Method executed by user equipment and user equipment

Abstract

The invention provides a method executed by user equipment and the user equipment. The method executed by user equipment UE comprises the following steps: the UE receives an RRC release message from a base station; the RRC release message comprises a first indication identifier, and the first indication identifier is used for indicating the UE to keep a small data transmission (SDT) process or indicating the MBS multicast session to be activated or indicating the UE not to execute an operation executed by entering RRCINACTIVE or RRCIDLE or indicating the UE to detect a multicast MCCH-RNTI or indicating the UE to detect a G-RNTI of a multicast MBS session. And executing corresponding operation.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and more particularly, to a method performed by a user equipment and a user equipment. Background Art

[0002] A research project SI on the improvement of the 5G multicast and broadcast service architecture (see SP-190625 for details) has been approved. One of the objectives of this SI (referred to as Objective A) is to support general 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 Internet of Things applications, etc. Correspondingly, at the 86th plenary session of the 3rd Generation Partnership Project (3GPP) RAN, a work item on NR multicast and broadcast service (NR MBS) was proposed (see non-patent document: RP-193248: New WID: NR Multicast and Broadcast Service) and approved. This work item aims to provide support for Objective A in RAN. The objectives of this work item have been basically achieved. Specific descriptions of relevant solutions can be found in 3GPP Release 17 technical documents, such as TS38.300-h70, TS38.331-h70, TS38.321-h70, etc. At the 94th plenary session of 3GPP RAN, a work item called enhanced NR broadcast multicast 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 broadcast multicast of Release 17, and one of its objectives is to support user equipment to receive MBS multicast services / sessions in the RRC inactive state.

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

[0004] To solve at least some of the above problems, the present invention provides a method performed by a user equipment and a user equipment.

[0005] According to a first aspect of the present invention, there is provided a method performed by a user equipment UE, including: the UE receives an RRC release message from a base station; and when a first indication identifier is included in the RRC release message, where the first indication identifier is used to indicate that the UE maintains a small data transfer SDT process or indicates that an MBS multicast session is activated or indicates that the UE does not perform operations performed when entering RRC_INACTIVE or RRC_IDLE or is used to indicate that the UE detects a multicast MCCH-RNTI or is used to indicate that the UE detects a G-RNTI of a multicast MBS session, perform at least one of the following operations:

[0006] Operation 1-1a: Apply a multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field included in the RRC release message;

[0007] Operation 1-1b: If the RRC release message includes a multicastConfigInactive field, apply a multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the RRC release message does not include a multicastConfigInactive field, obtain an MBSMulticastConfiguration message on the multicast MCCH;

[0008] Operation 1-1c: If the RRC release message includes a multicastConfigInactive field and at least one TMGI included therein indicates that the MBS multicast session is not indicated to stop detecting the corresponding G-RNTI and the PTM configurations of all MBS multicast sessions not indicated to stop detecting the G-RNTI are included in the multicastConfigInactive field, apply a multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the RRC release message does not include a multicastConfigInactive field or there is an MBS multicast session not indicated to stop detecting the G-RNTI whose PTM configuration is not included in the multicastConfigInactive field, obtain an MBSMulticastConfiguration message on the multicast MCCH;

[0009] Operation 1-1d: If the RRC release message contains the multicastConfigInactive field and / or the inactivePTM-Config field, apply the PTM configuration or apply the PTM configuration contained in the inactivePTM-Config field; and / or if the RRC release message does not contain the inactivePTM-Config field, obtain the MBSMulticastConfiguration message on the multicast MCCH;

[0010] Operation 1-1e: Detect the multicast MCCH-RNTI, or detect the G-RNTI of all joined MBS multicast sessions;

[0011] Operation 1-1f: The first indication identifier contains a list of G-RNTIs, and the UE detects the G-RNTIs contained in the first indication identifier;

[0012] Operation 1-1g: The process ends.

[0013] In the above method related to the first aspect of the present invention, it is also possible that the RRC release message contains the suspendConfig field, and the first indication identifier is contained in the suspendConfig field.

[0014] In the above method related to the first aspect of the present invention, it is also possible that when the first indication identifier is not contained in the RRC release message, the UE performs at least one of the following operations:

[0015] Operation 1-1A: Reset the MAC and / or release the default MAC cell group configuration;

[0016] Operation 1-1B: Suspend all SRBs and DRBs except SRB0 and the broadcast MRB;

[0017] Operation 1-1C: Suspend all multicast MRBs associated with multicast sessions that are not configured for RRC_INACTIVE reception;

[0018] Operation 1-1D: Enter RRC_INACTIVE and / or perform cell selection;

[0019] Operation 1-1E: Perform the operations performed when entering RRC_IDLE.

[0020] In the above method related to the first aspect of the present invention, it is also possible that when the multicastConfig Inactive field is contained in the suspendConfig, the first indication identifier is contained in the suspend Config.

[0021] In addition, according to a second aspect of the present invention, there is provided a method performed by a user equipment UE, including: the UE receives an RRC release message from a base station; and when a first indication identifier is included in the RRC release message, where the first indication identifier is used to indicate that the UE aborts a small data transmission SDT process or indicates that the RRC release message is not for MBS multicast activation, at least one of the following operations is performed:

[0022] Operation 1-1A: Reset the MAC and / or release the default MAC cell group configuration;

[0023] Operation 1-1B: Suspend all SRBs and DRBs except SRB0 and broadcast MRBs;

[0024] Operation 1-1C: Suspend all multicast MRBs associated with a multicast session not configured for RRC_INATIVE reception;

[0025] Operation 1-1D: Enter RRC_INACTIVE and / or perform cell selection;

[0026] Operation 1-1E: Perform the operations performed when entering RRC_IDLE.

[0027] In the method according to the second aspect of the present invention, at least one of the following operations may also be performed when the first indication identifier is not included in the RRC release message:

[0028] Operation 1-1a: Apply the multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field included in the RRC release message;

[0029] Operation 1-1b: If the RRC release message includes a multicastConfigInactive field, apply the multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the RRC release message does not include a multicastConfigInactive field, obtain an MBSMulticastConfiguration message on the multicast MCCH;

[0030] Operation 1-1 c: If the RRC release message contains the multicastConfigInactive field and at least one TMGI indicated in it for the MBS multicast session is not indicated to stop detecting the corresponding G-RNTI and the PTM configuration of all MBS multicast sessions not indicated to stop detecting the G-RNTI is included in the multicastConfigInactive field, apply the multicast PTM configuration or the multicast PTM configuration included in the multicastConfigInactive field; and / or if the RRC release message does not contain the multicastConfigInactive field or there is a PTM configuration of an MBS multicast session not indicated to stop detecting the G-RNTI that is not included in the multicastConfigInactive field, obtain the MBSMulticastConfiguration message on the multicast MCCH;

[0031] Operation 1-1 d: If the RRC release message contains the multicastConfigInactive field and / or the inactivePTM-Config field, apply the PTM configuration or the PTM configuration included in the inactivePTM-Config field; and / or if the RRC release message does not contain the inactivePTM-Config field, obtain the MBSMulticastConfiguration message on the multicast MCCH;

[0032] Operation 1-1 e: Detect the multicast MCCH-RNTI, or detect the G-RNTIs of all joined MBS multicast sessions;

[0033] Operation 1-1 f: The first indication identifier contains a list of G-RNTIs, and the UE detects the G-RNTIs contained in the first indication identifier;

[0034] Operation 1-1 g: The process ends.

[0035] In addition, according to the third aspect of the present invention, a method executed by a user equipment UE is provided, including: the UE starts an RRC connection recovery process; when the condition for starting small data transmission SDT is satisfied and the UE is configured to receive MBS multicast in RRC_INACTIVE and / or the UE is not detecting the multicast MCCH-RNTI, detect the multicast MCCH-RNTI.

[0036] In the method according to the third aspect of the present invention, it may further include: the UE receives an RRC release message from the base station; and when the multicastConfigInactive field is not included in the RRC release message, the UE stops detecting the multicast MCCH-RNTI.

[0037] In the method according to the third aspect of the present invention, it may further include: the UE receives an RRC release message from the base station; and when the multicastConfigInactive field is not included in the RRC release message and the UE does not detect any G-RNTI, the UE stops detecting the multicast MCCH-RNTI.

[0038] In addition, according to a fourth aspect of the present invention, a user equipment is provided, including: a processor; and a memory storing instructions, wherein the instructions, when run by the processor, execute the above-mentioned method.

[0039] Advantages of the Invention

[0040] According to the method executed by the user equipment and the user equipment according to the present invention, the user equipment UE can normally obtain the activation indication of the MBS multicast session during the SDT process. Description of the Drawings

[0041] Through the following detailed description in conjunction with the drawings, the above and other features of the present invention will become more obvious, wherein:

[0042] Figure 1 It is a schematic flowchart showing the method executed by the user equipment in Embodiment 1 of the present invention.

[0043] Figure 2 It is a schematic flowchart showing the method executed by the user equipment in Embodiment 2 of the present invention.

[0044] Figure 3 It is a schematic flowchart showing an embodiment of the operations performed by the UE when receiving an RRC release message.

[0045] Figure 4 It is a block diagram showing the user equipment UE according to the present invention. Detailed Embodiments

[0046] Some of the terms related to the present invention are described below. For the specific meanings of the terms, reference can be made to the latest relevant 3GPP documents, such as TS38.300-i00, TS38.321-i00, TS38.323-i00, TS38.331-i00 (some contents of the i00 version are still under discussion), etc. In addition, the embodiments of the present invention are described by taking the broadcast / multicast service as an example, but the embodiments of the present invention are not limited to the broadcast / multicast service and can also be applied to other application scenarios.

[0047] UE: User Equipment, the user equipment.

[0048] RRC: Radio Resource Control, the radio resource control.

[0049] RRC_CONNECTED: The RRC connected state.

[0050] RRC_INACTIVE: The RRC inactive state.

[0051] RRC_IDLE: The RRC idle state.

[0052] RAN: Radio Access Network, the radio access network.

[0053] NR: New RAT, the new radio access technology.

[0054] MBS: Multicast / Broadcast Services, the multicast / broadcast service. Multicast can also be referred to as groupcast.

[0055] AS: Access Stratum, the access stratum or the access layer.

[0056] NAS: Non Access Stratum, the non-access stratum or the non-access layer.

[0057] RB: Radio Bearer, the radio bearer. DRB is the data radio bearer.

[0058] MRB: MBS radio bearer, that is, a radio bearer configured for MBS transmission (Aradio bearer that isconfigured for MBS delivery). MRB is divided into multicast MRB and broadcast MRB. The multicast MRB is a radio bearer configured for MBS multicast transmission, and the broadcast MRB is a radio bearer configured for MBS broadcast transmission.

[0059] TMGI: Temporary Mobile Group Identity, a temporary mobile group identifier used to identify an MBS session.

[0060] RNTI: Radio Network Temporary Identifier, a wireless network temporary identifier.

[0061] PTM: Point to Multipoint, a delivery mode for MBS services. In the PTM delivery mode, the base station sends a single copy of MBS data packets to a set of UEs (gNB delivers a single copy of MBS data packets to a set of UEs). UEs use 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.

[0062] PTP: Point to Point, a delivery mode for MBS services. In the PTP delivery mode, the gNB individually delivers separate copies of MBS data packets to each UEs independently (gNB individually delivers separate copies of MBS data packets to each UEs independently). For example, the base station uses the UE-specific PDCCH scrambled with the UE-specific RNTI to schedule the UE-specific PDSCH scrambled with the same UE-specific RNTI.

[0063] PCell: Primary Cell, the main cell, the MCG cell, operating on the primary frequency, where the UE performs the initial connection establishment process or initiates the connection reconstruction process.

[0064] SCell: Secondary Cell. For UEs configured with carrier aggregation, the SCell is a cell that provides additional radio resources on top of the special cell. For dual-connectivity operation, the term special cell refers to the PCell of the MCG or the PSCell of the SCG. In carrier aggregation, the term special cell refers to the PCell. For dual-connectivity operation, the PSCell is the secondary cell group SCG cell where the UE performs random access during the synchronous reconfiguration process.

[0065] G-RNTI: Group RNTI, which is used to scramble the scheduling and transmission of PTM for one or more MBS multicast services.

[0066] G-CS-RNTI: Group Configuration Scheduling RNTI, which is used to scramble the semi-static scheduling SPS group common physical downlink shared channel PDSCH and activate / deactivate the SPS group common PDSCH for one or more MBS multicast services.

[0067] MTCH: MBS Traffic Channel, which 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 MTCHs involved in the embodiments of the present disclosure all refer to the multicast MTCHs used to transmit MBS multicast sessions.

[0068] MCCH: MBS Control Channel, which is a PTM downlink channel used to transmit MBS broadcast or MBS multicast control information associated with one or more MTCHs from the network to the UE. MCCH includes broadcast MCCH and multicast MCCH.

[0069] The RRC Resume Request message, RRCResumeRequest or RRCResumeRequest1, is used to request the resumption of a suspended RRC connection or to perform a RAN-based Notification Area (RNA) update. When the UE initiates an RRC connection resume request, if the useFullResumeID field is included in SIB1, it uses the RRCResumeRequest1 message and sets the resumeIdentity field in the RRCResumeRequest1 message to the fullI-RNTI stored by the UE; otherwise, it uses the RRCResumeRequest and sets the resumeIdentity field in the RRCResumeRequest message 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 an RRC connection. The RRC Resume message, RRCResume, is used to resume a suspended RRC connection. In this disclosure, the useFullResumeID field indicates the resume identity and resume request message used. When the field is included in SIB1, the fullI-RNTI and the RRCResumeRequest1 message are used; when the field is not included in SIB1, the shortI-RNTI and the RRCResumeRequest message are used. The shortI-RNTI uses fewer bits than the I-RNTI-Value to identify the suspended UE context of a UE in the RRC Inactive state. The RRC resume procedure (i.e., the RRC connection resume procedure) is used to resume a suspended RRC connection, including resuming SRB(s), DRB(s) and multicast MRB(s), or performing an RNA update, or implementing an MBS multicast reception request, or for initiating small data transmission (SDT) in the RRC_INACTIVE state, etc. During the RRC resume procedure, the UE sends an RRC resume request message to the base station and may receive an RRC resume message RRCResume or an RRC setup message RRCSetup or an RRC release message RRCRelease or an RRC reject message RRCReject from the base station.

[0070] In the present invention, the network, base station, and RAN can be used interchangeably. The network can be a Long-Term Evolution (LTE) network, a New Radio (NR) network, an enhanced Long-Term Evolution (eLTE) network, or other networks defined in subsequent evolved versions of 3GPP.

[0071] Currently, the NR MBS service includes MBS broadcast (also known as MBS broadcast session or broadcast MBS or MBS broadcast service or MBS broadcast service) and MBS multicast (also known as 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), enabling UEs in the RRC connected state, RRC idle state, and RRC inactive state to receive the MBS service. The UE obtains the MBS broadcast configuration information broadcast by the network through the MBS control channel (MCCH).

[0072] In Release 17, UEs are not supported to receive MBS multicast sessions in the RRC inactive state. Therefore, before receiving the MBS multicast service (i.e., MBS multicast session), the UE needs to establish an RRC connection with the base station, and then the base station (i.e., the network) configures the resources or PTM configuration for the UE to receive the MBS multicast service through dedicated RRC signaling (also known as RRC messages, such as RRC reconfiguration messages). The MBS radio bearer (MRB) for receiving these MBS multicast services is also configured for the UE by the base station through dedicated RRC signaling. Only UEs in the RRC connected state and configured with MRB can receive the 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 that supports MBS multicast notifies UEs in the RRC idle state or RRC inactive state through a group notification mechanism. When receiving the group notification, UEs that have joined the MBS multicast session or are interested in the MBS multicast session establish or resume an RRC connection with the network to receive the corresponding MBS multicast session. The group notification is addressed with P-RNTI on the physical downlink control channel (PDCCH), and the UE monitors the paging channel. The paging message for the 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 the RRC idle state or RRC inactive state. In other words, the base station does not page the UE separately (for the purpose of the UE receiving the MBS multicast session).

[0073] In version 18, the UE is supported to receive MBS multicast sessions in the RRC inactive state. For an MBS multicast session configured to be received in the RRC inactive state, the base station can provide or configure the PTM configuration information for receiving the MBS multicast session (also referred to as the configuration information of the MBS multicast session or the PTM configuration of the MBS multicast session or the MBS multicast configuration) for the UE through dedicated RRC signaling (such as the RRC Release message) or through the multicast MBS control channel MCCH (i.e., the multicast MCCH). The information required to obtain the multicast MCCH (or the multicast MCCH configuration) can be configured for the UE through dedicated RRC signaling or the system information block (denoted as SIB24), that is, SIB24 contains the information required to obtain the multicast MCCH / MTCH (i.e., MCCH and / or MTCH) configuration for MBS multicast reception in the RRC inactive state. The PTM configuration information may include the configuration information of the MRB corresponding to the MBS multicast session and / or the identification TMGI of the MBS multicast session and its corresponding G-RNTI / G-CS-RNTI and / or DRX and other configuration information fields. For example, the PTM configuration of a certain MBS multicast session is the information related to the reception of the MBS multicast session contained in the MBS multicast configuration MBSMulticastConfiguration message. Among them, the MBSMulticastConfiguration message contains the control information applicable for MBS multicast services transmitted via multicast MRBs for RRC_INACTIVE UEs. The MBSMulticastConfiguration message can be transmitted on the multicast MCCH or included in the RRC release message. Among them, 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 the MBS multicast session received in the RRC_INACTIVE state, in the embodiments of the present disclosure, the MBS multicast session being in the active state or being activated means that the MBS multicast session is in progress or about to start, the UE starts to receive (or is receiving) the MBS multicast session, or the UE starts to detect the G-RNTI corresponding to the MBS multicast session, or the UE starts to detect the multicast-MCCH-RNTI of the multicast MCCH. The network can indicate to the UE that the MBS multicast is activated or data transmission is resumed through RRC signaling (such as an RRC release message) or through a paging message. For example, including the TMGI of the MBS multicast session in the paging message indicates that the MBS multicast session is activated or data transmission is resumed. Not including the stopMonitoringRNTI in the RRC release message, which is used to indicate the G-RNTI domain for stopping detection corresponding to the MBS multicast session, indicates that the MBS multicast session is activated or data transmission is resumed. After receiving the indication, the UE starts to receive the MBS multicast session (i.e., the UE starts to detect the G-RNTI corresponding to the MBS multicast session). In the embodiments of the present disclosure, the activation of the MBS multicast also applies to the case of resuming data transmission of the MBS multicast session, which will not be elaborated below. In the embodiments of the present disclosure, the MBS multicast session being in the inactive state or being deactivated means that the MBS multicast session has ended or data transmission has been paused, or the UE stops receiving the MBS multicast session (i.e., the UE stops detecting the G-RNTI corresponding to the MBS multicast session). The network associates an indication identifier for each MBS multicast session in the multicast MCCH message to explicitly indicate that the MBS multicast session is deactivated or to stop detecting the G-RNTI corresponding to the MBS multicast session. After receiving the indication, the UE stops receiving the MBS multicast session. The UE's stopping to receive the MBS multicast session can be that the UE stops detecting the G-RNTI or G-CS-RNTI corresponding to the MBS multicast session. Therefore, in the present disclosure, the indication for deactivating the MBS multicast session or stopping data transmission is an indication for the UE to stop detecting the G-RNTI or G-CS-RNTI associated with the MBS multicast session. In addition, the indication for activating the MBS multicast session or resuming data transmission is an indication to start detecting the G-RNTI corresponding to the MBS multicast session. The deactivation of the MBS multicast session includes the situation where there is temporarily no data transmission in the MBS multicast session, and the activation of the MBS multicast session includes the situation where data transmission of the MBS multicast session is resumed. In the present disclosure, the multicast session or service is the MBS multicast session or service. In the following embodiments, the G-RNTI is taken as an example for illustration, and the embodiments obtained by replacing the G-RNTI with the G-CS-RNTI are also within the scope of the present disclosure.

[0074] Each MBS multicast session is identified by a TMGI and associated with a G-RNTI or G-CS-RNTI. The UE receives the MBS multicast session by detecting the G-RNTI or G-CS-RNTI associated with an MBS multicast session.

[0075] For a UE configured with an MBS multicast session that can be received in the RRC_INACTIVE state, when the MBS multicast session is activated or data transmission is resumed, if the MBS multicast session is configured and / or permitted to be received in the RRC_INACTIVE state and / or the UE has a (valid) PTM configuration for the MBS multicast session, the UE can directly receive the MBS multicast session without establishing an RRC connection with the base station. The network can configure the PTM configuration information (e.g., included in the MBSMulticastConfiguration message) of the MBS multicast session received in the RRC_INACTIVE state for the UE through the multicast MCCH and / or proprietary RRC signaling (e.g., RRC release message, RRC reconfiguration message). The MBS multicast configuration message MBSMulticastConfiguration can be transmitted on the multicast MCCH (in which case the MBSMulticastConfiguration message can be referred to as a multicast MCCH message), or can be included in the RRC release message. If the RRC release message is used to configure the PTM configuration information of the MBS multicast session received in the RRC_INACTIVE state for the UE, the network can include the MBSMulticastConfiguration message in the RRC release message sent to the UE.

[0076] In an embodiment of the present disclosure, the multicast MCCH-RNTI (i.e., Multicast MCCH-RNTI) is used for dynamically scheduled multicast MCCH signaling and / or multicast MCCH change notification or for dynamically scheduled MCCH signaling and / or MCCH change notification (Dynamically scheduled MCCH signaling and / or MCCH change notification) or for scrambling the CRC of a DCI or DCI format (format) or for scrambling the PDCCH for MBS multicast transmission purposes or for scrambling the CRC of a DCI or DCI format (format) for MBS multicast purposes or for scheduling the transmission of the PDSCH of an MBS multicast session. The DCI or DCI format can be DCI format 4_0 or DCI format 4_1.

[0077] When a UE in the RRC_INACTIVE state receives a paging message from a base station, if the paging message contains the TMGI of one or more MBS sessions that the UE has joined (the TMGI is included in the pagingGroupList field in the paging message), further, if the UE is not configured to receive MBS multicast in the RRC_INACTIVE state (i.e., the received RRC release message does not contain the multicastConfigInactive field) or there is at least one MBS multicast session joined by the UE indicated by the TMGI included in the paging message that is not indicated by the paging message as being receivable in the RRC_INACTIVE state (i.e., the paging message does not contain the inactiveReceptionAllowed field corresponding to the MBS session indicated by the TMGI included in the paging message that the UE has joined), if it also satisfies that the paging message does not contain the PagingRecordList field or any ue-Identity included in the pagingRecord in the PagingRecordList field included in the paging message does not match the UE identity assigned by the upper layer and the full-RNTI stored by the UE, then the RRC connection recovery process is initiated. Among them, the PagingRecordList field is a list of pagingRecord, the pagingRecord field contains the ue-Identity field, the ue-Identity field is used to indicate the ng-5G-S-TMSI or fullI-RNTI of the paged UE, the fullI_RNTI field carries the suspended UE context assigned by the base station for the UE through the RRC release message to identify the UE in the RRC_INACTIVE state, and the ng-5G-S-TMSI contains a 5G temporary mobile subscription identifier 5G-S-TMSI, which is used to uniquely identify a UE provided by the 5GC within a tracking area as a temporary UE identity.

[0078] The UE receives an RRC release message from the base station, and the multicastConfigInactive field included in the RRC release message indicates the multicast sessions or services that the UE can receive in the current serving cell (i.e., the cell that receives the RRC release message) when the UE is in the RRC_INACTIVE state. When the multicastConfigInactive field is included in the received RRC release message, it indicates that the UE has been configured to receive MBS multicast in the RRC_INACTIVE state.

[0079] In the present disclosure, embodiments obtained by replacing the function of the multicastConfigInactive field with one of the following are also within the scope of the present disclosure:

[0080] The multicastConfigInactive field indicates the multicast sessions or services that the UE can receive in the current serving cell when the UE is in RRC_INACTIVE, or the multicastConfigInactive field is used to indicate the multicast sessions or services that the UE can receive when the UE is in RRC_INACTIVE, or the multicastConfigInactive field is used to indicate the multicast sessions or services that the UE can receive in the current serving cell when the UE is in RRC_INACTIVE before obtaining the multicast MCCH, or the multicastConfigInactive field is used to indicate the multicast sessions or services that the UE can receive when the UE is in RRC_INACTIVE before obtaining the multicast MCCH.

[0081] Optionally, the multicastConfigInactive field further includes the corresponding configurations of these multicast sessions, and the configurations are valid in the current serving cell. The multicastConfigInactive field may include two fields, namely the inactivePTM-Config field and the inactiveMCCH-Config field. The inactivePTM-Config field carries the MBSMulticastConfiguration message. The inactiveMCCH-Config field carries the system information SIB24.

[0082] For a UE configured to receive an MBS multicast session in RRC_INACTIVE, the UE learns whether the joined MBS multicast session is activated and allowed to be received in the RRC_INACTIVE state by receiving a paging message. Specifically, if the paging message contains the TMGI of the MBS multicast session joined by the UE (at this time the UE considers the MBS multicast session to be activated) and its corresponding inactiveReceptionAllowed field, then the UE considers the MBS multicast session to be activated and allowed to be received in RRC_INACTIVE, or the UE can receive the MBS multicast session in RRC_INACTIVE, or the UE starts to detect the G-RNTI of the MBS multicast session in RRC_INACTIVE. It should be noted that whether the UE receives the MBS multicast session in RRC_INACTIVE also depends on whether all other MBS multicast sessions joined by the UE included in the paging message are indicated as being receivable in RRC_INACTIVE when the UE receives the paging message. If there is at least one MBS multicast session joined by the UE indicated by the TMGI included in the paging message that is not indicated by the paging message as being receivable in RRC_INACTIVE (that is, the paging message does not contain the inactiveReceptionAllowed field corresponding to at least one MBS session joined by the UE included in the paging message indicated by the TMGI), then for the other MBS multicast sessions joined by the UE indicated by the TMGI included in the paging message, even if the paging message contains its corresponding inactiveReceptionAllowed, the UE does not receive the MBS session in RRC_INACTIVE. In other words, only when all the inactiveReceptionAllowed fields corresponding to the MBS multicast sessions joined by the UE indicated by the TMGI included in the paging message are included in the paging message does the UE receive the MBS multicast session joined by the UE indicated by the TMGI included in the paging message in RRC_INACTIVE. Among them, the inactiveReceptionAllowed field is used to indicate whether a UE with a valid PTM configuration of the TMGI indicated in the pagingGroupList (i.e., pagingGroupList-r17) included in the paging message stays in RRC_INACTIVE to receive the MBS multicast session indicated by the TMGI.

[0083] Currently, the activation indication of the MBS multicast session can be achieved not only by including the TMGI of the MBS multicast session in the paging message, but also by indicating whether to stop detecting the corresponding G-RNTI in the MBSMulticastConfiguration message. Specifically, for an MBS multicast session whose TMGI is included in the MBSMulticastConfiguration message, if the MBSMulticastConfiguration message also includes the stopMonitoringRNTI field of the MBS multicast session, then the MBS multicast session is deactivated (i.e., the UE stops detecting the G-RNTI of the MBS multicast session); conversely (i.e., not including the stopMonitoringRNTI field of the MBS multicast session), the MBS multicast session is activated (i.e., the UE detects the G-RNTI of the MBS multicast session). Among them, the stopMonitoringRNTI field indicates that the UE stops detecting the G-RNTI corresponding to the MBS multicast session. By associating / configuring a stopMonitoringRNTI field for each MBS multicast session to indicate stopping the detection of the G-RNTI of the MBS multicast session. If an MBS multicast session is not associated / configured with the corresponding stopMonitoringRNTI field, it means that the MBS multicast session is not indicated to stop detecting the G-RNTI. The MBSMulticastConfiguration message can be transmitted on the multicast MCCH or included in the RRC release message for transmission. Specifically, the MBSMulticastConfiguration message can be included in the MulticastConfigInactive field of the suspendConfig field in the RRC release message. Among them, the suspendConfig field indicates the configuration in the RRC_INACTIVE state; the MulticastConfigInactive field is used to indicate one or more MBS multicast services that can be received in the RRC_INACTIVE (or one or more MBS multicast services that can be received in the RRC_INACTIVE for the current serving cell or one or more MBS multicast services that can be received in the RRC_INACTIVE before obtaining the multicast MCCH for the current serving cell), and optionally, also includes the configuration of the MBS multicast service (or the configuration of the MBS multicast service for the current serving cell or the configuration of the MBS multicast service that is valid for the current serving cell). The current serving cell refers to the cell where the UE receives the RRC release message.The serving cell or the cell where the UE last received or previously received an RRC release message may refer to the cell where the UE last received or previously received an RRC release message or the primary cell (PCell). If the RRC release message received by the UE contains an MBSMulticastConfiguration message or a MulticastConfigInactive field, it is considered that the UE is configured to receive MBS multicast in RRC_INACTIVE; or if the RRC release message (or the MBSMulticastConfiguration message contained in the RRC release message) received by the UE contains a TMGI, it is considered that the UE is configured to receive MBS multicast in RRC_INACTIVE. It should be noted that the UE obtaining the multicast MCCH means that the UE obtains an MBSMulticastConfiguration message from the multicast MCCH.

[0084] For all MBS multicast sessions that the UE has joined, if the UE is notified to stop detecting the corresponding G-RNTI, the UE stops detecting the multicast MCCH-RNTI. In other words, if the UE does not detect any G-RNTI, the UE stops detecting the multicast MCCH-RNTI.

[0085] For a UE that is simultaneously configured with small data transfer (SDT) and receives MBS multicast sessions in RRC_INACTIVE, during the SDT process, if the UE does not detect paging messages and / or does not detect the multicast MCCH-RNTI, it cannot obtain an indication that the MBS multicast sessions joined by the UE have been activated (including the case of resuming data transmission), thus missing the corresponding MBS multicast sessions. How to enable the UE to normally obtain an indication of the activation of the MBS multicast session during the SDT process is a problem to be solved.

[0086] The following provides embodiments to solve this problem. In addition, the following embodiments are merely examples and do not limit the present invention.

[0087] Unless otherwise specified, the UEs in the following embodiments are all UEs that are simultaneously configured with small data transfer (SDT) and receive MBS multicast sessions in RRC_INACTIVE, and the MBS multicast sessions are all MBS multicast sessions joined by the UE (or MBS multicast sessions joined by the UE and configured to receive in RRC_INACTIVE), which will not be elaborated.

[0088] Embodiment 1

[0089] During the SDT process, the base station indicates activation information of the MBS multicast session to the UE through dedicated RRC signaling, and the RRC signaling may be an RRC release message.

[0090] In the existing SDT process, if the UE receives an RRC release message, the UE will perform operations such as resetting the MAC and / or suspending radio bearers and / or entering RRC_INACTIVE or RRC_IDLE and / or performing cell selection, which will cause the SDT process to be interrupted (i.e., stopped). Therefore, an indication flag (denoted as the first indication flag) is added to the RRC release message to indicate the activation information of the MBS multicast session to the UE and avoid interrupting the SDT process. The function of the indication flag can be one of the following: used to indicate that the UE maintains the SDT process, used to indicate that the UE aborts the SDT process, used to indicate that the MBS multicast session is activated, used to indicate that the UE detects the G-RNTI of the MBS multicast session (i.e., used to indicate that the UE detects the G-RNTI of one or more MBS multicast sessions), used to indicate that the UE detects the multicast MCCH-RNTI, used to indicate that the UE does not perform the operations performed when entering RRC_INACTIVE or RRC_IDLE. After receiving the RRC release message with (or without) the indication flag, the UE receives the corresponding MBS multicast session but does not perform the operations that the existing UE performs when receiving the RRC release message (i.e., does not abort the SDT process, or does not reset the MAC and / or does not suspend radio bearers and / or does not perform cell selection, etc.). The following is a specific description.

[0091] The first indication flag can be directly included in the suspendConfig field in the RRC release message (i.e., the first indication flag and the multicastConfigInactive field are two independent fields directly included in suspendConfig), or can be included in the multicastConfigInactive field, and the indication flag can also be directly included in the RRC release message (i.e., the first indication flag and suspendConfig are two independent fields).

[0092] The following specifically describes the method performed by the user equipment according to Embodiment 1 of the present invention.

[0093] Figure 1 It is a schematic flowchart showing the method performed by the user equipment in Embodiment 1 of the present invention. As Figure 1 shown, the method performed by the user equipment in Embodiment 1 may include the following steps:

[0094] In step 101, the user equipment UE receives an RRC release message from the base station.

[0095] In step 103, if the RRC release message contains a first indication identifier (or contains a suspendConfig field and the first indication identifier is contained in the suspendConfig field), and the first indication identifier can be used to instruct the UE to maintain the SDT process or indicate that the MBS multicast session is activated or indicate that the UE does not perform the operations performed when entering RRC_INACTIVE or RRC_IDLE or is used to instruct the UE to detect the multicast MCCH-RNTI or is used to instruct the UE to detect the G-RNTI of the MBS multicast session, then at least one of the following operations is performed:

[0096] Operation 1-1a: Apply the multicast PTM configuration or apply the multicast PTM configuration contained in the RRC release message (or the multicast PTM configuration contained in the multicastConfigInactive field of the RRC release message).

[0097] Operation 1-1b: If the RRC release message contains a multicastConfigInactive field, apply the multicast PTM configuration or apply the multicast PTM configuration contained in the multicastConfigInactive field; and / or if the RRC release message does not contain a multicastConfigInactive field, obtain the MBSMulticastConfiguration message on the multicast MCCH.

[0098] Operation 1-1c: If the RRC release message contains a multicastConfigInactive field and the PTM configuration of at least one TMGI-indicated MBS multicast session contained therein is not indicated to stop detecting the G-RNTI and the PTM configuration of all MBS multicast sessions not indicated to stop detecting the G-RNTI is contained in the multicastConfigInactive field, apply the multicast PTM configuration or apply the multicast PTM configuration contained in the multicastConfigInactive field; and / or if the RRC release message does not contain a multicastConfigInactive field or the PTM configuration of an MBS multicast session (i.e., a joined MBS multicast session or a joined and configured RRC_INACTIVE-receiving MBS multicast session) not indicated to stop detecting the G-RNTI is not contained in the multicastConfigInactive field, obtain the MBSMulticastConfiguration message on the multicast MCCH.

[0099] Operation 1-1d: If the RRC release message contains the multicastConfigInactive field and / or the inactivePTM-Config field, apply the PTM configuration or apply the PTM configuration included in the inactivePTM-Config field; and / or if the RRC release message does not contain the inactivePTM-Config field, obtain the MBSMulticastConfiguration message on the multicast MCCH.

[0100] Operation 1-1e: Detect the multicast MCCH-RNTI (only execute when there is a multicast MCCH-RNTI or multicast MCCH is supported or system information SIB24 exists). Alternatively, detect the G-RNTI of all joined MBS multicast sessions (or all joined and configured for RRC_INACTIE reception MBS multicast sessions).

[0101] Operation 1-1f: The first indication identifier contains a list of G-RNTIs, and the UE detects the G-RNTIs included in the first indication identifier. Or the first indication identifier contains a bitmap corresponding one-to-one with the TMGI (the TMGI can be the TMGI of the MBS multicast session that the UE has joined and is configured for RRC_INACTIVE reception or the TMGI included in the previously received RRC release message), and the bits in the bitmap are used to indicate whether the corresponding MBS multicast session is activated or indicate whether the UE detects the G-RNTI of the corresponding MBS multicast session. According to the value of the bit in the bitmap of the UE, detect the corresponding G-RNTI. For example, the UE detects the G-RNTI of the MBS multicast session corresponding to the bit set to 1 or 0 in the bitmap.

[0102] Operation 1-1g: The process ends.

[0103] Optionally, if the RRC release message does not contain the first indication identifier, the UE may perform at least one of the following operations:

[0104] Operation 1-1A: Reset the MAC and / or release the default MAC cell group configuration (only execute if it exists).

[0105] Operation 1-1B: Suspend all SRBs and DRBs except SRB0 and broadcast MRBs.

[0106] Operation 1-1C: Suspend all multicast MRBs associated with multicast sessions not configured for RRC_INATIVE reception.

[0107] Operation 1-1D: Enter RRC_INACTIVE and / or perform cell selection.

[0108] Operation 1-1E: Perform the operations performed when entering RRC_IDLE, such as resetting MAC and / or entering RRC_IDLE and / or performing cell selection.

[0109] Optionally, it is specified that the first indication identifier is included in suspendConfig only when the multicastConfigInactive field is included in suspendConfig (i.e., included in the RRC release message). In other words, if the first indication identifier is included in suspendConfig, the multicastConfigInactive field must be included in suspendConfig.

[0110] If the first indication identifier is used to indicate that the UE aborts the SDT process or indicates that the RRC release message is not for MBS multicast activation, a new embodiment can be obtained by replacing step 103 with step 103a.

[0111] Step 103a: If the first indication identifier is not included in the RRC release message, perform at least one of Operations 1-1a to 1-1g. Optionally, if the first indication identifier is included in the RRC release message, perform at least one of Operations 1-1A to 1-1E.

[0112] If the first indication identifier is the multicastConfigInactive field, a new embodiment can be obtained by replacing step 103 with step 103b.

[0113] Step 103b: If the SDT process is in progress and / or the multicastConfigInactive field is included in the RRC release message, perform at least one of the following operations:

[0114] Operation 1-1I: Apply the multicastConfigInactive field and / or detect the multicast MCCH-RNTI (only executed when there is a multicast MCCH-RNTI or multicast MCCH is supported or system information SIB24 exists). Specifically, the application of the multicastConfigInactive field may include: If the multicastConfigInactive field (or the RRC release message) contains a multicast PTM configuration and / or all TMGIs are included in the RRC release message but the PTM configuration of the MBS multicast session not indicated to stop detecting the G-RNTI is included in the RRC release message, then apply the multicast PTM configuration in the RRC release message and / or detect the multicast MCCH-RNTI (only executed when there is a multicast MCCH-RNTI or multicast MCCH is supported or system information SIB24 exists). Optionally, if the multicastConfigInactive field (or the RRC release message) does not contain a multicast PTM configuration and / or there is at least one TMGI included in the RRC release message but the PTM configuration of the MBS multicast session not indicated to stop detecting the G-RNTI is not included in the RRC release message, then obtain and / or apply the MBSMulicastConfiguration message on the multicast MCCH and / or detect the multicast MCCH-RNTI. Among them, the application of the multicast PTM configuration (or the application of the MBSMulicastConfiguration message) includes the UE detecting the G-RNTI of the MBS multicast session not indicated to stop detecting the G-RNTI included in the multicast PTM configuration (or the MBSMulicastConfiguration message).

[0115] Operation 1-1II: Detect the multicast MCCH-RNTI. Specifically, if there is at least one MBS multicast session configured for RRC_INACTIVE reception not indicated to stop detecting the G-RNTI, then detect the multicast MCCH-RNTI.

[0116] Operation 1-1III: End of the process.

[0117] Optionally, if the RRC release message does not contain the multicastConfigInactive field, then perform at least one of Operations 1-lA to 1-1E.

[0118] Embodiment 2

[0119] If the multicast MCCH information (i.e., the information transmitted in the message sent on the multicast MCCH) changes, the base station will indicate it in the DCI used to schedule the multicast MCCH information, and the UE can learn of the change (i.e., obtain a multicast MCCH change notification) by detecting the multicast MCCH-RNTI. However, during the execution of the SDT process, if the UE does not detect any G-RNTI, at this time the UE also does not detect the multicast MCCH-RNTI and cannot learn of the activation information of the MBS multicast session (i.e., whether the corresponding MBS multicast session is activated or whether the corresponding MBS multicast session is indicated to stop detecting the G-RNTI). Therefore, during the execution of the SDT process, even if the UE does not detect any G-RNTI, at this time the UE also detects the multicast MCCH-RNTI. When the DCI detected according to the multicast MCCH-RNTI indicates that the multicast MCCH information has changed, the UE obtains the MBSMulticastConfiguration message from the multicast MCCH to learn of the activation information of the MBS multicast session.

[0120] Furthermore, since the change in the multicast MCCH information only occurs in specific frames, within a modification period, the same multicast MCCH information may be transmitted multiple times. For the purpose of energy saving, during the SDT process, if the UE does not detect any G-RNTI, then within the modification period of the multicast MCCH information, the UE detects the multicast MCCH-RNTI at least once. For example, the UE detects the multicast MCCH-RNTI at the start of each modification period. If no multicast MCCH change notification is received, then within the said modification period, the UE does not need to detect the multicast MCCH-RNTI anymore.

[0121] Among them, the "not detecting any G-RNT" can be replaced by all joined MBS multicast sessions (or MBS multicast sessions configured to be received in RRC_INACTIVE, or joined and configured to be received in RRC_INACTIVE MBS multicast sessions) being notified to stop detecting the corresponding G_RNTI.

[0122] The following, in combination with Figure 2 illustrates the method performed by the user equipment in Embodiment 2 of the present invention. Figure 2 is a schematic flowchart showing the method performed by the user equipment in Embodiment 2 of the present invention. As Figure 2 shown, the method performed by the user equipment in Embodiment 2 may include the following steps:

[0123] In step 201, the user equipment initiates an RRC connection restoration process.

[0124] In step 203, if the SDT start condition is satisfied, and further, if the UE is configured to receive MBS multicast in RRC_INACTIVE and / or the UE is not detecting the multicast MCCH-RNTI, then detect the multicast MCCH-RNTI.

[0125] Optionally, in step 205, start transmitting the RRC resume request message.

[0126] The SDT start conditions are briefly described below. For details, see TS38.331-i00 and TS38.321-i00. If all of the following conditions are satisfied, the UE in RRC_INACTIVE starts the RRC resume procedure for SDT:

[0127] For the RRC resume procedure triggered by the upper layer (i.e., mobile originated), all of the following conditions need to be satisfied:

[0128] (1) SIB1 contains sdt-ConfigCommon;

[0129] (2) sdt-Config is configured;

[0130] (3) All the pending uplink data is mapped to the radio bearers configured for SDT;

[0131] (4) For an (e)RedCap UE, when the (e)RedCap UE proprietary initial downlink BWP does not contain CD-SSB but is configured with ncd-SSB-RedCapInitialBWP-SDT;

[0132] (5) The lower layer (i.e., MAC layer) indicates that the condition for starting MO-SDT is satisfied.

[0133] For the RRC resume procedure triggered in response to RAN paging (i.e., mobile terminated), all of the following conditions need to be satisfied:

[0134] (i) The paging message contains the mt-SDT indication for the fullI-RNTI stored in the UE;

[0135] (ii) The lower layer (i.e., MAC layer) indicates that the condition for starting MT-SDT is satisfied.

[0136] The meanings or functions of the above-mentioned fields are briefly described below. The sdt-ConfigCommon field contains information such as parameters for determining whether to start the SDT process and the value of timer T319a used in the SDT process. For example, it includes fields such as sdt-RSRP-Threshold for determining the RSRP threshold for starting the SDT process and sdt-DataVolumeThreshold for determining the data volume threshold for starting the SDT process. The sdt-Config field is included in the RRC release message and is used to configure information related to radio bearers supporting SDT or resources used in the SDT process. The ncd-SSB-RedCapInitialBWP-SDT field is used to indicate that the UE uses the (e)RedCap-specific initial DL BWP associated with the NCD-SSB for SDT. The mt-SDT field is an SDT indication for the mobile side.

[0137]

Variant of Embodiment 2

[0138] An embodiment obtained by replacing step 203 in Embodiment 2 with the following step 203a.

[0139] In step 203a, if the condition for starting SDT is met, and further, if the UE is configured to receive MBS multicast in RRC_INACTIVE, the UE detects the G-RNTIs of all joined MBS multicast sessions (or all joined and configured-to-receive-in-RRC_INACTIVE MBS multicast sessions).

[0140] The following describes an embodiment of the operations performed by the UE when receiving an RRC release message.

[0141] When the UE receives an RRC release message, for example, the RRC release message is received after the RRC resume process started by the UE for SDT (i.e., during the UE's execution of the SDT process). If the UE is detecting the multicast MCCH-RNTI, but the UE is not configured to receive MBS multicast sessions in RRC_INACTIVE when receiving the RRC release message (i.e., the UE is no longer configured to receive MBS multicast sessions in RRC_INACTIVE) or all MBS multicast sessions joined by the UE (or all joined and configured-to-receive-in-RRC_INACTIVE MBS multicast sessions) are indicated to stop detecting the corresponding G-RNTI, then the UE stops detecting the multicast MCCH-RNTI.

[0142] Figure 3 It is a schematic flowchart showing an embodiment of the operations performed by the UE when receiving an RRC release message.

[0143] As Figure 3As shown, in step 301, the user equipment UE receives an RRC release message from the base station.

[0144] In step 303, if the multicastConfigInactive field is not included in the RRC release message, stop detecting the multicast MCCH-RNTI.

[0145] Optionally, for example, in step S303, it can also be that if the multicastConfigInactive field is not included in the RRC release message, and it also meets the condition that the UE does not detect any G-RNTI (that is, all joined and / or configured MBS multicast sessions for RRC_INACTIVE reception are notified to stop detecting G-RNTI), then stop detecting the multicast MCCH-RNTI.

[0146] The base station can indicate to the UE to end the SDT state by sending an RRC release message that does not include the multicastConfigInactive field. However, at the end of the SDT, if some MBS multicast configuration information needs to be changed, the base station needs to first send an RRC release message carrying the multicastConfigInactive field to configure or update the configuration of the MBS multicast session, and then send an RRC release message that does not include the multicastConfigInactive field to indicate to the UE to end the SDT process. This process has a large signaling overhead. Therefore, the step 303 can be replaced with the following step 303a to obtain a new embodiment to solve this problem.

[0147] In step 303a, if the multicastConfigInactive field is not included in the received RRC release message, further, if the SDT is in progress or has been configured to receive MBS multicast sessions in RRC_INACTIVE (that is, the UE was configured to receive MBS multicast sessions in RRC_INACTIVE before receiving the RRC release message), optionally, it also meets the condition that the UE does not detect the multicast MCCH-RNTI, and optionally, it also meets the condition that if the selected cell is the serving cell (or the cell that received the RRC release message), then obtain the MBSMulticastConfiguration message from the multicast MCCH.

[0148] It should be noted that in the present disclosure, obtaining the MBSMulticastConfiguration message on the multicast MCCH may refer to obtaining the MBSMulticastConfiguration message on the multicast MCCH of the concerned cell in the next repetition period. The cell or the concerned cell may refer to the serving cell or the cell where the UE receives the RRC release message or the PCell when the UE receives the RRC release message. The UE being configured to receive MBS multicast in RRC_INACTIVE in the present disclosure means that the UE contains the multicastConfigInactive field in the received (i.e., previously or most recently received) RRC release message.

[0149] In the present disclosure, the serving cell is the cell where the UE receives the RRC release message. The TMGI included in the paging message refers to the TMGI included in the pagingGroupList-r17 field included in the paging message. When the TMGI is included in the pagingGroupList-r17 field, it indicates that the MBS multicast session indicated by the TMGI is activated or starts data transmission. For an MBS multicast session configured to be received in the RRC_INACTIVE state, when the UE receives the TMGI of the MBS multicast session included in the received paging message, the UE further determines whether the paging message includes the inactiveReceptionAllowed field corresponding to the TMGI. If the paging message includes the inactiveReceptionAllowed field corresponding to the TMGI or the inactiveReceptionAllowed field corresponding to the TMGI included in the paging message is set to "true" or true, it indicates that the UE can receive the MBS multicast session in the RRC_INACTIVE state when receiving the paging message. The inactiveReceptionAllowed field is included in the pagingGroupList-v18xy field in the paging message, where x and y can be any natural numbers. For example, xy is "00". pagingGroupList-v18xy and pagingGroupList-r17 have the same number and order of elements. The first element in pagingGroupList-v18xy corresponds to the first TMGI in pagingGroupList-r17, the second element in pagingGroupList-v18xy corresponds to the second TMGI in pagingGroupList-r17, and so on. The inactiveReceptionAllowed field is used to indicate whether a UE with a valid PTM configuration having the TMGI indicated in the pagingGroupList (i.e., pagingGroupList-r17) stays in RRC_INACTIVE to receive the MBS multicast session indicated by the TMGI.

[0150] Currently, when the UE receives the RRC release message, if the multicastConfigInactive field is included in the RRC release message, and the PTM configuration of the multicast session that is not indicated to stop detecting the G-RNTI is provided in the RRC release message, and the UE selects the cell that receives the RRC release message, the UE applies the multicast PTM configuration included in the RRC release message and detects the multicast MCCH-RNTI. However, if the multicast PTM configuration included in the RRC release message is not applied due to non-satisfaction of conditions when receiving the RRC release message, when the UE receives a paging message, and the paging message includes the TMGI of the MBS multicast session joined by the UE and its corresponding inactiveReceptionAllowed field, and the PTM configuration of the MBS multicast session indicated by the TMGI is included in the previously received RRC release message, if the multicast MCCH is not provided in the current serving cell, at this time the UE will not be able to receive the MBS multicast session in RRC_INACTIVE. Among them, the inactiveReceptionAllowed field is used to indicate whether the UE with the valid PTM configuration of the TMGI indicated in the pagingGroupList (i.e., pagingGroupList-r17) included in the paging message stays in RRC_INACTIVE to receive the MBS multicast session indicated by the TMGI.

[0151] The following provides an embodiment to solve this problem.

[0152] In step 401, the UE receives an RRC release message from the base station.

[0153] In step 403, if the RRC release message configures the UE to receive the MBS multicast session in RRC_INACTIVE (i.e., the multicastConfigInactive field is included in the RRC release message), and the RRC release message provides the multicast PTM configuration of at least one MBS multicast session, and the UE selects the cell that receives the RRCRelease, the UE performs at least one of the following operations:

[0154] Operation 5-1: Apply the multicast PTM configuration included in the RRC release message.

[0155] Operation 5-2: If at least one MBS multicast session configured to receive in RRC_INACTIVE (or configured to receive in RRC_INACTIVE in the RRC release message) is not indicated to stop detecting the G-RNTI, detect the multicast MCCH-RNTI.

[0156] It should be noted that the RRC release messages in each embodiment may be the same RRC release message. The embodiments performed by the UE or the base station in the present disclosure may be performed by the RRC entity in the UE or the base station or at the RRC layer. In the present disclosure, fields, domains, and information elements may be used interchangeably. In the embodiments of the present disclosure, if there are multiple operations, the embodiments obtained by changing the execution order of the transformation operations are also within the scope of protection of the present disclosure. When there are multiple parallel judgment conditions, the embodiments obtained by changing the order of the judgment conditions are also within the scope of protection of the present disclosure.

[0157] Next, use Figure 4 to illustrate a user equipment that can execute the method performed by the user equipment described in detail above of the present invention.

[0158] Figure 4 is a block diagram showing the user equipment UE related to the present invention.

[0159] As Figure 4 shown, the user equipment UE400 includes a processor 401 and a memory 402. The processor 401 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 402 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. Program instructions are stored on the memory 402. When the instructions are run by the processor 401, the above method performed by the user equipment described in detail in the present invention can be executed.

[0160] Above, based on Embodiment 1, Embodiment 2, etc., the method performed by the user equipment and the user equipment related to the present invention have been described in detail. However, the present invention is not limited to the method performed by the user equipment and the user equipment, and can also be implemented by other means as long as the gist of the present invention can be achieved.

[0161] It is known to those skilled in the art that, for example, the present invention can be implemented by a method performed by a base station and a base station, or can be implemented by a communication system including a user equipment and a base station. For example, the method performed by the base station related to the present invention may include steps corresponding to the technical features of the method performed by the user equipment, and the base station related to the present invention may include features corresponding to the technical features of the structure of the user equipment. For specific details, reference may be made to the content in the above embodiments, which will not be elaborated here.

[0162] As an example, in a method executed by a base station, the base station may send an RRC release message to a user equipment UE. In addition, a first indication identifier may be included in the RRC release message. Regarding the RRC release message, the first indication identifier, and the action performed by the user equipment UE that receives the RRC release message, reference may be made to the above-described contents and will not be repeated here.

[0163] The method and the related equipment of the present disclosure have been described above in conjunction with the preferred embodiments. It can be understood by those skilled in the art that the method shown above is only 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.

[0164] 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 protection scope 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 protection scope 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...", "satisfy..." or "satisfy..." conditions" can be replaced with "under the condition of...". In the embodiments of the present disclosure, the embodiments obtained by replacing "and" in some or all of the conditions with "or" are also within the protection scope of the present disclosure; the embodiments obtained by replacing "or" in some or all of the conditions with "and" are also within the protection scope of the present disclosure.

[0165] 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.

[0166] 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, proprietary integrated circuits (ASICs), field programmable gate arrays (FPGAs), programmable logic devices (CPLDs), and the like.

[0167] In addition, the computer-executable instructions or programs running on the device according to the present invention can be programs that enable a computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or the information processed by the program can be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory systems.

[0168] The computer-executable instructions or programs for implementing the functions of the embodiments of the present invention can be recorded on a computer-readable storage 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. Herein, the so-called "computer system" can be a computer system embedded in the device and can include an operating system or hardware (such as peripheral devices). The "computer-readable storage medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium for temporarily storing a dynamic program, or any other recording medium readable by a computer.

[0169] The various features or functional modules of the device used in the above embodiments can be implemented or executed by a circuit (for example, a single-chip or multi-chip integrated circuit). The circuit designed to execute the functions described in this specification can 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 can be a microprocessor or any existing processor, controller, microcontroller, or state machine. The above circuit can be a digital circuit or an analog circuit. 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 invention can also be implemented using these new integrated circuit technologies.

[0170] Furthermore, the present invention is not limited to the above 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 devices, kitchen devices, cleaning devices, air conditioners, office devices, vending machines, and other household appliances.

[0171] As described above, 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 modifications that do not deviate from the gist of the present invention. In addition, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means invented in different embodiments are also included in the technical scope of the present invention. Furthermore, components having the same effect described in the above embodiments can be substituted for each other.

Claims

1. A method performed by a user equipment UE, comprising: The UE receives an RRC release message from a base station; And When a first indication identifier is included in the RRC release message, where the first indication identifier is used to indicate that the UE maintains a small data transmission SDT process or indicates that an MBS multicast session is activated or indicates that the UE does not perform operations performed when entering RRC_INACTIVE or RRC_IDLE or is used to indicate that the UE detects a multicast MCCH-RNTI or is used to indicate that the UE detects a G-RNTI of a multicast MBS session, perform at least one of the following operations: Operation 1-1a: Apply a multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field included in the RRC release message; Operation 1-1b: If the RRC release message includes a multicastConfigInactive field, apply a multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the RRC release message does not include a multicastConfigInactive field, obtain an MBSMulticastConfiguration message on the multicast MCCH; Operation 1-1c: If the RRC release message includes a multicastConfigInactive field and at least one TMGI included therein indicates that the MBS multicast session is not indicated to stop detecting the corresponding G-RNTI and the PTM configurations of all MBS multicast sessions not indicated to stop detecting the G-RNTI are included in the multicastConfigInactive field, apply a multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the RRC release message does not include a multicastConfigInactive field or there is an MBS multicast session whose PTM configuration not indicated to stop detecting the G-RNTI is not included in the multicastConfigInactive field, obtain an MBSMulticastConfiguration message on the multicast MCCH; Operation 1-1d: If the RRC release message includes a multicastConfigInactive field and / or an inactivePTM-Config field, apply a PTM configuration or apply the PTM configuration included in the inactivePTM-Config field; and / or if the RRC release message does not include an inactivePTM-Config field, obtain an MBSMulticastConfiguration message on the multicast MCCH; Operation 1-1e: Detect the multicast MCCH-RNTI, or detect the G-RNTI of all joined MBS multicast sessions; Operation 1-1f: The first indication identifier includes a list of G-RNTIs, and the UE detects the G-RNTIs included in the first indication identifier; Operation 1-1g: The process ends.

2. The method performed by a user equipment UE according to claim 1, comprising: The RRC release message includes a suspendConfig field, and the first indication identifier is included in the suspendConfig field.

3. The method performed by a user equipment UE according to claim 1 or 2, comprising: In the case where the first indication identifier is not included in the RRC release message, the UE performs at least one of the following operations: Operation 1-1A: Reset the MAC and / or release the default MAC cell group configuration; Operation 1-1B: Suspend all SRBs and DRBs except SRB0 and the broadcast MRB; Operation 1-1C: Suspend all multicast MRBs associated with multicast sessions that are not configured for RRC_INACTIVE reception; Operation 1-1D: Enter RRC_INACTIVE and / or perform cell selection; Operation 1-1E: Perform the operations performed to enter RRC_IDLE.

4. The method performed by a user equipment UE according to claim 2, comprising: When the multicastConfigInactive field is included in the suspendConfig, the first indication identifier is included in the suspendConfig.

5. A method performed by a user equipment UE, comprising: The UE receives an RRC release message from a base station; and When the first indication identifier is included in the RRC release message, and the first indication identifier is used to indicate that the UE aborts the small data transmission SDT process or indicates that the RRC release message is not for MBS multicast activation, perform at least one of the following operations: Operation 1-1A: Reset the MAC and / or release the default MAC cell group configuration; Operation 1-1B: Suspend all SRBs and DRBs except SRB0 and the broadcast MRB; Operation 1-1C: Suspend all multicast MRBs associated with multicast sessions that are not configured for RRC_INACTIVE reception; Operation 1-1D: Enter RRC_INACTIVE and / or perform cell selection; Operation 1-1E: Perform the operations performed to enter RRC_IDLE.

6. The method performed by a user equipment UE according to claim 5, wherein In the case where the first indication identifier is not included in the RRC release message, perform at least one of the following operations: Operation 1-1a: Apply the multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field included in the RRC release message; Operation 1-1b: If the multicastConfigInactive field is included in the RRC release message, apply the multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the multicastConfigInactive field is not included in the RRC release message, obtain the MBSMulticastConfiguration message on the multicast MCCH; Operation 1-1c: If the multicastConfigInactive field is included in the RRC release message and at least one TMGI indicated in the MBS multicast session included therein is not indicated to stop detecting the corresponding G-RNTI and the PTM configuration of all MBS multicast sessions not indicated to stop detecting the G-RNTI is included in the multicastConfigInactive field, apply the multicast PTM configuration or apply the multicast PTM configuration included in the multicastConfigInactive field; and / or if the multicastConfigInactive field is not included in the RRC release message or the PTM configuration of the MBS multicast session not indicated to stop detecting the G-RNTI is not included in the multicastConfigInactive field, obtain the MBSMulticastConfiguration message on the multicast MCCH; Operation 1-1d: If the multicastConfigInactive field and / or the inactivePTM-Config field is included in the RRC release message, apply the PTM configuration or apply the PTM configuration included in the inactivePTM-Config field; and / or if the inactivePTM-Config field is not included in the RRC release message, obtain the MBSMulticastConfiguration message on the multicast MCCH; Operation 1-1e: Detect the multicast MCCH-RNTI, or detect the G-RNTIs of all joined MBS multicast sessions; Operation 1-1f: The first indication identifier includes a list of G-RNTIs, and the UE detects the G-RNTIs included in the first indication identifier; Operation 1-lg: The process ends.

7. A method performed by a user equipment UE, comprising: The UE initiates an RRC connection restoration process; When the condition for starting small data transmission SDT is satisfied and the UE is configured to receive MBS multicast in RRC_INACTIVE and / or the UE is not detecting the multicast MCCH-RNTI, detect the multicast MCCH-RNTI.

8. The method performed by the user equipment UE according to claim 7, further comprising: The UE receives an RRC release message from the base station; And When the multicastConfigInactive field is not included in the RRC release message, stop detecting the multicast MCCH-RNTI.

9. The method performed by a user equipment UE according to claim 7, further comprising: The UE receives an RRC release message from a base station; and When the multicastConfigInactive field is not included in the RRC release message and the UE does not detect any G-RNTI, stop detecting the multicast MCCH-RNTI.

10. 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 9.

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