User equipment, base station and method thereof

Abstract

According to the present invention, a user equipment, a base station and a method thereof are provided. The method executed by user equipment UE comprises the following steps: for the UE in an RRC inactive state, if the UE is added and activated MBS multicast session exists, and a measurement result of a service cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during operation of the timer, in the case that a measurement result of a serving cell becomes higher than or not lower than a threshold configured for the MBS multicast session, stopping the timer.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more particularly, to user equipment, a base station and a method thereof. Background Art

[0002] A research project SI (see SP-190625 for details) on 5G multicast broadcast service architecture improvements has been approved. One of the goals of this SI (called goal A) is to support generic MBS services in 5GS. Use cases that can benefit from this feature include (but are not limited to) public safety, V2X applications, transparent IPv4 / IPv6 multicast transmission, IPTV, wireless software transmission, group communication and IoT applications. Accordingly, at the 3rd Generation Partnership Project (3GPP) RAN#86 plenary meeting, a work item on NR multicast and broadcast service (NR MBS) was proposed and approved (see non-patent literature: RP-193248: New WID: NR Multicast and Broadcast Service). This work item aims to provide support for goal A in RAN. The goals of this work item have been basically achieved, and the specific description of the relevant solutions can be found in 3GPP Release 17 technical documents, such as TS38.300-h50, TS38.331-h50, TS38.321-h50, etc. At the 3GPP RAN#94 plenary meeting, a work item named Enhanced NR Multicast and Broadcast Services was approved (see non-patent document: RP-213568: New WID: Enhancements of NR Multicast and Broadcast Services). This work item aims to further enhance the MBS Multicast and Broadcast Services of Release 17, one of its goals is to support user equipment to receive MBS multicast services / sessions in the RRC inactive state.

[0003] The present invention discusses the related issues involved in RAN supporting user equipment to receive MBS multicast services / sessions in an RRC inactive state. Summary of the invention

[0004] In order to solve the above problems, the object of the present invention is to provide a user equipment, a base station and a method thereof, which can effectively maintain or stop or restart a timer started by a UE in an RRC inactive state for an MBS multicast session.

[0005] In order to achieve the above-mentioned purpose, according to the present invention, a method performed by a user equipment UE is proposed, comprising: for a UE in an RRC inactive state, if there is an MBS multicast session to which the UE has joined and is activated, and the measurement result of the serving cell is lower than or not higher than the threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the operation of the timer, if the measurement result of the serving cell becomes higher than or not lower than the threshold configured for the MBS multicast session, stopping the timer.

[0006] In addition, according to the present invention, a method performed by a user equipment UE is proposed, comprising: for a UE in an RRC inactive state, if there is an MBS multicast session to which the UE has joined and is activated, and the measurement result of the serving cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the operation of the timer, if the MBS multicast session is deactivated, stopping the timer.

[0007] In addition, according to the present invention, a method performed by a user equipment UE is proposed, comprising: for a UE in an RRC inactive state, if there is an MBS multicast session to which the UE has joined and is activated, and the measurement result of the serving cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the operation of the timer, when dedicated RRC signaling or an MBS multicast configuration message is received, stopping the timer.

[0008] In addition, according to the present invention, a method performed by a user equipment UE is proposed, comprising: for a UE in an RRC inactive state, if there is an MBS multicast session that the UE has joined and is activated, and the measurement result of the serving cell is lower than or not higher than the threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the operation of the timer, when a dedicated RRC signaling or an MBS multicast configuration message is received, if the dedicated RRC signaling or the MBS multicast configuration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the current threshold or the MBS multicast configuration message indicates that the configuration of the MBS multicast session is updated, stopping the timer.

[0009] Preferably, the method further comprises: when the timer expires, the UE initiates the RRC recovery process or the UE initiates the RRC recovery process for MBS multicast reception.

[0010] Preferably, the method further comprises: in case of receiving the dedicated RRC signaling or the MBS multicast configuration message, if there is an RRC recovery process to be executed triggered by the expiration of a timer, canceling the RRC recovery process to be executed.

[0011] Preferably, the method further includes: when receiving dedicated RRC signaling or MBS multicast configuration message, for each MBS multicast session that UE has joined and activated, if the dedicated RRC signaling or MBS multicast configuration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the currently configured threshold, or the MBS multicast configuration message indicates that the configuration of the MBS multicast session is updated or the MBS multicast configuration message indicates that the MBS multicast session is deactivated, then canceling the RRC recovery process to be executed triggered by the expiration of the timer of the MBS multicast session.

[0012] In addition, according to the present invention, a user equipment is proposed, comprising: a processor; and a memory storing instructions, wherein the instructions execute the above method when executed by the processor.

[0013] In addition, according to the present invention, a method performed by a base station is proposed, wherein the base station communicates with a user equipment UE, and the method comprises: sending dedicated RRC signaling or an MBS multicast configuration message to the UE, wherein the dedicated RRC signaling or the MBS multicast configuration message can stop a timer started for an MBS multicast session by a UE in an RRC inactive state.

[0014] In addition, according to the present invention, a base station is proposed, comprising: a processor; and a memory storing instructions, wherein the instructions execute the above method when executed by the processor.

[0015] Effects of the Invention

[0016] According to the present invention, the timer started by the UE in the RRC inactive state for the MBS multicast session can be effectively maintained, stopped or restarted. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 is a flowchart showing a method executed by a user equipment according to embodiment 1 of the present invention.

[0019] Figure 2 is a flowchart showing a method executed by a user equipment according to embodiment 2 of the present invention.

[0020] Figure 3 is a flowchart showing a method executed by a user equipment according to embodiment 3 of the present invention.

[0021] Figure 4 is a flowchart showing a method executed by a user equipment according to embodiment 4 of the present invention.

[0022] Figure 5 is a block diagram schematically showing a user equipment involved in the present invention.

[0023] Figure 6 is a block diagram schematically showing a base station involved in the present invention. DETAILED DESCRIPTION

[0024] The following describes some terms involved in the present invention. For specific meanings of the terms, refer to the latest relevant 3GPP documents, such as TS38.300-h50, TS38.321-h50, TS38.323-h50, TS38.331-h50, etc. In addition, the embodiments of the present invention are described by taking broadcast / multicast services as an example, but the embodiments of the present invention are not limited to broadcast / multicast services and can also be applied to other application scenarios.

[0025] UE: User Equipment.

[0026] RRC: Radio Resource Control.

[0027] RRC_CONNECTED: RRC connected state.

[0028] RRC_INACTIVE: RRC inactive state.

[0029] RRC_IDLE: RRC idle state.

[0030] RAN; Radio Access Network, wireless access network.

[0031] NR: New RAT, new radio access technology.

[0032] MBS: Multicast / Broadcast Services. Multicast can also be called multicast.

[0033] AS: Access Stratum, access layer or access layer.

[0034] NAS: Non Access Stratum, non-access layer or non-access layer.

[0035] RB: Radio Bearer. DRB is a data radio bearer.

[0036] MRB: MBS radio bearer, i.e., a radio bearer that is configured for MBS delivery. MRB is divided into multicast MRB and broadcast MRB. Multicast MRB is a radio bearer configured for MBS multicast transmission, while broadcast MRB is a radio bearer configured for MBS broadcast transmission.

[0037] TMGI: Temporary Mobile Group Identity, used to identify an MBS session.

[0038] RNTI: Radio Network Temporary Identifier, wireless network temporary identifier.

[0039] PTM: Point to Multipoint, a delivery method for MBS services. In the PTM delivery method, the gNB delivers a single copy of MBS data packets to a set of UEs. The UE uses G-RNTI or G-CS-RNTI to receive PTM transmissions. For example, the base station uses the group common physical downlink control channel PDCCH using G-RNTI to schedule the same group common physical downlink shared channel PDSCH using G-RNTI.

[0040] PTP: Point to Point, a delivery method for MBS services. In the PTP delivery method, the gNB individually delivers separate copies of MBS data packets to each UEs independently. For example, the base station schedules the UE-specific PDCCH scrambled with the UE-specific RNTI and the UE-specific PDSCH scrambled with the same UE-specific RNTI.

[0041] PCell: Primary Cell, MCG cell, operates on the primary frequency, in which the UE performs the initial connection establishment process or initiates the connection re-establishment process.

[0042] SCell: Secondary Cell. For UEs configured with carrier aggregation, SCell is a cell that provides additional radio resources on top of a special cell. For dual connectivity operation, the term special cell refers to the PCell of an MCG or the PSCell of an SCG, otherwise the term special cell refers to the PCell. For dual connectivity operation, the PSCell is the secondary cell group SCG cell in which the UE performs random access when performing a synchronous reconfiguration procedure.

[0043] G-RNTI: Group RNTI, group RNTI, used to scramble the scheduling and transmission of PTM for one or more MBS multicast services.

[0044] G-CS-RNTI: Group configuration scheduling RNTI, used to scramble the semi-static scheduling SPS group common physical downlink shared channel PDSCH of one or more MBS multicast services and activate / deactivate the SPS group common PDSCH.

[0045] MTCH: MBS Traffic Channel, MBS traffic channel, is a PTM downlink channel used to transmit MBS data of a multicast session or a broadcast session from the network to the UE. Unless otherwise specified, the MTCH involved in the embodiments of the present disclosure refers to a multicast MTCH used to transmit an MBS multicast session.

[0046] MCCH:MBS Control Channel, MBS control channel, is a PTM downlink channel used for transmitting MBS broadcast or MBS multicast control informationassociated to one or several MTCH(s)from the network to the UE. MCCH includes broadcast MCCH and multicast MCCH.

[0047] The RRC recovery request message RRCResumeRequest or RRCResumeRequest1 is used to request the recovery of a suspended RRC connection or to perform a RAN-based notification area RNA update. When the UE initiates an RRC connection recovery request, if SIB1 contains the useFullResumeID field, the RRCResumeRequest1 message is used and the resumeIdentity field in the RRCResumeRequest1 message is set to the fullI-RNTI stored by the UE, otherwise RRCResumeRequest is used and the resumeIdentity field in the RRCResumeRequest message is set to the stored shortI-RNTI. The RRC release message RRCRelease is used to command the release of an RRC connection or to suspend an RRC connection. The RRC reconfiguration message RRCReconfiguration is used to command the modification of the RRC connection. The RRC recovery message RRCResume is used to recover a suspended RRC connection. In the present disclosure, the useFullResumeID field indicates the recovery identifier and recovery request message used. When the field is included in SIB1, fullI-RNTI and RRCResumeRequest1 message are used. When the field is not included in SIB1, shortI-RNTI and RRCResumeRequest message are used. ShortI-RNTI uses fewer bits than I-RNTI-Value to identify the suspended UE context of a UE in an RRC inactive state. The RRC recovery process (i.e., the RRC connection recovery process) is used to restore the suspended RRC connection, including restoring SRB(s), DRB(s) and multicast MRB(s), or performing RNA updates, or implementing MBS multicast reception requests, or initiating small data transmission SDT in the RRC_INACTIVE state, etc. During the RRC recovery process, the UE sends an RRC recovery request message to the base station, and may receive an RRC recovery message RRCResume or an RRC establishment message RRCSetup or an RRC release message RRCRelease or an RRC rejection message RRCReject from the base station.

[0048] In the present invention, network, base station and RAN can be used interchangeably, and the network can be a long-term evolution LTE network, a NR network, an enhanced long-term evolution eLTE network, or other networks defined in subsequent evolution versions of 3GPP.

[0049] At present, NR MBS services include MBS broadcast (also called MBS broadcast session or broadcast MBS or MBS broadcast service or MBS broadcast service) and MBS multicast (also called MBS multicast session or multicast MBS or MBS multicast service or MBS multicast service). MBS broadcast provides a downlink-only MBS transmission mode for services with low quality of service QoS, so that UEs in RRC connected state, RRC idle state and RRC inactive state can receive the MBS service. The UE obtains the MBS broadcast configuration information broadcast by the network through the MBS control channel MCCH.

[0050] In version 17, it is not supported for UE to receive MBS multicast session in RRC inactive state. Therefore, before receiving MBS multicast service (i.e., MBS multicast session), UE needs to establish RRC connection with base station, and then the base station configures resources or PTM configuration for receiving MBS multicast service for UE through dedicated RRC signaling (also called RRC message, such as RRC reconfiguration message). MBS radio bearer MRB for receiving these MBS multicast services is also configured for UE by base station through dedicated RRC signaling. Only UE in RRC connected state and configured with MRB can receive corresponding MBS multicast service. Therefore, when an MBS multicast session is activated by the core network or the base station has MBS multicast session data to send, the network supporting MBS multicast notifies UE in RRC idle state or RRC inactive state through group notification mechanism. Upon receiving the group notification, UE that has joined the MBS multicast session or is interested in the MBS multicast session establishes or restores RRC connection with the network to receive the corresponding MBS multicast session. The group notification is addressed with P-RNTI on PDCCH, and the UE monitors the paging channel. The paging message for group notification contains the MBS session identifier TMGI, which is used to page all UEs that have joined the relevant MBS multicast session and are in RRC idle state or RRC inactive state. In other words, the base station does not page the UE individually (for the purpose of UE receiving the MBS multicast session).

[0051] In version 18, UE is supported to receive MBS multicast sessions in RRC inactive state. For MBS multicast sessions received in RRC inactive state, the base station can provide or configure PTM configuration information (also called configuration information of MBS multicast session or PTM configuration of MBS multicast session) for UE to receive the MBS multicast session through dedicated RRC signaling (e.g., RRCRelease message) or through multicast MBS control channel MCCH (i.e., multicast MCCH). The information required to obtain multicast MCCH (or multicast MCCH configuration) can be configured for UE through dedicated RRC signaling or system information block (denoted as SIBx), that is, SIBx contains the information required to obtain the multicast MCCH configuration of MBS multicast received in RRC inactive state. The PTM configuration information may include the configuration information of the MRB corresponding to the MBS multicast session and / or the identifier TMGI of the MBS multicast session and its corresponding G-RNTI / G-CS-RNTI and / or DRX and other configuration information fields. The multicast MCCH is a PTM downlink channel used for transmitting control information of MBS multicast session associated to one or several MTCH(s)from the network to the UE in RRC_INACTIVE state. For an MBS multicast session received in the RRC_INACTIVE state, the MBS multicast session being in an active state or being activated in the embodiment of the present disclosure means that the MBS multicast session is in progress or about to start or the UE starts to receive the MBS multicast session. The network can indicate to the UE that the MBS multicast is activated or data transmission is resumed through RRC signaling (e.g., RRC release message) or through a paging message (e.g., including the TMGI of the MBS multicast session in a paging message indicates that the MBS multicast session is activated or data transmission is resumed), and the UE starts to receive the MBS multicast session after receiving the indication. The MBS multicast being activated in the embodiment of the present disclosure is also applicable to the case of resuming data transmission of the MBS multicast session, which will not be described in detail below. In the embodiment of the present disclosure, the MBS multicast session being in an inactive state or being deactivated means that the MBS multicast session has ended or data transmission has been suspended or the UE has stopped receiving the MBS multicast session.The network may notify the UE through a multicast MCCH message (for example, if the PTM configuration of the MBS multicast session does not appear in the multicast MCCH message, it indicates that the MBS multicast session is deactivated, and an indicator identifier may be associated with each MBS multicast session to explicitly indicate that the MBS multicast session is deactivated) or through a physical downlink control channel PDCCH (or downlink control information DCI) that schedules the multicast MCCH (or multicast MCCH message), for example, using 1 bit in the DCI of the PDCCH to indicate that the MBS multicast is deactivated or data transmission is suspended. The UE stops receiving the MBS multicast session after receiving the indication. The UE stopping receiving the MBS multicast session may be that the UE does not detect the G-RNTI or G-CS-RNTI corresponding to the MBS multicast session.

[0052] Each MBS multicast session is identified by a TMGI and is associated with a G-RNTI or G-CS-RNTI. The UE receives the MBS multicast session by monitoring the G-RNTI or G-CS-RNTI associated with the MBS multicast session. For MBS multicast, the MAC entity may be configured by RRC with a DRX functionality per G-RNTI or per G-CS-RNTI that controls the UE′s PDCCH monitoring activity for the MACentity′s G-RNTI(s) and G-CS-RNTI(s) respectively.

[0053] In 3GPP Release 18, UE is supported to receive MBS multicast session in RRC_INACTIVE state. For UE configured with MBS multicast session that can be received in RRC_INACTIVE state, when the MBS multicast session is activated, if the MBS multicast session is configured and / or allowed to be received in RRC_INACTIVE state and / or the UE has (valid) PTM configuration of the MBS multicast session, the MBS multicast session can be directly received without establishing an RRC connection with the base station. However, if the MBS multicast session is not configured and / or allowed to be received in the RRC_INACTIVE state, or the UE does not have the PTM configuration or valid PTM configuration for the MBS multicast session, or when the UE in the RRC inactive state performs cell reselection and reselects to another cell, the PTM configuration of the MBS multicast session received by the UE in the RRC inactive state is no longer valid, or the measurement result of the current cell is lower than or not higher than the threshold value configured for the MBS multicast session reception. In these cases, the UE is triggered to perform an RRC recovery process (i.e., an RRC connection recovery process) to obtain relevant information about the PTM configuration of the MBS multicast session or enter the RRC connected state to receive the MBS multicast session. If the UE triggers the RRC recovery process because the measurement result of the current cell is lower than or lower than the threshold value configured for receiving a certain MBS multicast session, in order to avoid the ping-pong problem, that is, the measurement result of the current cell is only temporarily lower than or lower than the threshold value configured for receiving a certain MBS multicast session and will soon recover to be not lower than or higher than the threshold value, by maintaining a timer for each activated MBS multicast session, when the measurement result of the current cell is lower than or lower than the threshold value configured for a certain MBS multicast session, the timer of the MBS multicast session is started. When the timer expires, the UE is triggered to perform the RRC recovery process. The value of the timer can be configured in the RRC release message or the MCCH message, and the configuration of the timer value can be for all MBS multicast sessions (that is, the base station only configures a timer value, and the timer value is applied to the timers of all MBS multicast sessions supported by the base station) or only for a certain or a group of MBS multicast sessions (that is, the base station configures a timer value for each or each group of MBS multicast sessions). During the operation of the timer, how to maintain, stop or restart the timer is a problem that needs to be solved.

[0054] It should be noted that the current cell may also be referred to as a serving cell or a cell in which the UE receives the MBS multicast, and the measurement result may be the RSRP (reference signal received power) and / or RSRQ (reference signal received quality) measured at layer 1 or layer 3 (i.e., layer 1 filtering or layer 3 filtering). The network may configure the threshold for MBS multicast through dedicated RRC signaling (e.g., an RRC release message) and / or multicast MCCH (i.e., a message transmitted on the multicast MCCH, referred to in this disclosure as a multicast MCCH message or an MBS multicast configuration message, denoted as an MBSMulticastConfiguration message). The MBS multicast threshold and the corresponding timer value may be configured through the same dedicated RRC signaling or MCCH message. The MBSMulticastConfiguration message contains the control information applicable for MBS multicast services transmitted viamulticast MRBs for RRC_INACTIVE UEs). The MBSMulticastConfiguration message may be transmitted via a multicast MCCH channel or may be included in a dedicated RRC signaling (e.g., an RRCRelease message). When the MBSMulticastConfiguration message is included in the dedicated RRC signaling, the network configuring the threshold via the dedicated RRC signaling may be that the network configures the threshold via the MBSMulticastConfiguration message included in the dedicated RRC signaling.

[0055] The following embodiments are provided to solve this problem.

[0056] For a UE in the RRC_INACTIVE state, if there is an MBS multicast session to which the UE has joined and is activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, then timer T is started or timer T is started for the MBS multicast session.

[0057] When the timer T expires, the UE initiates the RRC recovery procedure or the UE initiates the RRC recovery procedure for MBS multicast reception.

[0058] An embodiment of the operation performed by the UE during the running of the timer T is described below.

[0059] Example 1

[0060] Figure 1 is a flowchart showing a method executed by a user equipment according to embodiment 1 of the present invention.

[0061] like Figure 1 As shown, in step 101, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, then timer T is started or timer T is started for the MBS multicast session.

[0062] In step 103, during the running of the timer T, if the measurement result of the serving cell becomes higher than (or not lower than) the threshold configured for the MBS multicast session, the timer T is stopped.

[0063] Example 2

[0064] Figure 2 is a flowchart showing a method executed by a user equipment according to embodiment 2 of the present invention.

[0065] like Figure 2 As shown, in step 201, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, then timer T is started or timer T is started for the MBS multicast session.

[0066] In step 203, during the running of the timer T, if the MBS multicast session is deactivated, the timer T is stopped (this operation is performed only when the timer is running).

[0067] Example 3

[0068] Figure 3 is a flowchart showing a method executed by a user equipment according to embodiment 3 of the present invention.

[0069] like Figure 3 As shown, in step 301, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, then timer T is started or timer T is started for the MBS multicast session.

[0070] In step 303, when dedicated RRC signaling or an MBSMulticastConfiguration message is received during the running of the timer T, the timer T is stopped (this operation is performed only if the timer is running).

[0071] In fact, for a UE in the RRC_INACTIVE state, if a dedicated RRC signaling or MBSMulticastConfiguration message is received, all running timers T may be stopped.

[0072] Example 4

[0073] Figure 4 is a flowchart showing a method executed by a user equipment according to embodiment 4 of the present invention.

[0074] like Figure 4 As shown, in step 401, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, then timer T is started or timer T is started for the MBS multicast session.

[0075] In step 403, during the operation of the timer T, when dedicated RRC signaling or an MBSMulticastConfiguration message is received, if the dedicated RRC signaling or the MBSMulticastConfiguration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the current (or currently configured or saved) threshold or the MBSMulticastConfiguration message indicates that the configuration of the MBS multicast session is updated, the timer T is stopped (this operation is performed only if the timer is running).

[0076] In fact, for a UE in the RRC_INACTIVE state, when receiving dedicated RRC signaling or an MBSMulticastConfiguration message, for each MBS multicast session that the UE has joined (or for each MBS multicast session that the UE has joined and is in an activated state), if the dedicated RRC signaling or MBSMulticastConfiguration message does not configure a corresponding threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the current (or currently configured or saved) threshold of the MBS multicast session or the MBSMulticastConfiguration message indicates that the configuration of the MBS multicast session has been updated, the timing T corresponding to the MBS multicast session is stopped (this operation is performed only if the timer is running).

[0077] It should be noted that the timer T can also be represented by a time interval (time during) T', and the time interval T' is the time when the measurement result of the serving cell is lower than (or not higher than) the configured threshold to trigger the UE to start the RRC recovery process. In other words, for a certain MBS multicast session, from the first measurement of the RSRP and / or RSRQ of the serving cell (i.e., the measurement result of the serving cell) is lower than or not higher than the configured threshold of the MBS multicast session, within the time interval T', the measurement result of the serving cell is always lower than (or not higher than) the configured threshold, which triggers the UE to start the RRC recovery process. Accordingly, in the above embodiments 1-4, the embodiment obtained by replacing the operation of stopping the timer T with resetting the time interval T' also falls within the scope of the present disclosure. Since the time interval T' does not involve the start operation, the operation of starting the timer T is deleted accordingly; the operation is performed only when the timer is running, and is correspondingly replaced by the operation is performed only when the time interval T' exists. The time interval T' can also be configured separately for each MBS multicast session through dedicated RRC signaling or MCCH message.

[0078] Example 5

[0079] Supports the use of delta configuration for MBS multicast sessions received in RRC_INACTIVE state or full configuration only during cell reselection in some cases. Specifically:

[0080] For the MBSMulticastConfiguration message received (or obtained) by the UE or the MBSMulticastConfiguration message obtained from the reselected cell, if the MBSMulticastConfiguration message is the first MBSMulticastConfiguration message obtained after the UE reselects to a new cell, the UE will overwrite (overwrite) any stored multicast MCCH message with the MBSMulticastConfiguration message (i.e., the multicast MCCH message or MBSMulticastConfiguration message obtained by the multicast MCCH information acquisition process triggered by cell reselection) and the UE will not continue to use the domain not included in the MBSMulticastConfiguration message.

[0081] If the UE receives a multicast MCCH message or MBSMulticastConfiguration message obtained by the multicast MCCH information acquisition process triggered by a paging message containing the TMGI of the MBS multicast session that the UE has joined, the UE only obtains the configuration information related to the MBS multicast session from the MBSMulticastConfiguration message and applies the configuration information (delta configuration or full configuration may be used).

[0082] If the UE obtains a multicast MCCH message or MBSMulticastConfiguration message in the multicast MCCH information acquisition process triggered by receiving an MBSMulticastConfiguration message update notification, the UE only obtains the configuration information related to the MBS multicast session from the MBSMulticastConfiguration message and applies the configuration information (delta configuration or full configuration may be used).

[0083] In addition, based on the different purposes of establishing or restoring the RRC connection between the UE and the network or the different events that trigger the UE to establish or restore the RRC connection between the UE and the network, multiple access types (Access Category) are defined. When initiating (initiating) the process of restoring the RRC connection, the UE determines the access type and / or access identity (Access Identities) according to the triggering event, and performs a unified access control (UAC) process according to the determined access type and access identity. The purpose of this process is to perform an access prohibition check on the access attempt associated with the determined access category and one or more access identities (the event triggering the UE to initiate the RRC recovery process is an access attempt). The UE maintains an access prohibition timer T390 for each access type. When performing an access prohibition check on the access type corresponding to a certain access attempt, if the access attempt is prohibited, the timer T390 of the access type corresponding to the access attempt is started. When the UE performs cell selection or reselection, performs relay selection or reselection, enters the RRC connected state, receives an RRC reconfiguration message containing synchronization reconfiguration reconfigurationWithSync, changes the primary cell PCell in the RRC connected state, receives a MobilityFromNRCommand message, or receives an RRC release message, T390 is stopped. When T390 expires or stops, the operations performed during barring alleviation are performed. For example, when T390 corresponding to a certain access type expires, the barring of the corresponding access type is considered to be eliminated. If the UE has an access attempt of the corresponding access type at this time, the UE will perform the corresponding access attempt (for example, if there is a pending RNA update, the RRC connection recovery process is started).

[0084] When the RRC connection recovery is triggered (i.e., the RRC recovery process is started) due to the expiration of the timer T corresponding to a certain MBS multicast session (or because the measurement result of the serving cell is lower than or not higher than the threshold of a certain MBS multicast session), when the access prohibition check is performed according to the access type and / or access identity determined by the event triggering the RRC connection recovery, if the access attempt is prohibited (for example, because T390 corresponding to the access type is running), the RRC recovery process will not be performed. When T390 corresponding to the access type expires or stops, the UE will re-trigger the RRC connection recovery for the reception of the MBS multicast session. However, during this process (that is, the RRC recovery process triggered by the reception of the MBS multicast session is prohibited and the corresponding T390 is running), if the UE receives dedicated RRC signaling or MBSMulticastConfiguration message, and the dedicated RRC signaling or MBSMulticastConfiguration message reconfigures the threshold of the MBS multicast session (for example, the threshold for the MBS multicast session contained in the dedicated RRC signaling or MBSMulticastConfiguration message is lower than the threshold for the MBS multicast session currently saved by the UE) or the value of the timer, or the dedicated RRC signaling or MBSMulticastConfiguration message does not contain the threshold or timer value of the MBS multicast session, then whether the UE still needs to re-trigger RRC connection recovery for the reception of the MBS multicast session is a problem that needs to be solved.

[0085] The following embodiments are provided to solve this problem.

[0086] Example 6

[0087] When dedicated RRC signaling or an MBSMulticastConfiguration message is received, if there is a pending RRC recovery procedure triggered by the expiration of the timer T, the pending RRC recovery procedure is canceled.

[0088] Specifically, the following variable (i.e., the first variable) is defined, denoted as VarPendingPTM-Update or pendingPTM-Update, to indicate whether there is a pending RRC recovery process triggered by the expiration of timer T. It can be specified that the variable is of Boolean type, and if the variable value is set to the first value, it indicates that there is a pending RRC recovery process triggered by the expiration of timer T, and the first value can be true or "true".

[0089] VarPendingPTM-Update UE variables

[0090]

[0091] When dedicated RRC signaling or MBSMulticastConfiguration message is received or all MBS multicast sessions to which all UEs have joined are deactivated, if VarPendingPTM-Update or pendingPTM-Update is set to a first value, the VarPendingPTM-Update or pendingPTM-Update is set to a value corresponding to the absence of an RRC recovery process to be executed triggered by the expiration of timer T, and the value may be false or "false".

[0092] It should be noted that the RRC recovery process (to be executed) triggered by the expiration of timer T described in the present disclosure is the RRC recovery process (to be executed) triggered because the measurement result of the serving cell is lower than or not higher than the threshold of a certain MBS multicast session (i.e., the MBS multicast session corresponding to the timer T).

[0093] Example 7

[0094] When the UE receives the dedicated RRC signaling or MBSMulticastConfiguration message, for each MBS multicast session that the UE has joined and activated, if the dedicated RRC signaling or MBSMulticastConfiguration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the currently configured threshold, or the MBSMulticastConfiguration message indicates that the configuration of the MBS multicast session is updated or the MBSMulticastConfiguration message indicates that the MBS multicast session is deactivated, then the RRC recovery process to be executed triggered by the expiration of the timer T of the MBS multicast session is canceled. Specifically:

[0095] A variable VarPendingPTM-Update or pendingPTM-Update is defined for each MBS multicast session, and is used to indicate whether there is an RRC recovery process to be executed triggered by the expiration of the timer T of the MBS multicast session.

[0096] Upon receiving the dedicated RRC signaling or MBSMulticastConfiguration message, for each MBS multicast session that the UE has joined and activated, if the dedicated RRC signaling or MBSMulticastConfiguration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the currently configured threshold, or the MBSMulticastConfiguration message indicates that the configuration of the MBS multicast session is updated, or the MBSMulticastConfiguration message indicates that the MBS multicast session is deactivated, and if the VarPendingPTM-Update or pendingPTM-Update corresponding to the MBS multicast session (or the timer T of the MBS multicast session) is set to the first value (i.e., indicating that there is a pending RRC recovery process triggered by the expiration of the timer T), then the VarPendingPTM-Update or pendingPTM-Update is set to a value corresponding to the value indicating that there is no pending RRC recovery process triggered by the expiration of the timer T, and the value may be false or "false".

[0097] [Modifications]

[0098] Next, use Figure 5 A user equipment as a variation example that can execute the method executed by the user equipment described in detail above of the present invention is described.

[0099] Figure 5 It is a block diagram showing a user equipment UE involved in the present invention.

[0100] like Figure 5 As shown, the user equipment UE50 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.

[0101] Next, use Figure 6 A base station that can execute the method executed by the base station described above of the present invention is described as a variation example.

[0102] Figure 6 It is a block diagram showing a base station involved in the present invention.

[0103] like Figure 6 As shown, the base station 60 includes a processor 601 and a memory 602. The processor 601 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 602 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 602 stores program instructions. When the instructions are executed by the processor 601, the above method performed by the base station described in detail in the present invention may be executed.

[0104] Specifically, the base station according to the present invention communicates with a user equipment UE. The base station sends a dedicated RRC signaling or an MBS multicast configuration message to the UE. The dedicated RRC signaling or the MBS multicast configuration message can stop the timer started for the MBS multicast session by the UE in the RRC inactive state. For details, please refer to the above description.

[0105] The method and the devices involved in the present disclosure have been described above in conjunction with the preferred embodiments. It will be appreciated by those skilled in the art that the method shown above is merely exemplary, and the embodiments described above can be combined with each other without contradiction. The method of the present invention is not limited to the steps and sequence shown above.

[0106] In the embodiments of the present disclosure, when multiple operations are included, the embodiments of the present disclosure exemplarily list the execution order of each operation, and the embodiments obtained by changing the execution order of each operation are also within the scope of protection of the present disclosure. In addition, when multiple judgment conditions are included, the embodiments obtained by changing the execution order of each judgment condition are also within the scope of protection of the present disclosure. In addition, in the present disclosure, unless otherwise specified, the meaning of a field defined in one embodiment may also be applied to the corresponding fields involved in other embodiments. In addition, in the embodiments of the present disclosure, "if...", "when...", "when...", "when...", "satisfy..." or "satisfy the condition..." can be replaced by "under the condition of...".

[0107] In addition, the user equipment shown above may include more modules, for example, modules that can be developed or developed in the future and can be used for base stations, MMEs, or UEs, etc. The various identifiers shown above are only exemplary and not restrictive, and the present disclosure is not limited to the specific information elements used as examples of these identifiers. Those skilled in the art may make many changes and modifications based on the teachings of the illustrated embodiments.

[0108] It should be understood that the above embodiments of the present disclosure can be implemented by software, hardware, or a combination of software and hardware. For example, the various components inside the base station and user equipment in the above embodiments can be implemented by a variety of devices, including but not limited to: analog circuit devices, digital circuit devices, digital signal processing (DSP) circuits, programmable processors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), programmable logic devices (CPLDs), and the like.

[0109] In addition, the computer executable instructions or programs running on the device according to the present invention can be programs that enable the computer to implement the functions of the embodiments of the present invention by controlling the 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.

[0110] The computer executable instructions or programs for realizing the functions of various embodiments of the present invention can be recorded on a computer readable storage medium. The corresponding functions can be realized by making a computer system read the programs 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 storage 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 readable by a computer.

[0111] 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.

[0112] 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.

[0113] 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 invented by 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 by each other.

Claims

1. A method performed by a user equipment UE, comprising: For a UE in an RRC inactive state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than or not higher than the threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; as well as During the running of the timer, if the measurement result of the serving cell becomes higher than or not lower than a threshold configured for the MBS multicast session, the timer is stopped.

2. A method performed by a user equipment UE, comprising: For a UE in an RRC inactive state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and During the running of the timer, if the MBS multicast session is deactivated, the timer is stopped.

3. A method performed by a user equipment UE, comprising: For a UE in an RRC inactive state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than or not higher than the threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; as well as During the running of the timer, if a dedicated RRC signaling or an MBS multicast configuration message is received, the timer is stopped.

4. A method performed by a user equipment UE, comprising: For a UE in an RRC inactive state, if there is an MBS multicast session that the UE has joined and activated, and the measurement result of the serving cell is lower than or not higher than the threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; as well as During the operation of the timer, when dedicated RRC signaling or an MBS multicast configuration message is received, if the dedicated RRC signaling or the MBS multicast configuration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the current threshold or the MBS multicast configuration message indicates that the configuration of the MBS multicast session is updated, the timer is stopped.

5. The method according to any one of claims 1 to 4, further comprising: When the timer expires, the UE initiates the RRC recovery procedure or the UE initiates the RRC recovery procedure for MBS multicast reception.

6. The method according to claim 5, further comprising: In case of receiving the dedicated RRC signaling or the MBS multicast configuration message, if there is a pending RRC recovery procedure triggered by the expiration of a timer, the pending RRC recovery procedure is canceled.

7. The method according to claim 5, further comprising: When receiving dedicated RRC signaling or MBS multicast configuration message, for each MBS multicast session that UE has joined and activated, if the dedicated RRC signaling or MBS multicast configuration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the currently configured threshold, or the MBS multicast configuration message indicates that the configuration of the MBS multicast session is updated or the MBS multicast configuration message indicates that the MBS multicast session is deactivated, then the RRC recovery process to be executed triggered by the expiration of the timer of the MBS multicast session is canceled.

8. 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 7 is performed.

9. A method performed by a base station, the base station communicating with a user equipment UE, the method comprising: Sending a dedicated RRC signaling or an MBS multicast configuration message to the UE, The dedicated RRC signaling or MBS multicast configuration message can stop the timer started by the UE in the RRC inactive state for the MBS multicast session.

10. A base station, comprising: processor; as well as Memory, which stores instructions, Wherein, when the instructions are executed by the processor, the method of claim 9 is performed.

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