation, and use NES conditional switching threshold value to evaluate the conditional switching execution condition.

[0155] Optionally, when at least one of the first conditions is met, (optionally, if the UE currently uses the conditional execution condition for evaluation), the UE may also stop evaluating the conditional switching execution condition (condExecutionCond).

[0156] Optionally, when at least one of the following second conditions is met, (optionally, when receiving the conditional switching configuration, or according to the conditional switching configuration) the UE performs a conditional switching evaluation:

[0157] - the conditional handover configuration is included in the RRC reconfiguration message;

[0158] - the NES conditional handover evaluation indication information is not included in the RRC reconfiguration message or is not included in the NES conditional handover configuration;

[0159] -The NES conditional handover evaluation indication information indicates that the UE does not need to perform NES conditional handover;

[0160] - the NES conditional switching evaluation indication information is set to a second value;

[0161] - The source cell NES state indication information is not included in the RRC reconfiguration message or is not included in the NES conditional handover configuration;

[0162] - the source cell NES state indication information indicates that the source cell is currently (or by default, or initially) not in NES mode;

[0163] -The source cell NES status indication information is set to a fourth value.

[0164] Optionally, when at least one of the second conditions is met, (optionally, if the UE currently uses the NES conditional execution condition for evaluation), the UE may also stop evaluating the NES conditional switching execution condition (eg, NEScondExecutionCond).

[0165] Optionally, in step 103, when the UE determines that the candidate cell meets the NES conditional switching execution condition, the UE executes the conditional switching process and switches to the candidate cell.

[0166] Optionally, when at least one of the following conditions is met, the UE determines that the candidate cell meets the NES conditional switching execution condition, or the UE considers that the measurement identifier associated with the candidate cell (or the event associated with the measurement identifier) ​​is met:

[0167] -Configured with NES conditional switching configuration;

[0168] - the NES conditional handover configuration includes NES conditional handover evaluation indication information or source cell NES state indication information (optionally, the NES conditional handover evaluation indication information indicates that the UE needs to perform NES conditional handover evaluation, or the source cell NES state indication information indicates that the source cell is currently in the NES state);

[0169] - The measurement ID or NES conditional switching event or NES conditional switching threshold associated with the NES conditional switching execution condition is met.

[0170] Wherein, optionally, when at least one of the following conditions is met, the UE considers that the measurement ID associated with the NES conditional switching execution condition (or the event associated with the measurement ID, or the NES conditional switching event, or the NES conditional switching threshold) is met;

[0171] -Configured with NES conditional switching configuration;

[0172] - the NES conditional handover configuration includes NES conditional handover evaluation indication information or source cell NES state indication information (optionally, the NES conditional handover evaluation indication information indicates that the UE needs to perform NES conditional handover evaluation, or the source cell NES state indication information indicates that the source cell is currently in the NES state);

[0173] - The entry condition of the NES conditional switching event (or the event associated with the measurement ID associated with the NES conditional switching execution condition, or the event corresponding to the NES conditional switching threshold value) is met.

[0174] Example 2

[0175] According to Embodiment 1, this embodiment includes step 201 and step 203 .

[0176] Optionally, step 201 is the same as step 101.

[0177] Optionally, in step 203, when the UE has started to evaluate the NES conditional handover execution condition and the UE receives the DCI with NES indication information, the UE (immediately) performs the NES conditional handover and switches from the source cell to the target cell. Optionally, when receiving the DCI with NES indication information, if there are candidate cells that meet the NES conditional handover execution condition, the target cell is selected from the candidate cells; otherwise, the target cell may be the neighboring cell with the best quality that the UE can detect.

[0178] Among them, optionally, the DCI in the "DCI with NES indication information" is, for example, DCI 2-9, and the DCI is a group DCI, and all UEs in the cell monitor DCI 2-9 through a specific RNTI. Optionally, the DCI may carry NES mode indication information of the source cell to indicate whether the source cell has entered the NES mode; or the DCI may carry NES conditional switching indication information to instruct the UE to perform NES conditional switching. "DCI with NES indication information" means that the NES mode indication information of the source cell in the DCI indicates that the source cell has entered the NES mode, or that the NES conditional switching indication information in the DCI indicates that the UE is to perform NES conditional switching immediately.

[0179] Example 3

[0180] Optionally, steps 301 , 303 and 305 are included in this example.

[0181] Optionally, in step 301, after the handover is successful, the UE saves the successful handover information in a UE variable FarSuccessHO-Report.

[0182] Optionally, in step 303, the UE receives an RRC request message (UE Information Request message) sent by the network. The RRC request message includes a success HO-ReportReq information element for requesting the UE to report a saved success HO report.

[0183] Optionally, in step 305, the UE sends an RRC response message (UE Information Response UEInformationResponse message) to the network. The RRC response message includes a success HO-Report information element saved by the UE.

[0184] Optionally, when the UE determines the content of the success HO-Report information element in the UEInformationResponse message (optionally, when the last handover to the target PCell was triggered by receiving a DCI with NES indication information), at least one of the following information is included:

[0185] - (Last time) the switch to the target PCell was triggered by receiving a DCI with NES indication information;

[0186] -(Last) time when switching to the target PCell was triggered by receiving a DCI with NES indication information;

[0187] - The time from the (last) evaluation of the NES conditional switching execution condition of the target PCell to the (last) receipt of a DCI with NES indication information to trigger the switching to the target PCell;

[0188] -(the last time the NES conditional switching execution condition was met) and the time elapsed from the last time a DCI with NES indication information was received to trigger switching to the target PCell.

[0189] Optionally, the “DCI with NES indication information” in this embodiment and the “DCI with NES indication information” in Embodiment 2 have the same meaning.

[0190] Example 4

[0191] Optionally, steps 401 , 403 and 405 are included in this example.

[0192] Optionally, in step 401, the UE generates and saves a radio link failure report (RLF report) when RLF or handover failure occurs, and saves the radio link failure information in a UE variable VarRLF-Report.

[0193] Optionally, in step 403, the UE receives an RRC request message (UE Information Request message) sent by the network. The RRC request message includes an RLF report request (rlf-ReportReq) information element for requesting the UE to report its stored radio link failure report.

[0194] Optionally, in step 405, the UE sends an RRC response message (UE information response UEInformationResponse message) to the network. The RRC response message includes a radio link failure report (rlf-Report) information element saved by the UE. Optionally, when the UE determines the content of the radio link failure report (rlf-Report) information element in the UEInformationResponse message, for each neighboring cell in the RLF report, the UE performs the following operations: Set the conditional switching configuration (choConfig) information element to the execution conditions corresponding to the first two measurement identifiers (measId) in the conditional trigger configuration (condTriggerConfig) information element associated with the neighboring cell in the conditional reconfiguration variable FarConditionalReconfig of the MCG.

[0195] Optionally, before performing the above choConfig setting operation, the UE may also determine whether the UE supports RLF reporting for conditional switching, and when RLF is detected, the neighboring cell is a candidate target cell for conditional switching (the synchronization reconfiguration element reconfigurationWithSync corresponding to the cell is included in the MasterCellGroup element in the saved conditional reconfiguration variable), and then perform the above setting operation.

[0196] Optionally, when the UE determines the content of the radio link failure report (rlf-Report) information element in the UEInformationResponse message, if the UE performs conditional switching to the target PCell according to the condRRCReconfig of the target PCell, (optionally, when the last switching to the target PCell was triggered by receiving a DCI with NES indication information), the UE includes at least one of the following information in the rlf-Report:

[0197] - The conditional handover failure of the target PCell is triggered by receiving a DCI with NES indication information;

[0198] - The time from the evaluation of the NES conditional switching execution condition of the target PCell (included in conditionalReconfiguration) to the receipt of the DCI with NES indication information to the target PCell to perform the failed conditional switching;

[0199] -The time elapsed from the (last) satisfaction of the NES conditional switching execution condition and the (last) receipt of the DCI with NES indication information to the conditional switching failure of the target PCell.

[0200] Optionally, the “DCI with NES indication information” in this embodiment has the same meaning as the “DCI with NES indication information” in Embodiment 2.

[0201] Figure 5 1 is a simplified structural diagram of a user equipment UE according to the present invention. Figure 5 As shown, the user equipment UE500 includes a processor 501 and a memory 502. The processor 501 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 502 may include, for example, a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memories, etc. The memory 502 stores program instructions. When the instructions are executed by the processor 501, the above method performed by the user equipment described in detail in the present invention may be executed.

[0202] The program running on the device according to the present invention can be a program that enables a computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or the information processed by the program can be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory systems.

[0203] The program for realizing the functions of various embodiments of the present invention can be recorded on a computer-readable recording medium. The corresponding functions can be realized by making a computer system read the program recorded on the recording medium and executing these programs. The so-called "computer system" herein can be a computer system embedded in the device, and can include an operating system or hardware (such as a peripheral device). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium of a short-term dynamic storage program, or any other recording medium that is computer-readable.

[0204] The various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., single-chip or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. The general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above circuits may be digital circuits or analog circuits. In the case where new integrated circuit technologies have emerged to replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

[0205] In addition, the present invention is not limited to the above-mentioned embodiments. Although various examples of the embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0206] As mentioned above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design changes that do not deviate from the main purpose of the present invention. In addition, the present invention can be modified in various ways within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. In addition, the components with the same effect described in the above embodiments can be replaced with each other.

Claims

1. A method for performing conditional switching by a user equipment, comprising: receiving an RRC reconfiguration message including conditional handover configuration information from the network, When it is determined that the first condition is met based on the RRC reconfiguration message, an NES conditional switching evaluation is performed to determine whether the candidate cell meets the NES conditional switching execution condition for the network energy saving NES, wherein the first condition includes at least one of the following: the RRC reconfiguration message indicates that the NES conditional switching is performed; the RRC reconfiguration message indicates that the source cell is in NES mode; as well as When it is determined that there is a candidate cell that meets the NES conditional handover execution condition, the NES conditional handover process of handing over to the target cell is executed with the candidate cell as the target cell.

2. The method according to claim 1, wherein: When at least one of the following is met, it is determined that the RRC reconfiguration message indicates to perform NES conditional switching: The RRC reconfiguration message includes NES conditional switching configuration information for the NES; The RRC reconfiguration message includes NES conditional switching evaluation indication information; The RRC reconfiguration message includes NES conditional switching evaluation indication information, and the NES conditional switching evaluation indication information indicates to perform NES conditional switching, and / or When at least one of the following conditions is met, it is determined that the RRC reconfiguration message indicates that the source cell is in NES mode: The RRC reconfiguration message includes NES conditional switching configuration information for the NES; The RRC reconfiguration message includes source cell NES state indication information; The RRC reconfiguration message includes source cell NES state indication information, and the source cell NES state indication information indicates that the source cell is in NES mode.

3. The method according to claim 1 or 2, wherein: The conditional switching configuration information includes an NES conditional switching event for each candidate cell, an NES conditional switching threshold, and at least one of a switching condition determined based on the NES conditional switching event and the NES conditional switching threshold for each NES conditional switching event. The NES conditional switch evaluation includes performing at least one of the following: Execute an evaluation to determine whether the NES condition switching event is satisfied; The NES conditional switching threshold is used to evaluate the conditional switching execution condition; An evaluation is performed as to whether the switching condition is met.

4. The method according to claim 1 or 2, further comprising: When the first condition is satisfied, the evaluation of the execution condition for the conditional switching of the non-NES is stopped.

5. The method according to claim 1 or 2, further comprising: When the first condition is not satisfied, evaluation of execution conditions for conditional switching of the non-NES is performed.

6. The method according to claim 1 or 2, further comprising: monitoring a DCI with NES indication information, where the NES indication information is used to indicate at least one of the following: whether the source cell is in NES mode; Whether to execute NES conditional switching; The NES conditional handover evaluation has been started when a DCI with NES indication information is monitored, and when the NES indication information indicates to perform NES conditional handover and / or the source cell is in NES mode, the NES conditional handover process of switching to the target cell is performed.

7. The method according to claim 6, wherein: If, when executing the NES conditional handover process, a candidate cell satisfying the NES conditional handover condition has been determined through the NES conditional handover evaluation, the candidate cell is used as the target cell, If no candidate cell that meets the NES conditional switching condition is determined when executing the NES conditional switching process, the candidate cell with the best quality is selected as the target cell.

8. The method according to claim 6, further comprising: If the handover is successfully performed, a successful handover report is generated, wherein the successful handover report includes at least one of the following: Information indicating that the handover corresponding to the successful handover report is triggered due to receiving the NES indication information; The time when the NES condition switching is triggered due to receiving the NES indication information; The time interval from the start of NES conditional handover evaluation to the handover to the target cell; When executing the NES conditional switching process, in the case that a candidate cell that meets the NES conditional switching condition has been determined through the NES conditional switching evaluation, the time interval from judging that the NES conditional switching execution condition is met to switching to the target cell due to receiving the NES indication message.

9. The method according to claim 6, further comprising: In the case of handover failure, a radio link failure report is generated, wherein the radio link failure report includes at least one of the following: Information indicating that the corresponding radio link failure is caused by the failure of executing the conditional handover, wherein the conditional handover is triggered by receiving the NES indication information related to the NES; The time from the start of NES conditional switch evaluation to the failure of the conditional switch; When executing the NES conditional switching process, in a case where a candidate cell that meets the NES conditional switching condition has been determined through the NES conditional switching evaluation, the time elapsed from the judgment that the NES conditional switching execution condition is met to the conditional switching failure triggered by receiving the NES indication message.

10. A user equipment, comprising: processor; as well as Memory, which stores instructions, Wherein, when the instructions are executed by the processor, the method according to any one of claims 1 to 9 is performed.

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