Method and apparatus of communication

Description

1 / 49 METHOD AND APPARATUS OF COMMUNICATION CROSS-REFERENCE TO RELATED REQUESTS

[0001] This application claims priority to Chinese Patent Application No. 202310410430.X, filed with the National Intellectual Property Administration of China on April 7, 2023, and entitled COMMUNICATION METHOD AND APPARATUS, which is incorporated herein by reference in its entirety. TECHNICAL AREA

[0002] The modalities of this application relate to the field of wireless communication and, in particular, to a method and apparatus for communication. BACKGROUND

[0003] To minimize the need for repeated network infrastructure construction, save on total network investment, alleviate the enormous financial pressure on building a 5th generation (5G) mobile communication system, and accelerate the commercial use of the 5G mobile communication system, the intensity of shared network construction can be considered increased. Radio access network (RAN) sharing primarily means that a RAN can be connected to core network nodes of a plurality of operators. A plurality of operators can build a RAN together, or one operator can build a RAN independently and other operators can lease the RAN from that operator.

[0004] In a RAN sharing scenario, several public land mobile networks (PLMNs) can configure sessions for the same broadcast service. Therefore, how to save network resources in the session configuration process for the same broadcast service is a problem that deserves attention. SUMMARY

[0005] This application provides a method and apparatus for Petition 870250107448, dated 11 / 24 / 2025, page 8 / 64 2 / 49 communication to save network resources in a scenario where a plurality of PLMNs configure sessions for the same broadcast service.

[0006] According to a first aspect, this request provides a method of communication.The method includes: a first network device receives a request message, where the request message is used to request the creation of a first broadcast session for a first public landline mobile network (PLMN), and the first broadcast session is a session of a first broadcast service; the first network device determines, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, where the second broadcast session is a session created for a second PLMN; and the first network device sends a first indication to a second network device, where the first indication indicates not to configure a first broadcast channel for the first broadcast session, and the first broadcast channel is a channel to transmit the first broadcast service.

[0007] In the previous project, when the first network device determines, based on the request message, that the first broadcast session and the second broadcast session belong to the sessions of the first broadcast service, the first network device can indicate that the second network device does not need to configure the channel used to transmit the first broadcast service, so that network resources can be saved and the efficiency of network resource utilization can be improved.

[0008] In a possible project, the request message includes a first temporary multicast group identifier and a first broadcast service identifier, and the first temporary multicast group identifier. Petition 870250107448, dated 11 / 24 / 2025, page 9 / 64 3 / 49 includes an identifier for the first PLMN.

[0009] In one possible project, before the first broadcast session is created, there is a second transmission channel configured for the second broadcast session, and the second transmission channel is a channel to transmit the first broadcast service.

[0010] In a possible project, before the first network device sends the first indication information to the second network device, the first network device sends the second indication information to a third network device, where the second indication information tells the third network device not to configure the first transmission channel for the first broadcast session.

[0011] In the previous design, the third network device may not allocate address information from the first transmission channel, for example, an F1-U TNL CU, for the first broadcast session based on the second indication information, so that network resources can be saved.

[0012] In one possible design, the first network device receives the address information for the first transmission channel from the third network device, where the address information for the first transmission channel is null or an invalid value.

[0013] In a possible design, the first network device sends a third indication to the third network device, where the third indication tells the third network device not to set up a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device.

[0014] In the previous project, the third network device may not allocate address information from the third channel of Petition 870250107448, dated 11 / 24 / 2025, page 10 / 64 4 / 49 transmission, for example, an NG-U GTP DL TEID, for the first broadcast session based on the third indication information, so that network resources can be saved.

[0015] In a possible design, in a unicast scenario, the first network device receives the address information of the third transmission channel from the third network device, where the address information of the third transmission channel is null or an invalid value.

[0016] In one possible design, in a multicast scenario, the third network device ignores joining a multicast group.

[0017] In the previous project, the third network device may not join the multicast group based on the third indication information, so an NG-U tunnel between the third network device and the first core network device is not configured.

[0018] In a possible design, the first network device sends a fourth indication to the first core network device, where the fourth indication indicates not to configure the third transmission channel for the first broadcast session, and the third transmission channel is the channel to transmit the first broadcast service with the first core network device.

[0019] In the previous project, the first core network device may be indicated to not configure the address information of the first transmission channel, for example, the NG-U tunnel.

[0020] In one possible design, the first network device receives the request message from the first core network device.

[0021] In one possible design, the first network device is a CU or a CU-CP, and the second network device is a DU. Petition 870250107448, dated 11 / 24 / 2025, page 11 / 64 5 / 49

[0022] In a possible design, the first network device sends fifth indication information to the second network device, where the fifth indication information indicates not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device.

[0023] In the previous project, the second network device can tell the first core network device not to set up an NG-U tunnel.

[0024] In one possible design, after the first network device sends the first indication information to the second network device, the second network device sends a sixth indication information to a third network device, where the sixth indication information tells the third network device to release the first transmission channel.

[0025] In the previous project, the third network device can release, based on the sixth indication information, address information allocated to the first broadcast session, for example, an F1-U TNL CU, so that network resources can be saved.

[0026] In one possible design, the first network device receives the request message from the second network device.

[0027] In one possible design, the first network device is a DU, and the second network device is a CU-CP or a CU.

[0028] In one possible design, the first network device provides services to the first PLMN and the second PLMN.

[0029] According to a second aspect, this request provides a method of communication. The method includes: A first network device receives a request message, where the request message is used to request the creation of Petition 870250107448, dated 11 / 24 / 2025, page 12 / 64 6 / 49 a first broadcast session for a first PLMN, and the first broadcast session is a session of a first broadcast service; the first network device determines, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, wherein the second broadcast session is a session created for a second PLMN; and the first network device sends indication information 1 to a second network device, wherein indication information 1 indicates not to transmit data from the first broadcast service from the first PLMN or not to transmit data from the first broadcast service from the second PLMN.

[0030] In the method above, to avoid redundancy caused by sending data from the same first broadcast service in all F1-U tunnels, the indication 1 indicates that data from the first broadcast service is not transmitted from the first PLMN or that data from the first broadcast service is not transmitted from the second PLMN. That is, data can be sent through one of the F1-U tunnels, and data transmission is prohibited in other F1-U tunnels, so that redundant data transmission from the first broadcast service can be avoided.

[0031] In one possible design, before the first network device sends pointing information 1 to the second network device, the first network device determines pointing information 1 based on session information from the first broadcast session and session information from the second broadcast session.

[0032] In a possible project, the session information for the first broadcast session includes at least a number of neighboring cells corresponding to the first broadcast session, a quality of service parameter corresponding to the first broadcast session, and a number of devices. Petition 870250107448, dated 11 / 24 / 2025, page 13 / 64 7 / 49 terminals corresponding to the first broadcast session; and the session information for the second broadcast session includes at least a number of neighboring cells corresponding to the second broadcast session, a quality of service parameter corresponding to the second broadcast session, and a number of terminal devices corresponding to the second broadcast session.

[0033] In a possible design, when indication 1 indicates not to transmit the first broadcast service data from the first PLMN, the first network device sends indication 2 to the second network device, where indication 2 indicates to resume transmission of the first broadcast service data from the first PLMN; or when indication 1 indicates not to transmit the first broadcast service data from the second PLMN, the first network device sends indication 3 to the second network device, where indication 3 indicates to resume transmission of the first broadcast service data from the second PLMN.

[0034] In the previous project, when a problem occurs in the broadcast session for transmitting the first broadcast service, a broadcast session from another PLMN can be used in time to transmit data, i.e., another F1-U tunnel is selected in time to send the data, so that a delay in data transmission can be reduced.

[0035] In one possible design, the first network device provides services to the first PLMN and the second PLMN.

[0036] In one possible design, the first network device is a CU-CP and the second network device is a CU-UP; or the first network device is a DU and the second network device is a CU-CP.

[0037] According to a third aspect, this request Petition 870250107448, dated 11 / 24 / 2025, page 14 / 64 8 / 49 provides a communication apparatus. The apparatus is a first network device or a chip in the first network device, and the apparatus includes a transceiver unit and a processing unit.The transceiver unit is configured to receive a request message, where the request message is used to request the creation of a first broadcast session for a first PLMN, and the first broadcast session is a session of a first broadcast service; the processing unit is configured to determine, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, where the second broadcast session is a session created for a second PLMN; and the transceiver unit is configured to send the first indication information to a second network device, where the first indication information indicates not to configure a first transmission channel for the first broadcast session, and the first transmission channel is a channel to transmit the first broadcast service.

[0038] In a possible project, the request message includes a first temporary multicast group identifier and a first broadcast service identifier, and the first temporary multicast group identifier includes a first PLMN identifier.

[0039] In one possible project, before the first broadcast session is created, there is a second transmission channel configured for the second broadcast session, and the second transmission channel is a channel to transmit the first broadcast service.

[0040] In a possible project, the transceiver unit is configured to: before sending the first indication information to the second network device, send the second indication information to a third network device, Petition 870250107448, dated 11 / 24 / 2025, page 15 / 64 9 / 49 where the second indication tells the third network device not to configure the first transmission channel for the first broadcast session.

[0041] In one possible design, the transceiver unit is configured to receive address information for the first transmission channel from the third network device, where the address information for the first transmission channel is null or an invalid value.

[0042] In a possible design, the transceiver unit is configured to send third indication information to the third network device, where the third indication information tells the third network device not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device.

[0043] In one possible design, the transceiver unit is configured to: in a unicast scenario, receive third-channel transmission address information from the third network device, where the third-channel transmission address information is null or an invalid value.

[0044] In a possible design, the transceiver unit is configured to send fourth indication information to the first core network device, where the fourth indication information indicates not to configure the third transmission channel for the first broadcast session, and the third transmission channel is the channel to transmit the first broadcast service with the first core network device.

[0045] In one possible design, the transceiver unit is configured to: upon receiving the request message, receive the request message from the first core network device.

[0046] In a possible project, the first device of Petition 870250107448, dated 11 / 24 / 2025, page 16 / 64 The 10 / 49 network is a CU or a CU-CP, and the second network device is a DU.

[0047] In a possible design, the transceiver unit is configured to send a fifth indication to the second network device, where the fifth indication indicates not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device.

[0048] In a possible project, the transceiver unit is configured to: upon receiving the request message, receive the request message from the second network device.

[0049] In one possible design, the first network device is a DU, and the second network device is a CU-CP or a CU.

[0050] In one possible design, the first network device provides services to the first PLMN and the second PLMN.

[0051] For the technical effect of the third aspect, see the corresponding technical effect of the first aspect.

[0052] According to a fourth aspect, this application also provides an apparatus. The apparatus can carry out the design of the above method. The apparatus can be a chip or circuit that can perform the function corresponding to the above method, or a device that includes the chip or circuit.

[0053] In one possible implementation, the device includes: a memory, configured to store executable computer program code; and a processor, where the processor is coupled to the memory. The program code stored in the memory includes instructions. When the processor executes the instructions, the device or a device in which the device is installed is enabled to perform the method in any of the previous possible designs. Petition 870250107448, dated 11 / 24 / 2025, p. 17 / 64 11 / 49

[0054] The device may also include a communication interface. The communication interface may be a transceiver. Alternatively, if the device is a chip or a circuit, the communication interface may be an input / output interface of the chip, for example, an input / output pin.

[0055] In a possible design, the device includes corresponding functional units, configured respectively to implement the steps in the previous method. The function may be implemented by hardware or may be implemented by running corresponding software on hardware. The hardware or software includes one or more units that correspond to the previous function.

[0056] According to a fifth aspect, this application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program runs on a device, the method in any of the previous possible designs is performed.

[0057] According to a sixth aspect, this application provides a computer program product. The computer program product includes a computer program. When the computer program runs on an appliance, the method in any of the previous possible designs is performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG. 1 is a diagram of a data transmission process of an MBS service according to this request.

[0059] FIG. 2 is a diagram of an interface relationship in a CU-DU architecture according to this application.

[0060] FIG. 3A is a diagram of a MOCN network architecture according to this request.

[0061] FIG. 3B is a diagram of a MORAN network architecture according to this request.

[0062] FIG. 4A is a diagram of a network architecture in which a CU and a DU are shared according to this Petition 870250107448, dated 11 / 24 / 2025, p. 18 / 64 12 / 49 order.

[0063] FIG. 4B is a diagram of a network architecture in which only one DU is shared according to this request.

[0064] FIG. 5 is a diagram of a broadcast session setup procedure in accordance with this request.

[0065] FIG. 6 is a general flowchart of a communication method in accordance with this request.

[0066] FIG. 7 is a diagram of a broadcast session setup procedure initiated by a 5GC of a PLMN 2 in accordance with this request.

[0067] FIG. 8 is a diagram of another broadcast session setup procedure initiated by a 5GC of a PLMN 2 in accordance with this request.

[0068] FIG. 9 is a diagram of another broadcast session setup procedure initiated by a 5GC of a PLMN 2 in accordance with this request.

[0069] FIG. 10 is an overview flowchart of another communication method according to this request.

[0070] FIG. 11 is a diagram of the structure of a communication device according to this application; and

[0071] FIG. 12 is a diagram of an output from another communication device in accordance with this application. DESCRIPTION OF THE MODALITIES

[0072] In the embodiments of this application, at least one means one or more, and a plurality of means two or more than two. The term and / or describes an association relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may indicate the following cases: Only A exists, A and B exist, and only B exists, where A and B may be singular or plural. The character “ / ” generally indicates an “or” relationship between the associated objects. At least one of the following pieces (items) or a similar expression indicates any combination of these items, including a single item (piece). Petition 870250107448, dated 11 / 24 / 2025, p. 19 / 64 13 / 49 or any combination of a plurality of items (pieces). For example, at least one item (piece) of a, b, or c can represent a, b, c, aeb, aec, bec, or a, bec, where each of a, b, c can be an element, or it can be a set including one or more elements.

[0073] In this application, the terms example, in some embodiments, in some other embodiments, or similar terms are used to represent an example, an illustration, or a description. Any embodiment or design solution described as an example in this application should not be explained as being more preferred or having more advantages than another embodiment or design solution. Precisely, the term example serves to present a concept in a specific way.

[0074] Of (from), correspondent (correspondent, relevant) and correspondent (correspondent) in this request may sometimes be used interchangeably. It should be noted that the meanings expressed are the same when the differences are not emphasized. In some modalities of this request, communication and transmission may sometimes be used interchangeably. It should be noted that the meanings expressed are the same when the differences are not emphasized. For example, transmission may include sending and / or receiving and may be a noun or verb.

[0075] It should be noted that, in some forms of this application, words such as first and second are used only for the purpose of distinguishing descriptions and cannot be understood as an indication or implication of relative importance or an indication or implication of a sequence.

[0076] To facilitate understanding of the modalities of this request, several basic concepts in the modalities of this request are briefly described.

[0077] 1. Multicast and broadcast service (MBS) Petition 870250107448, dated 11 / 24 / 2025, p. 20 / 64 14 / 49

[0078] MBS is a service, for example, a live streaming service, a public safety service, and a batch software update service, geared toward a plurality of terminal devices.

[0079] MBS service data originates from a data server. FIG. 1 shows an MBS service data transmission process. First, the data server sends the MBS service data to a core network device, then the core network device sends the MBS service data to a base station, and finally, the base station sends the MBS service data to at least one terminal device that receives the MBS service data.

[0080] When the core network device sends MBS service data to the base station, the MBS service data is transmitted through a transmission channel corresponding to an MBS session, and each MBS session can include at least one MBS quality of service (QoS) stream.

[0081] When the base station sends MBS service data to the terminal device, the data packet is transmitted via an MBS radio carrier. For an MBS radio carrier, there are two transmission modes: a point-to-multipoint (point-to-multipoint, PTM) transmission mode and a point-to-point (point-to-point, PTP) transmission mode.

[0082] 2. Multicast service

[0083] The multicast service is designed for services with high QoS requirements and can provide the same level of QoS as a unicast service. For the multicast service, the core network device also needs to manage the entry and exit of the terminal device in a multicast group. Since transmission between the core network device and the base station depends on a protocol data unit session (PDU session), a new MBS stream Petition 870250107448, dated 11 / 24 / 2025, p. 21 / 64 15 / 49 QoS is introduced.

[0084] The base station supports data transmission to the terminal device in PTP and PTM transmission modes, and supports dynamic switching control between PTP and PTM transmission modes. Multicast service can only be provided to a terminal device in a radio resource control (RRC) connected state, and the base station and core network device need to maintain information about the terminal device corresponding to the multicast group. Furthermore, for multicast service, MBS session deactivation or activation, triggered by the core network device, is also supported, and the terminal device does not detect the MBS service state.

[0085] 3. CU-DU Architecture

[0086] A CU is a central unit and a DU is a distributed unit. The CU-DU architecture can also be called a CU-DU separate base station architecture and is a base station architecture recently introduced in 5G. In a 4th generation (4G) mobile communication system architecture, base stations are deployed independently and connected separately to a 4G core network. In a 5G architecture, DU parts from different base stations are deployed independently, but CU parts from different base stations are deployed centrally.

[0087] From the point of view of the structure of a physical module, a 4G base station is internally divided into several modules: a baseband processing unit (Building Base Band Unit, BBU), a remote radio unit (RRU), and an antenna. Each base station has a set of BBUs and is directly connected to the core network via the BBU. In a 5G CU-DU architecture, an original RRU and an original antenna are combined into an active antenna unit (Active Petition 870250107448, dated 11 / 24 / 2025, p. 22 / 64 16 / 49 The Antenna Unit (AAU) and the BBU are divided into a DU and a CU. Each base station has a set of DUs, and multiple stations share the same CU for centralized management.

[0088] From the perspective of a protocol stack structure, in the 5G CU-DU architecture, a lower physical layer of a BBU from an original 4G base station is transferred to an AAU for processing, an upper physical layer, a medium access control (MAC) layer, and a radio link control (RLC) layer that have a high real-time requirement are placed in the DU for processing, and a packet data convergence protocol (PDCP) layer, a service data adaptation protocol (SDAP) layer, an RRC layer, and similar layers that have a low real-time requirement are placed in the CU for processing.

[0089] In the CU-DU architecture, the interface between the CU and the DU is called the F1 interface. The CU can be further separated, being divided into a CU-CP and a CU-UP. The CU-CP is a central unit-control plane, and the CU-UP is a central unit-user plane.

[0090] An interface between the CU-CP and the CU-UP is called the E1 interface. Typically, a base station has only one CUCP, a plurality of CU-UPs, and a DU. A DU can be connected to only one CU-CP, and a CU-UP can also be connected to only one CU-CP. An interface between the CU-CP and the DU is called the F1-C (control plane), and an interface between the CU-UP and the DU is called the F1-U (user plane). It can be learned that there can be a plurality of F1-Us between a DU and a plurality of CU-UPs. The F1-U is generally used for data transmission and can also be called the F1-U tunnel, as shown in FIG. 2.

[0091] 4. RAN Sharing Petition 870250107448, dated 11 / 24 / 2025, p. 23 / 64 17 / 49

[0092] The following describes RAN sharing from the perspectives of resource sharing intensity, service independence, and similar factors.

[0093] A multi-operator core network (MOCN) can also be called frequency sharing between operators. In this sharing method, a core network is independent. Configuration management, alarm management, performance indicators, and other similar features need to be managed by a primary operator. Some performance indicators may distinguish PLMNs for monitoring, and features cannot be activated independently. A BBU, an RRU, or an AUU is shared, and one or more segments specific to different operators are shared, forming a shared carrier with a large continuous bandwidth, allowing for reduced infrastructure and device costs, as shown in FIG. 3A.

[0094] A multi-operator radio access network (MORAN) can also be called carrier frequency division sharing. In this sharing, the core network is independent, a 5G RAN device is shared, and a cell and spectrum are independent. Configuration management, alarm management, and similar tasks need to be managed by a primary operator. Performance indicators can be differentiated for monitoring, and cell-level resources can be planned and activated independently. The BBU is shared and connected to RRUs / AAUs from the same vendor. RRU / AAU operators are independent of each other, operators are configured and managed independently, and different logically independent cells are provided for a plurality of operators within the base station. Petition 870250107448, dated 11 / 24 / 2025, page 24 / 64 18 / 49 independent use, as shown in FIG. 3B.

[0095] It should also be understood that, in this request, RAN sharing and base station contribution can be mutually substituted.

[0096] The implementations in this request are primarily applied to a MOCN scenario, but may also be applied to other scenarios. This is not limited to this request. Below, we describe only some possible RAN sharing architectures in the MOCN scenario.

[0097] A RAN 1 sharing architecture is an architecture in which a CU and a DU are shared.

[0098] The main PLMN networks are configured independently, and the PLMN CUs and DUs are shared.

[0099] As shown in FIG. 4A, a 5G core network (5G core, 5GC) from PLMN A, a 5GC from PLMN B, and a 5GC from PLMN C are configured independently. One gNB-CU from PLMN A, one gNB-CU from PLMN B, and one gNB-CU from PLMN C are shared, i.e., the gNB-CUs are shared; and one gNB-DU from PLMN A, one gNB-DU from PLMN B, and one gNB-DU from PLMN C are shared, i.e., the gNB-DUs are shared.

[00100] For example, the 5GC of PLMN A sends a temporary multicast group identifier (temporary multicast group identifier, TMGI) A and a broadcast service identifier to the shared gNB-CU, where TMGI A includes an identifier for PLMN A. Similarly, the 5GC of PLMN B sends a TMGI B and a broadcast service identifier to the shared gNB-CU, where TMGI B includes an identifier for PLMN B. The shared gNB-CUs determine, based on the identifiers received from the two broadcast services, that the broadcast services requested by the two 5GCs are the same service. Alternatively, the shared gNB-CUs send the identifiers of the two broadcast services to the shared gNB-DU, and the shared gNB-DUs determine Petition 870250107448, dated 11 / 24 / 2025, p. 25 / 64 19 / 49 that the transmission services requested by the two 5GCs are the same service.

[00101] A RAN 2 sharing architecture is an architecture in which only one DU is shared.

[00102] PLMN core networks are configured independently, and PLMN CUs are not shared, but PLMN DUs are shared.

[00103] As shown in FIG. 4B, a 5GC from PLMN A, a 5GC from PLMN B, and a 5GC from PLMN C are configured independently. A gNB-CU from PLMN A, a gNB-CU from PLMN B, and a gNB-CU from PLMN C are not shared; and a gNB-DU from PLMNA, a gNB-DU from PLMN B, and a gNB-DU from PLMN C are shared, i.e., the gNB-DUs are shared.

[00104] Because PLMN gNB-CUs are not shared, PLMN gNB-CUs receive TMGIs and transmission service identifiers sent by the corresponding PLMN 5GCs and then send the TMGIs and transmission service identifiers to the shared gNB-DUs. The shared gNB-DUs determine that transmission services requested by different 5GCs are the same service.

[00105] It should also be understood that, in this application, each network element is described using only one network element name in a 5G network as an example. In another future network, a different naming convention may be used. This is not limited to this application.

[00106] 4. NG Interface

[00107] The NG interface is an interface between an evolved NodeB (gNB) and a 5GC in a 5G system (5GS). The NG interface is divided into an NG-C interface (a control plane interface between the gNB and the 5GC) and an NG-U interface (a user plane interface between the gNB and the 5GC).

[00108] FIG. 5 is a diagram of a procedure of Petition 870250107448, dated 11 / 24 / 2025, page 26 / 64 20 / 49 current broadcast session configuration.

[00109] S501: A 5GC sends a Broadcast Session Setup Request (NGAP) message to a gNB-CU-CP, where the message includes a TMGI. In addition, the message may include at least one of the following information: slice information, a 5G QoS file, area information, and transport layer information.

[00110] For example, in an NG-U multicast transmission scenario, the transport layer information includes a multicast IP address and a source-specific multicast IP address (which can also be denoted as 5G core NG-U transport network layer (5GC NG-U TNL) transport layer address information). NG-U multicast can also be called N3mb multicast; to be more specific, a common GTP-U tunnel is used for each MBS session; and NG-U multicast is abbreviated as multicast in this application.

[00111] In an NG-U unicast transmission scenario, the transport layer information includes a General Packet Radio Tunneling Protocol uplink tunnel endpoint identifier (GPRS tunneling protocol uplink tunnel endpoint identifier, GTP UP TEID) (which may also be denoted as 5GC NG-U TNL). NG-U unicast may also be called N3mb unicast; to be more specific, a separate GTP-U tunnel is used for each MBS session; and NG-U unicast is abbreviated as unicast in this request.

[00112] gNB-CU-CP can choose to transmit data using NG-U multicast or transmit data using NG-U unicast.

[00113] S502: The gNB-CU-CP sends a broadcast bearer context setup request (E1AP BC Bearer Context Setup Request) message to a gNB-CU-UP.

[00114] The message includes transport layer information from 5GC. The specific type of information from Petition 870250107448, dated 11 / 24 / 2025, p. 27 / 64 21 / 49 The transport layer to be ported depends on whether gNB-CU-CP selects NG-U multicast or NG-U unicast.

[00115] S503: gNB-CU-UP sends a broadcast carrier context setup response (E1AP BC Bearer Context Setup Response) message to gNB-CU-CP.

[00116] In the NG-U multicast transmission scenario, the message includes F1-U transport layer address information of a CU (F1-U TNL CU). The F1-U TNL CU includes an F1-U GTP UL TEID.

[00117] In the NG-U unicast transmission scenario, the message includes an NG-U GTP DL TEID (which can also be denoted as a gNB NG-U TNL) and an F1-U TNL CU, and the F1-U TNL CU includes an F1-U GTP UL TEID.

[00118] S504: In the NGU multicast transmission scenario, gNB-CU-UP joins an NG-U multicast group.

[00119] In the NG-U multicast transmission scenario, gNB-CU-CP configures an NG-U tunnel with 5GC.

[00120] S505: gNB-CU-CP sends a Broadcast Context Setup Request (F1AP) message to a DU.

[00121] The message includes MRB configuration information, other related session parameters, and similar information. Additionally, the message may optionally include an F1-U GTP UL TEID.

[00122] S506: DU sends a broadcast context setup response message (F1AP Broadcast Context Setup Response) to gNB-CU-CP.

[00123] The message includes an F1-U GTP DL TEID (which may also be denoted as an F1-U TNL DU).

[00124] S507: gNB-CU-CP sends a broadcast bearer context modification request (F1AP BC Bearer Context Modification Request) to gNB-CU-UP.

[00125] Optionally, the message includes an F1-U GTP DL TEID.

[00126] S508: gNB-CU-UP sends a reply message of Petition 870250107448, dated 11 / 24 / 2025, page 28 / 64 22 / 49 broadcast bearer context modification (F1AP BC Bearer Context Modification Response) for gNB-CU-CP.

[00127] S509: The DU provides broadcast configuration information for the UE.

[00128] For example, the DU configures a broadcast resource and provides the broadcast configuration information to the UE via a multicast control channel (MBS control channel, MCCH).

[00129] S510: The gNB-CU-CP sends a Broadcast Session Setup Response (NGAP) message to the 5GC.

[00130] In the NG-U unicast transmission scenario, the message includes an NG-U GTP DL TEID, and the NG-U GTP DL TEID is from S503. In this case, in the NG-U unicast transmission scenario, gNB-CU-CP configures an NG-U tunnel with 5GC.

[00131] It can be learned from the previous process that a data transmission channel, also known as an NG-U tunnel, can be configured through the interaction between the 5GC and a gNB.

[00132] An F1-U tunnel can be configured through the interaction between a gNB-CU and a gNB-DU. Furthermore, the F1-U tunnel is configured between the gNB-CU and the gNB-DU, provided that the broadcast session configuration procedure is initiated. That is, NG-U tunnel configuration and F1-U tunnel configuration are independent of each other.

[00133] During the current discussion, when a plurality of PLMNs share a base station, if the plurality of PLMNs create transmission sessions for the same broadcast service, to save resources, the base station can determine a number of NG-U tunnels to be configured. Although the base station can determine the number of NG-U tunnels to be configured, it can be concluded from the previous analysis that an F1-U tunnel is definitely configured whenever the broadcast session configuration procedure is initiated. Petition 870250107448, dated 11 / 24 / 2025, page 29 / 64 23 / 49

[00134] For example, in a RAN sharing scenario, there are five PLMNs in total. For the same broadcast service, if the base station decides to configure all five NG-U tunnels, five F1-U tunnels will definitely be configured between gNB-CU and gNB-DU. If the base station decides to configure only one NG-U tunnel, the transmission sessions of the remaining four PLMNs will still need to be configured, but the NG-U tunnel will not be configured. However, the five F1U tunnels will still be configured in this process. Therefore, even if there is only one NG-U tunnel, there will still be five F1U tunnels.

[00135] To save network resources in a scenario where multiple PLMNs configure sessions for the same broadcast service, this application provides a communication method. The method includes the following steps.

[00136] As shown in FIG. 6, the method includes the following steps.

[00137] 601: A first network device receives a request message, where the request message is used to request the creation of a first broadcast session for a first PLMN, and the first broadcast session is a session of a first broadcast service.

[00138] For example, the request message includes a first temporary multicast group identifier and a first broadcast service identifier, and the first temporary multicast group identifier includes a first PLMN identifier.

[00139] 602: The first network device determines, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, where the second broadcast session is a session created for a second PLMN.

[00140] The second broadcast session was configured before Petition 870250107448, dated 11 / 24 / 2025, page 30 / 64 24 / 49 of the first broadcast session, and the second broadcast session is a broadcast session that has been configured.

[00141] The first network device provides services to the first PLMN and the second PLMN. In addition, the first network device may also provide a service to another PLMN. This is not limited to this request.

[00142] For example, the first network device can determine whether a broadcast service corresponding to the first broadcast session is the same as a broadcast service corresponding to the second broadcast session; and if the broadcast service corresponding to the first broadcast session is the same as the broadcast service corresponding to the second broadcast session, determine that the first broadcast session and the second broadcast session belong to sessions of the same broadcast service; otherwise, determine that the first broadcast session and the second broadcast session belong to sessions of different broadcast services.

[00143] That the first network device determines, based on the request message, that the first broadcast session and the second broadcast session belong to the sessions of the first broadcast service can also be described as that the first network device determines, based on the request message, that the session of the first broadcast service already exists, or that the session of the first broadcast service has been configured for another PLMN.

[00144] 603: The first network device sends the first indication information to a second network device, where the first indication information indicates not to configure a first transmission channel for the first broadcast session, and the first transmission channel is a channel to transmit the first broadcast service.

[00145] In one possible design, the first transmission channel is an F1-U tunnel or an NG-U tunnel. Petition 870250107448, dated 11 / 24 / 2025, page 31 / 64 25 / 49

[00146] For example, before the creation of the first broadcast session, a second transmission channel is configured for the second broadcast session, and the second transmission channel is a channel for transmitting the first broadcast service. One type of second transmission channel is the same as the first transmission channel. For example, the second transmission channel is also an F1-U tunnel, and the second transmission channel is also used to transmit the first broadcast service.

[00147] In the previous project, when the first network device determines, based on the request message, that the first broadcast session and the second broadcast session belong to the sessions of the first broadcast service, the first network device can indicate that the second network device does not need to configure the channel used to transmit the first broadcast service, so that network resources can be saved and the efficiency of network resource utilization can be improved.

[00148] Next, we describe in more detail several RAN sharing scenarios.

[00149] Scenario 1: The first network device is a CU and the second network device is a DU.

[00150] For example, for 601, the first network device may receive the request message from a first core network device.

[00151] Furthermore, in a possible design, in a unicast scenario, the first network device may still send a fourth indication to the first core network device, where the fourth indication indicates the non-configuration of a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with the first core network device. The third transmission channel may be an NG-U tunnel. In the previous design, the Petition 870250107448, dated 11 / 24 / 2025, page 32 / 64 26 / 49 The first core network device may be indicated to not configure the third transmission channel, for example, the NG-U tunnel.

[00152] For details, see the related descriptions in Mode 1 below.

[00153] Scenario 2: The first network device is a CUCP, the second network device is a DU, and the third network device is a CU-UP.

[00154] In addition to the previous descriptions for scenario 1, in one possible design, the first network device also sends a second indication to the third network device, where the second indication tells the third network device not to configure the first transmission channel for the first broadcast session. Furthermore, the first network device may receive address information for the first transmission channel from the third network device, where the address information for the first transmission channel is null or an invalid value. In the previous design, the third network device may not allocate the address information for the first transmission channel, for example, an F1U TNL CU, for the first broadcast session based on the second indication, so that network resources can be conserved.

[00155] In another possible design, the first network device may send a third indication to the third network device, where the third indication indicates that the third network device should not configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device. The third transmission channel may be an NG-U tunnel.

[00156] Furthermore, in a unicast scenario, the first Petition 870250107448, dated 11 / 24 / 2025, page 33 / 64 27 / 49 network device can receive third-channel transmission address information from the third network device when the third-channel transmission address information is null or an invalid value. In the previous design, the third network device may not allocate the third-channel transmission address information, for example, an NG-U GTP DL TEID, for the first broadcast session based on the third-channel indication information, so that network resources can be saved.

[00157] In a multicast scenario, the third network device does not join a multicast group. In the previous design, the third network device might not join the multicast group based on the third indication information, so an NG-U tunnel between the third network device and the first core network device is not configured.

[00158] For details, see the related descriptions in Mode 2 below.

[00159] Scenario 3: The first network device is a DU and the second network device is a CU-CP or a CU.

[00160] For example, for 601, the second network device may receive a broadcast session configuration request message from a first core network device. The second network device sends the request message to the first network device based on the broadcast session request message.

[00161] In a possible design, in a unicast scenario, the first network device sends a fifth indication to the second network device, where the fifth indication indicates the non-configuration of a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with the first core network device. The third transmission channel can be a tunnel of Petition 870250107448, dated 11 / 24 / 2025, page 34 / 64 28 / 49 NG-U. The second network device can also send a fourth indication to the first core network device, where the fourth indication indicates not to configure the third transmission channel for the first broadcast session, and the third transmission channel is the channel to transmit the first broadcast service with the first core network device. In the previous design, the first core network device can be instructed not to configure the third transmission channel, for example, the NG-U tunnel.

[00162] For more details, see Modality 3 below.

[00163] Scenario 4: The first network device is a DU and the second network device is a CU-CP.

[00164] In addition to the previous descriptions for scenario 3, after the first network device sends the first indication information to the second network device, the second network device sends the sixth indication information to a third network device, where the sixth indication information tells the third network device to release the first transmission channel. In the previous design, the third network device can release, based on the sixth indication information, an address from the first transmission channel allocated to the first broadcast session, for example, an F1-U TNL CU, so that network resources can be saved.

[00165] For more details, see Modality 3 below. Mode 1:

[00166] As shown in FIG. 7, in a scenario shown in Mode 1 below, a gNB is split into a gNB-CU and a gNB-DU. A PLMN 1 and a PLMN 2 share the gNB-CU and the gNB-DU. A 5GC from PLMN 1 initiated a broadcast session setup procedure for PLMN 1, and a broadcast session configured for PLMN 1 is a session for a broadcast service x. Then, a 5GC from PLMN 2 also initiates a Petition 870250107448, dated 11 / 24 / 2025, page 35 / 64 29 / 49 broadcast session setup procedure, and a broadcast session configured for PLMN 2 is a session for broadcast service x. The 5GC of PLMN 1 and the 5GC of PLMN 2 are independent of each other. The fact that the 5GC of PLMN 1 starts the broadcast session setup procedure before the 5GC of PLMN 2 is just an example and is not intended to limit this request.

[00167] The broadcast session setup procedure initiated by PLMN 2's 5GC may specifically include the following steps.

[00168] S701: The 5GC sends a broadcast session configuration request message to the gNB-CU, where the message includes a TMGI 2 and a broadcast service identifier X, and the TMGI 2 includes a PLMN 2 identifier.

[00169] S702: gNB-CU determines that both the broadcast session configured for PLMN 2 and the broadcast session configured for PLMN 1 belong to the X broadcast service sessions.

[00170] S703: gNB-CU sends a broadcast context configuration request to gNB-DU.

[00171] The message includes initial information, and the initial information indicates not to configure an F1-U tunnel for the PLMN 2 broadcast session.

[00172] Specifically, the message includes F1-U tunnel address information (BC Carrier Context F1-U TNL Information in CU) from gNB-CU, this information being optional. When gNB-CU determines to send the initial indication information, gNB-CU may ignore it, i.e., the transmission context configuration request does not include this information.

[00173] S704: gNB-DU sends a broadcast context configuration response to gNB-CU.

[00174] For example, the message includes F1-U tunnel address information (Context F1-U TNL Information) Petition 870250107448, dated 11 / 24 / 2025, p. 36 / 64 30 / 49 For BC holders in DU) of gNB-DU, this information is mandatory and may contain a null or invalid value.

[00175] S705: DU provides broadcast configuration information for UE.

[00176] S706: The gNB-CU sends a broadcast session configuration response message to the 5GC.

[00177] For example, in a unicast scenario, the message may include a fourth piece of information, and the fourth piece of information indicates not to configure an NG-U tunnel for the PLMN 2 broadcast session. The fourth piece of information is optional information. Option 2:

[00178] As shown in FIG. 8, in a scenario shown in Mode 1, a gNB is divided into a gNB-CU and a gNB-DU, and the gNB-CU is divided into a gNB-CU-CP and a gNB-CU-UP. A PLMN 1 and a PLMN 2 share the gNB-CU-CP, the gNB-CU-UP, and the gNB-DU. A 5GC of PLMN 1 initiated a broadcast session setup procedure for PLMN 1, and a broadcast session configured for PLMN 1 is a session for broadcast service x. Then, a 5GC of PLMN 2 also initiates a broadcast session setup procedure, and a broadcast session configured for PLMN 2 is a session for broadcast service x. The 5GC of PLMN 1 and the 5GC of PLMN 2 are independent of each other. The fact that PLMN 1's 5GC initiates the broadcast session setup procedure before PLMN 2's 5GC is just one example and is not intended to limit this request.

[00179] The broadcast session setup procedure initiated by PLMN 2's 5GC may specifically include the following steps.

[00180] S801: The 5GC sends a broadcast session configuration request message to gNB-CU-CP, where the message includes a TMGI 2 and a broadcast service identifier X, and the TMGI 2 includes a PLMN 2 identifier. Petition 870250107448, dated 11 / 24 / 2025, page 37 / 64 31 / 49

[00181] S802: gNB-CU-CP determines that both the broadcast session configured for PLMN 2 and the broadcast session configured for PLMN 1 belong to the X broadcast service sessions.

[00182] S803: gNB-CU-CP sends a broadcast carrier context configuration request message to gNB-CU-UP.

[00183] The message includes second and / or third informational information. The second piece of information tells gNB-CU-UP not to configure an F1-U tunnel for the PLMN 2 broadcast session, and the third piece of information tells gNB-CU-UP not to configure an NG-U tunnel for the PLMN 2 broadcast session. The second and third pieces of information are optional.

[00184] S804: gNB-CU-UP sends a broadcast carrier context configuration response to gNB-CU-CP.

[00185] gNB-CU-UP may not allocate an F1-U TNL CU for the PLMN 2 broadcast session based on the second indication information. Therefore, the F1-U tunnel address information, including the gNB-CU, is mandatory information and may contain a null or invalid value.

[00186] Furthermore, in a unicast scenario, gNB-CU-UP may not allocate an NG-U GTP DL TEID for the PLMN 2 broadcast session based on the third indication information. Therefore, the message carries NG-U tunnel address information, and the NG-U tunnel address information is null or an invalid value. In a multicast scenario, gNB-CU-UP does not join a multicast group.

[00187] S805: gNB-CU-CP sends a broadcast context configuration request to gNB-DU.

[00188] The message includes initial indication information, and the initial indication information indicates not configuring a Petition 870250107448, dated 11 / 24 / 2025, page 38 / 64 32 / 49 F1-U tunnel for the PLMN 2 broadcast session.

[00189] Specifically, the message includes gNB-CU's F1-U tunnel address information, and this information is optional. When gNB-CU-CP determines to send the first indication information, gNB-CU-CP may ignore the information, i.e., the transmission context configuration request does not include this information.

[00190] S806: gNB-DU sends a broadcast context configuration response to gNB-CU-CP.

[00191] For example, the message includes gNB-DU F1-U tunnel address information, this information is mandatory and may contain a null or invalid value.

[00192] S807: gNB-CU-CP sends a broadcast carrier context modification request to gNB-CUUP.

[00193] S808: gNB-CU-UP sends a broadcast carrier context modification response to gNB-CU-CP.

[00194] S809: The DU provides broadcast configuration information for the UE.

[00195] S810: gNB-CU-CP sends a transmission session configuration response message to 5GC.

[00196] For example, in a unicast scenario, the message may include a fourth piece of information, and the fourth piece of information indicates not to configure an NG-U tunnel for the PLMN 2 broadcast session. The fourth piece of information is optional information. Mode 3:

[00197] As shown in FIG. 9, in a scenario shown in Mode 1, a gNB is divided into a gNB-CU and a gNB-DU, and the gNB-CU is divided into a gNB-CU-CP and a gNB-CU-UP. A PLMN and a PLMN 2 share gNB-DU, or PLMN 1 and PLMN 2 share gNB-CU-CP, gNB-CU-UP, and gNB-DU. However, the gNB-DU determines whether the transmission services are the same. Petition 870250107448, dated 11 / 24 / 2025, pp. 39 / 64 33 / 49 To be more specific, gNB-DU determines that both a broadcast session configured for PLMN 2 and a broadcast session configured for PLMN 1 belong to sessions of the same broadcast service. A 5GC of PLMN 1 initiated a broadcast session configuration procedure for PLMN 1, and the broadcast session configured for PLMN 1 is a service session for broadcast service x. Then, a 5GC of PLMN 2 also initiated a broadcast session configuration procedure, and the broadcast session configured for PLMN 2 is a session for broadcast service x. The 5GC of PLMN 1 and the 5GC of PLMN 2 are independent of each other. The fact that the 5GC of PLMN 1 initiated the broadcast session configuration procedure before the 5GC of PLMN 2 is only an example and is not intended to limit this request.

[00198] The broadcast session setup procedure initiated by PLMN 2's 5GC may specifically include the following steps.

[00199] S901: The 5GC sends a broadcast session configuration request message to gNB-CU-CP, where the message includes a TMGI 2 and a broadcast service identifier X, and the TMGI 2 includes a PLMN 2 identifier.

[00200] S902: gNB-CU-CP sends a broadcast carrier context configuration request message to gNB-CU-UP.

[00201] S903: gNB-CU-UP sends a broadcast carrier context configuration response to gNB-CU-CP.

[00202] S904: gNB-CU-CP sends a broadcast context configuration request to gNB-DU.

[00203] The message includes a TMGI 2 and an X service identifier.

[00204] S905: gNB-DU determines that both the broadcast session configured for PLMN 2 and the broadcast session configured for PLMN 1 belong to the service sessions of Petition 870250107448, dated 11 / 24 / 2025, page 40 / 64 34 / 49 broadcast X.

[00205] S906: gNB-DU sends a broadcast context configuration response to gNB-CU-CP.

[00206] For example, the message includes initial indication information, and the initial indication information indicates not to configure an F1-U tunnel for the PLMN 2 broadcast session.

[00207] In addition, the message includes gNB-DU F1-U tunnel address information; this information is mandatory and may contain a null or invalid value.

[00208] Optionally, the message may include fifth indication information, and the fifth indication information indicates not to configure an NG-U tunnel for the PLMN 2 broadcast session.

[00209] S907: gNB-CU-CP sends a broadcast carrier context modification request to gNB-CUUP.

[00210] Optionally, the message includes the sixth indication piece of information, and the sixth indication piece of information tells gNBCU-UP to clear the F1-U tunnel.

[00211] S908: gNB-CU-UP sends a broadcast carrier context modification response to gNB-CU-CP.

[00212] For example, gNB-CU-UP can release the F1U tunnel based on the sixth indication information.

[00213] S909: The DU provides broadcast configuration information for the UE.

[00214] S910: gNB-CU-CP sends a broadcast session configuration response message to 5GC.

[00215] For example, the message may include a fourth piece of information, and the fourth piece of information indicates not to configure an NG-U tunnel for the PLMN 2 broadcast session. The fourth piece of information is optional.

[00216] To save network resources in a scenario where Petition 870250107448, dated 11 / 24 / 2025, page 41 / 64 35 / 49 where multiple PLMNs configure sessions for the same broadcast service, this request provides a communication method. The method includes the following steps.

[00217] As shown in FIG. 10, the method includes the following steps.

[00218] 1001: A first network device receives a request message, where the request message is used to request the creation of a first broadcast session for a first PLMN, and the first broadcast session is a session of a first broadcast service.

[00219] The first network device is a CU-CP and the second network device is a CU-UP; or the first network device is a DU and the second network device is a CU-CP.

[00220] 1002: The first network device determines, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, where the second broadcast session is a session created for a second PLMN.

[00221] The first network device provides services to the first PLMN and the second PLMN. For 1001 and 1002, see 601 and 602. Details are not described again in this document.

[00222] 1003: The first network device sends indication 1 information to the second network device, where indication 1 information indicates not to transmit data from the first broadcast service from the first PLMN or not to transmit data from the first broadcast service from the second PLMN.

[00223] Before the first network device sends indication information 1 to the second network device, the first network device determines indication information 1 based on the session information from the first broadcast session and the session information from the second broadcast session. Petition 870250107448, dated 11 / 24 / 2025, page 42 / 64 36 / 49

[00224] The session information for the first broadcast session includes at least a number of neighboring cells corresponding to the first broadcast session, a quality of service parameter corresponding to the first broadcast session, and a number of terminal devices corresponding to the first broadcast session; and the session information for the second broadcast session includes at least a number of neighboring cells corresponding to the second broadcast session, a quality of service parameter corresponding to the second broadcast session, and a number of terminal devices corresponding to the second broadcast session.

[00225] A broadcast session with a larger number of neighboring cells, a better quality of service parameter, and / or a larger number of terminal devices is selected to transmit the data of the first broadcast service, and another broadcast session is not used to transmit the data of the first broadcast service.

[00226] It should be noted that, in the modes shown in FIG. 10, the first transmission session is created for the first PLMN, the second transmission session is created for the second PLMN, and there is an F1-U tunnel corresponding to the first transmission session and an F1-U tunnel corresponding to the second transmission session. To avoid redundancy caused by sending data from the same first broadcast service in all F1-U tunnels, the indication information 1 indicates that the data from the first broadcast service must be transmitted from the first PLMN or the data from the first broadcast service must be transmitted from the second PLMN. That is, data can be sent through one of the F1-U tunnels, and data transmission is prohibited in other F1-U tunnels, so that redundant data transmission from the first broadcast service can be avoided.

[00227] Furthermore, in a possible project, when the Petition 870250107448, dated 11 / 24 / 2025, page 43 / 64 37 / 49 indication information 1 indicates not transmitting the first broadcast service data from the first PLMN, the first network device sends indication information 2 to the second network device, where indication information 2 indicates resuming the transmission of the first broadcast service data from the first PLMN; or when indication information 1 indicates not transmitting the first broadcast service data from the second PLMN, the first network device sends indication information 3 to the second network device, where indication information 3 indicates resuming the transmission of the first broadcast service data from the second PLMN.

[00228] In the previous project, when a problem occurs in the broadcast session for transmitting the first broadcast service, a broadcast session from another PLMN can be used in time to transmit data, so that the delay in data transmission is reduced.

[00229] An MBS Neighbour Cell List (mbsNeighbourCellList) indicates a list of neighboring cells of an ongoing broadcast session provided by an MRB in a current cell, a list of neighboring cells that can provide a broadcast session, a list of neighboring cells that have already provided a broadcast session, or something similar. For example, an MBS Neighbour Cell List of a broadcast session 1 provided by cell 1 is (cellA, cellB, cellC, cellD). The MBS Neighbour Cell List is determined when an F1 interface is configured or updated. Therefore, in a scenario where a CU and a DU are shared (see the previous architecture where the CU and DU are shared), an MBS Neighbour Cell List of the CU is the same as an MBS Neighbour Cell List of the DU.

[00230] The MBS neighbor list is generally used in conjunction with an mtch-NeighbourCell neighbor. A Petition 870250107448, dated 11 / 24 / 2025, page 44 / 64 38 / 49 neighboring cell mtch indicates a neighboring cell that provides a broadcast service on a multicast traffic channel (MTCH). If the broadcast service is provided on an MTCH from a cell in the MBS neighboring cell list, the first bit in the mtch neighboring cell indication information is set to 1; otherwise, the first bit is set to 0. All or some of the cells in MBS's neighboring cell list are mtch neighboring cells.

[00231] In a scenario where only the DU is shared, the operators' CUs send MBS neighbor cell lists and mtch neighbor cell indication information from the CUs to the shared DU, and the mtch neighbor cell indication information indicates a list of neighbor cells that are currently providing a broadcast service. The MBS neighbor cell lists and mtch neighbor cell indication information received by the shared DU may be different.

[00232] Therefore, the shared DU needs to perform processing with reference to the neighboring cell lists of the MBS and the mtch neighboring cell indication information from the broadcast sessions.

[00233] The following solution applies to a scenario where only one DU is shared, the shared DU provides services to a first PLMN and a second PLMN, and the first PLMN and the second PLMN separately configure broadcast sessions for the same broadcast service. The maximum number of cells that can be included in the MBS neighboring cell list is a predefined value. For example, the maximum number of cells that can be included in the MBS neighboring cell list is 8. This is not limited to this request.

[00234] In a possible implementation 1, when all cells of the first PLMN and the second PLMN in the shared DU are shared cells, even if the orders of the neighboring cell lists of MBS planned for +PLMNs are different, Petition 870250107448, dated 11 / 24 / 2025, page 45 / 64 39 / 49 the names can also be different. Since all these cells are shared, the shared DU can use a list of neighboring MBS cells from the first PLMN or a list of neighboring MBS cells from the second PLMN, and does not need to regenerate a list of neighboring MBS cells.

[00235] In addition, the shared DU can also determine the use of a neighboring mtch cell of the first PLMN or a neighboring mtch cell of the second PLMN.

[00236] In a possible implementation 2, when some cells of the first PLMN and the second PLMN in the shared DU are shared cells, the shared gNB-DU transmits that a list of neighboring MBS cells needs to be regenerated. A specific generation method is not limited in this application.

[00237] Descriptions are given below with reference to specific examples.

[00238] Assuming that in the current shared DU, an operator A has configured a broadcast session 1, the shared DU receives a broadcast context configuration request sent by a CU-B from an operator B, where the broadcast context configuration request is used to request the configuration of a broadcast session 2, and the broadcast context configuration request may include mtch neighboring cell indication information.

[00239] Specifically, the following cases may occur based on whether each operator has a non-shared cell:

[00240] (1) All cells of operator A and operator B in the shared DU are shared cells, and this corresponds to possible implementation 1.

[00241] An area of ​​a broadcast session is determined by an application function (AF). Therefore, if all cells of operator A and operator B in the shared DU are shared cells, when the shared DU receives the context configuration request Petition 870250107448, dated 11 / 24 / 2025, pp. 46 / 64 40 / 49 broadcast sent by CU-B, if a broadcast service corresponding to the broadcast session is the same as a broadcast service corresponding to the broadcast session of operator A, and the shared cells are also the same, the shared DU may determine the use of a list of neighboring MBS cells from operator A or a list of neighboring MBS cells from operator B.

[00242] In addition, the shared DU may also determine the use of a neighboring mtch cell of operator A or a neighboring mtch cell of operator B. For example, when all shared cells transmit broadcast service data, or when a cell indicated by neighboring mtch cell indication information of operator A is the same as a cell indicated by neighboring mtch cell indication information of operator B, the shared DU may also determine the use of the neighboring mtch cell of operator A or the neighboring mtch cell of operator B. Furthermore, the shared DU may also determine, according to another policy, whether to use the neighboring mtch cell of operator A or the neighboring mtch cell of operator B. This is not limited in this order.

[00243] (2) Operator A and operator B have a non-shared cell in the shared DU, and this corresponds to possible implementation 2.

[00244] For example, a neighbor cell list (MBS neighbor cell list) sent by a CU-A to the shared gNB-DU is (cell1, cell2, cell3), and the neighbor cell indication information can be represented as (1, 1, 1). A neighbor cell list (MBS neighbor cell list) sent by a CU-B to the shared gNB-DU is (cell2, cell3, cell4), and the neighbor cell indication information can be represented as (1, 1, 1). The two pieces of neighbor cell indication information presented here are merely examples. Petition 870250107448, dated 11 / 24 / 2025, page 47 / 64 41 / 49

[00245] Although the content of the neighboring cells of the two operators is the same, cell 1 of operator A and cell 4 of operator B are not shared cells. Since the shared DU can only broadcast a list of neighboring MBS cells, if the list of neighboring MBS cells sent by CU-A is used, a broadcast service from CU-A may be correctly indicated, but a broadcast service from CU-B may be incorrectly indicated, since the broadcast service from CU-B does not exist in cell 1. Therefore, the gNB-DU needs to regenerate a new list of neighboring MBS cells. For example, the new list of neighboring MBS cells is (cell 1, cell 2, cell 4).

[00246] One advantage of the previous method is that, although a broadcast service from cell 3 is not indicated, it is guaranteed that no error will be indicated in the existing MBS neighboring cell list. For the MBS neighboring cell list that is not changed, an indication error may occur in the existing neighboring cell list.

[00247] It should also be understood that the MBS neighboring cell list mainly includes a cell name or a physical cell identifier, and cell 1, cell 2, cell 3 and cell 4 have the same understanding for operator A and operator B.

[00248] In a possible project, gNB-DU could determine if a cell name (or a physical cell identifier) ​​of each cell in the new MBS neighboring cell list has the same cell name (or the same physical cell identifier) ​​in the MBS neighboring cell list of operator A. If the cell name (or the physical cell identifier) ​​of each cell in the new MBS neighboring cell list has the same cell name (or the same physical cell identifier) ​​in the MBS neighboring cell list of operator A, an index corresponding to the cell in the mtch neighboring cell indication information of Petition 870250107448, dated 11 / 24 / 2025, pp. 48 / 64 42 / 49 operator A is 1; otherwise, an index corresponding to the cell in the neighboring cell indication information mtch of operator A is 0. For example, when the new MBS neighboring cell list is (cell1, cell2, cell4), cell1 and cell2 also exist in the MBS neighboring cell list (cell1, cell2, cell3) of operator A. In this case, an index corresponding to cell1 in the neighboring cell indication information mtch of operator A is set to 1, and an index corresponding to cell2 is set to 1. If the MBS neighboring cell list (cell1, cell2, and cell3) of operator A does not include cell4, an index of cell4 in the neighboring cell indication information mtch of operator A is set to 0. Therefore, the neighboring cell indication information mtch of operator A can be represented as (1, 1, 0), and similarly, the neighboring cell indication information mtch of operator B can be represented as (0, 1, 1).

[00249] In another possible design, gNB-DU may not perform the previous determination process and directly set an index corresponding to cell1 in the mtch neighboring cell indication information as 1. In this case, the mtch neighboring cell indication information of operator A may be represented as (1, 1, 1) and, similarly, the mtch neighboring cell indication information of operator B may be represented as (1, 1, 1).

[00250] In addition, for operator A, the DU can send a TMGI 1, the new MBS neighboring cell list and the mtch neighboring cell indication information of operator A to the UE using broadcast session 1, where TMGI 1 includes a PLMN ID of operator A. The mtch neighboring cell indication information of operator A indicates a cell that is actually being transmitted in the new MBS neighboring cell list of operator A.

[00251] For operator B, the DU can send a TMGI 2, the new list of neighboring MBS cells and the indication information. Petition 870250107448, dated 11 / 24 / 2025, pp. 49 / 64 43 / 49 of neighboring cells from operator B to the UE using broadcast session 2, where TMGI 2 includes a PLMN ID from operator B. The neighboring cells from operator B indicate a cell that is actually being transmitted in the new MBS neighboring cells list from operator B.

[00252] It should be noted that the newly generated MBS neighboring cell list and the multiple neighboring cell indication information for CU-A and CU-B are merely illustrative and are not intended to limit this request. The shared DU may further determine, in accordance with another policy, the new MBS neighboring cell list and the corresponding mtch neighboring cell indication information separately for different CUs. This is not limited to this request.

[00253] It can be understood that, to implement functions in the preceding embodiments, the devices include corresponding hardware structures and / or software modules to perform the functions. A person skilled in the art should be aware that, in combination with the units and steps of the method in the examples described in the embodiments disclosed in this application, this application can be implemented in a hardware form or a combination of computer hardware and software in this application. The implementation of a function by hardware or by hardware controlled by computer software depends on specific application scenarios and the design constraints of the technical solutions.

[00254] FIG. 11 and FIG. 12 are diagrams of possible communication device structures according to the embodiments of this application. These communication devices can be configured to implement the function of the terminal or base station in the above method embodiments. Therefore, the beneficial effect of the previous method embodiments can also be implemented. In embodiments of this application, the communication device can be the first network device shown in Petition 870250107448, dated 11 / 24 / 2025, pp. 50 / 64 44 / 49 FIG. 1, or it could be a module (e.g., a chip) used in the first network device.

[00255] As shown in FIG. 11, the communication apparatus 1100 includes a processing unit 1110 and a transceiver unit 1120. The communication apparatus 1100 is configured to implement the function of the terminal or base station in the method mode shown in FIG. 6.

[00256] When the communication device 1100 is configured to implement the function of the first network device in the method mode shown in FIG. 6.

[00257] Transceiver unit 1120 is configured to receive a request message, where the request message is used to request the creation of a first broadcast session for a first public land mobile network PLMN, and the first broadcast session is a session of a first broadcast service; processing unit 1110 is configured to determine, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, where the second broadcast session is a session created for a second PLMN; and transceiver unit 1120 is configured to send first indication information to a second network device, where the first indication information indicates not to configure a first transmission channel for the first broadcast session, and the first transmission channel is a channel to transmit the first broadcast service.

[00258] In a possible project, the request message includes a first temporary multicast group identifier and a first broadcast service identifier, and the first temporary multicast group identifier includes a first PLMN identifier.

[00259] In a possible project, before the first session of Petition 870250107448, dated 11 / 24 / 2025, pp. 51 / 64 If broadcast 45 / 49 is created, a second transmission channel is configured for the second broadcast session, and this second transmission channel is used to transmit the first broadcast service.

[00260] In a possible project, the 1120 transceiver unit is configured to: before sending the first indication information to the second network device, send the second indication information to a third network device, where the second indication information tells the third network device not to configure the first transmission channel for the first broadcast session.

[00261] In one possible design, the 1120 transceiver unit is configured to receive first-channel transmission address information from the third network device, where the first-channel transmission address information is null or an invalid value.

[00262] In a possible project, the 1120 transceiver unit is configured to send third indication information to the third network device, where the third indication information indicates to the third network device not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device.

[00263] In one possible design, the 1120 transceiver unit is configured to: in a unicast scenario, receive third-channel transmission address information from the third network device, where the third-channel transmission address information is null or an invalid value.

[00264] In a possible project, the 1120 transceiver unit is configured to send a fourth indication message to the first core network device, where the fourth indication message indicates not to configure the third channel of Petition 870250107448, dated 11 / 24 / 2025, pp. 52 / 64 Channels 46 / 49 are for the first broadcast session, and the third transmission channel is for transmitting the first broadcast service with the first core network device.

[00265] In one possible design, transceiver unit 1120 is configured to receive the request message from the first core network device.

[00266] In a possible project, the 1120 transceiver unit is configured to send a fifth indication to the second network device, where the fifth indication indicates not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel to transmit the first broadcast service with a first core network device.

[00267] In one possible design, transceiver unit 1120 is configured to receive the request message from the second network device.

[00268] For more detailed descriptions of processing unit 1110 and transceiver unit 1120, see the related descriptions in the embodiments of the method shown in FIG. 6.

[00269] As shown in FIG. 12, the communication device 1200 includes a processor 1210 and an interface circuit 1220. The processor 1210 and the interface circuit 1220 are coupled to each other. It can be understood that the interface circuit 1220 can be a transceiver or an input / output interface. Optionally, the communication device 1200 may also include a memory 1230, configured to: store instructions executed by the processor 1210, or store input data required by the processor 1210 to run the instructions, or store data generated after the processor 1210 runs the instructions.

[00270] When the 1200 communication device is configured to implement the method shown in FIG. 12, the Petition 870250107448, dated 11 / 24 / 2025, pp. 53 / 64 Processor 1210 is configured to implement a function of processing unit 1110, and interface circuit 1220 is configured to implement a function of transceiver unit 1120.

[00271] It may be understood that the processor in the embodiments of this application may be a Central Processing Unit (CPU), or it may be another general-purpose processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general-purpose processor may be a microprocessor, or it may be any conventional processor or similar.

[00272] The method steps in embodiments of this application may be implemented in hardware or in software instructions that may be performed by the processor. The software instructions may include a corresponding software module. The software module may be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, a register, a hard disk, a removable hard disk, a CD-ROM, or any other form of storage medium well known in the art. For example, a storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium may alternatively be a component of the processor.The processor and storage medium can be housed in an ASIC. Additionally, the ASIC can be located... Petition 870250107448, dated 11 / 24 / 2025, pages 54 / 64 48 / 49 in a base station or terminal. Alternatively, the processor and storage media may exist in the base station or terminal as discrete components.

[00273] All or some of the foregoing embodiments may be implemented by software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or some of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, the procedures or functions in the embodiments of this application are executed wholly or partially. The computer may be a general-purpose computer, a dedicated computer, a computer network, a network device, user equipment, or other programmable apparatus.Computer programs or instructions can be stored on a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer programs or instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless connection. A computer-readable storage medium can be any usable medium that can be accessed by a computer, or a data storage device, for example, a server or data center, integrating one or more usable media. The usable medium can be a magnetic medium, for example, a floppy disk, a hard disk, or magnetic tape; or it can be an optical medium, for example, a digital video disc; or it can be a semiconductor medium, for example, a solid-state drive.Computer-readable storage media can be either volatile or non-volatile. Petition 870250107448, dated 11 / 24 / 2025, pages 55 / 64 49 / 49 can include two types of storage media: a volatile storage medium and a non-volatile storage medium.

[00274] In various embodiments of this application, unless otherwise specified or if there is a logical conflict, terms and / or descriptions in different embodiments are consistent and can be mutually referenced, and technical features in different embodiments can be combined based on an internal logical relationship between them, to form a new embodiment.

[00275] It may be understood that various numbers in the modalities of this application are merely used for differentiation to facilitate description and are not used to limit the scope of the modalities of this application. The sequence numbers of the processes above do not represent an execution sequence, and the execution sequence of the processes must be determined based on the functions and internal logic of the processes. Petition 870250107448, dated 11 / 24 / 2025, pp. 56 / 64

Claims

1 / 7 CLAIMS 1. A communication method, characterized in that the method comprises: receiving, by a first network device, a request message, wherein the request message is used to request the creation of a first broadcast session for a first public terrestrial mobile network (PLMN), and the first broadcast session is a session of a first broadcast service; determining, by the first network device based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, wherein the second broadcast session is a session created for a second PLMN;and send, via the first network device, initial indication information to a second network device, wherein the initial indication information indicates not to configure a first transmission channel for the first broadcast session, and the first transmission channel is a channel for transmitting the first broadcast service.

2. A method according to claim 1, characterized in that the request message comprises a first temporary multicast group identifier and a first broadcast service identifier, and the first temporary multicast group identifier comprises a first PLMN identifier.

3. A method according to claim 1 or 2, characterized in that before the first broadcast session is created, there is a second transmission channel configured for the second broadcast session, and the second transmission channel is a channel for transmitting the first broadcast service.

4. Method, according to any one of claims 1 to 3, characterized in that before sending, by the first network device, the first indication information to the second network device, the method further comprises: sending, by the first network device, a second indication information to a third network device, wherein the second indication information instructs the third network device not to configure the first transmission channel for the first broadcast session.

5. Method according to claim 4, characterized in that it further comprises: receiving, by the first network device, address information of the first transmission channel from the third network device, wherein the address information of the first transmission channel is null or an invalid value.

6. A method according to any one of claims 1 to 5, characterized in that it further comprises: sending, by the first network device, a third indication information to the third network device, wherein the third indication information indicates to the third network device not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel for transmitting the first broadcast service with a first core network device.

7. A method according to claim 6, characterized in that it further comprises: in a unicast scenario, receiving, by the first network device, address information of the third transmission channel from the third network device, wherein the address information of the third transmission channel is null or an invalid value.

8. Method, according to claim 6, characterized in that it further comprises: in a multicast scenario, skipping, by the third network device, joining a multicast group.

9. A method according to any one of claims 1 to 7, characterized in that it further comprises: sending, by the first network device, a fourth indication message to the first core network device, wherein the fourth indication message indicates not to configure the third transmission channel for the first broadcast session, and the third transmission channel is the channel for transmitting the first broadcast service with the first core network device.

10. A method, according to any one of claims 1 to 9, characterized in that receiving, by the first network device, the request message comprises: receiving, by the first network device, the request message from the first core network device.

11. A method according to any one of claims 1 to 10, characterized in that the first network device is a central unit (CU) or a central unit control plane (CU-CP), and the second network device is a distributed unit (DU).

12. A method according to any one of claims 1 to 3, characterized in that it further comprises: sending, by the first network device, a fifth indication piece of information to the second network device, wherein the fifth indication piece of information indicates not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel for transmitting the first broadcast service with a first core network device.

13. A method, according to any one of claims 1 to 3 and 12, characterized in that after the first network device sends the first indication information to the second network device, the method further comprises: sending, by the second network device, the sixth indication information to a third network device, wherein the sixth indication information indicates to the third network device to release the first transmission channel.

14. A method according to any one of claims 1 to 3, 12 and 13, characterized in that the receipt, by the first network device, of the request message comprises: receiving, by the first network device, the request message from the second network device.

15. Method, according to any one of claims 1 to 3, 10, 11 and 12, characterized in that the first network device is a DU, and the second network device is a CU-CP or a CU.

16. A method, according to any one of claims 1 to 15, characterized in that the first network device provides services to the first PLMN and the second PLMN.

17. Communication apparatus, characterized in that the apparatus is a first network device or a chip in the first network device, and the apparatus comprises a transceiver unit and a processing unit, wherein the transceiver unit is configured to receive a request message, wherein the request message is used to request the creation of a first broadcast session for a first public terrestrial mobile network (PLMN), and the first broadcast session is a session of a first broadcast service; the processing unit is configured to determine, based on the request message, that the first broadcast session and a second broadcast session belong to sessions of the first broadcast service, wherein the second broadcast session is a session created for a second PLMN; and Petition 870250090890, dated 06 / 10 / 2025, p.15 / 19 5 / 7 the transceiver unit is configured to send first indication information to a second network device, where the first indication information indicates not to configure a first transmission channel for the first broadcast session, and the first transmission channel is a channel to transmit the first broadcast service.

18. Device according to claim 17, characterized in that the request message comprises a first temporary multicast group identifier and a first broadcast service identifier, and the first temporary multicast group identifier comprises a first PLMN identifier.

19. Apparatus, according to claim 17 or 18, characterized in that before the first broadcast session is created, there is a second transmission channel configured for the second broadcast session, and the second transmission channel is a channel for transmitting the first broadcast service.

20. Apparatus, according to any one of claims 17 to 19, characterized in that the transceiver unit is configured to: before sending the first indication information to the second network device, send a second indication information to a third network device, wherein the second indication information indicates to the third network device not to configure the first transmission channel for the first broadcast session.

21. Apparatus, according to claim 20, characterized in that the transceiver unit is configured to receive address information for the first transmission channel from the third network device, wherein the address information for the first transmission channel is null or an invalid value.

22. Apparatus, according to any of the claims in Petition 870250090890, dated 06 / 10 / 2025, pp. 16 / 19 6 / 7 17 to 21, characterized in that the transceiver unit is configured to send third indication information to the third network device, wherein the third indication information indicates to the third network device not to configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel for transmitting the first broadcast service with a first core network device.

23. Device according to claim 22, characterized in that the transceiver unit is configured to: in a unicast scenario, receive address information from the third transmission channel from the third network device, where the address information from the third transmission channel is null or an invalid value.

24. Apparatus, according to any one of claims 17 to 23, characterized in that the transceiver unit is configured to send fourth indication information to the first core network device, wherein the fourth indication information indicates not configuring the third transmission channel for the first broadcast session, and the third transmission channel is the channel for transmitting the first broadcast service with the first core network device.

25. Device according to any one of claims 17 to 24, characterized in that the transceiver unit is configured to: upon receiving the request message, receive the request message from the first core network device.

26. Apparatus, according to any one of claims 17 to 19, characterized in that the transceiver unit is configured to send a fifth indication information to the second network device, wherein the fifth indication information indicates that it does not configure a third transmission channel for the first broadcast session, and the third transmission channel is a channel for transmitting the first broadcast service with a first core network device.

27. Device according to any one of claims 17 to 19 and 26, characterized in that the transceiver unit is configured to: upon receiving the request message, receive the request message from the second network device.

28. Chip, characterized in that the chip is coupled to a memory and the chip reads a computer program stored in the memory to perform the method as defined in any one of claims 1 to 16.

29. Computer-readable storage medium, characterized in that the storage medium stores a computer program or instructions; and when the computer program or instructions are executed by a communication device, the method as defined in any one of claims 1 to 16 is implemented.

30. A communication apparatus, comprising a processor and an interface circuit, characterized in that the interface circuit is configured to receive a signal from another communication apparatus and transmit the signal to the processor, or to send a signal from the processor to another communication apparatus, and the processor is configured to implement the method as defined in any one of claims 1 to 16 using a logic circuit or by executing code instructions. Petition 870250090890, dated 06 / 10 / 2025, pp. 18 / 19

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