Method executed by user equipment and user equipment

Abstract

The invention provides a method executed by user equipment and the user equipment. A method performed by a user equipment (UE) comprises: a first step in which the UE receives a paging message from a base station; and a second step in which, if the UE is in an RRC inactive state and the paging message does not trigger the UE to initiate an RRC connection recovery procedure (excluding the RRC connection recovery procedure triggered by the mobile-end-oriented SDT), the UE is activated for an MBS multicast session indicated by the TMGI included in the paging message, which has been joined by the UE, if the UE is in the RRC inactive state, and if the paging message does not trigger the UE to initiate the RRC connection recovery procedure (except the RRC connection recovery procedure triggered by the mobile-end-oriented SDT). And if the MBS multicast session in the paging message is indicated to be capable of being received in the RRC inactive state, starting to receive the MBS multicast session in the RRC inactive state.

Description

Technical Field

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

[0002] A research project SI (see SP-190625 for details) on the improvement of the 5G multicast broadcast service architecture has been approved. One of the goals of this SI (called Goal A) is to support universal 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-h30, TS38.331-h30, TS38.321-h30, etc. At the 3GPP RAN#94 plenary meeting, a work item named 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, 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 problem, the present invention provides a method performed by a user equipment and the user equipment.

[0005] According to a first aspect of the present invention, a method performed by a user equipment UE is provided, comprising: a first step, the UE receiving a paging message from a base station; and a second step, if the UE is in an RRC inactive state and the paging message does not trigger the UE to start an RRC connection recovery process (except for the RRC connection recovery process triggered by an SDT for the mobile terminal), then, for an MBS multicast session indicated by a TMGI that the UE has joined and included in the paging message, if the MBS multicast session is indicated in the paging message as being receivable in the RRC inactive state, starting to receive the MBS multicast session in the RRC inactive state.

[0006] In the method of the first aspect above, preferably, the TMGI of the MBS multicast session is forwarded to an upper layer.

[0007] In the method of the first aspect above, preferably, for each PagingRecord field contained in the paging message, if the ue-Identity contained in the PagingRecord field matches the fullI-RNTI stored in the UE, the RRC connection recovery process is started.

[0008] In the method of the first aspect above, preferably, if the paging message includes a first field and a second field different from the first field, or includes the first field but not the second field, or includes the second field but not the first field, and

[0009] If condition A or B is met,

[0010] Condition A. If there are one or more MBS sessions to which the UE has joined and indicated only by the TMGI contained in the first field, and the paging message does not contain a ue-Identity or any ue-Identity in the paging message does not match a UE identity allocated by an upper layer;

[0011] Condition B. If there are one or more MBS multicast sessions to which the UE has joined and indicated by the TMGI contained in the second field, but the PTM configuration of the MBS multicast session is not available, and the paging message does not contain a ue-Identity or any ue-Identity in the paging message does not match a UE identity allocated by an upper layer;

[0012] The UE then starts the RRC connection recovery process.

[0013] In the method of the first aspect above, preferably, starting to receive the MBS multicast session in the RRC inactive state includes the following operations: if the MRB of the MBS multicast session has not been established, establishing the MRB according to the acquired PTM configuration information of the MBS multicast session.

[0014] In the method of the first aspect above, preferably, starting to receive the MBS multicast session in the RRC inactive state comprises the following operation: if an MRB of the MBS multicast session has been established, continuing or resuming the MRB.

[0015] In the method of the first aspect above, preferably, starting to receive the MBS multicast session in the RRC inactive state comprises one of the following operations:

[0016] Operation 1: instructing the lower layer to monitor the G-RNTI or G-CS-RNTI associated with the MBS multicast session;

[0017] Operation 2: Indicate to the lower layer that the MBS multicast session is activated;

[0018] Operation 3: indicating the MBS multicast session to a lower layer;

[0019] Operation 4: Instruct the lower layer to start or continue receiving the MBS multicast session.

[0020] In addition, according to a second aspect of the present invention, a user equipment is provided, comprising: a processor; and a memory storing instructions, wherein the instructions execute the method described above when executed by the processor.

[0021] Effects of the Invention

[0022] According to the present invention, a method executed by a user equipment and corresponding user equipment capable of reducing unnecessary energy consumption and inter-layer interaction of the user equipment UE in an MBS multicast session can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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:

[0024] Figure 1 It is a flowchart schematically showing a method executed by a user equipment UE according to an embodiment of the present invention.

[0025] Figure 2 It is a block diagram showing a simplified structure of a user equipment involved in the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. In addition, for the sake of simplicity, detailed descriptions of known technologies that are not directly related to the present invention are omitted to prevent confusion in understanding the present invention.

[0027] 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-h30, TS38.321-h30, TS38.323-h30, TS38.331-h30, 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.

[0028] UE: User Equipment.

[0029] RRC: Radio Resource Control.

[0030] RRC_CONNECTED: RRC connected state.

[0031] RRC_INACTIVE: RRC inactive state.

[0032] RRC_IDLE: RRC idle state.

[0033] RAN: Radio Access Network.

[0034] NR: New RAT, new radio access technology.

[0035] MBS: Multicast / Broadcast Services. Multicast can also be called groupcast.

[0036] AS: Access Stratum, access layer or access layer.

[0037] NAS: Non Access Stratum, non-access layer or non-access layer.

[0038] RB: Radio Bearer. DRB is a data radio bearer.

[0039] 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.

[0040] TMGI: Temporary Mobile Group Identity, used to identify an MBS session.

[0041] RNTI: Radio Network Temporary Identifier, wireless network temporary identifier.

[0042] 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. 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.

[0043] PTP: Point to Point, a delivery method for MBS services. In the PTP delivery method, the RAN node delivers separate copies of multiple MBS data packets to each UE (gNB individually deliversseparate copies of MBS data packets to each UEs independently). For example, the base station schedules the UE-specific PDCCH scrambled by the UE-specific RNTI and the UE-specific PDSCH scrambled by the same UE-specific RNTI.

[0044] G-RNTI: Group RNTI, group RNTI, used to scramble the scheduling and transmission of PTM for one or more MBS multicast services.

[0045] 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.

[0046] The RRC recovery 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 recovery request, if the 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 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 resume a suspended RRC connection. In the present disclosure, the useFullResumeID field indicates the resume identifier and resume 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.

[0047] 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.

[0048] At present, NR MBS services include MBS broadcast (also known as MBS broadcast session or broadcast MBS or MBS broadcast service) and MBS multicast (also known as MBS multicast session or multicast MBS 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. In 3GPP version 17, the UE needs to establish an RRC connection with the base station before receiving the MBS multicast service (i.e., MBS multicast session), and then the base station configures the resources for receiving the MBS multicast service for the UE through dedicated RRC signaling (also known as RRC message, such as RRC reconfiguration message). 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.

[0049] In Release 17, it is not supported for UE to receive MBS multicast sessions in RRC inactive state. 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 the UE in RRC idle state or RRC inactive state through a group notification mechanism. Upon receiving the group notification, the UE that has joined or is interested in the MBS multicast session establishes an 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 used 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 MBS session).

[0050] 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 the UE with PTM configuration information for receiving the MBS multicast session (also called configuration information of the MBS multicast session or PTM configuration of the MBS multicast session) through dedicated RRC signaling (e.g., RRCRelease message) or through the multicast MBS control channel MCCH (i.e., multicast MCCH). The information required to obtain the multicast MCCH (or multicast MCCH configuration) can be configured for the UE through dedicated RRC signaling or system information block (denoted as SIBx), that is, SIBx contains information for obtaining the MCCH configuration of MBS multicast. The PTM configuration information may include the field MRB-ToAddMod of the configuration information of the MRB corresponding to the MBS multicast session and / or the field MBS-RNTI-SpedificConfig for configuring the configuration information such as G-RNTI / G-CS-RNTI and DRX corresponding to the MBS multicast session. The field MBS-RNTI-SpedificConfig is included in the Mac-CellGroupConfig field.

[0051] 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.

[0052] Release 18 supports UEs in RRC inactive state to receive MBS multicast sessions. When a UE in RRC inactive state receives a paging message from a base station, message), the paging message includes the TMGI of one or more MBS multicast sessions that the UE has joined (or is interested in), and / or the paging message indicates that the UE (can) receive the MBS multicast session indicated by the TMGI in an RRC inactive state (that is, receive the MBS multicast session for which the PTM configuration indicated by the TMGI is available in the RRC inactive state): if the PTM configuration of the MBS multicast session indicated by the TMGI is available (this condition is optional, if the base station always guarantees that the PTM configuration of the MBS multicast session that can be received in the RRC inactive state indicated by the paging message is always available, then this condition is not required, and the understanding in other embodiments of the present disclosure is the same as here), then start to receive the MBS multicast session in the RRC inactive state; otherwise (that is, the PTM configuration of the MBS multicast session is not available), start the RRC connection recovery process (this operation is performed only when the UE needs to determine whether the PTM configuration of the MBS multicast session is available). If the paging message does not indicate that the UE (can) receive the MBS multicast session indicated by the TMGI in the RRC inactive state or the paging message does not indicate that the UE (can) receive the MBS multicast session available with the PTM configuration in the RRC inactive state (i.e., indicates that the UE cannot receive the MBS multicast session indicated by the TMGI or the MBS multicast session available with the PTM configuration in the RRC inactive state, or indicates that the UE receives the MBS multicast session indicated by the TMGI or the MBS multicast session available with the PTM configuration in the RRC connected state) or the paging message does not contain the indication field, the RRC connection recovery process is started.

[0053] In the embodiment of the present disclosure, the following descriptions may be used interchangeably: a paging message indicates that the UE receives the MBS multicast session available for the PTM configuration indicated as activating or resuming data transmission in an RRC inactive state, a paging message indicates that the UE (may) receive the MBS multicast session available for the PTM configuration in an RRC inactive state, a paging message indicates that the UE can receive the MBS session in an RRC inactive state, and a paging message notifies the UE with a valid PTM configuration for the MBS multicast session to receive the MBS multicast session in an RRC inactive state. Specifically, the indicator carried in the paging message may indicate whether the MBS multicast session or TMGI or G-RNTI available for each PTM configuration can be received in an RRC inactive state. The indicator carried in the paging message may also be used to indicate whether all MBS multicast sessions whose TMGI is included in the paging message can be received in an RRC inactive state. In addition, an MBS multicast session available for the PTM configuration is an MBS multicast session with a valid PTM configuration or an MBS multicast session with a valid PTM configuration.

[0054] The multiple MBS multicast sessions that the UE has joined indicated by the TMGI contained in the received paging message may only partially be indicated as being receivable in the RRC inactive state. In other words, if there is at least one MBS multicast session that the UE has joined and indicated in the paging message that it cannot be received in the RRC inactive state, or although the MBS multicast session is indicated as being receivable in the RRC inactive state, the PTM configuration of the MBS multicast session is not available, the UE will initiate the RRC connection recovery process so that the UE enters the RRC connected state. In this case, considering that the UE will enter the RRC connected state, the MBS multicast session can also be received in the RRC connected state. For those MBS multicast sessions that the UE has joined and indicated that they can be received in the RRC inactive state, even if their PTM configuration is available, the UE may not initiate the MBS multicast session reception process. However, if the paging message contains an indication indicating downlink (i.e., mobile terminated or user-oriented) small data SDT transmission (remembered as mt-SDT), the UE will initiate the RRC connection recovery process. During the SDT process, the UE is still in the RRC inactive state. At this time, for those MBS sessions of the MBS multicast sessions that are indicated by the paging message as activating or resuming the PTM configuration for data transmission and receivable in the RRC inactive state, how the UE handles this is a problem that needs to be solved.

[0055] In order to solve at least part of the above problems, the present disclosure provides corresponding embodiments. Specific embodiments are listed below to illustrate the processing method of the present invention. In addition, the embodiments listed below are only examples and are not intended to limit the present invention.

[0056] The embodiment of the present disclosure is described in detail below. The purpose of this embodiment is to prevent the UE from triggering the lower layer to monitor the MBS multicast session indicated in the paging message as (can be) received in the RRC inactive state when starting the RRC connection recovery process (but excluding the RRC connection recovery process triggered by the SDT facing the mobile terminal) (optionally, the PTM configuration of the MBS multicast is available). Figure 1 1 is a flow chart schematically showing a method performed by a user equipment UE according to an embodiment of the present invention. Figure 1 As shown, this embodiment may include the following steps:

[0057] Step 101: UE receives a paging message from a base station.

[0058] Step 102: If the UE is in the RRC inactive state, and the paging message does not trigger the UE to start the RRC connection recovery process (except for the RRC connection recovery process triggered by the SDT facing the mobile terminal), for the MBS multicast session that the UE has joined and the TMGI indicated by the TMGI contained in the paging message, if the MBS multicast session is indicated in the paging message as being receivable in the RRC inactive state (i.e., it can be received in the RRC inactive state when the PTM configuration of the MBS multicast session is available), start receiving the MBS multicast session in the RRC inactive state. Optionally, forward the TMGI of the MBS multicast session to an upper layer (e.g., a NAS layer). Optionally, if the MRB of the MBS multicast session is established when the paging message is received (i.e., the paging message triggers the UE to obtain the PTM configuration of the MBS multicast session and establish the corresponding MRB according to the PTM configuration), forward the TMGI of the MBS multicast session to an upper layer (e.g., a NAS layer). Optionally, if the MRB of the MBS multicast session has been established when the UE receives the paging message (that is, the MRB is established for receiving the MBS multicast session in the RRC inactive state), the UE starts to receive the MBS multicast session in the RRC inactive state. Optionally, if the MRB of the MBS multicast session has not been established when the UE receives the paging message, the UE obtains the PTM configuration of the MBS multicast session, establishes the corresponding MRB according to the PTM configuration, and then starts to receive the MBS multicast session in the RRC inactive state.

[0059] Among them, the paging message does not trigger the UE to start the RRC connection recovery process (except for the RRC connection recovery process triggered by the SDT for the mobile terminal), which may include two situations. One is that the paging message does not trigger the UE to start the RRC connection recovery process (the paging message does not contain the SDT indication for the mobile terminal and / or the MBS sessions indicated by the TMGI contained in the paging message to which the UE has joined are all determined by the UE to be receivable in the RRC inactive state); the other is that the paging message triggers the UE to start the RRC connection recovery process, but the RRC connection recovery process is triggered for the SDT for the mobile terminal (or resumeCause is set to the enumeration value mt-SDT), that is, the paging message contains the mt-SDT field and / or the paging message does not contain the TMGI of the MBS session to which the UE has joined and the MBS multicast session is determined by the UE to be not receivable in the RRC inactive state. Correspondingly, if the paging message triggers the UE in the RRC inactive state to start the RRC connection recovery process, then based on the condition satisfied by the paging message for triggering the UE to start the RRC connection recovery process, the RRC connection recovery process is started; in this case (except for the RRC connection recovery process triggered by the SDT for the mobile terminal), optionally, for the MBS multicast session that the UE has joined and indicated in the paging message as activated or resumed data transmission and the PTM configuration of the MBS multicast session is available, the UE does not instruct the lower layer to start receiving the MBS multicast session in the RRC inactive state. In other words, if there is only an SDT for the mobile terminal to trigger the RRC connection recovery process, for each MBS multicast session that the UE has joined and indicated in the paging message as activated or resumed data transmission, and / or the paging message indicates that the MBS session can be received in the RRC inactive state, the MBS multicast session is started to be received in the RRC inactive state. Among them, the mt-SDT field is an enumeration type, and its value can be "true" or "true". In addition, when the received paging message contains the TMGI of the MBS multicast session to which the UE has joined, and the paging message also indicates that the MBS multicast session can be received in the RRC inactive state, and the PTM configuration of the MBS multicast session is available, the UE can determine that the MBS multicast session can be received in the RRC inactive state; otherwise (the paging message indicates that the MBS multicast session cannot be received in the RRC inactive state, or the paging message indicates that the MBS multicast session can be received in the RRC inactive state but the PTM configuration of the MBS multicast session is not available), the UE can determine that the MBS multicast session cannot be received in the RRC inactive state.

[0060] The UE initiates the RRC connection recovery process to recover a suspended RRC connection or to start small data transmission in an RRC inactive state. During this process, the UE will generate an RRC recovery request message and receive a response message such as an RRC recovery message or an RRC release message from the base station.

[0061] As a variation of the above embodiment, it can be stipulated that in step 102, if the UE is in an RRC inactive state and the paging message does not trigger the UE to start the RRC connection recovery process (except for the RRC connection recovery process triggered by the SDT facing the mobile terminal), and also satisfies that there is no RRC connection recovery process triggered by other events (such as the arrival of uplink data or the UE performing a RAN-based notification area RNA update, etc.) (that is, there is no RRC connection recovery process that has been initiated or is in progress), then the UE will execute: for each MBS multicast session that the UE has joined and is indicated in the paging message as being activated or resuming data transmission and / or the paging message indicates that the MBS session can be received in the RRC inactive state, start receiving the MBS multicast session in the RRC inactive state.

[0062] It should be noted that in the embodiments of the present disclosure, in at least one of the following cases, the paging message will trigger the UE to start the RRC connection recovery process:

[0063] Case 1: For each PagingRecord field contained in the paging message, if the ue-Identity contained in the PagingRecord field matches (ie is the same as) the fullI-RNTI stored in the UE or matches the UE identity allocated by the upper layer, the UE initiates the RRC connection recovery process.

[0064] In the disclosed embodiment, the PagingRecord field includes a ue-Identity field, and optionally, it also includes an accessType field for indicating whether the paging message is initiated due to a PDU session from a non-3GPP access. The value indicated by the ue-Identity field is ng-5G-S-TMSI or fullI-RNTI. The ng-5G-S-TMSI includes the 5G S zero-time mobile identity, which is a temporary UE identity provided by the 5GC (5G core network, i.e., the upper layer) to uniquely identify the UE in the tracking area. The value I-RNTI-Value indicated by the fullI-RNTI is used to identify the suspended UE context of the UE in the RRC inactive state.

[0065] Case 2: For the paging message containing a first field and a second field different from the first field, or the paging message containing the first field but not the second field, or the paging message containing the second field but not the first field, if the following condition A or condition B or condition C is met, the UE initiates the RRC connection recovery procedure:

[0066] Condition A. If there are one or more MBS sessions to which the UE has joined and which are indicated only by the TMGI included in the first field (i.e., the paging message does not include the second field or includes the second field but the TMGI is not included in the second field), and / or the PagingRecordList field is not included in the paging message (i.e., the paging message does not include ue-Identity) or any ue-Identity in the paging message does not match the UE identity allocated by the upper layer and / or the fullI-RNTI stored by the UE (for the case where the PagingRecordList field is included in the paging message).

[0067] Condition B. If there is a UE that has joined one or more MBS multicast sessions indicated by the TMGI contained in the first field, but the MBS multicast session is indicated in the second field as not being receivable in the RRC inactive state or is indicated as being receivable in the RRC inactive state but its PTM configuration is not available (i.e., the PTM configuration is not available in the RRC inactive state), and / or the PagingRecordList field is not included in the paging message (i.e., the paging message does not include ue-Identity) or any ue-Identity in the paging message does not match the UE identity allocated by the upper layer and / or the fullI-RNTI stored by the UE (for the case where the PagingRecordList field is included in the paging message).

[0068] Condition C. If there are one or more MBS multicast sessions that the UE has joined and indicated by the TMGI included in the second field, but the PTM configuration of the MBS multicast session is not available, and / or the PagingRecordList field is not included in the paging message (i.e., the paging message does not include ue-Identity) or any ue-Identity in the paging message does not match the UE identifier allocated by the upper layer and / or does not match the fullI-RNTI stored by the UE (for the case where the PagingRecordList field is included in the paging message).

[0069] In the embodiment of the present disclosure, the one or more MBS multicast sessions that the UE has joined and indicated by the TMGI included in the second field means that the UE has joined the MBS multicast session indicated by the TMGI and the TMGI is included in the first field and the MBS session indicated by the TMGI is indicated in the second field as being receivable in the RRC inactive state. The second field does not include the TMGI means that the MBS multicast session indicated by the TMGI is indicated in the second field as not being receivable in the RRC inactive state (i.e., even if the PTM configuration of the MBS multicast session is available, the UE cannot receive the MBS multicast session in the RRC inactive state or the UE also needs to start the RRC connection recovery process) or there is no indication information of the TMGI in the second field or the paging message does not notify the UE with a valid PTM configuration for the MBS multicast session to receive the MBS multicast session in the RRC inactive state.

[0070] Preferably, in the embodiment of the present disclosure, the first field is denoted as pagingGroupList, which contains one or more TMGIs (i.e., a TMGI list), and the PagingRecordList field contains one or more PagingRecord fields (i.e., a PagingRecord list). For a UE supporting version 17, upon receiving the first field, for a UE in an RRC inactive state, if the UE has joined one or more MBS sessions indicated by the TMGI contained in the first field, and the PagingRecordList field is not included in the paging message (i.e., the paging message does not contain ue-Identity) or any ue-Identity in the paging message does not match the UE identifier assigned by the upper layer (for the case where the PagingRecordList field is included in the paging message), the UE always starts the RRC connection recovery process; for a UE in an RRC idle state, upon receiving the paging message containing the first field, the following operations are performed for each TMGI contained in the first field: if the UE has joined the MBS multicast session indicated by the TMGI, the TMGI is forwarded to the upper layer (e.g., the NAS layer).

[0071] Preferably, in the embodiment of the present disclosure, the second field is used to indicate whether an MBS multicast session is activated or data transmission is resumed, or the second field is used to indicate whether an MBS multicast session can be received in an RRC inactive state, or the second field is used to notify a UE with a valid PTM configuration for the MBS multicast session to receive the MBS multicast session in an RRC inactive state. In other words, the UE only determines whether to receive the MBS multicast session in an RRC inactive state according to whether its PTM configuration is available for the MBS multicast session whose TMGI is included in the second field. Specifically, the second field may include a TMGI list (referred to as the first TMGI list) to indicate the MBS multicast session for which data transmission is activated or resumed, and the MBS multicast session indicated by the TMGI appearing in the list is activated or data transmission is resumed. In addition to the first TMGI list, the second field may also include an indication identifier (referred to as the first indication identifier) ​​that corresponds one-to-one to the TMGI in the first field to indicate whether the MBS multicast session indicated by the TMGI included in the first field is activated or data transmission is resumed (i.e., whether it can be received in an RRC inactive state). The second field may also contain only the first TMGI list or only the first indication identifier. In the case where the second field contains the first TMGI list and the first indication identifier, it may be specified that the first TMGI list only contains TMGIs not contained in the first field. In other words, a TMGI cannot be contained in both the first field and the first TMGI list. In addition, the embodiment of the present disclosure does not limit the inclusion relationship between the first field and the second field. The second field may be contained in the first field or not contained in the first field. The first indication identifier may also not be contained in the second field, but may be contained in the first field or not contained in the first field and the second field. In this case, the TMGI described in the embodiment of the present disclosure is contained in the second field and corresponds to the situation indicated by the first indication identifier, which should be understood as the TMGI indicated in the first indication identifier. It may be specified that only the TMGI of the MBS session that can be obtained by the PTM configuration can be included in the second field. It may also be specified that the PTM configuration of the MBS multicast session that can be received in the RRC inactive state indicated in the second field must be available in the RRC inactive state.

[0072] Accordingly, in the embodiment of the present disclosure, the TMGI included in the second field may mean that the TMGI itself is included in the second field (i.e., included in the first TMGI list), or may mean that the TMGI is included in the first field, and the second field includes the first indication identifier. The TMGI included in the second field means that the MBS multicast session indicated by the TMGI is indicated in the second field as being activated or resuming data transmission.

[0073] As another variation of the above embodiment, in step 102, if the UE does not meet the conditions listed in the above situation 1-2, then for each MBS multicast session that the UE has joined and indicated in the paging message as being receivable in the RRC inactive state and / or the PTM configuration of the MBS multicast session is available, the UE starts to receive the MBS multicast session in the RRC inactive state.

[0074] As another variation of the above embodiment, in step 102, if the UE does not meet the conditions listed in the above situation 1-2, and there is no RRC connection recovery process triggered by other events (such as the arrival of uplink data or the UE performing a RAN-based notification area RNA update, etc.) (that is, there is no triggered RRC connection recovery process or an ongoing RRC connection recovery process), then the MBS multicast session that the UE has joined and is indicated in the paging message as being receivable in the RRC inactive state and / or the PTM configuration of the MBS multicast session is available, and the MBS multicast session is started to be received in the RRC inactive state.

[0075] The following is a detailed description through Example 1.

[0076] Example 1

[0077] The UE receives a paging message from a base station. The paging message includes a first field, and performs at least one of the following operations 1.1 to 1.4:

[0078] Operation 1.1: If the UE is in the RRC idle state, upon receiving the paging message containing the first field, perform the following operations for each TMGI contained in the first field: if the UE joins the MBS multicast session indicated by the TMGI, forward the TMGI to the upper layer (eg, NAS layer).

[0079] Operation 1.2: If the UE is in an RRC inactive state, upon receiving the paging message containing the first field, if the UE joins the MBS session indicated by one or more TMGIs contained in the first field, and the PagingRecordList field is not contained in the paging message (i.e., the paging message does not contain any ue-Identity) or any ue-Identity contained in the paging message does not match the UE identity allocated by the upper layer and / or the fullI-RNTI stored by the UE (for the case where the PagingRecordList field is contained in the paging message), then further determine whether the paging message contains the second field. If one of the following conditions 1.1-1.4 is met, the UE initiates the RRC connection recovery process.

[0080] Condition 1.1: The paging message does not include the second field.

[0081] Condition 1.2: The paging message contains a second field, and the MBS multicast session indicated by the TMGI indicated by the first field, to which the UE has joined, is indicated by the second field as being receivable in an RRC inactive state (i.e., the TMGI of the MBS multicast session indicated by the first field to which the UE has joined is included in the second field), but the PTM configuration of the MBS multicast session is not available.

[0082] Condition 1.3: The paging message includes a second field, and the MBS multicast session indicated by the TMGI to which the UE indicated by the first field has joined is indicated by the second field as not being receivable in the RRC inactive state (i.e., the MBC multicast session is not indicated in the second field or the TMGI of the multicast session is not included in the second field or the second field does not indicate that the MBS multicast session can be received in the RRC inactive state).

[0083] Condition 1.4: The paging message includes the second field, and there is a TMGI of an MBS multicast session to which the UE has joined that is not included in the first field and the MBS multicast session is indicated by the second field as not being receivable in an RRC inactive state, or being receivable in an RRC inactive state (i.e., the second field includes a TMGI that is not included in the first field) but the PTM configuration of the MBS multicast session is not available. (Condition 1.4 is only valid if it is supported that the paging message may include only one MBS multicast session indication information in the second field but the TMGI of the MBS multicast session is not included in the first field, otherwise, condition 1.4 is not considered in this embodiment).

[0084] Operation 1.3: If the paging message does not contain the first field but contains the second field, and the PagingRecordList field is not included in the paging message (that is, the paging message does not contain ue-Identity) or any ue-Identity in the paging message does not match the UE identifier allocated by the upper layer and / or the fullI-RNT stored by the UE (for the case where the PagingRecordList field is included in the paging message), further, if the following condition I is met, the UE initiates the RRC connection recovery process.

[0085] Condition I: If there is an MBS multicast session that the UE has joined and is indicated by the second field as being activated or continuing data transmission (ie, the TMGI of the MBS multicast session that the UE has joined is included in the second field), but the PTM configuration of the MBS multicast session is not available.

[0086] Operation 1.4: If: (1) the paging message contains the first field and the second field but does not satisfy conditions 1.2 and 1.3 (i.e., the paging message does not contain an MBS multicast session to which the UE has joined and which is indicated by the second field as not being receivable in the RRC inactive state, or the paging message does not contain an MBS multicast session to which the UE has joined and which is indicated by the second field as being receivable in the RRC inactive state but the PTM configuration of the MBS multicast session is not available), and (2) the PagingRecordList field is not included in the paging message (i.e., the paging message does not contain ue-Identity) or any ue-Identity in the paging message does not match the UE identity allocated by the upper layer and / or the fullI-RNTI stored by the UE, or there is a ue-Identity in the paging message that matches the fullI-RNTI stored by the UE but the corresponding mt-SDT field is included in the paging message (i.e., RAN paging is received, and the paging is for the purpose of SDT for the mobile terminal) (for the case where the PagingRecordList field is included in the paging message), then perform at least one of the following operations:

[0087] Operation 1.a: For an MBS multicast session that the UE has joined and that is indicated in the second field as being receivable in the RRC inactive state and / or whose PTM is available, start receiving the MBS multicast session in the RRC inactive state.

[0088] Operation 1.b: Preferably, forward the TMGI to an upper layer. Alternatively, if the PTM configuration of the MBS multicast session is established by triggering the paging message, forward the TMGI of the MBS multicast session to an upper layer.

[0089] If it is stipulated that the UE does not stop receiving the MBS multicast service in the RRC inactive state when initiating an RRC recovery request (i.e., after starting the RRC connection recovery request process but before receiving a response message from the base station), then when the UE receives a paging message, regardless of whether the paging message triggers the RRC connection recovery process, for the MBS multicast session indicated by the TMGI contained in the paging message, if the MBS multicast session is indicated in the paging message as being receivable in the RRC inactive state and / or the PTM configuration of the MBS multicast session is available, then the UE starts receiving the MBS multicast session in the RRC inactive state. However, in this process, how the UE triggers the RRC connection recovery process according to the paging message and how the UE receives the MBS multicast session that has been joined and the TMGI is contained in the paging message and indicated by the paging message as being receivable in the RRC inactive state are issues that need to be resolved.

[0090] Examples 2-4 are provided below to solve this problem.

[0091] Example 2

[0092] The UE receives a paging message from a base station. The paging message includes a first field, and performs at least one of the following operations 2.1 to 2.4:

[0093] Operation 2.1: If the UE is in the RRC idle state, upon receiving the paging message containing the first field, perform the following operations for each TMGI contained in the first field: if the UE joins the MBS multicast session indicated by the TMGI, forward the TMGI to the upper layer (eg, NAS layer).

[0094] Operation 2.2: If the UE is in an RRC inactive state, upon receiving the paging message containing the first field, if the UE joins one or more MBS sessions indicated by the TMGI contained in the first field, and the PagingRecordList field is not contained in the paging message (i.e., the paging message does not contain ue-Identity) or any ue-Identity contained in the paging message does not match the UE identity allocated by the upper layer (e.g., NAS layer) and / or the fullI-RNTI stored by the UE (for the case where the PagingRecordList field is contained in the paging message), then further determine whether the paging message contains the second field. If one of the following conditions 2.a-2.d is met, the UE initiates the RRC connection recovery process.

[0095] Condition 2.a: The paging message does not include the second field.

[0096] Condition 2.b: The paging message includes a second field, and the MBS multicast session indicated by the TMGI to which the UE indicated by the first field has joined is indicated by the second field as being receivable in the RRC inactive state, but the PTM configuration of the MBS multicast session is not available.

[0097] Condition 2.c: The paging message includes a second field, and the MBS multicast session indicated by the TMGI to which the UE indicated by the first field has joined is indicated by the second field as not being receivable in the RRC inactive state (i.e., the TMGI of the MBS multicast session is not indicated in the second field or the TMGI of the MBS multicast session is not included in the second field or the second field does not indicate that the MBS multicast session can be received in the RRC inactive state).

[0098] Condition 2.d: The paging message includes the second field, and there is a TMGI of an MBS multicast session that the UE has joined that is not included in the first field and the MBS multicast session is indicated by the second field as not being receivable in an RRC inactive state, or is indicated as being receivable in an RRC inactive state (i.e., the second field includes a TMGI that is not included in the first field) but the PTM configuration of the MBS multicast session is not available. (Condition 2.d is only valid if the paging message supports that only one MBS multicast session indication information can be included in the second field but the TMGI of the MBS multicast session is not included in the first field, otherwise, condition 2.d is not considered)

[0099] Operation 2.3: If the UE is in an RRC inactive state and the paging message includes the first field and / or the second field, perform at least one of the following operations 2.a-2.e:

[0100] Operation 2.a: For an MBS multicast session that the UE has joined and that is indicated by the TMGI in the first field, if the MBS multicast session indicates in the second field that it can be received in the RRC inactive state and / or the PTM configuration of the MBS multicast session is available, start receiving the MBS multicast session in the RRC inactive state.

[0101] Operation 2.b: For an MBS multicast session that the UE has joined and indicates in the second field that it can be received in the RRC inactive state and / or the PTM configuration of the MBS multicast session is available, start receiving the MBS multicast session in the RRC inactive state.

[0102] Operation 2.c: For the MBS multicast session to which the UE has joined and which is indicated by the TMGI contained in the first field, if the MBS multicast session indicates in the second field that it can be received in the RRC inactive state and / or the PTM configuration of the MBS multicast session is available, further, if the MRB of the MBS multicast session has been established, start receiving the MBS multicast session in the RRC inactive state; otherwise (the MRB of the MBS multicast session has not been established), obtain the configuration information of the MBS multicast session from the MCCH message, establish the MRB according to the configuration information, and then start receiving the MBS multicast session in the RRC inactive state.

[0103] Operation 2.d: The MBS multicast session that the UE has joined and is receivable in the RRC inactive state and / or the PTM configuration of the MBS multicast session indicated in the second field are available. Further, if the MRB of the MBS multicast session (i.e., the MRB used for reception in the RRC inactive state) has been established, start receiving the MBS multicast session in the RRC inactive state; otherwise (the MRB of the MBS multicast session has not been established), obtain the configuration information of the MBS multicast session from the MCCH message, establish the MRB according to the configuration information, and then start receiving the MBS multicast session in the RRC inactive state.

[0104] Operation 2.e: Forward the TMGI to an upper layer. Alternatively, if the PTM configuration of the MBS multicast session is established by triggering the paging message, forward the TMGI of the MBS multicast session to an upper layer.

[0105] Operation 2.4: If the UE is in the RRC inactive state, upon receiving the paging message containing the first field, for each MBS session to which the UE has joined and indicated by the TMGI contained in the first field, if the paging message contains a second field, and / or the MBS multicast session is indicated by the second field as being receivable in the RRC inactive state, and / or the PTM configuration of the MBS multicast session is available, then start receiving the MBS multicast session in the RRC inactive state.

[0106] Example 3

[0107] The UE receives a paging message from a base station. The paging message includes a first field, and the UE performs at least one of the following operations 3.1 to 3.3:

[0108] Operation 3.1: If the UE is in the RRC idle state, upon receiving the paging message containing the first field, perform the following operations for each TMGI contained in the first field: if the UE joins the MBS multicast session indicated by the TMGI, forward the TMGI to the upper layer (eg, NAS layer).

[0109] Operation 3.2: If the UE is in an RRC inactive state, upon receiving a paging message including the first field, if the UE joins one or more MBS sessions indicated by the TMGI included in the first field, further:

[0110] If the PagingRecordList field is not included in the paging message (that is, the paging message does not include ue-Identity) or any ue-Identity in the paging message does not match the UE identifier assigned by the upper layer or the fullI-RNTI stored by the UE (for the case where the PagingRecordList field is included in the paging message), it is further determined whether the paging message includes a second field:

[0111] If the paging message does not include the second field, the UE initiates the RRC connection recovery process.

[0112] The paging message includes a second field and satisfies the following conditions 3.a or 3.b:

[0113] Condition 3.a: There is an MBS to which the UE has joined and to which the TMGI indicated in the first field is included

[0114] The multicast session is indicated by the second field as being receivable in the RRC inactive state, but the

[0115] The PTM configuration for the MBS multicast session is not available.

[0116] Condition 3.b: There is an MBS to which the UE has joined and to which the TMGI indicated in the first field is included

[0117] The multicast session is indicated by the second field as not being receivable in the RRC inactive state,

[0118] The UE then starts the RRC connection recovery process.

[0119] Otherwise (if a certain ue-Identity in the paging message matches the UE identifier allocated by the upper layer), the TMGI to which the UE has joined and contained in the first field is forwarded to the upper layer.

[0120] Operation 3.3: If the UE is in the RRC inactive state, if the paging message contains the first field and / or the second field, for each MBS multicast session that the UE has joined and indicated by the TMGI contained in the first field, if the MBS multicast session is indicated by the second field as being receivable in the RRC inactive state, and / or the PTM configuration of the MBS multicast session is available, then start receiving the MBS multicast session in the RRC inactive state. The starting of receiving the MBS multicast session in the RRC inactive state may be replaced by at least one of the following operations:

[0121] (i) if an MRB for the MBS multicast session already exists or is established in the UE, that is, an MRB for receiving in the RRC inactive state, then starting to receive the MBS multicast session in the RRC inactive state;

[0122] (ii) If the MRB for the MBS multicast session does not exist or has not been established in the UE (i.e., the MRB for reception in the RRC inactive state), the configuration information of the MBS multicast session is obtained from the MCCH, and / or a corresponding MBR is established according to the obtained configuration information of the MBS multicast session, and the MBS multicast session is started to be received in the RRC inactive state; optionally, the TMGI of the MBS multicast session is forwarded to the upper layer.

[0123] Example 4

[0124] If, when the UE receives a paging message from a base station, for each MBS multicast session indicated by the TMGI included in the first field of the paging message to which the UE has joined, if the MBS multicast session is receivable by the UE in an RRC inactive state (whether the MBS multicast session can be received in an RRC inactive state can be indicated by the second field of the paging message), further, if an MRB for the MBS multicast session has not been established in the UE (i.e., an MRB for reception in an RRC inactive state), then configuration information of the MBS multicast session is obtained, and / or an MRB for the MBS multicast session is established (or The MRB of the multicast session is established according to the acquired configuration information of the MBS multicast session), and / or the TMGI of the MBS multicast session is indicated or forwarded to the upper layer, and / or the MBS multicast session is started to be received in the RRC inactive state (the embodiments obtained by reversing the execution order of the listed multiple operations are also within the scope of protection of the present disclosure, for example, the MBS multicast session is started to be received in the RRC inactive state first, and then the TMGI of the MBS multicast session is indicated or forwarded to the upper layer); otherwise (the MRB of the MBS multicast session has been established), the MBS multicast session is started to be received in the RRC inactive state.

[0125] In the embodiments of the present disclosure, the MBS multicast session can be received in the RRC inactive state, and the MBS multicast session does not need to enter the RRC connected state to receive the replacement use embodiment is also within the scope of protection of the present disclosure. Correspondingly, the MBS multicast session cannot be received in the RRC inactive state, and the MBS multicast session needs to be received in the RRC connected state to receive the replacement use embodiment is also within the scope of protection of the present disclosure.

[0126] It should be noted that, in the embodiments of the present disclosure, the PTM configuration of the MBS multicast session is available (that is, the PTM configuration of the MBS multicast session is available in the RRC inactive state), which may include the following cases A, B and C:

[0127] Case A. The UE includes the PTM configuration of the MBS multicast session in the (most recently) received RRCRelease message; or, the PTM configuration of the MBS multicast session is included in the RRCRelease message. Specifically, the UE receives an RRC release message from the base station, and for each MBS multicast session included in the RRC release message (or the PTM configuration of the MBS multicast session included in the RRC release message), considers its PTM configuration to be available. Optionally, for an MBS multicast session that the UE has joined but whose PTM configuration is not included in the RRC release message, its PTM configuration is considered to be unavailable. It can also be stipulated that when the UE receives an RRC release message, if the RRC release message does not include the PTM configuration of at least one MBS multicast session that the UE has joined, the UE obtains a multicast MCCH message to determine whether the PTM configuration of the MBS multicast session is available.

[0128] Case B. The UE receives the PTM configuration of the corresponding MBS multicast session in the multicast MCCH message. This may include two cases: one is that the UE receives the PTM configuration of the corresponding MBS multicast session in the multicast MCCH message that was recently received or currently being broadcast; the other is that the UE receives the PTM configuration of the multicast MBS from the multicast MCCH message after entering the RRC inactive state, that is, after the UE enters the RRC inactive state, although the multicast MCCH message that was recently received or currently being broadcast does not contain the PTM configuration of the multicast MBS, the PTM configuration of the multicast MBS was received in the multicast MCCH message that was previously broadcast. Specifically, when the UE receives a multicast MCCH message from the base station (that is, an MCCH message for MBS multicast or an MCCH message for an MBS multicast session), if the MCCH message contains the PTM configuration of the MBS multicast session that the UE has joined, the PTM configuration of the MBS multicast session is considered to be available. If the multicast MCCH message received by the UE does not contain the PTM configuration of an MBS multicast session that the UE has joined, but the multicast MCCH message received previously contains the PTM configuration of the MBS multicast session, the UE still considers the PTM configuration of the MBS multicast session to be available. In other words, as long as the PTM configuration of an MBS multicast session that the UE has joined is included in the RRC release message or the PTM configuration of the MBS multicast session has been received in the multicast MCCH message, the PTM configuration of the MBS multicast session is considered to be available, regardless of whether the PTM configuration of the MBS multicast session is included in the most recently received or broadcasted multicast MCCH message.

[0129] Case C: The UE has established the MRB for the MBS multicast session (ie, the MRB for receiving in an RRC inactive state), or the UE has established the MRB for the MBS multicast session and the MRB is not suspended.

[0130] In the disclosed embodiment, the PTM configuration of the MBS multicast session is unavailable, which may mean that the UE cannot obtain the PTM configuration in situation AC, that is, the PTM configuration of the MBS multicast session is neither included in the RRC release message nor obtained from the multicast MCCH message after entering the RRC inactive state or is not included in the multicast MCCH message being broadcast.

[0131] In addition, in the embodiment of the present disclosure, starting to receive the MBS multicast session in the RRC inactive state may be one of the following operations:

[0132] Operation 1: The UE (ie, the RRC layer of the UE) instructs a lower layer (the lower layer may be a MAC layer) to monitor the G-RNTI or G-CS-RNTI associated with the MBS multicast session.

[0133] Operation 2: The UE (ie, the RRC layer of the UE) indicates to the lower layer (the lower layer may be the MAC layer) that the MBS multicast session is activated and / or the G-RNTI or G-CS-RNTI associated with the MBS multicast session.

[0134] Operation 3: Indicate the MBS multicast session to a lower layer (the lower layer may be a MAC layer).

[0135] Operation 4: Instruct a lower layer (the lower layer may be a MAC layer) to start / continue / resume receiving the MBS multicast session.

[0136] Operation 5: If the MRB of the MBS multicast session has not been established, establish a corresponding MBR according to the received configuration information of the MBS multicast session and / or perform one of operations 1-4. Optionally, after the MRB is established, forward the TMGI of the MBS multicast session to an upper layer. Optionally, if the MRB of the MBS multicast session has been established, continue or resume the MRB and / or perform one of operations 1-4.

[0137] It should be noted that after receiving the indication, the MAC entity / layer starts to monitor the G-RNTI or G-CS-RNTI or monitors the G-RNTI or G-CS-RNTI according to the configured discontinuous reception DRX, for example, starting the DRX-related timer drx-onDurationTimerPTM for the G-RNTI or G-CS-RNTI. During the operation of the timer, the UE is considered to be in the activation time of DRX. When the timer is running, the UE monitors the G-RNTI or G-CS-RNTI

[0138] In addition, in the implementation of the present disclosure, stopping receiving the MBS multicast session in the RRC inactive state may be one of the following operations:

[0139] Operation I: The UE (ie, the RRC layer of the UE) instructs a lower layer (the lower layer may be a MAC layer) to stop monitoring (ie, stop receiving) the MBS multicast session.

[0140] Operation II: The UE (ie, the RRC layer of the UE) indicates to the lower layer (the lower layer may be the MAC layer) that the MBS multicast session is deactivated.

[0141] Operation III: The UE (ie, the RRC layer of the UE) instructs a lower layer (the lower layer may be a MAC layer) to stop monitoring the G-RNTI or G-CS-RNTI associated with the MBS multicast session.

[0142] Operation IV: The UE (ie, the RRC layer of the UE) indicates to the lower layer (the lower layer may be the MAC layer) that the MBS multicast session is deactivated and indicates its associated G-RNTI or G-CS-RNTI to the lower layer.

[0143] It should be noted that after receiving an instruction from the upper layer (ie, the RRC layer / entity), the MAC entity / layer stops the DRX timer of the MBS multicast session and / or stops monitoring the G-RNTI and / or G-CS-RNTI corresponding to the MBS multicast session.

[0144] When the UE initiates the RRC connection recovery process, if the process is successfully completed, the UE will enter the RRC connected state. At this time, those MBS multicast sessions received in the RRC inactive state will also be configured to be received in the RRC connected state. However, if the UE initiates the RRC connection recovery process but does not cause the UE to enter the RRC connected state, the MBS multicast sessions received in the RRC inactive state need to be maintained to improve the reliability and service continuity of the MBS multicast sessions received in the RRC inactive state. Therefore, it can be stipulated that the UE will stop receiving the MBS multicast session only when it receives the RRC recovery message or the RRC establishment message RRCSetup. Stopping the reception of the MBS multicast session can be achieved by resetting the MAC, or by the above-mentioned operation performed when stopping the reception of the MBS multicast session in the RRC inactive state. The RRC establishment message RRCSetup is used to establish SRB1.

[0145] In addition, the description of the functions of the fields involved in the present disclosure, unless otherwise specified, is applicable to all embodiments of the present disclosure. In the embodiments of the present disclosure, monitoring and detecting (detect) are interchangeable.

[0146] Figure 2 It is a block diagram showing a simplified structure of a user equipment involved in the present invention.

[0147] like Figure 2 As shown, the user equipment 20 includes at least a processor 201 and a memory 202. The processor 201 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 202 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 memory systems, etc. The memory 202 stores program instructions. When the instructions are executed by the processor 201, one or more steps of the processing method of the UE of the present disclosure may be executed.

[0148] 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 the judgment conditions are also within the protection scope of the present disclosure.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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: Step 1: The UE receives a paging message from a base station; and Step 2: If the UE is in an RRC inactive state and the paging message does not trigger the UE to start the RRC connection recovery process (except for the RRC connection recovery process triggered by the SDT facing the mobile terminal), for the MBS multicast session indicated by the TMGI that the UE has joined and included in the paging message, if the MBS multicast session is indicated in the paging message as being receivable in the RRC inactive state, start receiving the MBS multicast session in the RRC inactive state.

2. The method according to claim 1, comprising: The TMGI of the MBS multicast session is forwarded to an upper layer.

3. The method according to claim 1 or 2, wherein: For each PagingRecord field contained in the paging message, if the ue-Identity contained in the PagingRecord field matches the fullI-RNTI stored in the UE, the RRC connection recovery process is started.

4. The method according to claim 1 or 2, wherein If the paging message includes a first field and a second field different from the first field, or includes the first field but not the second field, or includes the second field but not the first field, and If condition A or B is met, Condition A. If there are one or more MBS sessions to which the UE has joined and indicated only by the TMGI contained in the first field, and the paging message does not contain a ue-Identity or any ue-Identity in the paging message does not match a UE identity allocated by an upper layer; Condition B. If there are one or more MBS multicast sessions to which the UE has joined and indicated by the TMGI contained in the second field, but the PTM configuration of the MBS multicast session is not available, and the paging message does not contain a ue-Identity or any ue-Identity in the paging message does not match a UE identity allocated by an upper layer; The UE then starts the RRC connection recovery process.

5. The method according to claim 1 or 2, wherein the starting to receive the MBS multicast session in the RRC inactive state comprises the following operations: If the MRB of the MBS multicast session has not been established, the MRB is established according to the acquired PTM configuration information of the MBS multicast session.

6. The method according to claim 1 or 2, wherein the starting to receive the MBS multicast session in the RRC inactive state comprises the following operations: If the MRB of the MBS multicast session has been established, continue or resume the MRB.

7. The method according to claim 1 or 2, wherein the starting to receive the MBS multicast session in the RRC inactive state comprises one of the following operations: Operation 1: instructing the lower layer to monitor the G-RNTI or G-CS-RNTI associated with the MBS multicast session; Operation 2: Indicate to the lower layer that the MBS multicast session is activated; Operation 3: indicating the MBS multicast session to a lower layer; Operation 4: Instruct the lower layer to start or continue receiving the MBS multicast session.

8. A user equipment, comprising: processor; as well as Memory, which stores instructions, Wherein, the above instructions, when executed by the above processor, execute the method according to any one of claims 1 to 7.

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