Multicast broadcast service in RRC inactive state

Abstract

The embodiment of the invention discloses equipment, a method and a device for multicast broadcast service (MBS). A terminal device receives, from a serving cell, MBS configurations for one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state. The terminal device uses the received MBS configuration to identify at least one type of MBS transmission suitable for one or more MBS services in one or more neighboring cells or neighboring frequencies. The terminal device performs a mobility-related operation based on at least one type of MBS transmission.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to the field of communications, and more particularly to devices, methods, apparatuses, and computer-readable storage media for Multicast Broadcast Service (MBS). Background Art

[0002] In 3rd Generation Partnership Project (3GPP) Release 17, terminal devices such as user equipment (UE) can only receive multicast / broadcast sessions in a radio resource control (RRC) connected state (which may be referred to as, for example, the RRC_CONNECTED state or mode). 3GPP Release 18 also proposes enabling reception of multicast MBS sessions in an RRC inactive state (which may be referred to as, for example, the RRC_INACTIVE state or mode).

[0003] For a terminal device in the RRC inactive state, it may need to reselect to another cell while maintaining MBS transmission. Therefore, further research and improvement of multicast mobility of UEs in the RRC inactive state is needed to enhance MBS transmission. Summary of the Invention

[0004] In general, example embodiments of the present disclosure provide devices, methods, apparatus, and computer-readable storage media for multicast mobility.

[0005] In a first aspect, a terminal device is provided. The terminal device may include one or more transceivers; and one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured to, together with the one or more processors, cause the terminal device to: receive, from a serving cell, a multicast / broadcast service (MBS) configuration for one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state; use the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and perform a mobility-related operation based on the at least one type of MBS transmission.

[0006] In a second aspect, a network device is provided. The network device may include one or more transceivers; and one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured to, together with the one or more processors, cause the network device to: send a multicast / broadcast service (MBS) configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to a terminal device, wherein the MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or frequencies; or a cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

[0007] In a third aspect, a method at a terminal device is provided. The method may include: receiving, from a serving cell, a multicast / broadcast service (MBS) configuration for one or more neighboring cells or neighboring frequencies for a terminal device in an inactive state; using the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and performing a mobility-related operation based on the at least one type of MBS transmission.

[0008] In a fourth aspect, a method at a network device is provided. The method may include: sending a multicast / broadcast service MBS configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to a terminal device, wherein the MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or a cell type of the one or more neighboring cells in terms of supporting or not supporting MBS.

[0009] In a fifth aspect, an apparatus of a terminal device is provided. The apparatus may include: a component for receiving, from a serving cell, a multicast / broadcast service MBS configuration for one or more neighboring cells or neighboring frequencies for a terminal device in an inactive state; a component for identifying, using the received MBS configuration, at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and a component for performing mobility-related operations based on the at least one type of MBS transmission.

[0010] In a sixth aspect, an apparatus of a network device is provided. The apparatus may include: a component for sending a multicast / broadcast service (MBS) configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to a terminal device, wherein the MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or a cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

[0011] In a seventh aspect, a terminal device is provided. The terminal device may include at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: receive, from a serving cell, a multicast / broadcast service (MBS) configuration for one or more neighboring cells or neighboring frequencies of a terminal device in an inactive state; use the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and perform mobility-related operations based on the at least one type of MBS transmission.

[0012] In an eighth aspect, a network device is provided. The network device may include at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to: send a multicast / broadcast service MBS configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to a terminal device, wherein the MBS configuration indicates information on one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or a cell type of the one or more neighboring cells in terms of whether or not they support MBS.

[0013] In a ninth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium comprising program instructions for causing an apparatus to execute the method according to at least the third aspect or the fourth aspect.

[0014] In a tenth aspect, a computer program is provided, comprising instructions which, when executed by an apparatus, cause the apparatus to at least: receive, from a serving cell, a multicast / broadcast service MBS configuration for one or more neighboring cells or neighboring frequencies of an inactive terminal device; use the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies; and perform mobility-related operations based on at least one type of MBS transmission.

[0015] In an eleventh aspect, a computer program is provided, comprising instructions which, when executed by an apparatus, cause the apparatus to at least: send a multicast / broadcast service MBS configuration of one or more neighboring cells or neighboring frequencies of a terminal device in an inactive state to a terminal device, wherein the MBS configuration indicates information about one of: at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies; or a cell type of one or more neighboring cells in terms of supporting or not supporting MBS.

[0016] In a twelfth aspect, a terminal device is provided. The terminal device may include: a receiving circuit system configured to: receive, from a serving cell, a multicast / broadcast service (MBS) configuration for one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state; use the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and perform a mobility-related operation based on the at least one type of MBS transmission.

[0017] In a thirteenth aspect, a network device is provided. The network device may include: a transmitting circuit system configured to: transmit to a terminal device a multicast / broadcast service MBS configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state, wherein the MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or a cell type of the one or more neighboring cells in terms of whether or not they support MBS.

[0018] It should be understood that the invention summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0020] Figure 1 illustrates an example network environment in which example embodiments of the present disclosure may be implemented;

[0021] Figure 2 An example flow chart of a method implemented at a terminal device according to an example embodiment of the present disclosure is illustrated;

[0022] Figure 3 An example flow chart illustrating a method implemented at a network device according to an example embodiment of the present disclosure is illustrated;

[0023] Figure 4 illustrates an example signaling procedure for reporting measurements on reference signals according to some embodiments of the present disclosure;

[0024] Figure 5 illustrates an example simplified block diagram of a device suitable for implementing embodiments of the present disclosure; and

[0025] Figure 6 illustrates an example block diagram of an example computer-readable medium according to some embodiments of the present disclosure;

[0026] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0027] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described only for illustrative purposes and to help those skilled in the art understand and implement the present disclosure, and do not represent any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various other ways in addition to the way described below.

[0028] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0029] In this disclosure, references to "one embodiment," "an embodiment," and "an example embodiment" indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with one embodiment, those skilled in the art believe that it is within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0030] It will be understood that although the terms "first" and "second" and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0031] The term used herein is only used to describe specific embodiments and is not intended to limit example embodiments. The singular "one", "an" and "the" used herein also include plural forms, unless the context clearly states otherwise. It is further understood that the terms "comprise", "include", "have", "contain", "cover" and / or "encompass" specify the existence of the features, elements and / or components etc. when used in this article, but do not exclude the existence or addition of one or more other features, elements, components and / or their combinations. As used in this article, "at least one of the following: <list of two or more elements>" and "at least one of the list of two or more elements>" and similar wording (wherein the list of two or more elements is connected by "and" or "or") refer to at least any one element in these elements, or at least any two or more elements in these elements, or at least all elements in these elements.

[0032] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0033] (a) a pure hardware circuit implementation (such as an implementation using only analog and / or digital circuitry), and

[0034] (b) a combination of hardware circuitry and software such as (if applicable):

[0035] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0036] (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software and memory(s) that work together to cause a device (such as a mobile phone or server) to perform various functions), and

[0037] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), that require software (e.g., firmware) to operate, but which may not be present when not required for operation.

[0038] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. For example, the term circuitry also covers a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or networking device, if applicable to the particular claim element.

[0039] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as Long Term Evolution (LTE), Advanced LTE (LTE-A), Wideband Code Division Multiplexing (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be performed according to any suitable generation of communication protocol, including but not limited to the third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and / or any other protocol currently known or to be developed in the future. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communications, there will certainly be future types of communication technologies and systems that can be used to embody the present disclosure. It should not be regarded as limiting the scope of the present disclosure to only the above-mentioned systems.

[0040] As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services from the network. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or an access point (AP), for example, a Node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a new radio (NR) NB (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, a low-power node (such as a femto, pico), etc.

[0041] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablet computers, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop mounted devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated process chain environments), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0042] The term "transceiver" may refer to any device that can be coupled to one or more antennas or antenna ports to wirelessly transmit and / or receive communication signals. The antennas or antenna ports may be of the same or different types. The antennas or antenna ports may be located at different locations on the device. One or more transceivers allow the device to communicate with other devices that may be wired and / or wireless. One or more transceivers may include circuitry such as a processor, a controller, a radio, a socket, a plug, a buffer, etc. to form one or more communication channels to one or more radio frequency units. One or more transceivers may be integrated into a device or system, such as a cellular communication device or system, a wireless local area network (WLAN) system, or a short-range system such as a Bluetooth system.

[0043] In 3GPP Release 17, UEs can only receive MBS multicast sessions in the RRC connected state. There are two possible delivery methods for sending MBS data between the 5G Core Network (5GC) and the Next Generation Radio Access Node (NG-RAN).

[0044] - Individual MBS service delivery method: This method is only applicable to multicast MBS sessions.

[0045] The 5GC may receive a single copy of MBS data packets and deliver individual copies of these MBS data packets to individual UEs via per-UE PDU sessions, so for each such UE one PDU session is required to be associated with the multicast MBS session.

[0046] - Shared MBS service delivery method: This method is applicable to both broadcast MBS sessions and multicast MBS sessions. The 5GC can receive a single copy of the MBS data packets and deliver a single copy of these MBS packets to the NG-RAN node.

[0047] The NG-RAN node then delivers the packet to one or more UEs.

[0048] Individual delivery mode is less efficient, but has the advantage of enabling multicast data delivery even when the UE is located in a legacy gNB (i.e., a gNB that does not support MBS at all).

[0049] Currently, 3GPP RAN has started a new work item in Release 18 to enable reception of multicast MBS sessions in the RRC inactive state. The scope of the work is as follows:

[0050] Specify support for multicast reception for UEs in RRC_INACTIVE state

[0051] [RAN2, RAN3];

[0052] Study the impact of mobility and state transitions in RRC_INACTIVE on UE multicast reception (seamless / lossless mobility is not required) [RAN2, RAN3].

[0053] For a terminal device in the RRC inactive state, it may need to reselect to another cell while maintaining MBS transmission. Therefore, further research and improvement of multicast mobility of UEs in the RRC inactive state is needed to enhance MBS transmission.

[0054] For broadcast sessions in Release 17, the following cell reselection solutions are available:

[0055] For a UE in RRC inactive state to receive a broadcast session (e.g., temporarily moved

[0056] Group Identifier (TMGI) 1:

[0057] - The network broadcasts in the System Information Block (SIB) in the serving cell a mapping between FSAI(s) (a frequency selection area identifier associated with the TMGI and structured relative to its broadcast area) and neighboring frequencies (i.e., frequencies used by neighboring cells);

[0058] - The UE has received the mapping between FSAI(s) and TMGI(s) of the broadcast service from the core network (CN) in a service announcement.

[0059] Using these two mappings, the UE can determine which frequency it should preferably select when doing cell reselection to keep the ongoing broadcast service TMGI 1.

[0060] The following example illustrates how broadcast version 17 works:

[0061] Service Announcement: TMGI 1 Mapping to FSAI1, FSAI20, and FSAI40

[0062] Serving cell SIB21: (adjacent frequency 1 mapped to FSAI 4, 5, 7, 9), (

[0063] Adjacent frequency 2 is mapped to FSAI 1, 2, 3)

[0064] If a UE is receiving broadcast session TMGI 1, and if it can choose between a cell with frequency 1 and a cell with frequency 2 upon cell reselection, it will preferably reselect the cell with frequency 2 because the neighboring frequency 2 supports FSAI 1 (according to SIB21), which is the FSAI that matches TMGI 1 (according to the earlier service announcement received by the UE from the CN). By selecting frequency 2 upon cell reselection, the continuity of the broadcast service is maintained.

[0065] Due to the similarity, it is proposed to reuse the same solution for RRC_inactive UE in Release 18 in the multicast case as in the broadcast case of Release 17. However, the inventors found that this solution may not be applicable to the multicast case due to some problems involved.

[0066] The inventors note that the key difference between broadcast and multicast transmissions is that a multicast session can enable the delivery of multicast data even in gNBs that do not support MBS services at all (i.e., referred to as MBS non-supporting nodes). This is known as individual delivery mode. Therefore, in Release 18, during mobility for a UE in RRC-inactive state (which is receiving a multicast session with TMGI 1 in a serving cell offering TMGI 1 in shared delivery mode), the UE may be traveling to different types of target cells as potential candidates for cell reselection:

[0067] - The target cell in the adjacent frequency provides multicast session TMGI 1 in MBS shared delivery mode (hereinafter referred to as example type 1);

[0068] - A target cell in a neighboring frequency provides a multicast session TMGI 1 in MBS individual delivery mode (hereinafter referred to as example type 2); and

[0069] - The target cell in the adjacent frequency does not provide TMGI 1 at all (eg, outside the TMGI 1 multicast service area) (hereinafter referred to as example type 3).

[0070] Therefore, different types of target cells to which the UE will eventually move will have different consequences.

[0071] - If the UE eventually happens to move into a target cell of type 1, the UE will continue to receive TMGI 1 smoothly without interruption.

[0072] If the UE eventually happens to move into a Type 2 target cell, the UE will experience a break in service continuity: the UE will first realize that TMGI 1 is not delivered in point-to-multipoint (PTM) mode with shared delivery in the target cell and will need to perform an RRC reconnection procedure in the target cell. It will then contact the Session Management Function (SMF) regarding TMGI 1, which will then trigger a switch from shared delivery mode to individual delivery mode. This generally results in a long outage, additional processing, and data loss. Furthermore, compared to a Type 1 target cell where PTM delivery is used at the radio interface, more radio resources are used for individual delivery to each UE via individual delivery, which is undesirable from an operator's perspective.

[0073] If the UE eventually happens to move into a target cell of type 3, the UE will not interrupt the TMGI 1 multicast service, but will lose the TMGI 1 multicast service completely because the target cell does not provide TMGI 1.

[0074] Therefore, in the RRC inactive state, mobility to a type 1 cell is more beneficial for the UE's multicast reception than mobility to a type 2 cell, and mobility to a type 2 cell is more beneficial for the UE's multicast reception than mobility to a type 3 cell. However, currently, the UE has no way to distinguish between these types of target cells to influence its mobility decision before and during cell reselection.

[0075] According to an embodiment of the present disclosure, a solution is provided to help a terminal device that is in an inactive state and receives a multicast session in a serving cell distinguish different types of potential targets during its mobility. With this solution, the terminal device in an inactive state receives the MBS configuration of one or more neighboring cells or neighboring frequencies of the terminal device from the serving cell. The MBS configuration may indicate information about the MBS transmission type applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies. The terminal device may use the received MBS configuration to perform mobility-related operations. For example, the terminal device may identify at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies, and then perform mobility-related operations based on the at least one type of MBS transmission.

[0076] Hereinafter, the principles and embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Figure 1 , which illustrates an example environment 100 in which example embodiments of the present disclosure may be implemented.

[0077] Environment 100 (which may be part of a communication network) includes a terminal device 110 and a network device 120 that communicate with each other or with other devices via each other. Communication environment 100 may include any suitable number of devices and cells. In communication environment 100, terminal device 110 and network device 120 may transmit data and control information to each other. The link from network device 120 to terminal device 110 is called a downlink (DL), while the link from terminal device 110 to network device 120 is called an uplink (UL).

[0078] It should be understood that the two devices shown in environment 100 are for illustration purposes only and are not intended to limit the scope of the present disclosure. In some example embodiments, environment 100 may include another device for communicating with terminal device 110 and network device 120.

[0079] Communications in environment 100 may follow any suitable communications standards or protocols already in existence or to be developed in the future, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Fifth Generation (5G) New Radio (NR), Wireless Fidelity (Wi-Fi), and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employ any suitable communications technology, including, for example, Multiple Input Multiple Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), Bluetooth, Zigbee, and Machine Type Communication (MTC), Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Ultra-Reliable Low Latency Communication (URLLC), Carrier Aggregation (CA), Dual Connectivity (DC), and New Radio Unlicensed (NR-U) technologies.

[0080] Network device 120 transmits a multicast / broadcast service (MBS) configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to terminal device 110. Terminal device 110 receives the MBS configuration and uses the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies. Terminal device 110 may perform mobility-related operations based on the at least one type of MBS transmission.

[0081] By identifying different types of potential target cells for its mobility, the inactive terminal device 110 can perform mobility-related operations based on the identified types to improve MBS multicast services. For example, when moving to a target cell identified as not supporting MBS, the terminal device 110 can re-establish an RRC connection state in the serving cell, thereby reducing interruptions and data loss caused by switching from shared delivery mode to individual delivery mode. In addition, when making cell reselection decisions, the terminal device 110 can also consider the frequency of the identified cell types in relation to the availability of MBS services to ensure the continuity of its MBS services.

[0082] Figure 2 FIG2 illustrates an example flow chart of a method 200 implemented at a terminal device according to an example embodiment of the present disclosure. For the purpose of discussion, reference will be made to Figure 1 The method 200 is described from the perspective of the terminal device 110 .

[0083] like Figure 2 As shown, at 210, the terminal device 110 receives a multicast / broadcast service MBS configuration for one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state from the serving cell. The terminal device 110 may receive the MBS configuration from the network device 120 providing the serving cell.

[0084] The received MBS configuration indicates information regarding at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies, or the cell type of one or more neighboring cells in terms of support or non-support of MBS. The type of MBS transmission can be, for example, TMGI-specific, cell-specific, or gNB-specific.

[0085] As used herein, the term "TMGI" may refer to an identifier used to identify a multicast session. A TMGI may correspond to an MBS session, such as an audio MBS session or a video MBS session. Therefore, "TMGI-specific" indicates that the type of MBS transmission is specific to the MBS session; that is, different sessions may have different types of MBS transmissions. In some embodiments, the type of MBS transmission may also be specific to the service type.

[0086] In some embodiments, the MBS configuration may include a list of one or more neighboring cells or frequencies and indication information corresponding to the one or more neighboring cells or frequencies. The indication information may indicate the type(s) of MBS transmission supported in the one or more neighboring cells, respectively, for the one or more MBS services. Alternatively or additionally, the indication information may indicate the cell type of the one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0087] In some embodiments, the network device 120 providing the serving cell may, for example, send a list set as an MBS configuration via a broadcast message, where the list set includes one or more information lists. The terminal device 110 may receive the list set and, based on these lists, derive the type(s) of one or more neighboring cells or frequencies, or derive the transmission mode of one or more MBS services applicable to one or more neighboring cells or frequencies, as will be described later. The list set sent from the serving cell may include any of the following:

[0088] ■ List 1: List of (neighboring cells, supported TMGI(s),

[0089] ■ List 2: List of neighboring cells that support or do not support MBS,

[0090] ■ List 3: List of (adjacent frequencies, TMGI(s) supported in that frequency).

[0091] Alternatively or additionally to List 1, the list set may include

[0092] ■ List 1b: List of (neighboring frequencies, supported TMGI(s)). Alternatively or additionally to List 2, the list set may include

[0093] ■ List 2b: List of neighboring frequencies that support or do not support MBS. Alternatively or additionally to List 3, the list set may include

[0094] ■ List 3b: List of (neighboring FSAI, neighboring cells supporting this FSAI),

[0095] ■ List 3c: List of (neighboring frequencies, neighboring cells on that frequency),

[0096] Therefore, List 1 includes one or more neighboring cells and one or more temporary mobile group identities TMGIs respectively supported in the one or more neighboring cells. List 1b includes one or more neighboring frequencies and one or more TMGIs respectively supported in the one or more neighboring frequencies.

[0097] List 2 includes neighboring cells that support or do not support MBS. List 2b includes neighboring frequencies that support or do not support MBS. Supporting MBS means that multicast service data can be sent in MBS shared delivery mode for cells within the multicast service area, while not supporting MBS means that multicast service data can only be sent in individual delivery mode for cells within the multicast service area. Therefore, List 2 can also be a list of neighboring cells that provide (multiple) MBS services in MBS shared delivery mode or MBS individual delivery mode, and List 2b can be a list of neighboring frequencies that provide (multiple) MBS services in MBS shared delivery mode or MBS individual delivery mode.

[0098] List 3 includes one or more adjacent frequencies and one or more FSAIs supported on each of the one or more adjacent frequencies. List 3b includes one or more adjacent FSAIs and at least one adjacent cell supporting each of the one or more adjacent FSAIs. List 3c includes one or more adjacent frequencies and at least one adjacent cell supported on each of the one or more adjacent frequencies.

[0099] It should be noted that the terminal device 110 may receive some of the above lists in the MBS configuration and derive one or more other lists based on the received lists and / or lists sent in other messages or also based on its own measurements.

[0100] At 220 , the terminal device 110 uses the received MBS configuration to identify at least one type of MBS transmission applicable for one or more MBS services in one or more neighboring cells or neighboring frequencies.

[0101] As described above, the terminal device 110 may receive one or more MBS services (e.g., including multicast services) from a serving cell in an MBS shared delivery mode. An MBS service may be represented by a TMGI (e.g., TMGI 1) of an MBS session. The received MBS configuration may indicate information about: at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies; or the cell type of one or more neighboring cells in terms of support or non-support of MBS. In this case, based on the received MBS configuration, the terminal device may identify at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies.

[0102] For example, at least one of the identified MBS transmission types may be MBS shared delivery (hereinafter referred to as "Type 1"), which indicates that the corresponding neighboring cell is capable of providing ongoing MBS services in shared delivery, just as in the serving cell. If the terminal device 110 moves to a neighboring cell in MBS shared delivery mode, it will continue to receive MBS services smoothly with minimal interruption.

[0103] In some embodiments, at least one of the identified MBS transmission types may be an MBS individual delivery mode (hereinafter referred to as "Type 2"), which indicates that the corresponding neighboring cell can only provide ongoing MBS services using individual delivery, rather than using shared delivery as in the serving cell. For example, network device 120 is a legacy gNB that does not support MBS at all. If terminal device 110 moves to a neighboring cell that only supports MBS individual delivery mode, it can still continue MBS services in that cell, but the switch from shared to individual delivery will result in additional overhead or greater disruption.

[0104] In some embodiments, at least one of the identified MBS transmission types may also be an MBS non-delivery mode (hereinafter referred to as "Type 3"), which indicates that the ongoing MBS service in the serving cell is not provided at all. If the terminal device 110 moves into a neighboring cell with an MBS non-delivery mode, the terminal device 110 will completely lose the MBS service.

[0105] In addition, in the case where the type of MBS transmission is TMGI-specific, cell-specific, or gNB-specific, the at least one type of MBS transmission identified may include: more than one type corresponding to more than one TMGI.

[0106] At block 230, the terminal device 110 may perform mobility-related operations based on at least one type of MBS transmission. By identifying the type(s) of MBS transmissions in one or more neighboring cells or neighboring frequencies, the terminal device 110, which is in an inactive state and receiving ongoing MBS service, may distinguish different types of potential target cells or frequencies for its mobility and perform mobility-related operations based on the identified types to improve its MBS service.

[0107] In some embodiments, the terminal device 110 may determine that the terminal device 110 is heading to a target cell that provides MBS services in individual delivery mode based on at least one type of identified MBS transmission. In other words, the terminal device 110 is heading to a target cell that provides MBS services in individual delivery mode, i.e., a type 2 cell. If the terminal device 110 checks and finds that it is heading to a type 2 target cell, it may perform RRC reconnection / reconfiguration in the serving cell. The trigger for the check may be based on a specific radio standard, such as a reference signal received power (RSRP) level of the serving cell, a difference between the RSRP of the serving cell and the RSRP of the target cell, etc. In some embodiments, reconnection with the serving cell occurs before cell reselection occurs.

[0108] In some embodiments, the terminal device 110 may perform cell reselection based on at least one type of the identified MBS transmission. For example, the terminal device 110 may perform cell reselection based on the frequency priority of one or more neighboring cells. The frequency priority of one or more neighboring cells may be determined based on at least one type of the identified MBS transmission applicable to one or more MBS services in the one or more neighboring cells.

[0109] In some embodiments, the terminal device 110 may obtain a priority list of neighboring frequencies of one or more neighboring cells based on at least one type of MBS transmission identified for one or more MBS services in the one or more neighboring cells. The neighboring frequencies may be prioritized in the order of supporting an MBS shared delivery mode, supporting an MBS individual delivery mode, and not supporting delivery of the one or more MBS services.

[0110] In other words, target cells (type 1 cells) in adjacent frequencies that provide multicast services for TMGI 1 in MBS shared delivery mode are prioritized over target cells (type 2 cells) in adjacent frequencies that provide TMGI 1 in MBS individual delivery mode. Type 2 cells are further prioritized over target cells (i.e., type 3 cells) in adjacent frequencies that do not provide TMGI 1 at all (e.g., outside the TMGI 1 multicast service area).

[0111] In some embodiments, at least one type of MBS transmission may be determined based on knowledge of the MBS service area. For example, if the target cell is outside the service area of ​​the TMGI(s) served by its(its) MBS service(s), the terminal device 110 may determine that the target cell is type 3.

[0112] For illustration purposes, some example solutions are given below to show how the terminal device 110 can distinguish or identify different types of neighboring cells or frequencies based on the MBS configuration, and how the terminal device behaves accordingly.

[0113] Example Solution 1a (Connectivity Solution Based on Cell or Frequency Broadcast List)

[0114] In this solution, serving gNB1 cell 1 may broadcast List 1 mapping (neighboring cells, supported TMGI(s)). Furthermore, serving gNB1 cell 1 may additionally broadcast List 2 of neighboring cells that support / do not support MBS (or at least those cells that support TMGI 1, i.e., in the serving area of ​​TMGI 1).

[0115] Before the cell reselection algorithm is triggered, the terminal device 110 can check whether it is heading to a target cell that supports TMGI 1 according to List 1 and does not support MBS according to List 2, that is, whether the target cell (gNB2 cell 2) is a Type 2 cell. If so, the terminal device 110 can trigger RRC reconnection in the current serving gNB1 cell 1 to reach RRC connected mode. The trigger for this check can be based on a radio criterion, such as the RSRP level of gNB1 cell 1, or the difference between the RSRP of the serving gNB1 cell 1 and the RSRP of the target gNB2 cell 2.

[0116] Example Solution 1b (Reselection Solution Based on Cell or Frequency Broadcast List)

[0117] In this solution, serving gNB1 cell 1 currently broadcasts List 1, which maps (neighboring cells, supported TMGI(s). Additionally, serving gNB1 cell 1 broadcasts List 1b, which maps (neighboring frequencies, supported TMGI(s),), or terminal device 110 can derive List 1b from existing List 1 using its own mapping of (neighboring cells, neighboring frequencies). Serving gNB1 cell 1 can broadcast List 2b of neighboring frequencies that support / do not support MBS, or serving gNB1 cell 1 can broadcast List 2 of neighboring cells that support / do not support MBS. Additionally, terminal device 110 can derive List 2b from List 2 using its own mapping of (neighboring cells, neighboring frequencies).

[0118] If serving gNB1 cell 1 only broadcasts List 1 and List 2, terminal device 110 may construct List 1b and List 2b based on List 1 and List 2 as described above. The cell reselection algorithm may consider List 1b and List 2b. In some embodiments, the terminal device prioritizes adjacent frequencies, for example, as follows:

[0119] ■ Target frequencies supporting TMGI 1 according to List 1b and MBS according to List 2b, followed by

[0120] ■ Target frequencies that support TMGI 1 according to List 1b and do not support MBS according to List 2b, followed by

[0121] ■Other target frequencies.

[0122] Example Solution 2a (Connectivity solution that reuses FSAI, which is assigned to shared delivery and individual delivery) Both)

[0123] In this solution, terminal device 110 may receive a service announcement that includes a mapping between TMGI(s) and FSAI(s). Terminal device 110 may receive an MBS configuration from serving gNB1 cell 1. Furthermore, serving gNB1 cell 1 may broadcast List 3, which maps (neighboring frequencies, FSAI(s). Furthermore, serving gNB1 cell 1 may additionally broadcast List 3b, which indicates a mapping between FSAI(s) and neighboring cells. Alternatively, serving gNB1 cell 1 may broadcast List 3c, which indicates a mapping between neighboring frequencies and neighboring cells. Furthermore, serving gNB1 cell 1 may additionally broadcast List 2, which indicates neighboring cells that support / do not support MBS. Alternatively, if gNB1 cell 1 does not broadcast either List 3b or List 3c, terminal device 110 may derive List 3c using its own (neighboring cells, neighboring frequencies) mapping.

[0124] In this solution, the terminal device 110 is configured or instructed to allocate (multiple) FSAIs to both shared delivery and individual delivery. Therefore, the (multiple) FSAIs in the MBS configuration may include: FSAIs associated with the MBS shared delivery mode and FSAIs associated with the MBS individual delivery mode.

[0125] Before the cell reselection algorithm is triggered, the terminal device 110 may check whether it is heading to a target cell that supports FSAI 1 (by using service announcements) for TMGI 1 according to List 3b (or alternatively according to Lists 3 and 3c) and does not support MBS according to List 2. That is, the terminal device 110 checks whether the target cell is a type 2 cell (i.e., supports TMGI but not MBS). If so, the terminal device 110 may perform an RRC reconnection in the current serving gNB1 cell 1 to reach RRC connected mode. As described above, the trigger for the check may be based on a radio criterion, such as based on the RSRP level of gNB1 cell 1, or such as the difference between the RSRP of the serving gNB1 cell 1 and the RSRP of the target gNB2 cell 2.

[0126] Example Solution 2b (Re-selection solution that reuses FSAI, FSAI is allocated to shared delivery and individual delivery) Both)

[0127] In this solution, the terminal device 110 may have a service announcement that includes a mapping between TMGI(s) and FSAI(s). The terminal device 110 may receive an MBS configuration from the serving gNB1 cell 1. In this solution, the serving gNB1 cell 1 may broadcast List 3 mapping (neighboring frequencies, FSAI(s). The serving gNB1 cell 1 may broadcast List 2b of neighboring frequencies that support / do not support MBS. Alternatively, the serving gNB1 cell 1 may broadcast List 2 of neighboring cells that support / do not support MBS, and if the serving gNB1 cell 1 does not broadcast, the terminal device 110 may derive List 2b from List 2 using its own (neighboring cells, neighboring frequencies) mapping.

[0128] In this solution, the terminal device 110 is configured with or indicates (multiple) FSAIs allocated to both shared delivery and individual delivery. Therefore, the (multiple) FSAIs in the MBS configuration may include: FSAIs associated with the MBS shared delivery mode and FSAIs associated with the MBS individual delivery mode.

[0129] In this solution, the reselection algorithm of the terminal device 110 may consider List 3 and List 2b. The terminal device 110 may prioritize the adjacent frequencies, for example, as follows:

[0130] ■ Target frequencies supporting FSAI 1 for TMGI 1 according to List 3 and MBS according to List 2b, followed by

[0131] ■ Target frequencies for FSAI 1 that supports TMGI 1 according to List 3 and does not support MBS according to List 2b, followed by

[0132] ■Other target frequencies.

[0133] Example Solution 3a (Connectivity solution that reuses FSAI, FSAI is only assigned to shared delivery and not Delivery to individuals)

[0134] In this solution, the terminal device 110 may have a service announcement that includes a mapping between (multiple) TMGIs and (multiple) FSAIs. The terminal device 110 may receive an MBS configuration from the serving gNB1 cell 1. In this solution, the serving gNB1 cell 1 may broadcast List 3 that maps (neighboring frequencies, (multiple) FSAIs). The serving gNB1 cell 1 may additionally broadcast List 3b that indicates the mapping between (multiple) FSAIs and neighboring cells. Alternatively, the serving gNB1 cell 1 may broadcast List 3c that indicates the mapping between neighboring frequencies and neighboring cells. Alternatively, if the serving gNB1 cell 1 does not broadcast either List 3b or List 3c, the terminal device 110 may derive List 3c based on its own (neighboring cells, neighboring frequencies) mapping.

[0135] In this solution, the terminal device 110 is configured with or indicates FSAI(s) allocated only to shared delivery, which means that no FSAI(s) are allocated to individual delivery. Therefore, the FSAI in the MBS configuration may include FSAIs associated only with the MBS shared delivery mode, or alternatively, FSAIs associated only with the MBS individual delivery mode.

[0136] Before the cell reselection algorithm is triggered, the terminal device 110 may check whether it is heading to a target cell that does not support FSAI 1 with TMGI 1 in shared delivery (e.g., by using a service announcement) according to List 3b (or alternatively, according to Lists 3 and 3c), but is still within the serving area. In other words, the terminal device 110 checks whether the target cell is a Type 2 cell (i.e., supports TMGI but is still within the serving area and is therefore assumed to not support MBS). If so, the terminal device 110 may trigger an RRC reconnect in the current serving gNB1 cell 1 to reach RRC connected mode.

[0137] Example Solution 3b (Re-election Solution Reusing FSAI, FSAI is only assigned to shared delivery and not assigned Delivery to individuals)

[0138] In this solution, terminal device 110 may receive a service announcement that includes a mapping between TMGI(s) and FSAI(s). Terminal device 110 may receive an MBS configuration from serving gNB1 cell 1. In this embodiment, serving gNB1 cell 1 may broadcast List 3, which maps (neighboring frequencies, FSAI(s). Serving gNB1 cell 1 may also broadcast List 3c, which indicates the mapping between neighboring frequencies and neighboring cells. Alternatively, if serving gNB1 cell 1 does not broadcast, terminal device 110 may derive List 3c based on its own (neighboring cells, neighboring frequencies) mapping.

[0139] In this embodiment, the terminal device 110 is also configured with or indicates (multiple) FSAIs allocated only to shared delivery. Therefore, the FSAI in the MBS configuration may include: FSAIs associated only with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include: FSAIs associated only with the MBS individual delivery mode.

[0140] The reselection algorithm of the terminal device 110 may consider List 3 and List 3c. The terminal device 110 may prioritize the adjacent frequencies, for example, as follows:

[0141] ■ Target frequency for FSAI 1 supporting TMGI 1 according to Table 3, followed by

[0142] ■ FSAI 1 supporting TMGI 1 in shared delivery according to List 3 but corresponding to the target frequency of the target cell within the multicast area of ​​TMGI 1 according to List 3c, followed by

[0143] ■Other target frequencies.

[0144] Figure 3 An example flow chart of a method 300 implemented at a network device according to an example embodiment of the present disclosure is illustrated. For discussion purposes, reference will be made to Figure 1 and Figure 2 Method 300 is described from the perspective of network device 120 .

[0145] like Figure 3 As shown, at block 310, the network device 120 may send a multicast / broadcast service MBS configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to the terminal device 110. The MBS configuration indicates information about at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies, or a cell type of one or more neighboring cells in terms of support or non-support of MBS.

[0146] In some example embodiments, the at least one type of MBS transmission may include any one of: an MBS shared delivery mode; an MBS individual delivery mode; or an MBS non-delivery mode.

[0147] In some example embodiments, an MBS configuration may include a list of one or more neighboring cells or frequencies and indication information corresponding to the one or more neighboring cells or frequencies. The indication information may indicate at least one type of MBS transmission for the one or more MBS services, respectively supported in the one or more neighboring cells. Additionally or alternatively, the indication information may indicate the cell type of the one or more neighboring cells in terms of MBS support or non-MBS support. For example, cells that do not support MBS may be because they belong to a gNB that does not support MBS.

[0148] In some example embodiments, the MBS configuration may also include any of: a list of neighboring cells that support MBS; a list of neighboring cells that provide one or more MBS services in MBS shared delivery mode; a list of neighboring cells that do not support MBS; or a list of neighboring cells that provide one or more MBS services in MBS individual delivery mode.

[0149] In some example embodiments, the MBS configuration may further include one or more of the following:

[0150] ■ A list of adjacent frequencies that support MBS;

[0151] ■ A list of adjacent frequencies that do not support MBS;

[0152] ■ a list of adjacent frequencies providing one or more MBS services in MBS shared delivery mode; or

[0153] ■ A list of adjacent frequencies providing one or more MBS services in MBS individual delivery mode.

[0154] In some example embodiments, the MBS configuration may include any of: one or more neighboring cells and a list of one or more TMGIs supported in the one or more neighboring cells, respectively; or one or more neighboring frequencies and a list of one or more TMGIs supported on the one or more neighboring frequencies, respectively.

[0155] In some example embodiments, the MBS configuration may further include one or more adjacent frequencies, and a list of one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0156] In some example embodiments, the MBS configuration may further include one or more of: one or more neighboring FSAIs and a list of at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or one or more neighboring frequencies and a list of at least one neighboring cell that respectively supports the one or more neighboring frequencies.

[0157] In some example embodiments, the FSAI in the MBS configuration may include both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include only the FSAI associated with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include only the FSAI associated with the MBS individual delivery mode.

[0158] Figure 4 FIGURE 1 illustrates an example signaling process for reporting measurements on reference signals according to some embodiments of the present disclosure. For discussion purposes, reference will be made to Figures 1 to 3 Describe process 400. Process 400 may involve Figure 1 The terminal device 110 and the network device 120 are shown. It should be understood that although Figure 1 The process 400 is described in the communication environment 100 of FIG. 1 , but the process can also be applied to other communication scenarios with similar problems.

[0159] Network device 120 may provide a serving cell to terminal device 110. In process 600, at 401, network device 120 transmits MBS configurations of one or more neighboring cells or neighboring frequencies of an inactive terminal device to terminal device 110. At 403, terminal device 110 receives MBS configuration 402 from network device 120. MBS configuration 402 indicates information regarding at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies, or a cell type of one or more neighboring cells in terms of whether or not MBS is supported.

[0160] In some example embodiments, an MBS configuration may include a list of one or more neighboring cells or frequencies and indication information corresponding to the one or more neighboring cells or frequencies. The indication information may indicate at least one type of MBS transmission supported in the one or more neighboring cells, respectively, for the one or more MBS services. Additionally or alternatively, the indication information may indicate a cell type of the one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0161] In some example embodiments, the MBS configuration may further include any of the following:

[0162] ■ A list of neighboring cells that support MBS;

[0163] ■ a list of neighboring cells providing one or more MBS services in MBS shared delivery mode;

[0164] ■ a list of neighboring cells that do not support MBS; or

[0165] ■ A list of neighboring cells providing one or more MBS services in MBS individual delivery mode.

[0166] In some example embodiments, the MBS configuration may also include any of: a list of adjacent frequencies that support MBS; a list of adjacent frequencies that do not support MBS; a list of adjacent frequencies that provide one or more MBS services in an MBS shared delivery mode; or a list of adjacent frequencies that provide one or more MBS services in an MBS individual delivery mode.

[0167] In some example embodiments, the MBS configuration may include any of the following:

[0168] ■ a list of one or more neighboring cells and one or more TMGIs supported in each of the one or more neighboring cells; or

[0169] ■ A list of one or more adjacent frequencies, and one or more TMGIs supported on the one or more adjacent frequencies, respectively.

[0170] In some example embodiments, the MBS configuration may further include one or more adjacent frequencies, and a list of one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0171] In some example embodiments, the MBS configuration may further include one or more of: one or more neighboring FSAIs and a list of at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or one or more neighboring frequencies and a list of at least one neighboring cell that respectively supports the one or more neighboring frequencies.

[0172] In some example embodiments, the FSAI in the MBS configuration may include both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include only the FSAI associated with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include only the FSAI associated with the MBS individual delivery mode.

[0173] At 404, terminal device 110 uses the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or neighboring frequencies. In some embodiments, the at least one type of MBS transmission may include any of the following: MBS shared delivery mode; MBS individual delivery mode; or MBS non-delivery mode. In some embodiments, the at least one type of MBS transmission is determined based on knowledge of the MBS service area.

[0174] At 405, the terminal device 110 performs a mobility-related operation based on the at least one type of MBS transmission. In some embodiments, performing the mobility-related operation may include determining, based on the identified at least one type of MBS transmission, that the terminal device is heading to a target cell that provides MBS services in an individual delivery mode; and performing an RRC reconnection in the serving cell before cell reselection.

[0175] Additionally or alternatively, performing the mobility-related operation may include performing cell reselection based on frequency priorities of one or more neighboring cells.The frequency priorities of the one or more neighboring cells may be determined based on at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells.

[0176] In some embodiments, determining the frequency priority of one or more neighboring cells may include obtaining a priority list of neighboring frequencies of the one or more neighboring cells based on at least one type of MBS transmission identified for one or more MBS services in the one or more neighboring cells. The neighboring frequencies may be prioritized in the order of supporting an MBS shared delivery mode, supporting an MBS individual delivery mode, and not supporting delivery of the one or more MBS services.

[0177] In some embodiments, a terminal device capable of executing method 200 is provided. The device may include components for executing the corresponding steps of method 300. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0178] The apparatus of the terminal device may include a component for receiving a multicast / broadcast service MBS configuration for one or more neighboring cells or neighboring frequencies for a terminal device in an inactive state from a serving cell; a component for using the received MBS configuration to identify at least one type of MBS transmission applicable to one or more MBS services in one or more neighboring cells or frequencies; and a component for performing mobility-related operations based on at least one type of MBS transmission.

[0179] In some example embodiments, the at least one type of MBS transmission may include any one of: an MBS shared delivery mode; an MBS individual delivery mode; or an MBS non-delivery mode.

[0180] In some example embodiments, the components for performing mobility-related operations based on the MBS configuration may include components for determining that the terminal device is heading to a target cell that provides MBS services in an individual delivery mode based on at least one type of identified MBS transmission; and components for performing radio resource control (RRC) reconnection in the serving cell before cell reselection.

[0181] In some example embodiments, the means for performing mobility-related operations based on at least one type of MBS transmission may include means for performing cell reselection based on frequency priorities of one or more neighboring cells. The frequency priorities of the one or more neighboring cells may be determined based on at least one type of identified MBS transmission applicable to one or more MBS services in the one or more neighboring cells.

[0182] In some example embodiments, the means for performing mobility-related operations based on at least one type of MBS transmission may include means for obtaining a prioritized list of neighboring frequencies of one or more neighboring cells based on at least one type of MBS transmission identified for one or more MBS services in the one or more neighboring cells. The neighboring frequencies may be prioritized in the order of supporting a shared MBS delivery mode, supporting an individual MBS delivery mode, and not supporting delivery of the one or more MBS services.

[0183] In some example embodiments, an MBS configuration may include a list of one or more neighboring cells or frequencies and indication information corresponding to the one or more neighboring cells or frequencies. The indication information may indicate at least one type of MBS transmission supported in the one or more neighboring cells, respectively, for the one or more MBS services. Additionally or alternatively, the indication information may indicate a cell type of the one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0184] In some example embodiments, the MBS configuration may also include any of: a list of neighboring cells that support MBS; a list of neighboring cells that provide one or more MBS services in MBS shared delivery mode; a list of neighboring cells that do not support MBS; or a list of neighboring cells that provide one or more MBS services in MBS individual delivery mode.

[0185] In some example embodiments, the MBS configuration may also include any of: a list of adjacent frequencies that support MBS; a list of adjacent frequencies that do not support MBS; a list of adjacent frequencies that provide one or more MBS services in an MBS shared delivery mode; or a list of adjacent frequencies that provide one or more MBS services in an MBS individual delivery mode.

[0186] In some example embodiments, the MBS configuration may include any of: one or more neighboring cells and a list of one or more TMGIs supported in the one or more neighboring cells, respectively; or one or more neighboring frequencies and a list of one or more TMGIs supported on the one or more neighboring frequencies, respectively.

[0187] In some example embodiments, the MBS configuration may further include one or more adjacent frequencies, and a list of one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0188] In some example embodiments, the MBS configuration may further include one or more of: one or more neighboring FSAIs and a list of at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or one or more neighboring frequencies and a list of at least one neighboring cell that respectively supports the one or more neighboring frequencies.

[0189] In some example embodiments, the FSAI in the MBS configuration may include both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include only the FSAI associated with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include only the FSAI associated with the MBS individual delivery mode.

[0190] In some example embodiments, at least one type of MBS transmission for an MBS service may be determined based on knowledge of an MBS service area of ​​the MBS service.

[0191] In some embodiments, a network device capable of executing method 300 may include a component for executing the corresponding steps of method 300. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit system or a software module.

[0192] A network device apparatus is also provided. The apparatus may include a component for sending a multicast / broadcast service (MBS) configuration of one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state to a terminal device, wherein the MBS configuration indicates information about at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies, or a cell type of the one or more neighboring cells in terms of whether or not they support MBS.

[0193] In some example embodiments, the at least one type of MBS transmission may include any one of: an MBS shared delivery mode; an MBS individual delivery mode; or an MBS non-delivery mode.

[0194] In some example embodiments, an MBS configuration may include a list of one or more neighboring cells or frequencies and indication information corresponding to the one or more neighboring cells or frequencies. The indication information may indicate at least one type of MBS transmission supported in the one or more neighboring cells, respectively, for the one or more MBS services. Additionally or alternatively, the indication information may indicate a cell type of the one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0195] In some example embodiments, the MBS configuration may also include any of: a list of neighboring cells that support MBS; a list of neighboring cells that provide one or more MBS services in MBS shared delivery mode; a list of neighboring cells that do not support MBS; or a list of neighboring cells that provide one or more MBS services in MBS individual delivery mode.

[0196] In some example embodiments, the MBS configuration may also include any of: a list of adjacent frequencies that support MBS; a list of adjacent frequencies that do not support MBS; a list of adjacent frequencies that provide one or more MBS services in an MBS shared delivery mode; or a list of adjacent frequencies that provide one or more MBS services in an MBS individual delivery mode.

[0197] In some example embodiments, the MBS configuration may include any of: one or more neighboring cells and a list of one or more TMGIs supported in the one or more neighboring cells, respectively; or one or more neighboring frequencies and a list of one or more TMGIs supported on the one or more neighboring frequencies, respectively.

[0198] In some example embodiments, the MBS configuration may further include one or more adjacent frequencies, and a list of one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0199] In some example embodiments, the MBS configuration may further include one or more of: one or more neighboring FSAIs and a list of at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or one or more neighboring frequencies and a list of at least one neighboring cell that respectively supports the one or more neighboring frequencies.

[0200] In some example embodiments, the FSAI in the MBS configuration may include both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include only the FSAI associated with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include only the FSAI associated with the MBS individual delivery mode.

[0201] Compared to related technologies, the proposed solution can achieve various advantages because an inactive terminal device, while receiving an ongoing multicast service in a serving cell, can distinguish different types of potential target cells for its mobility and perform mobility-related operations based on the identified types to improve MBS multicast services. For example, during mobility to a target cell identified as not supporting MBS, the terminal device can re-establish the RRC connection state in the serving cell, thereby reducing the interruption and data loss caused by switching from shared delivery mode to individual mode. In addition, when making cell reselection decisions, the terminal device can also consider the frequency of the identified potential target cell types in relation to the availability of MBS services to ensure the continuity of its MBS services.

[0202] Figure 5 is a simplified block diagram of a device 500 suitable for implementing embodiments of the present disclosure. The device 500 may be provided to implement a communication device, such as Figure 1 The terminal device 110 or the network device 120 is shown. As shown, the device 500 includes one or more processors 510, one or more memories 520 can be coupled to the processor 510, and one or more transmitters and / or receivers (TX / RX) 540 can be coupled to the processor 510.

[0203] The TX / RX 540 is used for bidirectional communication. The TX / RX 540 has at least one antenna to facilitate communication. The communication interface may represent any interface required for communication with other network elements. The communication interface may be a hardware or software based interface. For example, the communication interface may be one or more transceivers. The one or more transceivers may be coupled to one or more antennas or antenna ports to wirelessly transmit and / or receive communication signals. The antennas or antenna ports may be of the same or different types. The antennas or antenna ports may be located at different locations on the device. The one or more transceivers allow the device to communicate with other devices which may be wired and / or wireless. The transceiver may support one or more radio technologies. For example, the one or more transceivers may include a cellular subsystem, a WLAN subsystem, and / or a Bluetooth subsystem. TM Subsystem. One or more transceivers may include a processor, controller, radio, jack, plug, buffer, and other circuitry to form one or more communication channels to one or more radio frequency units.

[0204] Processor 510 may be of any type suitable for the local technology network and, as non-limiting examples, may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 500 may have multiple processors, such as application-specific integrated circuit chips that are time-slave to a clock synchronized with a main processor.

[0205] The memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 524, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) 522 and other volatile memories that do not persist during power outages.

[0206] Computer program 530 includes computer-executable instructions that are executed by associated processor 510. Program 530 may be stored in ROM 524. Processor 510 may perform any suitable actions and processes by loading program 530 into RAM 522.

[0207] The embodiments of the present disclosure may be implemented through a program so that the device 500 can execute the reference Figures 2 to 4 The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0208] In some embodiments, the program 530 may be tangibly embodied in a computer-readable medium that may be included in the device 500 (such as in the memory 520) or in other storage devices accessible to the device 500. The device 500 may load the program 530 from the computer-readable medium into the RAM 522 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Figure 6 An example of a computer readable medium 600 in the form of a CD or DVD is shown. The computer readable medium has a program 530 stored thereon.

[0209] In general, various embodiments of the present disclosure may be implemented using hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented using hardware, while other aspects may be implemented using firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented using hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or a controller or other computing device, or some combination thereof.

[0210] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer executable instructions, such as instructions included in a program module, which are executed in a device on a target real or virtual processor to perform the above referenced Figure 3 、 Figure 4 and Figure 5 Methods 300, 400, or process 500 are described. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or split between program modules as needed. The machine-executable instructions of program modules can be executed on local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0211] The program code for executing the disclosed method can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when executed by the processor or controller, enables the function / operation specified in the flow chart and / or block diagram to be realized. The program code can be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0212] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0213] Computer-readable media can be computer-readable signal media or computer-readable storage media.Computer-readable media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing.More specific examples of computer-readable storage media will include electrical connections with one or more wires, portable computer floppy disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disc read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.The term "non-transient" as used herein is a restriction on the medium itself (i.e., tangible, rather than signal), rather than a restriction on data storage persistence (e.g., RAM vs. ROM).

[0214] In addition, although the operations are described in a particular order, this should not be understood as requiring the specific order shown or performing such operations in order or performing all shown operations to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Equally, although several specific implementation details have been included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure, but rather as a description of features that may be specific to a particular embodiment. Some features described in the context of individual embodiments may also be combined in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable subcombination in multiple embodiments.

[0215] Although the disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the above-described features.

[0216] Instead, the above-mentioned specific features or actions are disclosed as implementing rights.

[0217] Example form of claim.

Claims

1. A method at a terminal device, comprising: receiving, from a serving cell, a multicast / broadcast service MBS configuration for one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state, identifying, using the received MBS configuration, at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and Mobility-related operations are performed based on the at least one type of MBS transmission.

2. The method according to claim 1, wherein the at least one type of MBS transmission comprises any one of the following: MBS shared delivery model; MBS individual delivery model; or MBS non-delivery mode.

3. The method according to claim 1 or 2, wherein the performing the mobility-related operation comprises: determining, based on the identified at least one type of MBS transmission, that the terminal device is heading to a target cell that provides MBS services in an individual delivery mode; as well as Before cell reselection, a radio resource control (RRC) reconnection is performed in the serving cell.

4. The method according to claim 1 or 2, wherein the performing the mobility-related operation comprises: performing cell reselection based on the frequency priority of the one or more neighboring cells, The frequency priorities of the one or more neighboring cells are determined based on at least one type of identified MBS transmission applicable to the one or more MBS services in the one or more neighboring cells.

5. The method according to claim 4, wherein the frequency priority of the one or more neighboring cells is determined by: obtaining a priority list of neighboring frequencies of the one or more neighboring cells based on at least one type of the identified MBS transmission of the one or more MBS services in the one or more neighboring cells, The adjacent frequencies are prioritized in the order of supporting an MBS shared delivery mode, supporting an MBS individual delivery mode, and not supporting delivery of the one or more MBS services.

6. The method according to any one of claims 1 to 5, wherein the MBS configuration comprises: the one or more neighboring cells or frequencies, and a list of indication information corresponding to the one or more neighboring cells or frequencies, The instruction information indicates at least one of the following: at least one type of the MBS transmission respectively supported in the one or more neighboring cells for the one or more MBS services; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

7. The method according to any one of claims 1 to 5, wherein the MBS configuration further comprises any one of the following: A list of neighboring cells that support MBS; or a list of neighboring cells providing the one or more MBS services in MBS shared delivery mode; or A list of neighboring cells that do not support MBS; or A list of neighboring cells for the one or more MBS services is provided in an MBS individual delivery mode.

8. The method according to any one of claims 1 to 5, wherein the MBS configuration further comprises any one of the following: A list of adjacent frequencies that support MBS; A list of adjacent frequencies that do not support MBS; a list of adjacent frequencies providing the one or more MBS services in MBS shared delivery mode; or A list of adjacent frequencies of the one or more MBS services is provided in an MBS individual delivery mode.

9. The method according to claim 7 or 8, wherein the MBS configuration comprises any one of the following: the one or more neighboring cells, and a list of one or more temporary mobile group identities TMGIs respectively supported in the one or more neighboring cells; or A list of one or more adjacent frequencies and one or more TMGIs supported in the one or more adjacent frequencies, respectively.

10. The method according to any one of claims 1 to 8, wherein the MBS configuration further comprises: A list of one or more adjacent frequencies and one or more frequency selection area identifiers FSAI supported respectively on the one or more adjacent frequencies.

11. The method according to claim 10, wherein the MBS configuration further comprises one or more of the following: a list of one or more neighboring FSAIs and at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or One or more neighboring frequencies and a list of at least one neighboring cell supported on the one or more neighboring frequencies, respectively.

12. The method according to claim 11, wherein the one or more neighboring frequencies and the list of at least one neighboring cell supported on the one or more neighboring frequencies, respectively, are determined based on information about the neighboring cells and the corresponding neighboring frequencies.

13. The method according to any one of claims 10 to 12, wherein the FSAI in the MBS configuration comprises: Both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode.

14. The method according to any one of claims 10 to 12, wherein the FSAI in the MBS configuration comprises: FSAI associated with only one of the MBS Shared Delivery Mode or the MBS Individual Delivery Mode.

15. The method according to any one of claims 1 to 14, wherein at least one type of MBS transmission for an MBS service is determined based on knowledge of an MBS service area for the MBS service.

16. A method at a network device, comprising: sending a multicast / broadcast service MBS configuration of one or more neighboring cells or frequencies of the terminal device in an inactive state to the terminal device, The MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

17. The method according to claim 16, wherein the at least one type of MBS transmission comprises any one of the following: MBS shared delivery model; MBS individual delivery model; or MBS non-delivery mode.

18. The method according to claim 16, wherein the MBS configuration comprises: the one or more neighboring cells or frequencies, and a list of indication information corresponding to the one or more neighboring cells or frequencies, The instruction information indicates at least one of the following: at least one type of the MBS transmission respectively supported in the one or more neighboring cells for the one or more MBS services; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

19. The method according to claim 16 or 17, wherein the MBS configuration further comprises any one of the following: A list of neighboring cells that support MBS; or a list of neighboring cells providing the one or more MBS services in MBS shared delivery mode; or A list of neighboring cells that do not support MBS; or A list of neighboring cells for the one or more MBS services is provided in an MBS individual delivery mode.

20. The method according to claim 16 or 17, wherein the MBS configuration further comprises any one of the following: A list of adjacent frequencies that support MBS; or A list of adjacent frequencies that do not support MBS; or a list of adjacent frequencies providing the one or more MBS services in MBS shared delivery mode; or A list of adjacent frequencies of the one or more MBS services is provided in an MBS individual delivery mode.

21. The method according to any one of claims 16 to 20, wherein the MBS configuration comprises any one of the following: the one or more neighboring cells, and a list of one or more temporary mobile group identities TMGIs respectively supported in the one or more neighboring cells; or A list of one or more adjacent frequencies and one or more TMGIs supported on the one or more adjacent frequencies, respectively.

22. The method according to any one of claims 16 to 20, wherein the MBS configuration further comprises: A list of one or more adjacent frequencies and one or more frequency selection area identifiers FSAI supported respectively on the one or more adjacent frequencies.

23. The method according to claim 22, wherein the MBS configuration further comprises one or more of the following: a list of one or more neighboring FSAIs and at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or One or more neighboring frequencies and a list of at least one neighboring cell supported on the one or more neighboring frequencies, respectively.

24. The method according to claim 22 or 23, wherein the FSAI in the MBS configuration comprises: Both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode.

25. The method according to claim 22 or 23, wherein the FSAI in the MBS configuration comprises: FSAI associated with only one of the MBS Shared Delivery Mode or the MBS Individual Delivery Mode.

26. A terminal device comprising: at least one processor; as well as at least one memory, the at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: receiving, from a serving cell, a multicast / broadcast service MBS configuration for one or more neighboring cells or neighboring frequencies of the terminal device in an inactive state, identifying, using the received MBS configuration, at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; and Mobility-related operations are performed based on the at least one type of MBS transmission.

27. The terminal device according to claim 26, wherein the at least one type of MBS transmission comprises any one of the following: MBS shared delivery model; MBS individual delivery model; or MBS non-delivery mode.

28. The terminal device according to claim 26 or 27, wherein the performing the mobility-related operation comprises: The at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: determining, based on the identified at least one type of MBS transmission, that the terminal device is heading to a target cell that provides MBS services in an individual delivery mode; and Before cell reselection, a radio resource control (RRC) reconnection is performed in the serving cell.

29. The terminal device according to claim 26 or 27, wherein the performing the mobility-related operation comprises: The at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: performing cell reselection based on the frequency priority of the one or more neighboring cells, The frequency priorities of the one or more neighboring cells are determined based on at least one type of identified MBS transmission applicable to the one or more MBS services in the one or more neighboring cells.

30. The terminal device according to claim 29, wherein the frequency priority of the one or more neighboring cells is determined by: obtaining a priority list of neighboring frequencies of the one or more neighboring cells based on at least one type of the identified MBS transmission of the one or more MBS services in the one or more neighboring cells, The adjacent frequencies are prioritized in the order of supporting an MBS shared delivery mode, supporting an MBS individual delivery mode, and not supporting delivery of the one or more MBS services.

31. The terminal device according to any one of claims 26 to 30, wherein the MBS configuration comprises: the one or more neighboring cells or frequencies, and a list of indication information corresponding to the one or more neighboring cells or frequencies, The instruction information indicates at least one of the following: at least one type of the MBS transmission respectively supported in the one or more neighboring cells for the one or more MBS services; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

32. The terminal device according to any one of claims 26 to 30, wherein the MBS configuration further comprises any one of the following: A list of neighboring cells that support MBS; or a list of neighboring cells providing the one or more MBS services in MBS shared delivery mode; or A list of neighboring cells that do not support MBS; or A list of neighboring cells for the one or more MBS services is provided in an MBS individual delivery mode.

33. The terminal device according to any one of claims 26 to 30, wherein the MBS configuration further comprises any one of the following: A list of adjacent frequencies that support MBS; A list of adjacent frequencies that do not support MBS; a list of adjacent frequencies providing the one or more MBS services in MBS shared delivery mode; or A list of adjacent frequencies of the one or more MBS services is provided in an MBS individual delivery mode.

34. The terminal device according to claim 32 or 33, wherein the MBS configuration comprises any one of the following: the one or more neighboring cells, and a list of one or more temporary mobile group identities TMGIs respectively supported in the one or more neighboring cells; or A list of one or more adjacent frequencies and one or more TMGIs supported in the one or more adjacent frequencies, respectively.

35. The terminal device according to any one of claims 26 to 33, wherein the MBS configuration further comprises: A list of one or more adjacent frequencies and one or more frequency selection area identifiers FSAI supported respectively on the one or more adjacent frequencies.

36. The terminal device according to claim 35, wherein the MBS configuration further comprises one or more of the following: a list of one or more neighboring FSAIs and at least one neighboring cell that respectively supports the one or more neighboring FSAIs; or One or more neighboring frequencies and a list of at least one neighboring cell supported on the one or more neighboring frequencies, respectively.

37. The terminal device according to claim 36, wherein the one or more neighboring frequencies and the list of at least one neighboring cell supported on the one or more neighboring frequencies are determined based on information about the neighboring cells and the corresponding neighboring frequencies.

38. The terminal device according to any one of claims 35 to 37, wherein the FSAI in the MBS configuration comprises: Both the FSAI associated with the MBS shared delivery mode and the FSAI associated with the MBS individual delivery mode.

39. The terminal device according to any one of claims 35 to 37, wherein the FSAI in the MBS configuration comprises: FSAI associated with only one of the MBS Shared Delivery Mode or the MBS Individual Delivery Mode.

40. The terminal device according to any one of claims 26 to 39, wherein at least one type of MBS transmission for an MBS service is determined based on knowledge of an MBS service area for the MBS service.

41. A network device comprising: at least one processor; as well as at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device providing a serving cell to: sending a multicast / broadcast service MBS configuration of one or more neighboring cells or frequencies of the terminal device in an inactive state to the terminal device, The MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

42. The network device of claim 41 , wherein the at least one type of MBS transmission comprises any one of the following: MBS shared delivery model; MBS individual delivery model; or MBS non-delivery mode.

43. The network device of claim 41 , wherein the MBS configuration comprises: the one or more neighboring cells or frequencies, and a list of indication information corresponding to the one or more neighboring cells or frequencies, The instruction information indicates at least one of the following: at least one type of the MBS transmission respectively supported in the one or more neighboring cells for the one or more MBS services; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

44. The network device according to claim 41 or 42, wherein the MBS configuration further comprises any one of the following: A list of neighboring cells that support MBS; or a list of neighboring cells providing the one or more MBS services in MBS shared delivery mode; or A list of neighboring cells that do not support MBS; or A list of neighboring cells for the one or more MBS services is provided in an MBS individual delivery mode.

45. A terminal device comprising: means for receiving, from a serving cell, a multicast / broadcast service MBS configuration for one or more neighbouring cells or neighbouring frequencies of the terminal device in an inactive state; means for identifying, using the received MBS configuration, at least one type of MBS transmission applicable for one or more MBS services in the one or more neighboring cells or neighboring frequencies; as well as Means for performing mobility-related operations based on at least one type of MBS transmission.

46. ​​A network device comprising: means for sending to a terminal device a multicast / broadcast service MBS configuration of one or more neighboring cells or frequencies of the terminal device in an inactive state, The MBS configuration indicates information about one of the following: at least one type of MBS transmission applicable to one or more MBS services in the one or more neighboring cells or neighboring frequencies; or The cell type of the one or more neighboring cells in terms of whether they support or do not support MBS.

47. A non-transitory computer-readable medium comprising program instructions for causing an apparatus to at least perform the method according to claims 1 to 25.

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