User equipment and method therefor, and base station and method therefor

Abstract

Provided in the present disclosure are a user equipment (UE) and a method therefor, and a base station and a method therefor. The method, which is executed by a UE, comprises: for a UE in an RRC inactive state, if there is an MBS multicast session that has been joined by the UE and activated, and a measurement result of a serving cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the operation of the timer, when the measurement result of the serving cell becomes higher than or not lower than the threshold configured for the MBS multicast session, stopping the timer.

Description

User equipment, base station and method thereof Technical Field

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

[0002] A study project (SI) on improving the 5G multicast broadcast service architecture (see SP-190625) has been approved. One of the objectives of this SI (referred to as Objective A) is to support universal MBS services in the 5GS. Use cases that could benefit from this feature include (but are not limited to) public safety, vehicle-to-everything (V2X) applications, transparent IPv4 / IPv6 multicast transmission, IPTV, wireless software delivery, group communications, 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 document RP-193248: New WID: NR Multicast and Broadcast Service). This work item aims to provide support for Objective A in the RAN. The objectives of this work item have been largely achieved, and the relevant solutions are described in 3GPP Release 17 technical documents such as TS 38.300-h50, TS 38.331-h50, and TS 38.321-h50. At the 3GPP RAN#94 plenary meeting, a work item titled Enhanced NR Multicast and Broadcast Services was approved (see non-patent literature: RP-213568: New WID: Enhancements of NR Multicast and Broadcast Services). This work item aims to further enhance MBS Multicast and Broadcast Services in Release 17, with one of its goals being to support user equipment receiving MBS multicast services / sessions even when RRC is not active.

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

[0004] Summary of the Invention

[0005] In order to solve the above problem, the object of the present invention is to provide a user equipment, a base station and a method thereof, which can effectively maintain, stop or restart a timer started by a UE in an RRC inactive state for an MBS multicast session.

[0006] To achieve the above-mentioned object, according to the present invention, a method performed by a user equipment (UE) is proposed, comprising: for a UE in an RRC inactive state, if there is an MBS multicast session to which the UE has joined and is activated, and the measurement result of the serving cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the running of the timer, if the measurement result of the serving cell becomes higher than or not lower than the threshold configured for the MBS multicast session, stopping the timer.

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

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

[0009] In addition, according to the present invention, a method performed by a user equipment (UE) is proposed, comprising: for a UE in an RRC inactive state, if there is an MBS multicast session that the UE has joined and is activated, and the measurement result of the serving cell is lower than or not higher than a threshold configured for the MBS multicast session, starting a timer or starting a timer for the MBS multicast session; and during the running of the timer, when dedicated RRC signaling or an MBS multicast configuration message is received, if the dedicated RRC signaling or the MBS multicast configuration message does not configure a threshold for the MBS multicast session, or the threshold configured for the MBS multicast session is lower than the current threshold, or the MBS multicast configuration message indicates that the configuration of the MBS multicast session is updated, stopping the timer.

[0010] Preferably, the method further comprises: when the timer expires, the UE initiates an RRC recovery process or the UE initiates an RRC recovery process for MBS multicast reception.

[0011] Preferably, the method further comprises: upon receiving the dedicated RRC signaling or the MBS multicast configuration message, if there is an RRC recovery process to be executed triggered by expiration of a timer, canceling the RRC recovery process to be executed.

[0012] Preferably, the method further includes: when receiving dedicated RRC signaling or MBS multicast configuration message, for each MBS multicast session that UE has joined and activated, if the dedicated RRC signaling or MBS multicast configuration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the currently configured threshold, or the MBS multicast configuration message indicates that the configuration of the MBS multicast session is updated, or the MBS multicast configuration message indicates that the MBS multicast session is deactivated, then canceling the RRC recovery process to be executed triggered by the expiration of the timer of the MBS multicast session.

[0013] In addition, according to the present invention, a user equipment is proposed, comprising: a processor; and a memory storing instructions, wherein the instructions execute the above method when executed by the processor.

[0014] In addition, according to the present invention, a method performed by a base station is proposed, wherein the base station communicates with a user equipment UE, and the method includes: sending dedicated RRC signaling or an MBS multicast configuration message to the UE, wherein the dedicated RRC signaling or MBS multicast configuration message can stop a timer started for an MBS multicast session by a UE in an RRC inactive state.

[0015] In addition, according to the present invention, a base station is proposed, comprising: a processor; and a memory storing instructions, wherein the instructions execute the above method when executed by the processor.

[0016] Effects of the Invention

[0017] According to the present invention, the timer started by the UE in the RRC inactive state for the MBS multicast session can be effectively maintained, stopped or restarted. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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:

[0019] FIG1 is a flowchart illustrating a method executed by a user equipment according to embodiment 1 of the present invention.

[0020] FIG2 is a flowchart illustrating a method executed by a user equipment according to embodiment 2 of the present invention.

[0021] FIG3 is a flowchart illustrating a method executed by a user equipment according to embodiment 3 of the present invention.

[0022] FIG4 is a flowchart illustrating a method executed by a user equipment according to embodiment 4 of the present invention.

[0023] FIG5 is a block diagram schematically illustrating a user equipment involved in the present invention.

[0024] FIG6 is a block diagram schematically showing a base station involved in the present invention. DETAILED DESCRIPTION

[0025] The following describes some of the terms involved in the present invention. For their specific meanings, please refer to the latest relevant 3GPP documents, such as TS38.300-h50, TS38.321-h50, TS38.323-h50, and TS38.331-h50. Furthermore, the embodiments of the present invention are described using broadcast / multicast services as an example. However, the embodiments of the present invention are not limited to broadcast / multicast services and can also be applied to other application scenarios.

[0026] UE: User Equipment.

[0027] RRC: Radio Resource Control.

[0028] RRC_CONNECTED: RRC connected state.

[0029] RRC_INACTIVE: RRC inactive state.

[0030] RRC_IDLE: RRC idle state.

[0031] RAN: Radio Access Network.

[0032] NR: New RAT, new radio access technology.

[0033] MBS: Multicast / Broadcast Services. Multicast can also be called multicast.

[0034] AS: Access Stratum, access layer or access layer.

[0035] NAS: Non Access Stratum, non-access layer or non-access layer.

[0036] RB: Radio Bearer. DRB is a data radio bearer.

[0037] MBS Radio Bearer (MRB): A radio bearer configured for MBS delivery. MRBs are classified into multicast MRBs and broadcast MRBs. A multicast MRB is a radio bearer configured for MBS multicast transmission, while a broadcast MRB is a radio bearer configured for MBS broadcast transmission.

[0038] TMGI: Temporary Mobile Group Identity, used to identify an MBS session.

[0039] RNTI: Radio Network Temporary Identifier, wireless network temporary identifier.

[0040] PTM (Point to Multipoint) is a method for delivering MBS services. In PTM, the gNB delivers a single copy of MBS data packets to a group of UEs. UEs use a G-RNTI or G-CS-RNTI to receive PTM transmissions. For example, the gNB uses the G-RNTI-based group-common physical downlink control channel (PDCCH) to schedule the same G-RNTI-based group-common physical downlink shared channel (PDSCH).

[0041] PTP: Point to Point, a delivery method for MBS services. In PTP, the gNB individually delivers separate copies of MBS data packets to each UE independently. For example, the base station schedules a UE-specific PDCCH scrambled with a UE-specific RNTI, using the same UE-specific RNTI, using the UE-specific PDSCH.

[0042] PCell: Primary Cell, MCG cell, operates on the primary frequency, in which the UE performs the initial connection establishment process or initiates the connection re-establishment process.

[0043] SCell: Secondary Cell. For UEs configured with carrier aggregation, an SCell is a cell that provides additional radio resources on top of a special cell. For dual connectivity, the term special cell refers to the PCell of an MCG or the PSCell of an SCG; otherwise, the term special cell refers to the PCell. For dual connectivity, the PSCell is the SCG cell in the secondary cell group (SCG) where the UE performs random access during the synchronous reconfiguration procedure.

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

[0047] MCCH: MBS Control Channel, MBS control channel, is a PTM downlink channel used for transmitting MBS broadcast or MBS multicast control information associated to one or several MTCH(s) from the network to the UE. MCCH includes broadcast MCCH and multicast MCCH.

[0048] 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 resumption 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 the suspension of 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 recovery identifier and recovery request message used. When the field is included in SIB1, fullI-RNTI and RRCResumeRequest1 message are used. When the field is not included in SIB1, shortI-RNTI and RRCResumeRequest message are used. ShortI-RNTI uses fewer bits than I-RNTI-Value to identify the suspended UE context of a UE in an RRC inactive state. The RRC recovery process (i.e., the RRC connection recovery process) is used to restore the suspended RRC connection, including restoring SRB(s), DRB(s) and multicast MRB(s), or performing RNA updates, or implementing MBS multicast reception requests, or initiating small data transmission SDT in the RRC_INACTIVE state, etc. During the RRC recovery process, the UE sends an RRC recovery request message to the base station, and may receive an RRC recovery message RRCResume or an RRC setup message RRCSetup or an RRC release message RRCRelease or an RRC rejection message RRCReject from the base station.

[0049] In the present invention, network, base station and RAN can be used interchangeably. 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.

[0050] Currently, NR MBS services include MBS broadcast (also known as MBS broadcast session, broadcast MBS, MBS broadcast service, or MBS broadcast service) and MBS multicast (also known as MBS multicast session, multicast MBS, MBS multicast service, or MBS multicast service). MBS broadcast provides a downlink-only MBS transmission mode for services with low quality of service (QoS), allowing UEs in RRC connected, RRC idle, and RRC inactive states to receive the MBS service. UEs obtain MBS broadcast configuration information broadcast by the network through the MBS control channel (MCCH).

[0051] In Release 17, it is not supported for UEs to receive MBS multicast sessions in the RRC inactive state. Therefore, before receiving MBS multicast services (i.e., MBS multicast sessions), the UE needs to establish an RRC connection with the base station. The base station then configures the resources or PTM configuration for receiving MBS multicast services for the UE 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 that are in the RRC connected state and configured with MRBs can receive the corresponding MBS multicast services. 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. Upon 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 using the P-RNTI on the Physical Downlink Control Channel (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 or RRC Inactive state. In other words, the base station does not page UEs individually (for the purpose of UEs receiving the MBS multicast session).

[0052] Version 18 supports UEs receiving MBS multicast sessions in an RRC inactive state. For MBS multicast sessions received in an RRC inactive state, the base station can provide or configure the UE with PTM configuration information for receiving the MBS multicast session (also called MBS multicast session configuration information or MBS multicast session PTM configuration) 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 the information required to obtain the multicast MCCH configuration of the MBS multicast received 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 identifier TMGI of the MBS multicast session and its corresponding G-RNTI / G-CS-RNTI and / or DRX and other configuration information fields. The multicast MCCH is a PTM downlink channel used for transmitting control information of an MBS multicast session associated with one or several MTCH(s) from the network to the UE in the RRC_INACTIVE state. For an MBS multicast session received in the RRC_INACTIVE state, the MBS multicast session being in an active state or being activated in the embodiments of the present disclosure means that the MBS multicast session is ongoing or about to start, or that the UE has started receiving the MBS multicast session. The network may indicate to the UE via RRC signaling (e.g., an RRC release message) or a paging message that the MBS multicast session has been activated or that data transmission has resumed (e.g., including the TMGI of the MBS multicast session in a paging message indicates that the MBS multicast session has been activated or that data transmission has resumed). Upon receiving the indication, the UE begins receiving the MBS multicast session. The "MBS multicast being activated" in the embodiments of the present disclosure also applies to the case of resuming data transmission of the MBS multicast session, which will not be further described below. In the embodiment of the present disclosure, the MBS multicast session being in an inactive state or being deactivated means that the MBS multicast session has ended or data transmission has been suspended or the UE has stopped receiving the MBS multicast session.The network may notify the UE through a multicast MCCH message (for example, if the PTM configuration of the MBS multicast session does not appear in the multicast MCCH message, it indicates that the MBS multicast session is deactivated, or an indicator identifier may be associated with each MBS multicast session to explicitly indicate that the MBS multicast session is deactivated) or through the physical downlink control channel PDCCH (or downlink control information DCI) that schedules the multicast MCCH (or multicast MCCH message), for example, using 1 bit in the DCI of the PDCCH to indicate that the MBS multicast is deactivated or data transmission is suspended. After receiving the indication, the UE stops receiving the MBS multicast session. The UE stopping receiving the MBS multicast session may be that the UE does not detect the G-RNTI or G-CS-RNTI corresponding to the MBS multicast session.

[0053] 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 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 MAC entity's G-RNTI(s)and G-CS-RNTI(s).

[0054] 3GPP Release 18 supports UEs receiving MBS multicast sessions in the RRC_INACTIVE state. 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, if the MBS multicast session is configured and / or reception in the RRC_INACTIVE state is allowed 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. However, if the MBS multicast session is not configured and / or allowed to be received in the RRC_INACTIVE state, or the UE does not have the PTM configuration or valid PTM configuration for the MBS multicast session, or when the UE in the RRC inactive state performs cell reselection and reselects to another cell, the PTM configuration of the MBS multicast session received in the RRC inactive state by the UE's current configuration is no longer valid, or the measurement result of the current cell is lower than or not higher than the threshold configured for the MBS multicast session reception, in these cases, the UE is triggered to perform an RRC recovery process (i.e., an RRC connection recovery process) to obtain relevant information about the PTM configuration of the MBS multicast session or enter the RRC connected state to receive the MBS multicast session. If a UE triggers an RRC recovery procedure because the measurement result of the current cell is below or below the threshold configured for a particular MBS multicast session, to avoid the ping-pong problem (i.e., the measurement result of the current cell is only temporarily below or below the threshold configured for a particular MBS multicast session and will soon recover to be above or below the threshold), a timer is maintained for each activated MBS multicast session. When the measurement result of the current cell is below or below the threshold configured for a particular MBS multicast session, the timer for the MBS multicast session is started. When the timer expires, the UE is triggered to perform an RRC recovery procedure. The timer value can be configured in an RRC release message or an MCCH message. The timer value can be configured for all MBS multicast sessions (i.e., the base station configures only one timer value, which applies to the timers of all MBS multicast sessions supported by the base station) or for only a particular MBS multicast session or group of MBS multicast sessions (i.e., the base station configures a timer value for each MBS multicast session or group of MBS multicast sessions). While the timer is running, how to maintain, stop, or restart the timer is a problem that needs to be solved.

[0055] It should be noted that the current cell may also be referred to as a serving cell or a cell in which the UE receives the MBS multicast, and the measurement result may be the RSRP (reference signal received power) and / or RSRQ (reference signal received quality) measured at layer 1 or layer 3 (i.e., layer 1 filtering or layer 3 filtering). The network may configure the threshold for MBS multicast through dedicated RRC signaling (e.g., an RRC release message) and / or multicast MCCH (i.e., a message transmitted on the multicast MCCH, referred to in this disclosure as a multicast MCCH message or an MBS multicast configuration message, denoted as an MBSMulticastConfiguration message). The MBS multicast threshold and the corresponding timer value may be configured through the same dedicated RRC signaling or MCCH message. The MBSMulticastConfiguration message contains the control information applicable for MBS multicast services transmitted via multicast MRBs for RRC_INACTIVE UEs). The MBSMulticastConfiguration message may be transmitted via a multicast MCCH channel or may be included in dedicated RRC signaling (e.g., an RRCRelease message). When the MBSMulticastConfiguration message is included in the dedicated RRC signaling, the network configuring the threshold via the dedicated RRC signaling may be configuring the threshold via the MBSMulticastConfiguration message included in the dedicated RRC signaling.

[0056] The following embodiments are provided to solve this problem.

[0057] For a UE in the RRC_INACTIVE state, if there is an MBS multicast session to which the UE has joined and is activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, then timer T is started or timer T is started for the MBS multicast session.

[0058] When the timer T expires, the UE initiates the RRC recovery process or the UE initiates the RRC recovery process for MBS multicast reception.

[0059] An embodiment of the operation performed by the UE during the running of the timer T is described below.

[0060] Example 1

[0061] FIG1 is a flowchart illustrating a method executed by a user equipment according to embodiment 1 of the present invention.

[0062] As shown in Figure 1, in step 101, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and is activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, timer T is started or timer T is started for the MBS multicast session.

[0063] In step 103, during the running of the timer T, if the measurement result of the serving cell becomes higher than (or not lower than) the threshold configured for the MBS multicast session, the timer T is stopped.

[0064] Example 2

[0065] FIG2 is a flowchart illustrating a method executed by a user equipment according to embodiment 2 of the present invention.

[0066] As shown in Figure 2, in step 201, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and is activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, timer T is started or timer T is started for the MBS multicast session.

[0067] In step 203, when the MBS multicast session is deactivated while the timer T is running, the timer T is stopped (this operation is performed only when the timer is running).

[0068] Example 3

[0069] FIG3 is a flowchart illustrating a method executed by a user equipment according to embodiment 3 of the present invention.

[0070] As shown in Figure 3, in step 301, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and is activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, timer T is started or timer T is started for the MBS multicast session.

[0071] In step 303 , when dedicated RRC signaling or an MBSMulticastConfiguration message is received while the timer T is running, the timer T is stopped (this operation is performed only if the timer is running).

[0072] In fact, for a UE in the RRC_INACTIVE state, if dedicated RRC signaling or an MBSMulticastConfiguration message is received, all running timers T may be stopped.

[0073] Example 4

[0074] FIG4 is a flowchart illustrating a method executed by a user equipment according to embodiment 4 of the present invention.

[0075] As shown in Figure 4, in step 401, for a UE in the RRC_INACTIVE state, if there is an MBS multicast session that the UE has joined and is activated, and the measurement result of the serving cell is lower than (or not higher than) the threshold configured for the MBS multicast session, timer T is started or timer T is started for the MBS multicast session.

[0076] In step 403, during the running of the timer T, when dedicated RRC signaling or an MBSMulticastConfiguration message is received, if the dedicated RRC signaling or the MBSMulticastConfiguration message does not configure a threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the current (or currently configured or saved) threshold or the MBSMulticastConfiguration message indicates that the configuration of the MBS multicast session is updated, the timer T is stopped (this operation is performed only if the timer is running).

[0077] In fact, for a UE in the RRC_INACTIVE state, when receiving dedicated RRC signaling or an MBSMulticastConfiguration message, for each MBS multicast session that the UE has joined (or for each MBS multicast session that the UE has joined and is in the active state), if the dedicated RRC signaling or MBSMulticastConfiguration message does not configure a corresponding threshold for the MBS multicast session or the threshold configured for the MBS multicast session is lower than the current (or currently configured or saved) threshold of the MBS multicast session or the MBSMulticastConfiguration message indicates that the configuration of the MBS multicast session is updated, the timing T corresponding to the MBS multicast session is stopped (this operation is performed only if the timer is running).

[0078] It should be noted that the timer T can also be represented by a time interval (time period T'). The time interval T' is the time during which the serving cell's measurement result is lower than (or lower than) a configured threshold, triggering the UE to initiate the RRC recovery process. In other words, for a certain MBS multicast session, from the first time the RSRP and / or RSRQ of the serving cell (i.e., the serving cell's measurement result) is measured to be lower than or lower than the configured threshold for the MBS multicast session, the UE is triggered to initiate the RRC recovery process only if the serving cell's measurement result is consistently lower than (or lower than) the configured threshold within the time interval T'. Accordingly, in the above-mentioned embodiments 1-4, the operation of stopping timer T is replaced by resetting time interval T'. Since time interval T' does not involve a startup operation, the operation of starting timer T is correspondingly deleted; the operation of performing this operation only when the timer is running is correspondingly replaced by performing this operation only when the time interval T' exists. The time interval T' can also be configured separately for each MBS multicast session through dedicated RRC signaling or MCCH message.

[0079] Example 5

[0080] Supports the use of delta configuration for MBS multicast sessions received in RRC_INACTIVE state or full configuration only during cell reselection in some cases.

[0081] For the MBSMulticastConfiguration message received (or obtained) by the UE or the MBSMulticastConfiguration message obtained from the reselected cell, if the MBSMulticastConfiguration message is the first MBSMulticastConfiguration message obtained after the UE reselects to a new cell, the UE will overwrite (overwrite) any stored multicast MCCH message with the MBSMulticastConfiguration message (i.e., the multicast MCCH message or MBSMulticastConfiguration message obtained by the multicast MCCH information acquisition process triggered by cell reselection) and the UE will not continue to use the domain not included in the MBSMulticastConfiguration message.

[0082] If the UE receives a multicast MCCH message or MBSMulticastConfiguration message obtained by the multicast MCCH information acquisition process triggered by the TMGI of the MBS multicast session that the UE has joined in the paging message, the UE only obtains the configuration information related to the MBS multicast session from the MBSMulticastConfiguration message and applies the configuration information (delta configuration or full configuration may be used).

[0083] If the UE obtains a multicast MCCH message or MBSMulticastConfiguration message in the multicast MCCH information acquisition process triggered by receiving an MBSMulticastConfiguration message update notification, the UE only obtains the configuration information related to the MBS multicast session from the MBSMulticastConfiguration message and applies the configuration information (delta configuration or full configuration may be used).

[0084] In addition, based on the different purposes of establishing or restoring the RRC connection between the UE and the network or the different events that trigger the establishment or restoration of the RRC connection between the UE and the network, multiple access types (Access Categories) are defined. When the UE initiates (initiates) the restoration of the RRC connection, it determines the access type and / or access identity (Access Identities) according to the triggering event, and performs a unified access control (UAC) process according to the determined access type and access identity. The purpose of this process is to perform an access prohibition check on the access attempt associated with the determined access category and one or more access identities (the event that triggers the UE to initiate the RRC recovery process is an access attempt). The UE maintains an access prohibition timer T390 for each access type. When performing an access prohibition check on the access type corresponding to a certain access attempt, if the access attempt is prohibited, the timer T390 of the access type corresponding to the access attempt is started. T390 is stopped when the UE performs cell selection or reselection, performs relay selection or reselection, enters the RRC connected state, receives an RRC reconfiguration message containing synchronization reconfiguration reconfigurationWithSync, a primary cell (PCell) changes in the RRC connected state, receives a MobilityFromNRCommand message, or receives an RRC release message. When T390 expires or stops, the operations performed for barring alleviation are performed. For example, when T390 corresponding to a certain access type expires, the barring of the corresponding access type is considered to be lifted. If the UE has an access attempt for the corresponding access type at this time, the UE will perform the corresponding access attempt (for example, if there is a pending RNA update, the RRC connection recovery procedure is initiated).

[0085] When RRC connection recovery is triggered (i.e., the RRC recovery procedure is initiated) due to the expiration of the timer T corresponding to a certain MBS multicast session (or because the measurement result of the serving cell is lower than or lower than the threshold of a certain MBS multicast session), when performing an access prohibition check based on the access type and / or access identity determined by the event that triggered the RRC connection recovery, if the access attempt is prohibited (for example, because T390 corresponding to the access type is running), the RRC recovery procedure will not be performed. When T390 corresponding to the access type expires or stops, the UE will re-trigger RRC connection recovery for reception of the MBS multicast session. However, during this process (i.e., the RRC recovery process triggered by the reception of the MBS multicast session is prohibited and the corresponding T390 is running), if the UE receives dedicated RRC signaling or MBSMulticastConfiguration message, and the dedicated RRC signaling or MBSMulticastConfiguration message reconfigures the threshold of the MBS multicast session (for example, the threshold for the MBS multicast session included in the dedicated RRC signaling or MBSMulticastConfiguration message is lower than the threshold for the MBS multicast session currently saved by the UE) or the timer value, or the dedicated RRC signaling or MBSMulticastConfiguration message does not include the threshold or timer value of the MBS multicast session, then whether the UE still needs to re-trigger RRC connection recovery for the reception of the MBS multicast session is a problem that needs to be solved.

[0086] The following embodiments are provided to solve this problem.

[0087] Example 6

[0088] When dedicated RRC signaling or an MBSMulticastConfiguration message is received, if there is a pending RRC resumption procedure triggered by the expiration of the timer T, the pending RRC resumption procedure is canceled.

[0089] Specifically, the following variable (i.e., the first variable) is defined, denoted as VarPendingPTM-Update or pendingPTM-Update, to indicate whether there is a pending RRC recovery procedure triggered by the expiration of timer T. It can be specified that the variable is of Boolean type, and if the variable value is set to the first value, it indicates that there is a pending RRC recovery procedure triggered by the expiration of timer T. The first value can be true or "true".

[0090] VarPendingPTM-Update UE variable

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

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

[0093] Example 7

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

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

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

[0097] [Modification]

[0098] 5 is used to illustrate a user equipment as a modified example that can execute the method executed by the user equipment described in detail above in the present invention.

[0099] FIG5 is a block diagram showing a user equipment UE according to the present invention.

[0100] As shown in Figure 5, the user equipment UE50 includes a processor 501 and a memory 502. The processor 501 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 502 may include, for example, a volatile memory (such as a random access memory (RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory. The memory 502 stores program instructions. When executed by the processor 501, the instructions may execute the above-described method performed by the user equipment as described in detail in the present invention.

[0101] Next, FIG. 6 is used to illustrate a base station as a modified example that can execute the method executed by the base station described above in the present invention.

[0102] FIG6 is a block diagram showing a base station according to the present invention.

[0103] As shown in Figure 6, the base station 60 includes a processor 601 and a memory 602. The processor 601 may include, for example, a microprocessor, a microcontroller, or an embedded processor. The memory 602 may include, for example, a volatile memory (such as a random access memory (RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory. The memory 602 stores program instructions. When executed by the processor 601, these instructions may execute the above-described method performed by the base station as described in detail in the present invention.

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

[0105] The method and related apparatus of the present disclosure have been described above in conjunction with preferred embodiments. Those skilled in the art will appreciate that the methods described above are merely exemplary and that the various embodiments described above can be combined with one another unless conflicts arise. The method of the present disclosure is not limited to the steps and sequence described above.

[0106] In the embodiments of the present disclosure, when multiple operations are included, the embodiments of the present disclosure exemplarily list the execution order of each operation, and the embodiments obtained by changing the execution order of each operation are also within the scope of protection of the present disclosure. In addition, when multiple judgment conditions are included, the embodiments obtained by changing the execution order of each judgment condition are also within the scope of protection of the present disclosure. In addition, in the present disclosure, unless otherwise specified, the meaning of the fields 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...", "at...", "satisfy..." or "satisfy the conditions..." can be replaced with "under the condition of...".

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

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

[0109] In addition, the computer executable instructions or programs running on the device according to the present invention can be programs that enable the computer to implement the functions of the embodiments of the present invention by controlling the central processing unit (CPU). The program or the information processed by the program can be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory systems.

[0110] The computer executable instructions or program for realizing each embodiment of the present invention function can be recorded on a computer-readable storage medium. The corresponding function can be realized by making a computer system read the program recorded on the recording medium and executing these programs. The so-called "computer system" herein can be a computer system embedded in the device, and can include an operating system or hardware (such as a peripheral device). "Computer-readable storage medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-term dynamic storage program recording medium or any other recording medium that is computer-readable.

[0111] The various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., single-chip or multi-chip integrated circuits). The circuits designed to perform the functions described in this specification may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. The general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above circuits may be digital circuits or analog circuits. In the event that new integrated circuit technologies have emerged to replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

[0112] Furthermore, the present invention is not limited to the above-described embodiments. Although various examples of the embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0113] As described 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-described embodiments, and the present invention also includes any design changes that do not deviate from the main purpose 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 by different embodiments are also included in the technical scope of the present invention. In addition, components with the same effect described in the above embodiments can be replaced with each other.

Claims

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

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

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

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

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

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

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

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

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

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

Images