Method performed by a user equipment and the user equipment

Abstract

The present invention provides a method performed by a user equipment and the user equipment. The method includes: detecting that an MCG failure has occurred; if T316 is configured, and if SCG transmission is not suspended or if SCG transmission is suspended due to the SCG being deactivated, initiating an MCG failure information procedure; otherwise, initiating an RRC connection reestablishment procedure.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communication technologies. More specifically, the present disclosure relates to a method for recovery after a radio link failure and a corresponding user equipment. Background Art

[0002] The 3GPP RAN working group is currently conducting a research project for Release 17 (see 3GPP document RP-193249 (New WID on further enhancements on Multi-Radio Dual-Connectivity)). Among them, in order to further reduce the power consumption of the UE in the dual-connectivity (DC) scenario, one of the research objectives is to implement a dynamic Secondary Cell Group (SCG) activation / deactivation mechanism. In the state where the SCG is deactivated, the UE does not have to perform the downlink physical channel monitoring of the serving cells associated with the SCG, nor does it need to perform the relevant link status detection or link status reporting, so as to achieve the purpose of power saving. In the NR system of Release 16, there is a mechanism called fast primary cell group recovery. When the UE is configured with DC, if a radio link failure of the primary cell group is detected and the secondary cell group is in an active state at this time, the UE can report the occurred failure to the primary base station through the secondary cell group link and wait for a response from the network side to quickly recover the failed link.

[0003] The present disclosure proposes a solution to the problem of how to perform link recovery in the NR system under the introduction of the SCG activation / deactivation mechanism. Summary of the Invention

[0004] The purpose of the embodiments of the present disclosure is to propose a solution to the problem of how to perform link recovery in the NR system under the introduction of the SCG activation / deactivation mechanism. The embodiments of the present disclosure provide a link recovery method and a corresponding user equipment in the user equipment.

[0005] According to a first aspect of the present disclosure, a method executed in a user equipment UE is proposed, including: detecting that an MCG failure has occurred; if T316 is configured, and if SCG transmission is not suspended or if SCG transmission is suspended due to the SCG being deactivated, initiating an MCG failure information procedure; otherwise, initiating an RRC connection re-establishment procedure.

[0006] In the method executed by the user equipment according to the first aspect of the present invention, the SCG is activated during the MCG failure information procedure.

[0007] In the method executed by the user equipment according to the first aspect of the present invention, the initiation of the MCG failure information procedure is performed when there is no ongoing PSCell change procedure.

[0008] A method performed by a user equipment according to the first aspect of the present invention, wherein the MCG failure refers to a radio link failure.

[0009] A method performed by a user equipment according to the first aspect of the present invention, wherein the suspension of the SCG transmission due to the deactivation of the SCG means that the SCG transmission is not suspended due to an SCG failure.

[0010] A method performed by a user equipment according to the first aspect of the present invention, wherein the SCG failure refers to the occurrence of an SCG failure information procedure.

[0011] A method performed by a user equipment according to the first aspect of the present invention, wherein the SCG failure information procedure is initiated due to one or more of the following: detecting an RLF of the SCG, occurring a synchronization reconfiguration failure of the SCG, a SCG configuration failure, or receiving an integrity check failure indication of the signaling radio bearer SRB3 from the SCG lower layer.

[0012] A method performed by a user equipment according to the first aspect of the present invention, wherein activating the SCG at least includes restoring the SRB of the SCG.

[0013] A user equipment according to the second aspect of the present invention, comprising: a processor; and a memory storing instructions; wherein the instructions, when run by the processor, perform the method of the first aspect described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more fully understand the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 A flowchart of the basic process of the method performed by the user equipment in the first embodiment of the invention.

[0016] Figure 2 Is a block diagram showing a user equipment according to an embodiment of the present invention.

[0017] In the drawings, the same or similar structures are identified by the same or similar reference numerals. DETAILED DESCRIPTION

[0018] From the following detailed description of the exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, other aspects, advantages and salient features of the present disclosure will become apparent to those skilled in the art.

[0019] In the present disclosure, the terms "comprising" and "including" and their derivatives are intended to be inclusive rather than restrictive; the term "or" is inclusive and means and / or.

[0020] In this specification, the following various embodiments for describing the principles of the present disclosure are illustrative only and should not be construed in any way as limiting the scope of the disclosure. The following description with reference to the accompanying drawings is used to assist in a comprehensive understanding of the exemplary embodiments of the present disclosure defined by the claims and their equivalents. The following description includes various specific details to assist in the understanding, but these details should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and structures are omitted for clarity and conciseness. Further, throughout the drawings, the same reference numerals are used for similar functions and operations. Unless otherwise specified, the terms, definitions, and methods before the embodiments can be shared and can work together before the embodiments.

[0021] The following uses the Long Term Evolution (LTE) / NR mobile communication system and its subsequent evolved versions as an example application environment to specifically describe multiple embodiments according to the present disclosure. However, it should be noted that the present disclosure is not limited to the following embodiments, but is applicable to more other wireless communication systems. Without special instructions, in the present disclosure, the concepts of cell and base station can be replaced with each other; PSCell change refers to the change of the UE's PSCell from the source PSCell to the target PSCell, where the source PSCell and the target PSCell can be the same cell or different cells. The source PSCell is also called the source base station, and can also be the source beam, source transmission point (TRP), source secondary cell group (SCG). The target PSCell can also be called the target base station, and can also be the target beam, target transmission point, target SCG. The PSCell change command described in the present disclosure is an RRC reconfiguration message containing the reconfiguration with sync information element in the SCG configuration in the NR system, also called the synchronous reconfiguration of the SCG. In the LTE system, it is an RRC connection reconfiguration message containing the mobility control info information element in the SCG configuration. Among them, the reconfiguration with sync information element or the mobility control info information element contains one or more configuration information of the following target cells, such as target cell identifier, target cell frequency, common configuration of the target cell such as system information, random access configuration used by the UE to access the target cell, security parameter configuration of the UE in the target cell, radio bearer configuration of the UE in the target cell, etc. Cancel, release, delete, empty, and clear can be replaced. Execute, use, and apply can be replaced. Configure and reconfigure can be replaced. Link and connection can be replaced. Monitor and detect can be replaced. Without special instructions, the embodiments of the present disclosure are also applicable to the LTE system.

[0022] The prior art related to the embodiments of the present disclosure will be briefly described below.

[0023] Dual Connectivity (DC):

[0024] To improve the data transmission efficiency of the UE, the UE establishes links with two base stations simultaneously, that is, the radio resources used by the UE are provided by different schedulers located in two base stations. The radio access between these two base stations and the UE can be of the same or different radio access technologies (RATs), such as both being NR, or one being NR and the other being LTE, also known as Evolved Universal Terrestrial Radio Access (E-UTRA). Among these two base stations, one is called the Master Node (MN) or MgNB, MeNB, and the serving cell group under the master base station is called the Master Cell Group (MCG); the other is called the Secondary Node (SN) or SgNB, SeNB, and the serving cell group under the secondary base station is called the Secondary Cell Group (SCG). The MCG includes a Primary Cell (PCell) and optionally one or more Secondary Cells (SCells). The PCell operates on the primary frequency, and the UE performs the initial connection establishment process or connection re-establishment process through the primary frequency. The SCG includes a PSCell and optionally one or more SCells. The PSCell refers to the SCG cell where the UE performs random access when executing the synchronous reconfiguration process or the SCG addition process. The PCell and the PSCell are also collectively referred to as the special cell SpCell. In this disclosure, the SCG is taken as an example of the SCG under dual connectivity DC, but it is not limited to the SCG only in the case of dual connectivity DC. For example, it can be multiple SCGs in the case of more than two connections, that is, the UE is connected to more than two base stations. At this time, the operations described in the embodiments are performed for a corresponding SCG.

[0025] Link recovery mechanism in the existing mechanism:

[0026] Next, introduce the link recovery mechanism in the existing mechanism, i.e., versions 15 and earlier. In the existing mechanism, after the UE experiences a radio link failure (RLF) of the primary cell group or fails to execute the handover process (HandOver Failure, HOF) (i.e., T304 timeout), the UE will initiate an RRC connection re-establishment process to re-establish / recover the connection with the network side. During the initiated RRC connection re-establishment process, the UE first performs a cell selection process to select a re-establishment cell and sends an RRC connection re-establishment request message to it. When the UE receives a response message as an RRC connection re-establishment message, the UE re-establishes the RRC connection according to the configuration in the RRC connection re-establishment message and feeds back an RRC connection re-establishment complete message to the base station, successfully ending the RRC connection re-establishment process. The re-establishment cell refers to the cell used by the UE to send the RRC connection re-establishment request message and receive the corresponding response message for re-establishing the RRC connection in the RRC connected state. A timer T311 is defined during the RRC re-establishment process. When the UE initiates the RRC connection re-establishment process, T311 is started. When a suitable cell for re-establishment is selected during the cell selection process, T311 is stopped; if T311 times out and the UE cannot select a suitable cell, at this time, the UE is generally considered to be out of coverage, and the UE will leave the RRC connected state and enter the RRC idle state or the RRC inactive state (RRC_Inactive).

[0027] Fast MCG Link Recovery Mechanism:

[0028] The Dual Connectivity and Carrier Aggregation Enhancement Project in Release 16 (see RP-190452) introduced a fast MCG link recovery mechanism. The so-called "fast" is relative to the existing link recovery mechanism (i.e., recovering the link connection through the RRC connection re-establishment process). In the fast MCG link recovery mechanism, when the RLF of the UE's MCG occurs, if the link quality of the UE's Secondary Cell Group (SCG) is good (i.e., no RLF occurs, the timer T310 is not running, or it is not in the process of PSCell change (i.e., T04 corresponding to the SCG is not running), or the SCG is not in the suspended state), at this time, if neither the MCG nor the SCG is in the suspended (or interrupted) state or the timer T316 is not running, the UE initiates the MCG failure information procedure, and reports the MCG link failure information to the primary base station through the SCG link (such as the split Signalling Radio Bearer (split SRB) or Signalling Radio Bearer 3 (SRB3)), instead of directly triggering the RRC connection re-establishment process. In the MCG failure information procedure, the UE suspends the transmission on the MCG side corresponding to all SRBs and DRBs except SRB0, and resets the MAC entity corresponding to the MCG. The primary base station that receives the MCG link failure information report can send an RRC connection reconfiguration message containing a synchronization reconfiguration information element to trigger the UE to switch to a new cell or send an RRC release message to release the UE's RRC connection. This fast MCG link recovery mechanism / procedure can be applied to the case configured with MR-DC (Multi-Radio access technology Dual Connectivity), such as NE-DC (NR E-UTRA Dual Connectivity), EN-DC (E-UTRA NR Dual Connectivity), NR DC (New Radio Dual Connectivity), NGEN-DC (Next Generation-radio access network E-UTRA NR Dual Connectivity), LTE DC (intra-E-UTRAN DC), etc. In this disclosure, the MCG failure information procedure and the fast MCG link recovery procedure are equivalent.

[0029] UE energy saving mechanism at the cell granularity in the existing mechanism:

[0030] In the NR system of version 16, considering the change in the UE's traffic volume, the power consumption of the UE on an SCell can be reduced by deactivating the SCell or changing the bandwidth part (BWP) on which the SCell operates to a dormant BWP.

[0031] In the SCell activation / deactivation mechanism, one or more SCell are activated or deactivated mainly through Medium Access Control (MAC) Control Element (CE) or Radio Resource Control signaling. In addition, when the SCell deactivation timer associated with the SCell running on the UE expires or stops, the UE deactivates the corresponding SCell. When the UE receives an SCell activation / deactivation MAC CE, if the bit corresponding to an SCell in the MAC CE is set to "1" (i.e., indicating activation of the SCell), the UE activates the SCell; if it is set to "0" (i.e., indicating deactivation of the SCell), the UE deactivates the SCell. In addition, if the information element (sCellState) used to indicate the SCell activation / deactivation state of the SCell described in the RRC message received by the UE is set to "activated", the UE activates the SCell; otherwise, if the sCellState of the SCell described in the RRC message received by the UE is not set to "activated" or is set to "deactivated", the UE deactivates the SCell. When an SCell is in the active state, the UE performs normal operations on the SCell, including, for example: normally sending uplink and downlink data on the SCell, sending a Sounding Reference Signal (SRS) on the SCell, reporting Channel State Information (CSI) for the SCell, performing Physical Downlink Control Channel (PDCCH) monitoring on the SCell, performing PDCCH monitoring for the SCell and sending a Physical Uplink Control Channel (PUCCH) on the SCell, etc. When an SCell is deactivated, the UE stops the timer associated with the SCell, deactivates the activated Bandwidth Part (BWP) associated with the SCell, clears the configured downlink assignment or Type 2 configured uplink grant (Configured Grant, CG) associated with the SCell, suspends the Type 1 configured uplink grant, empties the Hybrid Automatic Repeat reQuest (HARQ) buffer associated with the SCell, etc.For a deactivated SCell, the UE does not perform normal operations on the SCell, including one or more of the following: does not send sounding reference signals (SRS) on the SCell, does not perform channel state indication (CSI) reporting for the SCell, does not perform physical downlink control channel (PDCCH) monitoring on the SCell, does not perform PDCCH monitoring for the SCell, does not perform physical uplink control channel (PUCCH) transmission on the SCell, does not send the uplink shared channel (UL-SCH) and random access channel (RACH) on the SCell.

[0032] In the SCell sleep mechanism, further energy saving is achieved by operating the active SCell on a configured sleep bandwidth part (BWP). The base station configures the UE with a sleep BWP identifier for an SCell through RRC signaling. When the active BWP of an SCell is the sleep BWP, it can be considered that the BWP or the SCell is in the sleep state. The base station notifies the UE to operate on the sleep BWP through RRC signaling or downlink control information (DCI) for BWP change. For a sleep BWP, the UE's operations include one or more of the following: does not monitor the PDCCH on the BWP, does not monitor the PDCCH for the BWP, does not receive the downlink shared channel (DL-SCH) on the BWP, does not perform CSI measurement for the BWP, stops all uplink behaviors associated with the SCell, etc.

[0033] However, the energy-saving mechanism of the above SCell does not apply to the PSCell. That is to say, the SpCell including the PCell and PSCell in Release 16 is always in the 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 transmissions or link monitoring when the UE traffic is low. One way is to introduce an activation / deactivation mechanism for the SCG, which quickly activates and deactivates the entire SCG cell group to adapt to the dynamically changing UE traffic / service rate, thereby improving the power utilization rate. The content and embodiments described in this disclosure focus on how to handle the problem of MCG link failure under the SCG activation / deactivation mechanism. Through the method described in this disclosure, when the UE has an MCG failure in the state where the SCG is deactivated, it can still use the SCG link to inform the network side of the link failure information, so that the network side can repair the link through means such as handover, avoiding the greater link interruption caused by the link repair mechanism of the UE through the traditional RRC connection re-establishment process, and also avoiding the DC configuration delay caused by the DC release during the unnecessary RRC re-establishment process. The activation / deactivation of the SCG, the resume / suspension of the SCG, and the activation / deactivation of the PSCell can be replaced with each other. The SCG activation / deactivation command is a general term for the SCG activation command and the SCG deactivation command.

[0034] Embodiment 1

[0035] This embodiment provides a link recovery method when the UE is simultaneously configured with fast MCG recovery and SCG deactivation.

[0036] Step 1: The UE detects that an MCG failure has occurred. Preferably, the MCG failure refers to a Radio Link Failure (RLF). The RLF of the MCG is generally considered to have detected the MCG RLF when one or more of the following conditions are met: when the T310 timer in the PCell times out, when the T312 timer in the PCell times out, when a random access problem indication is received from the Medium Access Control (MAC) layer of the MCG and at this time the T300, T301, T304, T311, and T319 timers are not running, or when an indication message is received from the Radio Link Control (RLC) layer of the MCG indicating that the maximum retransmission count has been reached.

[0037] Step 2: If T316 is configured, and if the SCG transmission is not suspended or if the SCG transmission is suspended because the SCG is deactivated, and if there is no ongoing PSCell change procedure (i.e., the T304 timer or the T307 timer for the SCG is not running), then initiate the MCG failure information procedure; otherwise, initiate the RRC connection re-establishment procedure.

[0038] Among them, the statement "if the SCG transmission is suspended because the SCG is deactivated" can also be expressed as if the SCG transmission is not suspended due to an SCG failure. The SCG failure refers to the occurrence of an SCG failure information procedure. Preferably, the SCG failure information procedure is initiated due to detecting an RLF of the SCG; alternatively, it is due to the occurrence of an SCG synchronization reconfiguration failure, an SCG configuration failure, or receiving an integrity check failure indication for SRB3 from the SCG lower layer.

[0039] Step 3: During the MCG failure information procedure, when initializing the MCG failure information procedure, activate the SCG. Activating the SCG includes resuming the SCG transmission. By activating this SCG transmission, the UE initiates the sending of an MCG failure information RRC message on the SCG side of SRB3 or the split SRB1, thereby informing the network side of the MCG failure.

[0040] Activating the SCG at least includes resuming the SRBs of the SCG, such as SRB1 and / or SRB3.

[0041] Optionally, it further includes Step 4, where the UE receives a response RRC message from the network side and executes the RRC message. The response message can be an RRC connection reconfiguration message for indicating a handover (carrying the reconfigurationwithsync information element for the MCG), or an RRC connection release message for indicating that the UE releases / suspends the RRC connection. In addition, Step 4 can also be that T316 times out, the UE does not receive a response RRC message from the network side, and initiates the RRC connection re-establishment procedure.

[0042] The MCG failure information procedure is also referred to as the fast MCG link recovery procedure.

[0043] As mentioned above, the UE usually initiates the MCG failure information procedure when the following conditions are met: the UE is configured with parameters for fast MCG link recovery, i.e., the timer T316, the UE is configured with a split SRB or SRB3, both the MCG and the SCG are not in a suspended state, and the timer T316 is not running.

[0044] Timer T316 is used to monitor the process of MCG failure information. The UE starts T316 when sending the MCG failure information message. T316 is stopped when the MCG transmission is restored, or when receiving the response RRC release message from the network side, or when initiating the RRC reestablishment process. When T316 times out, the UE considers the fast MCG link restoration process to have failed and ended, thus triggering the RRC reestablishment process to attempt to restore the connection with the network side.

[0045] Embodiment 2

[0046] In this embodiment, in order to prevent the UE from being unable to perform fast MCG link restoration through the deactivated SCG link when MCG failure occurs, certain restrictions are imposed on the configuration of the network side. The restriction is that the network side will not deactivate the SCG while enabling / configuring the fast MCG restoration mechanism for the UE. Preferably, the enabling / configuring of the fast MCG restoration mechanism means configuring T316. Through such configuration restrictions, when the MCG fails for the UE, if the fast MCG link restoration is configured, its SCG is always in the active state, thus ensuring that the fast MCG link restoration mechanism can be executed.

[0047] Preferably, if the UE receives a command from the network side to deactivate the SCG when the fast MCG restoration is configured, the UE ignores the SCG deactivation command. Alternatively, if the UE receives an RRC message for configuring fast MCG restoration in the SCG deactivated state, the UE ignores the configuration or considers the RRC reconfiguration to have failed. If the same RRC message received by the UE contains both the enabling configuration of fast MCG restoration and the deactivation indication of the SCG, the UE considers the RRC reconfiguration to have failed.

[0048] In the current 3GPP progress, the UE behavior when the SCG is activated and deactivated has not been finalized. In this disclosure, the specific behavior of the UE when in the SCG active state and the SCG deactivated state is not limited either.

[0049] As an example, when the UE changes an SCG from the deactivated state to the active state, the UE performs one or more of the following operations:

[0050] Operation 1: Activate all the SCells in the SCG, which is executed at the MAC layer or the RRC layer;

[0051] Operation 2: Activate the PSCell corresponding to the SCG, which is executed at the MAC layer or the RRC layer;

[0052] Operation 3: Activate the downlink BWP and uplink BWP indicated by the firstActiveDownlinkBWP-Id information element and / or the firstActiveDownlinkBWP-Id information element respectively; wherein the firstActiveDownlinkBWP-Id information element and the firstActiveDownlinkBWP-Id information element are configured by the network side through RRC signaling (such as the RRC reconfiguration message), and are used to indicate the downlink / uplink BWP identifier activated when the configuration of the RRC signaling is executed or the downlink / uplink BWP identifier used when the MAC layer activates an SCell or a PSCell, and is executed at the MAC layer;

[0053] Operation 4: Start or restart the sCellDeactivationTimer timer associated with the SCell or PSCell; wherein the sCellDeactivationTimer is used for the activation / deactivation state control of the SCell or PSCell. When it times out, the UE considers the associated cell to be in the deactivated state. When it is running, the UE considers the associated cell to be in the activated state. It is executed at the UE MAC layer. In another way, this operation includes starting or restarting the SCGdeactivationTimer timer associated with the SCG, wherein the sCellDeactivationTimer is used for the activation / deactivation state control of the SCG. When it times out, the UE considers the associated SCG to be in the deactivated state. When it is running, the UE considers the associated SCG to be in the activated state. In yet another way, this operation includes stopping the SCG activation / deactivation timer, and the SCG activation / deactivation timer is used for the activation / deactivation state control of the SCG. When it times out, the UE considers the associated SCG to be in the activated state, and the UE executes the state change operation from the deactivated state to the activated state described in this embodiment; when it is running, the UE considers the associated SCG to be in the deactivated state.

[0054] Operation 5: Initialize or re-initialize the suspended type 1 configured uplink grant associated with the SCell or PSCell; executed at the UE MAC layer

[0055] Preferably, the above operations 3 to 5 are performed when the firstActiveDownlinkBWP-Id is not set to the dormant BWP. Optionally, when the SCG activation command is a MAC CE or RRC signaling, in the SCG activation command, in addition to indicating that the status of the PSCell / SCG is active, the activation status of each SCG SCell is separately indicated as active or deactivated. In this case, the SCell in operation 1 refers to all SCells with the activation status indicated as active, and the above operations 3 to 5 are also performed on all SCells with the activation status indicated as active.

[0056] Operation 6: Resume all DRBs and SRBs associated with the SCG. This includes the SCG part of the split bearer. Execute at the RRC layer of the UE

[0057] Operation 7: Start or restart the uplink timing alignment timer timeAlighmentTimer for uplink timing alignment associated with the uplink timing advance group (TAG) of the SCG / PSCell or PSCell; Execute at the MAC layer of the UE

[0058] Operation 8: Perform the operation of resetting the MAC entity; Preferably, the operation of resetting the MAC entity does not include canceling the triggered buffer status report process (BSR). Execute at the MAC layer of the UE.

[0059] Operation 9: Trigger 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 parameters in the SCG activation command are configured in the SCG activation command, the UE performs the random access procedure of the PSCell. The random access parameters (identified by the RACH-ConfigDeadicated information element) refer to the time-frequency resources of the physical random access channel PRACH for performing the RACH procedure, the reference signal received power (RSRP) threshold configuration of the synchronization signal block (SSB) / channel status information reference signal (CSI-RS), and priority parameters (such as the ra-Prioritization information element), etc. Optionally, if the uplink timing alignment timer associated with the PSCell is in a non-operating state, the UE performs random access; otherwise, the UE does not perform random access.

[0060] 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, such as when the BSR is triggered or the random access procedure is triggered, the MAC entity indicates the SCG activation information to the upper layer (such as the RRC layer).

[0061] Operation 11: If the SCG activation command is obtained through the physical layer signaling DCI, such as the SCG activation field included in the DCI indicates SCG activation or the BWP identification included in the DCI indicates that the BWP is not a dormant BWP, the physical layer indicates the SCG activation information or the PSCell activation information or the BWP change information to the upper layer (such as the MAC layer or the RRC layer). Preferably, the DCI refers to the DCI for the PSCell or SCell of the SCG. In this case, the BWP refers to the BWP configured for the PSCell or the SCell.

[0062] Operation 12: If the SCG activation command is obtained through the received RRC signaling, or the SCG activation decision is determined by the RRC, such as when the CPC execution procedure is triggered, the RRC layer indicates the SCG activation information to the lower layer (such as the MAC layer). The SCG activation information can also be expressed as the PSCell activation information.

[0063] When the UE receives the SCG activation command, it performs the above operations of transitioning from the SCG deactivation state to the SCG activation state. Alternatively, when the MAC layer or RRC layer of the UE receives the inter-layer interaction indication information for Operations 10 to 12, such as information indicating SCG activation, it performs the relevant operations above.

[0064] Operation 13: Start radio link monitoring (RLM) of the SCG link;

[0065] Operation 14: Transition from relaxed requirement radio resource management (RRM) measurements to performing normal RRM measurements for the SCG.

[0066] Operation 15: Start beam failure monitoring and possible beam failure recovery for the SCG link.

[0067] Operation 16: Start the transmission of sounding reference signal (SRS).

[0068] As an example, when the UE changes an SCG from the active state to the active state, the UE performs one or more of the following operations:

[0069] Operation 1: Deactivate all SCell in the SCG, which is performed at the MAC layer or RRC layer;

[0070] Operation 2: Deactivate the PSCell corresponding to the SCG, which is performed at the MAC layer or RRC layer;

[0071] Operation 3: Deactivate all BWPs of the PSCell or SCell of the SCG, which is performed at the MAC layer;

[0072] Operation 4: Stop the sCellDeactivationTimer timer associated with the SCell or PSCell or SCG; wherein, the sCellDeactivationTimer is used for the activation / deactivation state control of the SCell or PSCell or SCG. When it expires, the UE considers the associated cell or SCG to be in the deactivation state. This is performed at the UE MAC layer. In one way, this operation includes starting the SCG activation / deactivation timer, which is used for the activation / deactivation state control of the SCG. When it expires, the UE considers the associated SCG to be in the active state, and the UE performs the state change operation from the SCG deactivation state to the active state described in this embodiment; when it is running, the UE considers the associated SCG to be in the deactivation state.

[0073] Operation 5: Suspend the uplink grant and / or downlink allocation of the suspended Type 1 configuration associated with the SCell or PSCell, and clear the corresponding Type 2 configuration uplink grant; execute at the UE MAC layer.

[0074] Operation 6: Suspend all DRBs and SRBs associated with all SCGs. This includes the SCG part of the split bearer. Execute at the RRC layer of the UE.

[0075] Operation 7: Stop the uplink timing alignment timer used for uplink timing alignment associated with the SCG; execute at the UE MAC layer. In another way, this operation can also be performed as applying the SCG deactivation associated timer value to the uplink timing alignment timer timeAlignmentTimer. The value of the timer refers to the value used to configure the timer duration (configured by the timeAlignmentTimer information element in the TAG-Config information element); the timer refers to the timer corresponding to the TAG associated with the PSCell or SCell of the SCG. The SCG deactivation associated timer value means that the configured duration value of the timer is different in the SCG deactivation state from the timer duration value used in the SCG activation state.

[0076] Operation 8: Execute the operation of resetting the MAC entity; execute at the UE MAC layer.

[0077] 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, such as when the deactivation timer associated with the PSCell expires or the timer associated with the SCG deactivation expires, the MAC entity indicates the SCG deactivation information to the upper layer (such as the RRC layer).

[0078] Operation 10: If the SCG deactivation command is obtained through the physical layer signaling DCI, such as the SCG deactivation field included in the DCI indicates SCG deactivation or the BWP identification included in the DCI indicates that the BWP is a dormant BWP, the physical layer indicates the SCG deactivation information or the PSCell deactivation information or the BWP change information to the upper layer (such as the MAC layer or the RRC layer). Preferably, the DCI refers to the DCI for the PSCell or SCell of the SCG, and at this time the BWP refers to the BWP configured for the PSCell or the SCell.

[0079] Operation 11: If the command for deactivating the SCG is obtained through the received RRC signaling, or the decision for deactivating the SCG is determined by the RRC, such as when the CPC execution process is triggered, the RRC layer indicates the information for deactivating the SCG to the lower layer (such as the MAC layer). The information for deactivating the SCG can also be expressed as the information for deactivating the PSCell.

[0080] Operation 12: If a DRB or SRB is configured as a split bearer, and if its primary path information element primaryPath is set to SCG, then set the primary path or the primarypath information element to MCG. Preferably, this operation is performed when the RB is not configured with PDCP duplication (indicated by the pdcp-Duplication information element). The primarypath information element is used to indicate the logical channel identifier and cell group identifier of the primary RLF entity for uplink transmission when the PDCP entity of a bearer is associated with more than one RLC entity.

[0081] Operation 13: Change the currently active working BWP of the PSCell and / or SCell of the SCG to a dormant BWP.

[0082] The UE performs the operations from the SCG active state to the SCG deactivated state as described above when receiving the SCG deactivation command or when the UE determines the SCG deactivation (such as when the corresponding deactivation timer expires), or when the MAC layer or 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, and performs the relevant operations as described above.

[0083] The SCG activation / deactivation command can be included in the RRC signaling, MAC CE, or the physical layer L1 signaling DCI. In one way, the SCG deactivation command can indicate the state of the PSCell or each SCell, such as indicating that the cell is in the deactivated state, or indicating that the cell changes the active working BWP to a dormant BWP.

[0084] Operation 14: Stop the radio link monitoring (RLM) of the SCG link;

[0085] Operation 15: Switch from the normal RRM measurement of the SCG to performing relaxed requirement radio resource management (RRM) measurement.

[0086] Operation 16: Stop performing beam failure monitoring and possible beam failure recovery for the SCG link.

[0087] Operation 17: Stop transmitting the Sounding Reference Signal (SRS).

[0088] As an example, the UE operations in the SCG deactivation state include one or more of the following:

[0089] Do not transmit SRS on the PSCell and SCell of the SCG;

[0090] Do not report CSI for the PSCell and SCell of the SCG;

[0091] Do not transmit UL-SCH on the PSCell and SCell of the SCG;

[0092] Do not transmit RACH on the PSCell and SCell of the SCG;

[0093] Do not monitor PDCCH on the PSCell and SCell of the SCG;

[0094] Do not monitor the PDCCH for the PSCell and SCell of the SCG;

[0095] Do not transmit PUCCH on the PSCell and SCell of the SCG;

[0096] Do not receive UL-SCH on the PSCell and SCell of the SCG;

[0097] Do not perform the beam failure detection and beam failure recovery procedures for the PSCell and / or SCell of the SCG;

[0098] The DRB or SRB associated with the SCG is in a suspended state;

[0099] Do not trigger BSR;

[0100] Do not trigger the PHR procedure for power headroom reporting;

[0101] The PSCell and SCell of the SCG operate on the dormant BWP corresponding to the cell.

[0102] Do not perform radio link monitoring (RLM) on the SCG link;

[0103] Do not perform normal RRM measurements for the SCG, but perform relaxed requirement radio resource management (RRM) measurements.

[0104] Do not perform beam failure monitoring and possible beam failure recovery on the SCG link.

[0105] The transmission of the sounding reference signal (SRS) is not performed.

[0106] As an example, a UE in the SCG active state performs normal communication operations on the PSCell and SCell of the SCG, including one or more of the following:

[0107] Transmit SRS on the PSCell and SCell of the SCG;

[0108] Report CSI for the PSCell and SCell of the SCG;

[0109] Transmit UL-SCH on the PSCell and SCell of the SCG;

[0110] Transmit RACH on the PSCell and SCell of the SCG;

[0111] Monitor PDCCH on the PSCell and SCell of the SCG;

[0112] Monitor the PDCCH for the PSCell and SCell of the SCG;

[0113] Transmit PUCCH on the PSCell and SCell of the SCG;

[0114] Receive UL-SCH on the PSCell and SCell of the SCG;

[0115] Perform beam failure detection and beam failure recovery procedures for the PSCell and / or SCell of the SCG;

[0116] The DRB or SRB associated with the SCG is in a non-suspended state;

[0117] The PSCell and SCell of the SCG do not operate on the dormant BWP corresponding to the cell.

[0118] In addition, when only the PSCell is in the active state or the PSCell does not operate on the dormant BWP in the SCG active state, one or more of the above operations are for the active PSCell and SCell or the SCell operating on the non-dormant BWP.

[0119] Perform radio link monitoring (RLM) on the SCG link;

[0120] Perform normal RRM measurements for the SCG.

[0121] Perform beam failure monitoring and possible beam failure recovery for the SCG link.

[0122] Perform the transmission of uplink sounding reference signals (SRS).

[0123] In the present disclosure, a "base station" refers to a mobile communication data and control switching center with a relatively large transmission power and a relatively wide coverage area, including functions such as resource allocation scheduling, data reception and transmission, etc. A "user equipment" refers to a user mobile terminal, such as a mobile phone, a notebook, etc., which are terminal devices capable of wireless communication with a base station or a small base station.

[0124] The methods and related devices of the present disclosure have been described above in combination with preferred embodiments. Those skilled in the art can understand that the methods shown above are merely exemplary. The methods of the present disclosure are not limited to the steps and sequences shown above. The base stations and user equipments shown above may include more modules, for example, may also include modules that can be developed or will be developed and can be used for base stations, MMEs, or UEs, etc. The various identifiers shown above are merely exemplary rather than restrictive, and the present disclosure is not limited to the specific cells that are examples of these identifiers. Those skilled in the art can make many changes and modifications according to the teachings of the illustrated embodiments.

[0125] The program running on the device according to the present disclosure can be a program that enables a computer to implement the functions of the embodiments of the present disclosure 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.

[0126] The programs for implementing the functions of the embodiments of the present disclosure can be recorded on a computer-readable recording medium. The corresponding functions can be implemented by causing a computer system to read the programs recorded on the recording medium and execute these programs. The so-called "computer system" here can be a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). A "computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium for short-time dynamically storing programs, or any other recording medium readable by a computer.

[0127] The various features or functional modules of the devices used in the above embodiments may be implemented or executed by circuitry (e.g., a single or multiple integrated circuits). The circuitry designed to perform the functions described in this specification 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 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 circuitry may be digital circuitry or analog circuitry. In the case where new integrated circuit technologies that replace existing integrated circuits emerge due to the progress of semiconductor technology, one or more embodiments of the present disclosure may also be implemented using these new integrated circuit technologies.

[0128] In addition, the present disclosure is not limited to the above embodiments. Although various examples of the described embodiments have been described, the present disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors may be used as terminal devices or communication devices, such as AV devices, kitchen appliances, cleaning devices, air conditioners, office equipment, vending machines, and other household appliances, etc.

[0129] As described above, the embodiments of the present disclosure 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 disclosure also includes any design modifications that do not deviate from the gist of the present disclosure. Additionally, various modifications may be made to the present disclosure within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Furthermore, components having the same effects described in the above embodiments may be substituted for each other.

Claims

1. A method performed by a user equipment, comprising: Detecting that an MCG failure has occurred; If T316 is configured, and if SCG transmission is not suspended or if SCG transmission is suspended due to the SCG being deactivated, initiating an MCG failure information procedure; Otherwise, initiating an RRC connection re-establishment procedure; If T316 times out and the UE does not receive a response RRC message from the network side, initiating an RRC connection re-establishment procedure; The SCG transmission being suspended due to the SCG being deactivated means that the SCG transmission is not suspended due to an SCG failure; The SCG failure refers to the occurrence of an SCG failure information procedure; The SCG failure information procedure is initiated due to one or more of monitoring an RLF of the SCG, occurrence of a synchronization reconfiguration failure of the SCG, SCG configuration failure, or receiving an integrity check failure indication regarding the signaling radio bearer SRB3 from the SCG lower layer; The UE initiating the MCG failure information procedure includes: activating the SCG during an initialization process after the MCG failure information procedure is initiated, and the activating the SCG includes at least restoring the SRB of the SCG.

2. The method performed by a user equipment according to claim 1, wherein: Initiating the MCG failure information procedure is performed when there is no ongoing PSCell change procedure.

3. The method performed by a user equipment according to claim 1, wherein: The MCG failure refers to a radio link failure.

4. A user equipment, comprising: A processor; And A memory storing instructions; Wherein, the instructions, when run by the processor, perform the method according to any one of claims 1 to 3.

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