Multicast / Broadcast Service in RRC Inactive State

Abstract

The present disclosure provides a device, method, and apparatus for a multicast broadcast service (MBS). A terminal device receives an MBS configuration for one or more neighboring cells or frequencies from a serving cell for the inactive terminal device. The terminal device uses the received MBS configuration to identify at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or frequencies. The terminal device performs mobility-related operations based on the at least one type of MBS transmission.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to the field of communications, and more particularly to devices, methods, apparatus, and computer-readable storage media for multicast broadcast services (MBS). [Background technology]

[0002] In 3GPP Release 17, a terminal device such as a user equipment (UE) can receive multicast / broadcast sessions only in a Radio Resource Control (RRC) connected state (e.g., which may be referred to as an RRC_CONNECTED state or mode). 3GPP Release 18 also proposes to enable reception of multicast MBS sessions in an RRC inactive state (e.g., which may be referred to as an RRC_INACTIVE state or mode). Summary of the Invention [Problem to be solved by the invention]

[0003] For a terminal device in an RRC inactive state, it may require cell reselection to another cell while maintaining MBS transmission. Therefore, multicast mobility for UEs in an RRC inactive state needs to be further investigated and improved to enhance MBS transmission. [Means for solving the problem]

[0004] Generally, the 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, using the one or more processors, are configured to: receive from a serving cell multicast / broadcast service (MBS) configurations for one or more neighboring cells or frequencies for the terminal device in an inactive state; identify at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or frequencies using the received MBS configurations; 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, using the one or more processors, to cause a network device providing a serving cell to transmit, to the terminal device, a multicast / broadcast service (MBS) configuration of one or more neighboring cells or neighboring frequencies for the terminal device in an inactive state, the MBS configuration indicating: at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells; or frequencies; or information regarding one of the cell types of the one or more neighboring cells in terms of supporting or not supporting MBS.

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

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

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

[0010] In a sixth aspect, an apparatus for a network device is provided, the apparatus may comprise: means for transmitting a multicast / broadcast service, MBS, configuration of one or more neighboring cells or neighboring frequencies for a terminal device in an inactive state to the terminal device, the MBS configuration indicating: at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or neighboring frequencies; or information regarding one of the cell types of the one or more neighboring cells in terms of supporting or not supporting 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 containing computer program code, wherein the at least one memory and the computer program code are configured, using the at least one processor, to cause the terminal device to: receive from a serving cell a multicast / broadcast service (MBS) configuration for one or more neighboring cells or frequencies for the terminal device in an inactive state; identify at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or frequencies using the received MBS configuration; and perform a mobility-related operation 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, the at least one memory and the computer program code being configured, using the at least one processor, to cause a network device providing a serving cell to transmit, to the terminal device, a multicast / broadcast service (MBS) configuration for one or more neighboring cells or neighboring frequencies for the terminal device in an inactive state, the MBS configuration indicating at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or neighboring frequencies; or one piece of cell type information of the one or more neighboring cells in terms of whether they support or do not support MBS.

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

[0014] In a tenth aspect, there is provided a computer program comprising instructions, which when executed by an apparatus, cause the apparatus to at least receive multicast / broadcast service, MBS, configurations for one or more neighboring cells or neighboring frequencies for an inactive terminal device from a serving cell, use the received MBS configurations to identify at least one type of MBS transmission for one or more MBS services applicable 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.

[0015] In an eleventh aspect, there is provided a computer program comprising instructions that, when executed by an apparatus, cause the apparatus to at least transmit to the terminal device a multicast / broadcast service, MBS, configuration of one or more neighboring cells or neighboring frequencies for an inactive terminal device, the MBS configuration indicating at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or neighboring frequencies, or information regarding one of the cell types of the 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 configured to: receive from a serving cell a multicast / broadcast service (MBS) configuration for one or more neighboring cells or neighboring frequencies for the terminal device in an inactive state; identify at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or neighboring frequencies using the received MBS configuration; 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 configured to cause a terminal device to transmit, for an inactive terminal device, a multicast / broadcast service (MBS) configuration of one or more neighboring cells or neighboring frequencies, the MBS configuration indicating: at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or neighboring frequencies; or information regarding one of the cell types of the one or more neighboring cells in terms of supporting or not supporting MBS.

[0018] It should be understood that this summary section is not intended to identify key features or essential features of the embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will be readily apparent through the following description.

[0019] Some exemplary embodiments will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram of an example network environment in which example embodiments of the present disclosure may be implemented; [Figure 2] 1 is an example flowchart of a method implemented in a terminal device, according to an example embodiment of the present disclosure. [Figure 3] 1 is an example flowchart of a method implemented in a network device, according to an example embodiment of the present disclosure. [Figure 4] 1 illustrates an example signaling process for reporting measurements related to a reference signal, in accordance with some embodiments of the present disclosure. [Figure 5] FIG. 1 is a simplified block diagram of a device suitable for practicing embodiments of the present disclosure. [Figure 6] FIG. 1 is an example block diagram of an example computer-readable medium according to some example embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Throughout the drawings, the same or similar reference numbers represent the same or similar elements.

[0022] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are set forth for illustrative purposes only and to assist those skilled in the art in understanding and implementing the present disclosure, and are not intended to imply any limitation on the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

[0023] In the following description and claims, unless otherwise defined, 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.

[0024] In this disclosure, references such as "one embodiment," "an embodiment," "an exemplary embodiment," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments need include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with one embodiment, it is believed to be within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly stated.

[0025] Although terms such as "first" and "second" may be used herein to describe various elements, it should be understood that these elements are not limited by these terms. These terms are used only 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 illustrated embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting to example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "having," "includes," and / or "including," as used herein, specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. As used herein, "at least one of: " and "at least one of " and similar expressions, when a list of two or more elements is connected by "and" or "or", mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0027] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuit implementations (e.g., analog and / or digital-only circuit implementations); (b) A combination of hardware circuitry and software, such as (if applicable): (i) a combination of analog and / or digital hardware circuitry and software / firmware; and (ii) any portion of a hardware processor (including a digital signal processor), software, and memory with software that cooperates to cause a device, such as a mobile phone or server, to perform various functions; and (c) A hardware circuit and / or processor, such as a microprocessor or part of a microprocessor, that requires software (e.g., firmware) to operate, but where the software may not be present when not required for operation.

[0028] This definition of circuit applies to all uses of the term in this application, including any claims. As a further example, when used in this application, the term circuit also covers simply a hardware circuit or processor (or processors) or portion of a hardware circuit or processor, as well as its (or their) accompanying software and / or firmware implementations. The term circuit also covers, for example, baseband or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices, if applicable to certain claim elements.

[0029] As used herein, the term "communication network" refers to a network conforming to any suitable communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communications between terminal devices and network devices in a communication network may be conducted according to any suitable generation of communication protocols, including, but not limited to, third-generation (3G), fourth-generation (4G), 4.5G, future fifth-generation (5G) communication protocols, and / or any other protocols currently known or developed in the future. Embodiments of the present invention may be applied to various communication systems. Given the rapid development of communications, there are of course future communication technologies and systems in which the present disclosure may be embodied. The scope of the present disclosure should not be considered limited to only the aforementioned systems.

[0030] As used herein, the term "network device" refers to a node of a communication network through which a terminal device accesses and receives services from the network. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or access point (AP), e.g., a Node B (NodeB or NB), evolved Node B (eNodeB or eNB), new radio (NR) NB (also referred to as gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, low-power node such as femto, pico, etc.

[0031] The term "terminal device" refers to any end device that may be 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, smartphones, voice over IP (VoIP) phones, wireless local loop phones, tablets, 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 equipment, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMD), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms “terminal device,” “communications device,” “terminal,” “user equipment,” and “UE” may be used interchangeably.

[0032] The term "transceiver" may refer to any device that can be coupled to one or more antennas or antenna ports for wirelessly transmitting and / or receiving 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 enable the device to communicate with other devices, which may be wired and / or wireless. The one or more transceivers may include a processor, controller, radio, socket, plug, buffer, or similar circuitry to form one or more communication channels to one or more radio frequency units. The one or more transceivers may be incorporated into a device or system, for example, a cellular communication device or system, a wireless local area network (WLAN) system, or a short-range system, for example, a Bluetooth system.

[0033] In 3GPP Release 17, a UE can only receive MBS multicast sessions in the RRC connected state. Between the 5G Core Network (5GC) and the New Generation Radio Access Node (NG-RAN), there are two possible delivery methods for transmitting MBS data: - Individual MBS traffic delivery method: This method applies only to multicast MBS sessions. The 5GC can receive a single copy of MBS data packets and deliver separate copies of those MBS data packets to individual UEs via per-UE PDU sessions. Therefore, for each such UE, one PDU session needs to be associated with the multicast MBS session. - Shared MBS traffic delivery method: This method applies to both broadcast and multicast MBS sessions. The 5GC can receive a single copy of MBS data packets and deliver the single copy of those MBS packets to an NG-RAN node, which then delivers the packets to one or more UEs. The dedicated delivery mode, although less efficient, has the advantage of enabling multicast data delivery even when the UE is located at a legacy gNB, i.e., a gNB that does not support MBS at all.

[0034] Now, 3GPP RAN has initiated a new work item in Release 18 that will also enable reception of multicast MBS sessions in RRC inactive state, with the following scope of work: · Specify support for multicast reception by UEs in RRC_INACTIVE state [RAN2, RAN3]; Study the impact of mobility and state transitions for UEs receiving multicast in RRC_INACTIVE (seamless / lossless mobility is not required) [RAN2, RAN3].

[0035] For a terminal device in an RRC inactive state, it may require cell reselection to another cell while maintaining MBS transmission. Therefore, multicast mobility for UEs in an RRC inactive state needs to be further investigated and improved to enhance MBS transmission.

[0036] For broadcast sessions in Release 17, it has the following solutions for cell reselection: When the UE receives a broadcast session (e.g., Temporary Mobile Group Identity (TMGI)) 1 in RRC inactive state: - the network broadcasts in the serving cell in the System Information Block (SIB) a mapping between FSAIs (Frequency Selective Area Identities associated with TMGIs and established in relation to their broadcast areas) and neighboring frequencies (i.e. frequencies used by neighboring cells); - The UE receives a mapping between the FSAI and TMGI of the broadcast service in a service announcement from the core network (CN). Using these two mappings, the UE can determine which frequency to preferably select when performing cell reselection in order to maintain the ongoing broadcast service TMGI1.

[0037] The example below shows how this works for Broadcast Release 17: Service Announcement: TMGI1 maps to FSAI1, FSAI20, and FSAI40 Serving cell SIB21: (Neighboring frequency 1 maps to FSAIs 4, 5, 7, and 9), (Neighboring frequency 2 maps to FSAIs 1, 2, and 3) If a UE is receiving broadcast session TMGI1 and it has a choice in cell reselection between a cell on Frequency 1 and a cell on Frequency 2, the UE preferably reselects to a cell on Frequency 2 because neighboring Frequency 2 supports FSAI1 (according to SIB21), which matches TMGI1 (according to a previous service announcement received by the UE from the CN). By selecting Frequency 2 in cell reselection, broadcast service continuity is maintained.

[0038] By analogy, it has been proposed to reuse the same solution described above for RRC_inactive UEs in the broadcast case in Rel-17 for RRC_inactive UEs in Rel-18 for the multicast case. However, the inventors have found that such a solution may not work well in the multicast case, as several problems may be involved.

[0039] The inventors have noticed that the main difference between broadcast and multicast transmission is that a multicast session may enable the delivery of multicast data even in gNBs that do not support MBS services at all, i.e., gNBs called MBS non-supporting nodes. This is called individual delivery mode. Thus, in Release 18, during mobility of a UE in RRC inactive state receiving a multicast session for TMGI1 in a serving cell providing TMGI1 in shared delivery mode, the UE can be towards different types of target cells as potential candidates for cell reselection: - a target cell in a neighboring frequency that provides the multicast session TMGI1 in MBS shared distribution mode (hereinafter referred to as Type 1); - a target cell in a neighboring frequency that provides the multicast session TMGI1 in MBS individual distribution mode (hereinafter referred to as type 2); and - A target cell in an adjacent frequency that does not provide TMGI1 at all (e.g., outside the TMGI1 multicast service area) (hereinafter referred to as type 3).

[0040] Therefore, different types of target cells that the UE eventually moves to will have different consequences.

[0041] - If the UE happens to eventually move to a Type 1 target cell, the UE continues to receive TMGI1 smoothly without interruption.

[0042] If instead the UE happens to eventually move into a Type 2 target cell, the UE will experience a disruption in service continuity: the UE first needs to recognize that TMGI1 is not delivered in the target cell in shared delivery point-to-multipoint (PTM) mode and perform an RRC reconnection procedure in the target cell. It then contacts the Session Management Function (SMF) for TMGI1, which triggers a switch from shared delivery mode to individual delivery mode. This overall leads to long interruptions, extra processing, and data loss. In addition, more radio resources are used for separate delivery to each UE via individual delivery than in a Type 1 target cell where PTM delivery is used over the air interface, which is undesirable from an operator's perspective.

[0043] Alternatively, if the UE happens to eventually move to a Type 3 target cell, the UE will have not only an interruption but also a total loss of the TMGI1 multicast service, since that target cell does not provide TMGI1.

[0044] Therefore, mobility towards a Type 1 cell is better for multicast reception of a UE in RRC inactive state than moving towards a Type 2 cell, which is better than moving towards a Type 3 cell. However, currently the UE has no means to distinguish between these types of target cells to influence its mobility decision, either before or during cell reselection.

[0045] According to an embodiment of the present disclosure, a solution is provided that helps a terminal device in an inactive state receiving a multicast session in a serving cell distinguish between different types of potential targets during its mobility. In this solution, a terminal device in an inactive state receives MBS configurations for the terminal device from the serving cell for one or more neighboring cells or frequencies. The MBS configurations may indicate information regarding types of MBS transmissions for one or more MBS services applicable in the one or more neighboring cells or frequencies. The terminal device can perform mobility-related operations using the received MBS configurations. For example, the terminal device can identify at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or frequencies, and then perform mobility-related operations based on the at least one type of MBS transmission.

[0046] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principles and embodiments of the present invention will now be described in detail with reference to the drawings. Reference is first made to Figure 1, which illustrates an example environment 100 in which an example embodiment of the present disclosure may be implemented.

[0047] The environment 100, which may be part of a communication network, includes terminal devices 110 and network devices 120 that communicate with each other or with other devices through each other. The communication environment 100 may include any suitable number of devices and cells. In the communication environment 100, the terminal devices 110 and the network devices 120 may communicate data and control information with each other. The link from the network devices 120 to the terminal devices 110 is referred to as the downlink (DL), while the link from the terminal devices 110 to the network devices 120 is referred to as the uplink (UL).

[0048] It should be understood that the two devices are shown in environment 100 for illustrative purposes only, without implying any limitation to the scope of the present disclosure. In some example embodiments, environment 100 may comprise additional devices for communicating with terminal device 110 and network device 120.

[0049] Communications in environment 100 may be in accordance with any suitable communications standard or protocol, whether existing or 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 may use 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.

[0050] The network device 120 transmits a multicast / broadcast service (MBS) configuration for one or more neighboring cells or frequencies for an inactive terminal device to the terminal device 110. The terminal device 10 receives the MBS configuration and uses the received MBS configuration to identify at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or frequencies. The terminal device 110 may perform mobility-related operations based on the at least one type of MBS transmission.

[0051] By identifying potential target cells of different types for its mobility, the terminal device 110 in the inactive state performs mobility-related operations based on the identified type to improve the MBS multicast service. For example, during movement to a target cell identified as not supporting MBS, the terminal device 110 may reestablish an RRC connection state in the serving cell so that it can reduce interruptions and data loss caused by switching from a shared distribution mode to a dedicated distribution mode. In addition, the terminal device 110 may also take into account the frequency of the identified type of cell to enable the use of the MBS service when determining cell reselection to ensure continuity of the MBS service.

[0052] 2 shows an example flowchart of a method 200 implemented in a terminal device according to an example embodiment of the present disclosure. For purposes of explanation, the method 200 will be described from the perspective of the terminal device 110 with reference to FIG.

[0053] 2, at 210, the terminal device 110 receives a multicast / broadcast service, MBS, configuration for one or more neighboring cells or neighboring frequencies for the inactive terminal device from a serving cell. The terminal device 110 can receive the MBS configuration from a network device 120 providing the serving cell.

[0054] The received MBS configuration indicates at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or neighboring frequencies, or information about the cell type of one or more neighboring cells in terms of supporting or not supporting MBS. The type of MBS transmission can be, for example, TMGI-specific, cell-specific, or gNB-specific.

[0055] The term "TMGI" as used herein may refer to an identity for identifying a multicast session. A TMGI may correspond to an MBS session, for example, an audio MBS session or a video MBS session. Thus, "TMGI-specific" means that the type of MBS transmission is MBS-session specific, i.e., different sessions may have different types of MBS transmission. In some embodiments, the type of MBS transmission may also be service-type specific.

[0056] In some embodiments, the MBS configuration may include a list of one or more neighboring cells or frequencies and corresponding indication information. The indication information may indicate the type of MBS transmission supported in one or more neighboring cells for one or more MBS services, respectively. Alternatively or additionally, the indication information may indicate the cell type of one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0057] In some embodiments, the network device 120 providing the serving cell may transmit, for example, by a broadcast message, a set of lists including one or more information lists as MBS configurations. The terminal device 110 may receive the set of lists and, based on the lists, estimate the types of one or more neighboring cells or frequencies, or estimate transmission modes for one or more MBS services applicable to one or more neighboring cells or frequencies, as described below. The set of lists transmitted from the serving cell may include any of the following: List 1: List of (neighboring cells, supported TMGI), List 2: A list of neighboring cells that support or do not support MBS; List 3: List of (adjacent frequencies, TMGIs supported on this frequency). For List 1, alternatively or in addition, the set of lists is List 1b: (List of adjacent frequencies, supported TMGI) may include: For List 2, alternatively or in addition, the set of lists is List 2b: List of adjacent frequencies that do or do not support MBS may include: For Listing 3, alternatively or in addition, the set of lists is List 3b: List of (neighbor FSAI, neighbor cells supporting this FSAI), List 3c: List of (neighboring frequencies, neighboring cells on this frequency) may include:

[0058] Thus, List 1 includes one or more neighboring cells and one or more Temporary Mobile Group Identities, TMGIs, supported in the one or more neighboring cells, respectively. List 1b includes one or more neighboring frequencies, and one or more TMGIs supported in the one or more neighboring frequencies, respectively.

[0059] 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 transmitted in an MBS shared distribution mode for cells in the multicast service area, while not supporting MBS means that multicast service data can only be transmitted in an individual distribution mode for cells in the multicast service area. Therefore, List 2 may be a list of neighboring cells that provide MBS service in an MBS shared distribution mode or an MBS individual distribution mode, and List 2b may be a list of neighboring frequencies that provide MBS service in an MBS shared distribution mode or an MBS individual distribution mode.

[0060] List 3 includes one or more adjacent frequencies and one or more FSAIs supported on the one or more adjacent frequencies, List 3b includes one or more adjacent FSAIs and at least one adjacent cell supporting the one or more adjacent FSAIs, and List 3c includes one or more adjacent frequencies and at least one adjacent cell supported on the one or more adjacent frequencies.

[0061] It should be noted that the terminal device 110 may receive some of the above-mentioned lists in the MBS configuration and may estimate one or more of the other lists based on the received lists and / or lists sent in other messages, or also based on its own measurements.

[0062] At 220, the terminal device 110 uses the received MBS configuration to identify at least one type of MBS transmission for one or more MBS services applicable in one or more adjacent cells or adjacent frequencies.

[0063] As described above, the terminal device 110 may receive one or more MBS services (e.g., including a multicast service) from the serving cell in the MBS shared distribution mode. The MBS service may be represented by a TMGI (e.g., TMGI1) of the MBS session. The received MBS configuration may indicate at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or adjacent frequencies; or information regarding the cell types of one or more neighboring cells in terms of whether they support or do not support MBS. In such a case, based on the received MBS configuration, the terminal device may identify at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or adjacent frequencies.

[0064] For example, at least one type of identified MBS transmission may be MBS shared distribution (hereinafter, "Type 1"), which means that the corresponding neighboring cell can provide ongoing MBS services in shared distribution as in the serving cell. When the terminal device 110 moves to a neighboring cell in MBS shared distribution mode, it continues to receive the MBS service smoothly with minimal interruption.

[0065] In some embodiments, the identified at least one type of MBS transmission may be an MBS dedicated distribution mode (hereinafter, "Type 2"), which means that the corresponding neighboring cell can only provide the ongoing MBS service in dedicated distribution, but not in shared distribution as done in the serving cell. For example, the network device 120 is a legacy gNB that does not support MBS at all. If the terminal device 110 moves to a neighboring cell that supports only the MBS dedicated distribution mode, it can still continue the MBS service in the cell, but switching from shared distribution to dedicated distribution will cause extra overhead or a much larger interruption.

[0066] In some embodiments, the identified at least one type of MBS transmission may be an MBS non-delivery mode (hereinafter, "Type 3"), which means that no ongoing MBS service is provided in the serving cell. If the terminal device 110 moves to a neighboring cell in the MBS non-delivery mode, the terminal device 110 will lose the MBS service completely.

[0067] Additionally, when the type of MBS transmission is TMGI-specific, cell-specific, or gNB-specific, the identified at least one type of MBS transmission may include two or more types corresponding to two or more TMGIs.

[0068] Terminal device 110 may perform mobility-related operations based on at least one type of MBS transmission in block 230. By identifying the type of MBS transmission in one or more neighboring cells or neighboring frequencies, terminal device 110 that is in an inactive state and receiving an ongoing MBS service can distinguish between different types of potential target cells or frequencies for its mobility and perform mobility-related operations based on the identified type to improve its MBS service.

[0069] In some embodiments, the terminal device 110 may determine, based on the identified at least one type of MBS transmission, that the terminal device 110 is heading toward a target cell that provides MBS service in dedicated distribution mode. In other words, the terminal device 110 is heading toward a target cell that provides MBS service in dedicated distribution mode, i.e., a Type 2 cell. If the terminal device 110 checks and finds that it is heading toward a Type 2 target cell, it may perform RRC reconnection / reconfiguration in the serving cell. The trigger for the check may be based on specific radio criteria, such as based on 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 to the serving cell is performed before cell reselection is performed.

[0070] In some embodiments, the terminal device 110 may perform cell reselection based on the identified at least one type of MBS transmission. For example, the terminal device 110 may perform cell reselection based on the frequency priorities of one or more neighboring cells. The frequency priorities of the one or more neighboring cells may be determined based on the identified at least one type of MBS transmission for one or more applicable MBS services in the one or more neighboring cells.

[0071] In some embodiments, terminal device 110 may obtain a prioritized list of neighboring frequencies for one or more neighboring cells based on the identified at least one type of MBS transmission 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 distribution mode, supporting an MBS individual distribution mode, and not supporting distribution of one or more MBS services.

[0072] In other words, a target cell (Type 1 cell) in a neighboring frequency that provides a multicast service for TMGI1 in MBS shared distribution mode has priority over a target cell (Type 2 cell) in a neighboring frequency that provides TMGI1 in MBS dedicated distribution mode, and a Type 2 cell has even more priority over a target cell (Type 3 cell) in a neighboring frequency that does not provide TMGI1 at all (e.g., outside the TMGI1 multicast service area).

[0073] In some embodiments, at least one type of MBS transmission may be determined based on knowledge of the MBS service area. For example, terminal device 110 may determine that the target cell is Type 3 if the target cell is outside the service area of ​​the TMGI of the MBS service.

[0074] For illustrative purposes, some example solutions are provided below to illustrate how the terminal device 110 distinguishes or identifies different types of neighboring cells or frequencies based on the MBS configuration and how the terminal device behaves accordingly.

[0075] Example Solution 1a (Connection Solution Based on Broadcast List of Cells or Frequencies) In this solution, cell 1 of serving gNB1 may broadcast list 1 of mappings (neighbor cells, supported TMGIs). In addition, cell 1 of serving gNB1 may further broadcast list 2 of neighbor cells that support / do not support MBS (or at least among those cells that support TMGI1, i.e., in the service area of ​​TMGI1).

[0076] Before the cell reselection algorithm is triggered, terminal device 110 may check whether it is heading to a target cell that supports TMGI1 according to List 1 and does not support MBS according to List 2, i.e., whether the target cell (cell2 of gNB2) is a type 2 cell. If so, terminal device 110 may trigger an RRC reconnection in cell1 of the current serving gNB1 to reach an RRC connected mode. The trigger for the check may be based on radio criteria, such as based on the RSRP level of cell1 of gNB1 or the difference between the RSRP of cell1 of the serving gNB1 and the RSRP of cell2 of the target gNB2.

[0077] Exemplary Solution 1b (Reselection Solution Based on Broadcast List of Cells or Frequencies) In this solution, cell 1 of serving gNB1 currently broadcasts list 1 of mappings (neighboring cells, supported TMGI). In addition, cell 1 of serving gNB1 broadcasts list 1b of mappings (neighboring frequencies, supported TMGI), or terminal device 110 may infer list 1b from existing list 1 using its own mapping of (neighboring cells, neighboring frequencies). cell 1 of serving gNB1 may broadcast list 2b of neighboring frequencies that support / do not support MBS, or cell 1 of serving gNB1 may broadcast list 2 of neighboring cells that support / do not support MBS. Also, terminal device 110 may infer list 2b from list 2 using its own mapping of (neighboring cells, neighboring frequencies).

[0078] If Cell 1 of serving gNB 1 broadcasts only List 1 and List 2, terminal device 110 may construct List 1b and List 2b from List 1 and List 2 as described above. A cell reselection algorithm may take List 1b and List 2b into account. In some embodiments, the terminal device prioritizes neighboring frequencies, for example, as follows: Target frequencies that support TMGI1 according to List 1b and MBS according to List 2b, followed by Target frequencies that support TMGI1 according to List 1b and do not support MBS according to List 2b, followed by · Other target frequencies.

[0079] Example Solution 2a (Connection solution with FSAI reuse, FSAI is allocated to both shared and individual streams) In this solution, the terminal device 110 may have a service announcement including a mapping between the TMGI and the FSAI. The terminal device 110 may receive an MBS configuration from the serving gNB1 cell 1. In addition, the serving gNB1 cell 1 may broadcast List 3 of mappings (neighboring frequency, FSAI). In addition, the serving gNB1 cell 1 may further broadcast List 3b indicating the mapping between the FSAI and neighboring cells. Alternatively, the serving gNB1 cell 1 may broadcast List 3c indicating the mapping between neighboring frequencies and neighboring cells. Furthermore, the serving gNB1 cell 1 may also further broadcast List 2 of neighboring cells that support / do not support MBS. Alternatively, if the gNB1 cell 1 does not broadcast List 3b or List 3c, the terminal device 110 may estimate List 3c using its own (neighboring cell, neighboring frequency) mapping.

[0080] In this solution, the terminal device 110 is configured or indicated to allocate an FSAI for both shared and individual distribution, and thus, the FSAI in the MBS configuration may include both an FSAI associated with the MBS shared distribution mode and an FSAI associated with the MBS individual distribution mode.

[0081] Before the cell reselection algorithm is triggered, terminal device 110 can check whether it is heading toward a target cell that supports FSAI1 for TMGI1 according to List 3b (or alternatively according to Lists 3 and 3c) (through the use of a service announcement) and does not support MBS according to List 2. That is, terminal device 110 checks whether the target cell is a type 2 cell (i.e., supports TMGI and does not support MBS). If so, terminal device 110 may perform an RRC reconnection in cell 1 of the current serving gNB1 to reach the RRC connected mode. As mentioned above, the trigger for the check may be based on radio criteria, such as based on the RSRP level of cell 1 of gNB1 or the difference between the RSRP of cell 1 of the serving gNB1 and the RSRP of cell 2 of the target gNB2.

[0082] Example Solution 2b (FSAI Reuse Reselection Solution, FSAI is allocated to both shared and individual deliveries) In this solution, the terminal device 110 may have a service announcement including a mapping between the TMGI and the FSAI. 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 a list 3 of mappings (neighboring frequencies, FSAI). The serving gNB1 cell 1 may broadcast a list 2b of neighboring frequencies that support / do not support MBS. Alternatively, the serving gNB1 cell 1 may broadcast a list 2 of neighboring cells that support / do not support MBS, and the terminal device 110 may infer list 2b from list 2 using its own (neighboring cell, neighboring frequency) mapping if it is not broadcast by the serving gNB1 cell 1.

[0083] In this solution, the terminal device 110 is configured or indicated with an FSAI allocated for both shared and individual distribution, and thus the FSAI in the MBS configuration may include both an FSAI associated with the MBS shared distribution mode and an FSAI associated with the MBS individual distribution mode.

[0084] In this solution, the reselection algorithm of the terminal device 110 may take into account List 3 and List 2b. The terminal device 110 may prioritize neighboring frequencies, for example, as follows: A target frequency that supports FSAI1 of TMGI1 according to List 3 and MBS according to List 2b, followed by Target frequencies that support FSAI1 for TMGI1 according to List 3 and do not support MBS according to List 2b, followed by · Other target frequencies.

[0085] Example solution 3a (connection solution with FSAI reuse, FSAI is allocated only to shared deliveries, not individual deliveries) In this solution, the terminal device 110 may have a service announcement including a mapping between the TMGI and the FSAI. 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 a list 3 of mappings (neighboring frequencies, FSAIs). The serving gNB1 cell 1 may further broadcast a list 3b indicating the mapping between the FSAI and neighboring cells. Alternatively, the serving gNB1 cell 1 may broadcast a list 3c indicating the mapping between neighboring frequencies and neighboring cells. Alternatively, the terminal device 110 may infer list 3c from its own (neighboring cell, neighboring frequency) mappings if the serving gNB1 cell 1 does not broadcast list 3b or list 3c.

[0086] In this solution, the terminal device 110 is configured or indicated with FSAIs allocated only to shared distribution, meaning that there are no FSAIs allocated to individual distribution. Thus, the FSAIs in an MBS configuration may include FSAIs associated only with the MBS shared distribution mode, or alternatively, FSAIs associated only with the MBS individual distribution mode.

[0087] Before the cell reselection algorithm is triggered, terminal device 110 may check whether it is heading to a target cell that does not support FSAI1 for TMGI1 but is still within its service area (e.g., by using a service announcement) in shared distribution according to List 3b (or alternatively according to Lists 3 and 3c). That is, terminal device 110 checks whether the target cell is a type 2 cell (i.e., supports TMGI but is still within its service area and is therefore assumed not to support MBS). If so, terminal device 110 can trigger an RRC reconnection in cell 1 of current serving gNB 1 to reach an RRC connected mode.

[0088] Example Solution 3b (FSAI reuse reselection solution, FSAI is allocated only to shared streams, not individual streams) In this solution, the terminal device 110 may have a service announcement including a mapping between TMGI and FSAI. The terminal device 110 may receive an MBS configuration from cell 1 of the serving gNB1. In this embodiment, cell 1 of the serving gNB1 may broadcast list 3 of mappings (neighboring frequencies, FSAI(s)). Cell 1 of the serving gNB1 may further broadcast list 3c indicating mappings between neighboring frequencies and neighboring cells. Alternatively, the terminal device 110 may infer list 3c from its own (neighboring cell, neighboring frequency) mappings if not broadcast by cell 1 of the serving gNB1.

[0089] In this embodiment, the terminal device 110 is configured or indicated with an FSAI allocated only for shared delivery. Thus, the FSAI in the MBS configuration may comprise an FSAI associated only with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include an FSAI associated only with the MBS individual delivery mode.

[0090] The reselection algorithm of the terminal device 110 may take into account List 3 and List 3c. The terminal device 110 may prioritize neighboring frequencies, for example, as follows: Target frequency that supports FSAI1 of TMGI1 according to Listing 3, followed by Supporting FSAI1 of TMGI1 in shared distribution according to List 3, but target frequencies corresponding to target cells in the multicast area of ​​TMGI1 according to List 3c, followed by · Other target frequencies.

[0091] 3 shows an example flowchart of a method 300 implemented in a network device, according to an example embodiment of the present disclosure. For purposes of explanation, the method 300 will be described from the perspective of the network device 120 with reference to FIGS. 1 and 2.

[0092] 3, in block 310, network device 120 may transmit multicast / broadcast service, MBS, configurations of one or more neighboring cells or neighboring frequencies to terminal device 110 for the terminal device in an inactive state. The MBS configuration indicates at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or neighboring frequencies, or information regarding the cell types of one or more neighboring cells in terms of supporting or not supporting MBS.

[0093] In some example embodiments, the at least one type of MBS transmission may include any of: an MBS shared distribution mode; an MBS individual distribution mode; or an MBS non-distribution mode.

[0094] In some example embodiments, the MBS configuration includes 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 each of the one or more MBS services 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 whether they support MBS or do not support MBS. For example, the cell that does not support MBS may be due to the fact that it belongs to a gNB that does not support MBS.

[0095] In some example embodiments, the MBS configuration may further 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 distribution 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 distribution mode.

[0096] In some example embodiments, the MBS configuration may further include one or more of the following: List of adjacent frequencies that support MBS; List of neighboring frequencies that do not support MBS; A list of adjacent frequencies that provide one or more MBS services in MBS shared distribution mode; or · A list of adjacent frequencies that provide one or more MBS services in MBS individual distribution mode.

[0097] In some example embodiments, the MBS configuration may include either: a list of one or more neighboring cells and one or more TMGIs supported in the one or more neighboring cells, respectively; or a list of one or more neighboring frequencies and one or more TMGIs supported on the one or more neighboring frequencies, respectively.

[0098] In some example embodiments, the MBS configuration may further include a list of one or more adjacent frequencies and one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0099] 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 supports the one or more neighboring FSAIs, respectively; or one or more neighboring frequencies and a list of at least one neighboring cell that is supported on the one or more neighboring frequencies, respectively.

[0100] In some example embodiments, the FSAI in the MBS configuration may include both an FSAI associated with the MBS shared delivery mode and an FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include an FSAI associated only with the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include an FSAI associated only with the MBS individual delivery mode.

[0101] 4 shows an example signaling process for reporting measurements related to a reference signal in accordance with some embodiments of the present disclosure. For illustrative purposes, process 400 is described with reference to FIGS. 1 through 3. Process 400 may include terminal device 110 and network device 120, as shown in FIG. 1. Although process 400 is described in communication environment 100 of FIG. 1, it will be understood that this process may be similarly applied to other communication scenarios having similar problems.

[0102] The network device 120 may provide a serving cell to the terminal device 110. In process 600, at 401, the network device 120 transmits an MBS configuration of one or more neighboring cells or neighboring frequencies for the inactive terminal device to the terminal device 110. At 403, the terminal device 110 receives an MBS configuration 402 from the network device 120. The MBS configuration 402 indicates at least one type of MBS transmission for one or more MBS services applicable in one or more neighboring cells or neighboring frequencies, or information regarding the cell type of the one or more neighboring cells in terms of supporting or not supporting MBS.

[0103] In some example embodiments, the MBS configuration may include a list of one or more neighboring cells or frequencies and corresponding indication information. The indication information may indicate at least one type of MBS transmission supported in one or more neighboring cells for one or more MBS services, respectively. Additionally or alternatively, the indication information may indicate the cell type of one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0104] In some example embodiments, the MBS configuration may further include any of the following: · List of neighboring cells that support MBS; · A list of neighboring cells that provide one or more MBS services in MBS shared distribution 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.

[0105] In some example embodiments, the MBS configuration may further include any of: a list of neighboring frequencies that support MBS; a list of neighboring frequencies that do not support MBS; a list of neighboring frequencies that provide one or more MBS services in an MBS shared distribution mode; or a list of neighboring frequencies that provide one or more MBS services in an MBS individual distribution mode.

[0106] In some exemplary embodiments, the MBS configuration comprises: a list of one or more neighboring cells and one or more TMGIs supported in each of the one or more neighboring cells; or A list of one or more adjacent frequencies and one or more TMGIs supported on each of the one or more adjacent frequencies It may include any of the following.

[0107] In some example embodiments, the MBS configuration may further include a list of one or more adjacent frequencies and one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0108] In some example embodiments, the MBS configuration may further include one or more of a list of one or more neighboring FSAIs and at least one neighboring cell that supports the one or more neighboring FSAIs, respectively, or a list of one or more neighboring frequencies and at least one neighboring cell that is supported on the one or more neighboring frequencies, respectively.

[0109] In some example embodiments, the FSAI in the MBS configuration may include both an FSAI associated with the MBS shared delivery mode and an FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include an FSAI associated with only the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include an FSAI associated with only the MBS individual delivery mode.

[0110] At 404, the terminal device 110 uses the received MBS configuration to identify at least one type of MBS transmission for one or more MBS services applicable in one or more adjacent cells or adjacent frequencies. In some embodiments, the at least one type of MBS transmission may include any of: an MBS shared distribution mode; an MBS individual distribution mode; or an MBS non-distribution mode. In some embodiments, the at least one type of MBS transmission is determined based on knowledge of the MBS service area.

[0111] 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 toward a target cell that provides MBS service in a dedicated delivery mode, and performing an RRC reconnection at the serving cell before cell reselection.

[0112] Additionally or alternatively, performing the mobility-related operation may include performing cell reselection based on frequency priorities of one or more neighboring cells, which may be determined based on at least one type of MBS transmission for one or more applicable MBS services in the one or more neighboring cells.

[0113] In some embodiments, determining the frequency priority of the one or more neighboring cells may include obtaining a prioritized list of neighboring frequencies for the one or more neighboring cells based on the identified at least one type of MBS transmission for the 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 distribution mode, supporting an MBS individual distribution mode, and not supporting distribution of the one or more MBS services.

[0114] In some embodiments, an apparatus of a terminal device capable of performing method 200 is provided. The apparatus may include means for performing each step of method 300. The means may be implemented in any suitable form. For example, the means may be implemented as a circuit or a software module.

[0115] The terminal device apparatus may include means for receiving multicast / broadcast service, MBS, configurations for one or more neighboring cells or neighboring frequencies for the inactive terminal device from a serving cell, means for using the received MBS configurations to identify at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or frequencies, and means for performing a mobility-related operation based on the at least one type of MBS transmission.

[0116] In some example embodiments, the at least one type of MBS transmission may include either an MBS shared distribution mode, an MBS individual distribution mode, or an MBS non-distribution mode.

[0117] In some example embodiments, the means for performing a mobility-related operation based on the MBS configuration includes means for determining, based on the identified at least one type of MBS transmission, that the terminal device is heading toward a target cell that provides MBS service in a dedicated delivery mode; and means for controlling radio resources in the serving cell before cell reselection. and means for performing RRC and reconnection.

[0118] In some example embodiments, the means for performing a mobility-related operation based on at least one type of MBS transmission may comprise means for performing cell reselection based on frequency priorities of one or more neighboring cells, where the frequency priorities of the one or more neighboring cells may be determined based on the identified at least one type of MBS transmission for the applicable one or more MBS services in the one or more neighboring cells.

[0119] In some example embodiments, the means for performing a mobility-related operation based on the at least one type of MBS transmission may include means for obtaining a prioritized list of neighboring frequencies of the one or more neighboring cells based on the identified at least one type of MBS transmission for the 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 distribution mode, supporting an MBS individual distribution mode, and not supporting distribution of the one or more MBS services.

[0120] In some example embodiments, the MBS configuration may include a list of one or more neighboring cells or frequencies and corresponding indication information. The indication information may indicate at least one type of MBS transmission supported in one or more neighboring cells for one or more MBS services, respectively. Additionally or alternatively, the indication information may indicate the cell type of one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0121] In some example embodiments, the MBS configuration may further 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 distribution 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 distribution mode.

[0122] In some example embodiments, the MBS configuration may further include any of: a list of neighboring frequencies that support MBS; a list of neighboring frequencies that do not support MBS; a list of neighboring frequencies that provide one or more MBS services in an MBS shared distribution mode; or a list of neighboring frequencies that provide one or more MBS services in an MBS individual distribution mode.

[0123] In some example embodiments, the MBS configuration may include either: a list of one or more neighboring cells and one or more TMGIs supported in the one or more neighboring cells, respectively; or one or more neighboring frequencies and one or more TMGIs supported on the one or more neighboring frequencies, respectively.

[0124] In some example embodiments, the MBS configuration may further include a list of one or more adjacent frequencies and one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0125] In some example embodiments, the MBS configuration may further comprise one or more of: one or more neighboring FSAIs and a list of at least one neighboring cell that supports the one or more neighboring FSAIs, respectively; or one or more neighboring frequencies and a list of at least one neighboring cell that is supported on the one or more neighboring frequencies, respectively.

[0126] In some example embodiments, the FSAI in the MBS configuration may comprise both an FSAI associated with the MBS shared delivery mode and an FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may comprise an FSAI associated with only the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may comprise an FSAI associated with only the MBS individual delivery mode.

[0127] In some example embodiments, at least one type of MBS transmission for an MBS service may be determined based on knowledge of the MBS service area of ​​that MBS service.

[0128] In some embodiments, a network device capable of performing method 300 may include means for performing each step of method 300. The means may be implemented in any suitable form. For example, the means may be implemented as a circuit or a software module.

[0129] An apparatus for a network device is also provided, which may comprise means for transmitting a multicast / broadcast service, MBS, configuration of one or more neighboring cells or neighboring frequencies for a terminal device in an inactive state to the terminal device, the MBS configuration indicating at least one type of MBS transmission for one or more MBS services applicable in the one or more neighboring cells or neighboring frequencies, or information about the cell types of the one or more neighboring cells in terms of supporting or not supporting MBS.

[0130] In some example embodiments, the at least one type of MBS transmission may include any of: an MBS shared distribution mode; an MBS individual distribution mode; or an MBS non-distribution mode.

[0131] In some example embodiments, the MBS configuration may include a list of one or more neighboring cells or frequencies and corresponding indication information. The indication information may indicate at least one type of MBS transmission supported in one or more neighboring cells for one or more MBS services, respectively. Additionally or alternatively, the indication information may indicate the cell type of one or more neighboring cells in terms of whether they support MBS or do not support MBS.

[0132] In some example embodiments, the MBS configuration may further 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 distribution 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 distribution mode.

[0133] In some example embodiments, the MBS configuration may further include any of: a list of neighboring frequencies that support MBS; a list of neighboring frequencies that do not support MBS; a list of neighboring frequencies that provide one or more MBS services in an MBS shared distribution mode; or a list of neighboring frequencies that provide one or more MBS services in an MBS individual distribution mode.

[0134] In some example embodiments, the MBS configuration may include either: a list of one or more neighboring cells and one or more TMGIs supported in the one or more neighboring cells, respectively; or a list of one or more neighboring frequencies and one or more TMGIs supported on the one or more neighboring frequencies, respectively.

[0135] In some example embodiments, the MBS configuration may further include a list of one or more adjacent frequencies and one or more FSAIs supported on the one or more adjacent frequencies, respectively.

[0136] In some example embodiments, the MBS configuration may further comprise one or more of: one or more neighboring FSAIs and a list of at least one neighboring cell that supports the one or more neighboring FSAIs, respectively; or one or more neighboring frequencies and a list of at least one neighboring cell that is supported on the one or more neighboring frequencies, respectively.

[0137] In some example embodiments, the FSAI in the MBS configuration may include both an FSAI associated with the MBS shared delivery mode and an FSAI associated with the MBS individual delivery mode. Alternatively, in some example embodiments, the FSAI in the MBS configuration may include an FSAI associated with only the MBS shared delivery mode. Alternatively, the FSAI in the MBS configuration may include an FSAI associated with only the MBS individual delivery mode.

[0138] The proposed solution can achieve various advantages over related art in that a terminal device in an inactive state can distinguish between potential target cells of different types for its mobility while receiving an ongoing multicast service in a serving cell and perform mobility-related operations based on the identified types to improve MBS multicast services. For example, while moving to a target cell identified as not supporting MBS, the terminal device can re-establish an RRC connection state in the serving cell to reduce interruptions and data loss caused by switching from shared distribution mode to dedicated mode. In addition, the terminal device can also take into account the frequencies of potential target cells of the identified types to enable the use of MBS services when determining cell reselection, ensuring continuity of the MBS service.

[0139] 5 is a simplified block diagram of a device 500 suitable for practicing embodiments of the present disclosure. The device 500 may be configured to implement a communications device such as, for example, the terminal device 110 or the network device 120 shown in FIG. 1. As shown, the device 500 includes one or more processors 510, one or more memories 520 may be coupled to the processor 510, and one or more transmitters and / or receivers (TX / RX) 540 may be coupled to the processor 510.

[0140] The TX / RX 540 is for bidirectional communication. The TX / RX 540 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary 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 type or different types. The antennas or antenna ports may be located at different locations on the device. The one or more transceivers enable the device to communicate with other devices, which may be wired and / or wireless. The transceivers may support one or more wireless technologies. For example, the one or more transceivers may include a cellular subsystem, a WLAN subsystem, and / or a Bluetooth™ subsystem. The one or more transceivers may include a processor, controller, radio, socket, plug, buffer, or similar circuitry to form one or more communication channels to one or more radio frequency units.

[0141] Processor 510 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of the following: a general-purpose computer, an application-specific 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-slaved to a clock that synchronizes a main processor.

[0142] The memory 520 can 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 down periods.

[0143] The computer program 530 includes computer-executable instructions that are executed by the associated processor 510. The program 530 may be stored in the ROM 524. The processor 510 may load the program 530 into the RAM 522 to perform any appropriate actions and processes.

[0144] The embodiments of the present disclosure may be implemented by a program such that the device 500 may perform any process of the present disclosure, such as those described with reference to Figures 2 to 4. The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0145] In some embodiments, the program 530 may be tangibly contained on a computer-readable medium that may be included in the device 500 (such as in the memory 520) or other storage device accessible by the device 500. The device 500 may load the program 530 from the computer-readable medium into RAM 822 for execution. The computer-readable medium may include any type of tangible non-volatile storage device, such as a ROM, an EPROM, a flash memory, a hard disk, a CD, a DVD, etc. Figure 6 shows an example of a computer-readable medium 600 in the form of a CD or DVD. The computer-readable medium has the program 530 stored thereon.

[0146] In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representations, it should be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting example, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller, or other computing device, or some combination thereof.

[0147] The present disclosure also provides at least one computer program product tangibly stored on a computer-readable medium, such as a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that execute on a target real or virtual processor device to perform the method 300, 400, or process 500 described above with reference to FIGS. 3, 4, and 5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split among program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed in local or distributed devices. In distributed devices, program modules may be located in both local and remote storage media.

[0148] Program code for executing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus such that, when executed by the processor or controller, the program code implements the functionality / acts specified in the flowcharts and / or block diagrams. The program code may run entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine, or entirely on a remote machine or server, as a stand-alone software package.

[0149] In the context of the present disclosure, computer program code or associated data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0150] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium includes, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term "non-transitory" as used herein refers to the medium itself (i.e., tangible, not a signal), as opposed to a limitation on the persistence of data storage (e.g., RAM vs. ROM).

[0151] Additionally, while operations are depicted in a particular order, this should not be understood as requiring such operations to be performed in the particular order or sequential order shown, or that all of the operations depicted be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above description, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

[0152] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the present disclosure, as defined in the appended claims, is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. 1. A method in a terminal device, comprising: receiving a multicast / broadcast service, MBS, configuration for one or more neighboring cells or neighboring frequencies for an inactive terminal device from a serving cell; using the received MBS configuration to identify at least one type of MBS transmission for one or more MBS services applicable in one or more adjacent cells or adjacent frequencies; performing a mobility-related action based on at least one type of MBS transmission; A method comprising:

2. At least one type of MBS transmission MBS shared distribution mode, MBS individual distribution mode, or MBS non-distribution mode 2. The method of claim 1, comprising:

3. performing a mobility-related operation, determining, based on the identified at least one type of MBS transmission, that the terminal device is heading toward a target cell that provides MBS service in a dedicated delivery mode; Performing radio resource control (RRC) reconnection in the serving cell before cell reselection 3. The method of claim 1 or 2, comprising:

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

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

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

7. MBS configuration: a list of neighboring cells that support MBS, or a list of neighboring cells that provide one or more MBS services in MBS shared distribution mode; or 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 distribution mode The method of claim 1 , further comprising:

8. MBS configuration: A list of adjacent frequencies that support MBS; A list of neighboring frequencies that do not support MBS; a list of neighboring frequencies that provide one or more MBS services in MBS shared distribution mode; or A list of adjacent frequencies that provide one or more MBS services in MBS individual distribution mode. The method of claim 1 , further comprising:

9. MBS configuration: a list of one or more neighboring cells and 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 within each of the one or more adjacent frequencies.

9. The method of claim 7 or 8, comprising:

10. MBS configuration: a list of one or more adjacent frequencies and one or more Frequency Selective Area Identities (FSAIs) supported on the one or more adjacent frequencies, respectively; 9. The method of claim 1, further comprising:

11. MBS configuration: one or more neighboring FSAIs and a list of at least one neighboring cell that supports each of the one or more neighboring FSAIs; or a list of one or more neighboring frequencies and at least one neighboring cell each supported on the one or more neighboring frequencies; The method of claim 10 further comprising one or more of:

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

13. The method according to claim 10 , wherein the FSAI in the MBS configuration includes both an FSAI associated with an MBS shared distribution mode and an FSAI associated with an MBS individual distribution mode.

14. The method of claim 10 , wherein the FSAIs in the MBS configuration include FSAIs associated with only one of an MBS shared distribution mode or an MBS individual distribution 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 the MBS service area of ​​that MBS service.

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

17. At least one type of MBS transmission MBS shared distribution mode, MBS individual distribution mode, or MBS non-distribution mode 17. The method of claim 16, comprising any one of:

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

19. MBS configuration: a list of neighboring cells that support MBS, or a list of neighboring cells that provide one or more MBS services in MBS shared distribution mode; or 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 distribution mode 18. The method of claim 16 or 17, further comprising any one of:

20. MBS configuration: A list of adjacent frequencies that support MBS, or A list of neighboring frequencies that do not support MBS, or a list of neighboring frequencies that provide one or more MBS services in MBS shared distribution mode; or A list of adjacent frequencies that provide one or more MBS services in MBS individual distribution mode.

18. The method of claim 16 or 17, further comprising any one of:

21. MBS configuration: a list of one or more neighboring cells and 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 each of the one or more adjacent frequencies.

21. The method of any one of claims 16 to 20, comprising:

22. MBS configuration: a list of one or more adjacent frequencies and one or more Frequency Selective Area Identities (FSAIs) supported on the one or more adjacent frequencies, respectively; 21. The method of any one of claims 16 to 20, further comprising:

23. The MBS configuration is as follows: one or more neighboring FSAIs and a list of at least one neighboring cell that supports each of the one or more neighboring FSAIs; or a list of one or more neighboring frequencies and at least one neighboring cell each supported on the one or more neighboring frequencies; 23. The method of claim 22, further comprising one or more of:

24. The method according to claim 22 or 23, wherein the FSAI in the MBS configuration includes both an FSAI associated with an MBS shared distribution mode and an FSAI associated with an MBS individual distribution mode.

25. 24. The method of claim 22 or 23, wherein the FSAIs in the MBS configuration include FSAIs associated with only one of an MBS shared distribution mode or an MBS individual distribution mode.

26. at least one processor; at least one memory containing computer program code; and a computer program code for causing the terminal device, using at least one processor, to: receiving, from a serving cell, a multicast / broadcast service, MBS, configuration of one or more neighboring cells or neighboring frequencies for the inactive terminal device; using the received MBS configuration to identify at least one type of MBS transmission for one or more MBS services applicable in one or more adjacent cells or adjacent frequencies; Performing mobility-related actions based on at least one type of MBS transmission A terminal device configured to:

27. At least one type of MBS transmission MBS shared distribution mode, MBS individual distribution mode, or MBS non-distribution mode 27. The terminal device of claim 26, comprising:

28. At least one memory and computer program code are configured to execute a mobility-related operation on a terminal device using at least one processor, determining, based on the identified at least one type of MBS transmission, that the terminal device is heading toward a target cell that provides MBS service in a dedicated delivery mode; Perform radio resource control (RRC) reconnection in the serving cell before cell reselection 28. A terminal device according to claim 26 or 27, comprising being configured to:

29. At least one memory and computer program code are configured to execute a mobility-related operation on a terminal device using at least one processor, configured to cause cell reselection based on frequency priorities of one or more neighboring cells; 28. The terminal device according to claim 26 or 27, wherein the frequency priority of the one or more neighboring cells is determined based on the identified at least one type of MBS transmission for the applicable one or more MBS services in the one or more neighboring cells.

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

31. MBS configuration: a list of one or more neighboring cells or frequencies and indication information corresponding to the one or more neighboring cells or frequencies; Indication information is at least one type of MBS transmission supported in one or more neighboring cells for one or more MBS services, respectively; or The cell type of one or more neighboring cells in terms of whether they support MBS or not.

31. A terminal device according to any one of claims 26 to 30, exhibiting at least one of:

32. MBS configuration: a list of neighboring cells that support MBS, or a list of neighboring cells that provide one or more MBS services in MBS shared distribution mode; or 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 distribution mode 31. The terminal device according to any one of claims 26 to 30, further comprising:

33. MBS configuration: A list of adjacent frequencies that support MBS; A list of neighboring frequencies that do not support MBS; a list of neighboring frequencies that provide one or more MBS services in MBS shared distribution mode; or A list of adjacent frequencies that provide one or more MBS services in MBS individual distribution mode.

31. The terminal device according to any one of claims 26 to 30, further comprising:

34. MBS configuration: a list of one or more neighboring cells and 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 within each of the one or more adjacent frequencies.

34. A terminal device according to claim 32 or 33, comprising either

35. MBS configuration:

34. A terminal device according to any one of claims 26 to 33, further comprising a list of one or more neighbouring frequencies and one or more Frequency Selective Area Identities, FSAIs, respectively supported on the one or more neighbouring frequencies.

36. MBS configuration: one or more neighboring FSAIs and a list of at least one neighboring cell that supports each of the one or more neighboring FSAIs; or a list of one or more neighboring frequencies and at least one neighboring cell each supported on the one or more neighboring frequencies; 36. The terminal device of claim 35, further comprising one or more of:

37. 37. The terminal device of claim 36, wherein a list of one or more neighboring frequencies and at least one neighboring cell respectively supported on the one or more neighboring frequencies is determined from information about the neighboring cells and corresponding neighboring frequencies.

38. The terminal device according to any one of claims 35 to 37, wherein the FSAI in the MBS configuration includes both an FSAI associated with an MBS shared distribution mode and an FSAI associated with an MBS individual distribution mode.

39. The terminal device according to any one of claims 35 to 37, wherein the FSAI in the MBS configuration includes an FSAI associated with only one of an MBS shared distribution mode or an MBS individual distribution mode.

40. 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 of ​​that MBS service.

41. at least one processor; at least one memory containing computer program code; 1. A network device comprising: at least one memory and computer program code for causing, using at least one processor, the network device to provide a serving cell, configured to cause the terminal device to transmit a multicast / broadcast service, MBS, configuration of one or more neighboring cells or frequencies for the terminal device in an inactive state; The MBS configuration is as follows: at least one type of MBS transmission for one or more MBS services applicable in one or more adjacent cells or adjacent frequencies; or The cell type of one or more neighboring cells in terms of whether they support MBS or not. Shows information about one of the network devices.

42. At least one type of MBS transmission MBS shared distribution mode, MBS individual distribution mode, or MBS non-distribution mode 42. The network device of claim 41, comprising:

43. MBS configuration: a list of one or more neighboring cells or frequencies and indication information corresponding to one or more neighboring cells or neighboring frequencies; Indication information is at least one type of MBS transmission supported in one or more neighboring cells for one or more MBS services, respectively; or The cell type of one or more neighboring cells in terms of whether they support MBS or not.

42. The network device of claim 41, exhibiting at least one of:

44. MBS configuration: a list of neighboring cells that support MBS, or a list of neighboring cells that provide one or more MBS services in MBS shared distribution mode; or 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 distribution mode 43. The network device of claim 41 or 42, further comprising:

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

46. 1. A network device comprising: means for transmitting to a terminal device a multicast / broadcast service, MBS, configuration of one or more neighboring cells or frequencies for an inactive terminal device, the network device comprising: The MBS configuration is as follows: at least one type of MBS transmission for one or more MBS services applicable in one or more adjacent cells or adjacent frequencies; or The cell type of one or more neighboring cells in terms of whether they support MBS or not. Shows information about one of the network devices.

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

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