Method executed by user equipment, and user equipment

Abstract

The present invention provides a user equipment (UE). A processor of the UE is configured to: start a multicast MCCH information acquisition process, and acquire a first MBS multicast configuration message; and use the first MBS multicast configuration message to overwrite stored multicast MCCH information, wherein the stored multicast MCCH information is a second MBS multicast configuration message, and the second MBS multicast configuration message is an MBS multicast configuration message received from an RRC release message or an MBS multicast configuration message received from a multicast MCCH logical channel.

Description

Method performed by user equipment and user equipment Technical Field

[0001] The present invention relates to the technical field of wireless communications, and more particularly, to a method executed by a user equipment and the user equipment. 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 services (NRMBS) 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 at least part of the above problems, the present invention provides a method performed by a user equipment and the user equipment.

[0006] According to a first aspect of the present invention, a method performed by a user equipment (UE) is provided, comprising: the UE being triggered to start a multicast MCCH information acquisition process; and overwriting any stored multicast MCCH information with an MBS multicast configuration acquired from the multicast MCCH through the multicast MCCH information acquisition process.

[0007] In the method of the first aspect above, at least the following three situations will trigger the UE to start the multicast MCCH information acquisition process: receiving a change notification; an MBS multicast session configured and / or allowed to be received in the RRC_INACTIVE state is activated; the UE reselects to a new cell.

[0008] In the method of the first aspect above, the MBS multicast configuration may also cover the PTM configuration of the MBS multicast session configured through a dedicated RRC message.

[0009] In the method of the first aspect above, the multicast MCCH information may be information transmitted in a message sent via the multicast MCCH.

[0010] In the method of the first aspect above, the multicast MCCH information may include: information transmitted in a message sent via the multicast MCCH, and a PTM configuration of the MBS multicast session configured via a dedicated RRC message.

[0011] In the method of the first aspect above, the MBS multicast session may be an MBS multicast session configured to be received in an RRC_INACTIVE state.

[0012] In the method of the first aspect above, when the MBS multicast configuration is the MBS multicast configuration acquired for the first time by the UE after reselecting to the current cell, the MBS multicast configuration may overwrite any stored multicast MCCH information and the PTM configuration of the MBS multicast session configured through a dedicated RRC message.

[0013] In the method of the first aspect above, when the MBS multicast configuration is the MBS multicast configuration acquired for the first time by the UE after reselecting to the current cell, the MBS multicast configuration may overwrite any stored multicast MCCH information.

[0014] In the method of the first aspect above, when the MBS multicast configuration is not the first MBS multicast configuration acquired by the UE after reselecting to the current cell, delta configuration may be performed on the PTM configuration of the MBS multicast configured for RRC_INACTIVE reception using the received MBS multicast configuration.

[0015] In addition, according to a second aspect of the present invention, there is provided a user equipment, 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] The method performed by the user equipment and the corresponding user equipment provided by the present invention can solve the related problems involved in RAN supporting the user equipment to receive MBS multicast services / sessions in the RRC inactive state. 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 schematic flow chart showing a method executed by a user equipment in embodiment 1 of the present invention.

[0020] FIG2 is a schematic flow chart showing a method executed by a user equipment in embodiment 2 of the present invention.

[0021] FIG3 is a block diagram showing a user equipment UE according to the present invention. DETAILED DESCRIPTION

[0022] 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.

[0023] UE: User Equipment.

[0024] RRC: Radio Resource Control.

[0025] RRC_CONNECTED: RRC connected state.

[0026] RRC_INACTIVE: RRC inactive state.

[0027] RRC_IDLE: RRC idle state.

[0028] RAN: Radio Access Network.

[0029] NR: New RAT, new radio access technology.

[0030] MBS: Multicast / Broadcast Services. Multicast can also be called multicast.

[0031] AS: Access Stratum, access layer or access layer.

[0032] NAS: Non Access Stratum, non-access layer or non-access layer.

[0033] RB: Radio Bearer. DRB is a data radio bearer.

[0034] 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.

[0035] TMGI: Temporary Mobile Group Identity, used to identify an MBS session.

[0036] RNTI: Radio Network Temporary Identifier, wireless network temporary identifier.

[0037] 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).

[0038] PTP (Point to Point) is 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 the UE-specific PDCCH scrambled with the UE-specific RNTI and the UE-specific PDSCH scrambled with the same UE-specific RNTI.

[0039] 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.

[0040] 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.

[0041] G-RNTI: Group RNTI, group RNTI, used to scramble the scheduling and transmission of PTM for one or more MBS multicast services.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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 UUE 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, the fullI-RNTI and RRCResumeRequestl message are used. When the field is not included in SIB1, the 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.

[0046] 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.

[0047] 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).

[0048] Release 17 does not support UEs receiving 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 (i.e., the network) then configures the resources or PTM configuration for the UE to receive MBS multicast services through dedicated RRC signaling (also known as RRC messages, such as RRC reconfiguration messages). The MBS radio bearer (MRB) for receiving these MBS multicast services is also configured for the UE by the base station through dedicated RRC signaling. Only UEs in the RRC connected state and configured with 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).

[0049] Release 18 supports UEs receiving MBS multicast sessions in an RRC inactive state. For MBS multicast sessions configured for reception 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 referred to as MBS multicast session configuration information or MBS multicast session PTM configuration or MBS multicast 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 blocks (denoted as SIBx), i.e., SIBx contains the information required to obtain the multicast MCCH configuration for MBS multicast received in an RRC inactive state. The PTM configuration information may include the configuration information of the MRB corresponding to the MBS multicast session and / or the 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, in the embodiments of the present disclosure, the MBS multicast session being in an active state or being activated means that the MBS multicast session is ongoing or about to start, or the UE starts receiving the MBS multicast session, or the UE starts detecting the G-RNTI corresponding to the MBS multicast session. The network may indicate to the UE that the MBS multicast session is activated or data transmission is resumed through RRC signaling (e.g., an RRC release message) or a paging message (e.g., including the TMGI of the MBS multicast session in a paging message indicates that the MBS multicast session is activated or data transmission is resumed). Upon receiving the indication, the UE starts receiving the MBS multicast session (i.e., the UE starts detecting the G-RNTI corresponding to the MBS multicast session). The MBS multicast activation described in the embodiment of the present disclosure is also applicable to the case of resuming data transmission of the MBS multicast session, which will not be described in detail below.In the embodiments 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 (i.e., the UE has stopped detecting the G-RNTI corresponding to the MBS multicast session). The network may notify the UE via a multicast MCCH message (for example, if the PTM configuration of the MBS multicast session or a specific portion of the PTM configuration does not appear in the multicast MCCH message, it indicates that the MBS multicast session is deactivated. Alternatively, an indicator may be associated with each MBS multicast session to explicitly indicate that the MBS multicast session is deactivated) or via the physical downlink control channel (PDCCH) (or downlink control information (DCI)) that schedules the multicast MCCH (or multicast MCCH message). For example, one bit in the PDCCH DCI indicates 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 mean that the UE does not detect the G-RNTI or G-CS-RNTI corresponding to the MBS multicast session. Therefore, in the present disclosure, the MBS multicast session deactivation indication instructs the UE to stop monitoring the G-RNTI or G-CS-RNTI associated with the MBS multicast session. Furthermore, the MBS multicast session deactivation indication indicates the UE stops detecting the G-RNTI corresponding to the MBS multicast session, and the MBS multicast session activation indication indicates the UE starts detecting the G-RNTI corresponding to the MBS multicast session. MBS multicast session deactivation includes situations where the MBS multicast session is temporarily not transmitting data.

[0050] There are multiple implementations for using a multicast MCCH message to notify the UE that an MBS multicast session has been deactivated. One implementation method is to use one bit in the DCI to indicate that an MBS multicast session has been deactivated or data transmission has been suspended, and / or to define a field in the multicast MCCH message that contains the TMGI and / or G-RNTI of the multicast MBS multicast session that has been deactivated or whose data transmission has been suspended. The advantage of this approach is that when the PTM configuration of the MBS multicast session has not been updated, the UE only needs to obtain the field to determine whether an MBS multicast session being received has been deactivated, thereby not affecting the reception of ongoing MBS multicast sessions that have not been indicated as deactivated.

[0051] 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 0r 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)

[0052] 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 allowed to be received in the RRC_INACTIVE state and / or the UE has a (valid) PTM configuration for the MBS multicast session, the MBS multicast session can be directly received without establishing an RRC connection with the base station. The network can configure the PTM configuration information of the MBS multicast session received in the RRC_INACTIVE state for the UE via the multicast MCCH and / or dedicated RRC signaling (e.g., RRC release message, RRC reconfiguration message). The MBS Multicast Configuration MBSMulticastConfiguration message contains the control information applicable for MBS multicast services transmitted via multicast MRBs for RRC_INACTIVE UEs. The MBS multicast configuration message can be transmitted on the multicast MCCH (referred to as a multicast MCCH message) or included in an RRC release message. If an RRC release message is used to configure the PTM configuration information for an MBS multicast session received by a UE in the RRC_INACTIVE state, the network can include the MBSMulticastConfiguration message in the RRC release message sent to the UE.

[0053] When the UE receives a change notification (i.e., a multicast MCCH change notification) or an MBS multicast session that is configured and / or allowed to be received in the RRC_INACTIVE state is activated or the UE reselects to a new cell, for the purpose of obtaining the updated MBS multicast configuration or PTM configuration or obtaining the PTM configuration of the activated MBS multicast session or for the purpose of obtaining the PTM configuration of the MBS multicast session of the new cell (or the activated MBS multicast session or the MBS multicast session that the UE has joined and activated), after the UE receives the MBS multicast configuration MBSMulticastConfiguration message from the multicast MCCH, how to perform PTM configuration according to the MBSMulticastConfiguration message is a problem that needs to be solved.

[0054] In the present disclosure, activation of an MBS multicast session can be achieved by including the TMGI in a paging message. That is, when a UE receives a paging message, if the UE has already joined the MBS multicast session indicated by the TMGI included in the paging message, the MBS multicast session is activated. Therefore, activation of the MBS multicast session means that the TMGI of the MBS multicast session is included in the received paging message. The change notification is used to indicate a change in the MBS multicast configuration and can be indicated via downlink control information (DCI).

[0055] The following embodiments are provided to solve this problem. In addition, the following embodiments are merely illustrative and are not intended to limit the present invention.

[0056] Example 1 (Full Configuration Mode)

[0057] The following describes the method performed by the user equipment in embodiment 1 of the present invention in conjunction with Figure 1. Figure 1 is a schematic flow chart showing the method performed by the user equipment in embodiment 1 of the present invention. As shown in Figure 1, the method performed by the user equipment in embodiment 1 may include the following steps:

[0058] Step S101: The UE is triggered to start the multicast MCCH information acquisition process;

[0059] Step S102: The MBS multicast configuration acquired by the UE from the multicast MCCH using the multicast MCCH information acquisition process overwrites (or always overwrites) any stored multicast MCCH information and the PTM configuration of the MBS multicast session configured through the dedicated RRC message.

[0060] Optionally, the MBS multicast session is an MBS multicast session configured to be received in an RRC_INACTIVE state. The multicast MCCH information is information transmitted in a message sent via the multicast MCCH.

[0061] In the embodiments of the present disclosure, the PTM configuration of the MBS multicast session configured through a dedicated RRC message may be the PTM configuration of the MBS multicast session configured through an RRC release message and / or an RRC reconfiguration message and / or an RRC resume message. The PTM configuration of the MBS multicast session configured through an RRC release message may be configuration information carried by an MBS multicast configuration message included in the RRC release message.

[0062] In the embodiment of the present disclosure, at least the following three situations will trigger the UE to start the multicast MCCH information acquisition process: receiving a change notification, an MBS multicast session that is configured and / or allowed to be received in the RRC_INACTIVE state is activated (or an MBS multicast session that is configured and / or allowed to be received in the RRC_INACTIVE state is activated but the UE does not have a PTM configuration or a valid PTM configuration for the MBS multicast session), and the UE reselects to a new cell.

[0063] Example 2 (Full Configuration Mode)

[0064] The following describes a method performed by a user equipment in accordance with Embodiment 2 of the present invention in conjunction with FIG2 . FIG2 is a schematic flow chart illustrating a method performed by a user equipment in accordance with Embodiment 2 of the present invention. As shown in FIG2 , the method performed by a user equipment in accordance with Embodiment 2 may include the following steps:

[0065] Step S201: The UE is triggered to start the multicast MCCH information acquisition process;

[0066] Step S202: The UE uses the multicast MCCH information acquisition process to obtain an MBS multicast configuration from the multicast MCCH, overwriting (or always overwriting) any stored multicast MCCH information. The multicast MCCH information includes information transmitted in a message sent via the multicast MCCH and a PTM configuration of an MBS multicast session configured via a dedicated RRC message. Optionally, the MBS multicast session is an MBS multicast session configured for reception in the RRC_INACTIVE state.

[0067] Example 3 (Full Configuration Mode)

[0068] The UE is triggered to initiate a multicast MCCH information acquisition process. The UE uses the multicast MCCH information acquisition process to obtain an MBS multicast configuration from the multicast MCCH, overwriting or always overwriting any stored multicast MCCH information. The multicast MCCH information is information transmitted in a message sent via the multicast MCCH. Furthermore, when applying the MBS multicast configuration obtained from the multicast MCCH, the UE first releases the PTM configuration of the MBS multicast session configured via a dedicated RRC message. Optionally, the MBS multicast session is an MBS multicast session configured for reception in the RRC_INACTIVE state.

[0069] Example 4

[0070] The UE is triggered to initiate a multicast MCCH information acquisition process. The UE acquires an MBS multicast configuration from the multicast MCCH using the multicast MCCH information acquisition process. If the MBS multicast configuration is the first MBS multicast configuration acquired by the UE after reselecting to the current cell, the MBS multicast configuration overwrites any stored multicast MCCH information and the PTM configuration of the MBS multicast session configured via a dedicated RRC message. Optionally, the MBS multicast session is an MBS multicast session configured for reception in the RRC_INACTIVE state. The multicast MCCH information is information transmitted in a message sent via the multicast MCCH.

[0071] Otherwise (ie, the MBS multicast configuration is not satisfied to be the MBS multicast configuration acquired for the first time after the UE reselects to the current cell), the received MBS multicast configuration is used to perform delta configuration for the PTM configuration of the MBS multicast configured for RRC_INACTIVE reception.

[0072] Example 5

[0073] The UE is triggered to initiate a multicast MCCH information acquisition process. The UE uses the multicast MCCH information acquisition process to acquire an MBS multicast configuration from the multicast MCCH. If the MBS multicast configuration is the first MBS multicast configuration acquired by the UE after reselecting to the current cell, the MBS multicast configuration overwrites any stored multicast MCCH information. The multicast MCCH information includes information transmitted in a message sent via the multicast MCCH and a PTM configuration for an MBS multicast session configured via a dedicated RRC message. Optionally, the MBS multicast session is an MBS multicast session configured for reception in the RRC_INACTIVE state.

[0074] Otherwise (ie, the MBS multicast configuration is not satisfied to be the MBS multicast configuration acquired for the first time after the UE reselects to the current cell), the received MBS multicast configuration is used to perform delta configuration for the PTM configuration of the MBS multicast configured for RRC_INACTIVE reception.

[0075] Example 6

[0076] The MBS multicast configuration obtained from the MBS multicast MCCH adopts the full configuration, and the MBS multicast configuration obtained from the proprietary RRC signaling adopts the delta configuration.

[0077] A UE receives an MBS multicast configuration message from the network. If the MBS multicast configuration message is obtained by the UE from a multicast MCCH using a multicast MCCH information acquisition procedure, the UE performs the operations specified in Embodiment 1, Embodiment 2, or Embodiment 3. If the MBS multicast configuration message is configured for the UE by the network through dedicated RRC signaling, the UE performs delta configuration on the PTM configuration of the MBS multicast configured for RRC_INACTIVE reception using the received MBS multicast configuration. If the MBS multicast configuration message is configured for the UE by the network through dedicated RRC signaling, for each TMGI included in the MBS multicast configuration message, the UE considers that the MBS multicast session indicated by the TMGI is configured to be receivable in the RRC_INACTIVE state.

[0078] Example 7

[0079] The MBS multicast configuration obtained from the MBS multicast MCCH adopts the full configuration, and the MBS multicast configuration obtained from the proprietary RRC signaling adopts the delta configuration.

[0080] In this embodiment, different messages are used for MBS multicast configuration information when transmitted via the multicast MCCH and when transmitted via dedicated RRC signaling. Specifically, the MBS multicast configuration is included in an MBS multicast configuration message transmitted on the multicast MCCH. When the UE receives the MBS multicast configuration message from the network, the operation specified in Embodiment 1, Embodiment 2, or Embodiment 3 is performed. If the MBS multicast configuration is configured for the UE by the network via dedicated RRC signaling, that is, the configuration information of the MBS multicast session is included in the RRC release message, the configuration information is not configured by directly including the MBS multicast configuration message in the RRC release message. Instead, the RRC release message includes an information element different from the MBS multicast configuration message to indicate the configuration information of the MBS multicast session. The MBS multicast configuration received from the RRC release message is used to perform delta configuration for the PTM configuration of the MBS multicast configured for RRC_INACTIVE reception. In other words, the configuration information included in the RRC release message uses delta configuration.

[0081] In this embodiment, the advantage of not directly including the MBS multicast configuration message in the RRC release message is that the MBS multicast configuration information received from the RRC release message can adopt the delta configuration, and when receiving the MBS multicast configuration message, the UE always adopts the full configuration, which unifies the behavior of the UE when receiving the MBS multicast configuration message.

[0082] Unless otherwise specified, the coverage described in the embodiments of the present disclosure may be one of the following situations:

[0083] (1) The overwriting is to delete the existing configuration and apply the new configuration;

[0084] (2) The overwriting is to compare the new configuration with the existing configuration. If they are different, the existing configuration is updated. If they are the same, the existing configuration is kept unchanged. For new configurations that do not exist in the existing configuration, the new configuration can be applied (for example, an MBS multicast session that the UE has joined and is configured to be receivable in the RRC_INACTIVE state is activated, but the UE does not have the PTM configuration for the session). Existing configurations that are not included in the new configuration can be deleted or left unchanged.

[0085] In the embodiments of the present disclosure, the following provides exemplary descriptions of full and delta configurations, which comply with the definitions in TS 38.331-h50. A full configuration is when a UE receives new configuration information and, if a field is not included in the received new configuration information, the UE no longer uses the field or releases the corresponding configuration (i.e., the UE always releases the existing configuration and applies the new configuration). A delta configuration modifies the existing configuration using add, modify, or delete operations.

[0086] In the following cases, applying the full configuration to the received MBS multicast configuration message is insufficient:

[0087] A UE in RRC_INACTIVE mode has joined MBS multicast sessions A and B, and both MBS multicast sessions A and B are configured for RRC_INACTIVE reception. If the UE is receiving MBS multicast session A (i.e., MBS multicast session A is activated), and MBS multicast session B is activated but the UE does not have the PTM configuration for MBS multicast session B (i.e., the UE does not locally store the configuration information for MBS multicast session B or has not established a corresponding MRB), the UE will initiate a multicast MCCH information acquisition process to receive an MBS multicast configuration message. If the full configuration is applied to the received MBS multicast configuration message, the transmission of MBS multicast session A will be affected. For example, if the MBS multicast configuration message contains the PTM configuration for MBS multicast session A, the UE needs to release the current PTM configuration for MBS multicast session A and apply the PTM configuration for MBS multicast session A contained in the MBS multicast configuration message, which will interrupt the reception of MBS multicast session A.

[0088] In addition, a UE in RRC_INACTIVE mode has joined MBS multicast sessions A and B, and both MBS multicast sessions A and B are configured for RRC_INACTIVE reception. The UE has the PTM configuration for MBS multicast session A but does not have the PTM configuration for MBS multicast session B. When MBS multicast session B is activated but MBS multicast session A is not activated, the UE initiates a multicast MCCH information acquisition process to receive an MBS multicast configuration message (to obtain the PTM configuration for MBS multicast session B). The received MBS multicast configuration message includes the PTM configuration for MBS multicast session B but does not include the PTM configuration for MBS multicast session A. If full configuration is used for the received MBS multicast configuration message, the PTM configuration for MBS multicast session A stored locally on the UE will be released. When MBS multicast session A is activated, the UE initiates a multicast MCCH information acquisition process to receive an MBS multicast configuration message (to obtain the PTM configuration for MBS multicast session A). If the PTM configuration of the MBS multicast session A remains unchanged during this period, this will cause unnecessary signaling overhead and transmission delay.

[0089] In the present disclosure, during the multicast MCCH information acquisition process, the UE receives an MBS multicast configuration message from a base station, where the message includes MBS multicast configuration information.

[0090] In order to avoid that an MBS multicast session that has been configured to be receivable in RRC_INACTIVE triggers an RRC recovery process when being activated to enter RRC_CONNECTED to receive the MBS multicast session, the MBS multicast session is allowed to be received in the RRC_INACTIVE state in the paging message indicating that the session is activated. It can be stipulated that when the MBS multicast session configured to be receivable in the RRC_INACTIVE state is activated, the PTM configuration of the MBS multicast session must be transmitted on the multicast MCCH.

[0091] For an MBS multicast session configured to be receivable in the RRC_INACTIVE state, the MRB or PTM configuration for the MBS multicast session has been configured in an RRC-specific message and the UE is in the RRC_CONNECTED state. When the UE receives an RRCRelease message, if the RRCRelease message indicates that the MBS multicast session with an MRB or PTM configuration is deactivated, how to handle the already established MRB is a problem that needs to be solved.

[0092] In one embodiment, upon receiving an RRCRelease message, the UE releases the MRB corresponding to the MBS multicast session indicated as deactivated in the RRCRelease message. Optionally, the UE also releases other PTM configuration information related to the MBS multicast session. The operation of releasing the MRB may include releasing the corresponding PDCP entity and MRB identifier. If no other multicast MRB is configured with the same MBS session identifier as the released MRB, the UE indicates to the upper layer that the user plane resources of the MBS session identifier have been released.

[0093] In one embodiment, when the UE receives an RRCRelease message containing a suspendConfig field, for the MRB corresponding to the MBS multicast session indicated as deactivated in the RRCRelease message, the UE suspends the MRB. In other words, when the UE receives an RRCRelease message containing a suspendConfig field, the UE suspends all radio bearers except SRB0, broadcast MRB, and MRB of the MBS multicast session configured to be received under RRC_INACTIVE and indicated as activated. In other words, when the UE receives an RRCRelease message containing a suspendConfig field, the UE suspends all SRBs and DRBs except SRB0 and broadcast MRB, and suspends all multicast MRBs except MRB of the MBS multicast session configured to be received under RRC_INACTIVE and indicated as activated. The suspendConfig field is used to indicate the configuration of RRC_INACTIVE.

[0094] In the disclosed embodiment, indicating that the MBS multicast session is deactivated means indicating not to detect or stop detecting the G-RNTI corresponding to the MBS multicast session; indicating that the MBS multicast session is activated means indicating to detect the G-RNTI corresponding to the MBS multicast session.

[0095] 3 is used to illustrate a user equipment as an embodiment that can execute the method executed by the user equipment described in detail above in the present invention.

[0096] FIG3 is a block diagram showing a user equipment UE according to the present invention.

[0097] As shown in Figure 3, the user equipment UE 300 includes a processor 301 and a memory 302. The processor 301 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 302 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 302 stores program instructions. When executed by the processor 301, these instructions may execute the above-described method performed by the user equipment as described in detail in the present invention.

[0098] 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.

[0099] In the embodiments of the present disclosure, when multiple operations are involved, 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 involved, 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...".

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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 general-purpose processors, digital signal processors (DSPs), proprietary 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 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.

[0105] 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.

[0106] 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 user equipment UE, wherein a processor of the UE is configured to: Start the multicast MCCH information acquisition process and obtain the first MBS multicast configuration message MBSMulticastConfiguration; The first MBS multicast configuration message overwrites the stored multicast MCCH information, wherein: The stored multicast MCCH information is a second MBS multicast configuration message, where the second MBS multicast configuration message is an MBS multicast configuration message received from an RRC release message or an MBS multicast configuration message received from a multicast MCCH logical channel.

2. A method performed by a user equipment UE, comprising: Start the multicast MCCH information acquisition process and obtain the first MBS multicast configuration message MBSMulticastConfiguration; The first MBS multicast configuration message overwrites the stored multicast MCCH information, wherein the stored multicast MCCH information is a second MBS multicast configuration message, and the second MBS multicast configuration message is an MBS multicast configuration message received from an RRC release message or an MBS multicast configuration message received from a multicast MCCH logical channel.

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