CN118175510A

CN118175510A - Communication method and communication device

Info

Publication number: CN118175510A
Application number: CN202211572149.8A
Authority: CN
Inventors: 李濛; 张海森; 李秉肇; 王燕
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-12-08
Filing date: 2022-12-08
Publication date: 2024-06-11
Also published as: WO2024120299A1; WO2024120299A9

Abstract

The application provides a communication method and a communication device, wherein a first multicast/broadcast session management network element receives identification information of a first multicast/broadcast service from an application server; the first multicast/broadcast session management network element sends first indication information to the corresponding first multicast/broadcast user plane function network element, where the first indication information is used to instruct the first multicast/broadcast user plane function network element to increment a first serial number corresponding to data of the first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data. By the method, the multicast/broadcast session management network element in the MOCN can instruct the corresponding multicast/broadcast user plane function network element to carry out special configuration, so that the multicast/broadcast user plane function network element in the MOCN can synchronously update the serial numbers of the data of the same multicast/broadcast service, and the serial numbers of the data of the same multicast/broadcast service can be synchronously realized in different PLMNs.

Description

Communication method and communication device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and a communication device.

Background

The current standard protocols are discussing how different operator access network devices share access network devices, mainly focusing on network optimization schemes for multi-operator core network (MOCN) shared access network devices. The network optimization scheme can enable the access network equipment to identify the same service which is aimed at by different operators when the request of establishing the broadcast session is made, so that further, the resources of the air interface can be reused (namely, the sessions of the same service and different operators use the same air interface resources), and further, the air interface transmission efficiency is improved.

In a network optimization scheme of a MOCN shared access network device, it is assumed that the MOCN scenario comprises at least two public land mobile networks (publiclandmobilenetwork, PLMNs) and an access network device that can access two different PLMNs, e.g., PLMN a and PLMN b. Further, taking multicast service as an example, let PLMN a use MB-UPF a as an anchor point for multicast session x, and PLMN b use MB-UPF b as an anchor point for multicast session y, both multicast sessions x and y being used to transport the multicast service. The MB-UPF a and the MB-UPF b may generate different sequence numbers for the same multicast service data, so that when the same access network device accessing to PLMN a and PLMN b receives the same multicast service data from PLMN a and PLMN b, the sequence numbers corresponding to the same multicast service data are different, and thus the access network device is caused to confuse the cognition of the sequence numbers of the same multicast service data, and further, the continuity of the multicast service is affected. Therefore, how to guarantee the continuity of multicast service in MOCN scenario is a problem to be solved.

Disclosure of Invention

The application provides a communication method and a communication device, which can realize the synchronization of serial numbers of data of the same multicast/broadcast service in different PLMNs in MOCN scenes, realize the synchronization of data transmission and further ensure the service continuity.

In a first aspect, the present application provides a first communication method, where the method is performed by a multicast/broadcast session management network element, or may be performed by a component (such as a processor, a chip, or a system-on-a-chip) of the multicast/broadcast session management network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the multicast/broadcast session management network element. For example by a first multicast/broadcast session management network element in the multi-operator network. Wherein the first multicast/broadcast session management network element receives a first session establishment request message from the application server, the first session establishment request message including identification information of the first multicast/broadcast service; the first multicast/broadcast session management network element sends first indication information to the first multicast/broadcast user plane function network element according to the first session establishment request message, wherein the first indication information is used for indicating the first multicast/broadcast user plane function network element to increment a first serial number corresponding to data of a first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data; wherein the first multicast/broadcast session management network element and the first multicast/broadcast user plane function network element are located in a first public land mobile network PLMN of a multi-operator core network MOCN.

In the method, the first multicast/broadcast session management network element in the MOCN may instruct the corresponding first multicast/broadcast user plane function network element to perform special configuration, for example, instruct the first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data of the first multicast/broadcast service when the data is received (for example, add 1 to the first sequence number). Therefore, the first multicast/broadcast user plane function network element synchronously updates the sequence numbers of the data of the same multicast/broadcast service according to the indication of the first multicast/broadcast session management network element, and is beneficial to realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation, the first session establishment request message further includes an identification of the first PLMN; the first sequence number is used for an access network device in the MOCN to identify data from a first multicast/broadcast service of a first PLMN.

In the method, the first sequence number can be identified by different access network devices (belonging to the same PLMN or different PLMNs) in the MOCN; and the first sequence numbers of the data identified by different access network devices are the same for the data of the first multicast/broadcast service, thereby facilitating data synchronization.

In a possible implementation, the first session establishment request message further includes a type of the multicast/broadcast service. When the type of the first multicast/broadcast service is a multicast service, the first multicast/broadcast session management network element sends first indication information to the first multicast/broadcast user plane function network element.

In the method, when the type of the multicast/broadcast service is a multicast service, a scene that the sequence numbers cannot be aligned exists (the broadcast service does not identify specific access network equipment and terminal equipment, so that the problem that the sequence numbers cannot be aligned does not exist). If the first session establishment request message includes multicast service, the first multicast/broadcast session management network element sends first indication information to the first multicast/broadcast user plane function network element, so that the first multicast/broadcast user plane function network element synchronously updates the sequence number of the data of the same multicast/broadcast service according to the indication of the first multicast/broadcast session management network element, which is beneficial to realizing synchronization of the sequence number of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the first session establishment request message further includes network sharing identification information; the network share identification information is used to indicate that the first multicast/broadcast service is shared in a temporary multicast group identification, TMGI, list of a second PLMN of the MOCN, the second PLMN being different from the first PLMN. The first multicast/broadcast session management network element sends first indication information to the first multicast/broadcast user plane function network element according to the network sharing identification information.

In this method, when the first multicast/broadcast service is shared in the TMGI list of the other PLMNs of the MOCN, it means that the first multicast/broadcast service may be sent to different access network devices (belonging to the same PLMN or different PLMNs) in the MOCN. The first multicast/broadcast session management network element sends the first indication information to the first multicast/broadcast user plane function network element, so that the first multicast/broadcast user plane function network element synchronously updates the serial numbers of the data of the same multicast/broadcast service according to the indication of the first multicast/broadcast session management network element, thereby being beneficial to realizing the synchronization of the serial numbers of the data of the same multicast/broadcast service in different PLMNs.

In a second aspect, the present application provides a second communication method, where the method is performed by a multicast/broadcast session management network element, or may be performed by a component (such as a processor, a chip, or a system-on-a-chip) of the multicast/broadcast session management network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the multicast/broadcast session management network element. For example by a second multicast/broadcast session management network element in the multi-operator network. Wherein the second multicast/broadcast session management network element receives a second session establishment request message from the application server, the second session establishment request message including identification information of the first multicast/broadcast service; the second multicast/broadcast session management network element sends second indication information to the second multicast/broadcast user plane function network element according to the second session establishment request message, wherein the second indication information is used for indicating the second multicast/broadcast user plane function network element to increment a second serial number corresponding to the data of the first multicast/broadcast service when the second multicast/broadcast user plane function network element receives the data; wherein the second multicast/broadcast session management network element and the second multicast/broadcast user plane function network element are located in a second public land mobile network PLMN of the multi-operator core network MOCN.

In the method, the second multicast/broadcast session management network element in the MOCN may instruct the corresponding second multicast/broadcast user plane function network element to perform special configuration, for example, instruct the second multicast/broadcast user plane function network element to increment a second sequence number corresponding to the data when receiving the data of the first multicast/broadcast service (for example, add 1 to the second sequence number). Therefore, the second multicast/broadcast user plane function network element synchronously updates the sequence numbers of the data of the same multicast/broadcast service according to the indication of the second multicast/broadcast session management network element, thereby realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the second session establishment request message further includes an identification of the second PLMN; the second sequence number is used for the access network device in the MOCN to identify data from the first multicast/broadcast service of the second PLMN.

In the method, the second sequence number can be identified by different access network devices (belonging to the same PLMN or different PLMNs) in the MOCN; and the second sequence numbers of the data identified by different access network devices are the same for the data of the first multicast/broadcast service, thereby facilitating data synchronization.

In a possible embodiment, the first indication information includes a start value of a first sequence number, and the second indication information includes a start value of a second sequence number, the start value of the first sequence number being identical to a start value of a second sequence number corresponding to data of the first multicast/broadcast service in the second PLMN of the MOCN.

In this method, it is assumed that the starting values of sequence numbers of data for the same multicast/broadcast service are the same (for example, sequentially increasing from 0), so that sequence number synchronization of data for the same multicast/broadcast service between different PLMNs is facilitated.

In a possible implementation, the second session establishment request message further includes a type of the multicast/broadcast service. When the type of the first multicast/broadcast service is a multicast service, the second multicast/broadcast session management network element sends first indication information to the second multicast/broadcast user plane function network element.

In a possible implementation manner, the second session establishment request message further includes network sharing identification information; the network share identification information is used to indicate that the first multicast/broadcast service is shared in a temporary multicast group identification, TMGI, list of a second PLMN of the MOCN, the second PLMN being different from the first PLMN. The second multicast/broadcast session management network element sends second indication information to the second multicast/broadcast user plane function network element according to the network sharing identification information.

In a third aspect, the present application provides a third communication method, where the method is performed by a multicast/broadcast user plane function network element, or may be performed by a component (such as a processor, a chip, or a system on a chip) of the multicast/broadcast user plane function network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the multicast/broadcast user plane function network element. For example by a first multicast/broadcast user plane function network element in a multi-operator network. The first multicast/broadcast user plane function network element receives first indication information from the multicast/broadcast session management network element, wherein the first indication information is used for indicating the first multicast/broadcast user plane function network element to increment a first serial number corresponding to data of a first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data; the first multicast/broadcast user plane function network element receives data of a first multicast/broadcast service from the application server and increases a first serial number corresponding to the data according to the first indication information.

In the method, the first multicast/broadcast user plane function network element in the MOCN may perform special configuration on the processing of the user plane according to the indication, for example, increment the first sequence number corresponding to the data when the data of the first multicast/broadcast service is received, whether the data is sent to the access network device or not. Therefore, the first multicast/broadcast user plane function network element can synchronously update the sequence numbers of the data of the same multicast/broadcast service, and realize the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the first multicast/broadcast user plane function network element sends the data of the first multicast/broadcast service and the first sequence number corresponding to the data to an access network device in the multi-operator core network MOCN, where the first multicast/broadcast user plane function network element is located in a first PLMN of the MOCN, and the first sequence number is used for identifying the data of the first multicast/broadcast service from the first PLMN by the access network device.

In the method, the first multicast/broadcast user plane network element may send the first sequence number to different access network devices (belonging to the same PLMN or different PLMNs) in the MOCN, and for the data of the first multicast/broadcast service, the first sequence numbers of the data identified by the different access network devices are the same, so as to be beneficial to realizing data synchronization.

In a fourth aspect, the present application provides a fourth communication method, where the method is performed by a multicast/broadcast user plane function network element, or may be performed by a component (such as a processor, a chip, or a system on a chip) of the multicast/broadcast user plane function network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the multicast/broadcast user plane function network element. For example by a second multicast/broadcast user plane function network element in the multi-operator network. The second multicast/broadcast user plane function network element receives second indication information from the second multicast/broadcast session management network element, wherein the second indication information is used for indicating the second multicast/broadcast user plane function network element to increment a second serial number corresponding to data of the first multicast/broadcast service when receiving the data; the second multicast/broadcast user plane function network element receives the data of the first multicast/broadcast service from the application server, and increases the second serial number corresponding to the data according to the second indication information.

In the method, the second multicast/broadcast user plane function network element in the MOCN may perform special configuration on the processing of the user plane according to the indication, for example, increment the second sequence number corresponding to the data of the first multicast/broadcast service when the data is received, whether the data is sent to the access network device or not. Therefore, the second multicast/broadcast user plane function network element can synchronously update the sequence numbers of the data of the same multicast/broadcast service, and realize the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the second multicast/broadcast user plane function network element sends data of the first multicast/broadcast service and a second serial number corresponding to the data to the access network device in the MOCN, where the second multicast/broadcast user plane function network element is located in a second PLMN of the MOCN, and the second serial number is used for the access network device to identify the data of the first multicast/broadcast service from the second PLMN.

In the method, the second multicast/broadcast user plane network element may send the second sequence number to a different access network device (belonging to the same PLMN or a different PLMN) in the MOCN, and for the data of the first multicast/broadcast service, the second sequence number of the data identified by the different access network device is the same and aligned with the first sequence number, thereby facilitating data synchronization.

In a fifth aspect, the present application provides a fifth communication method, where the method is performed by an application server, or may be performed by a component (such as a processor, a chip, or a system-on-chip) of the application server, or may be implemented by a logic module or software that can implement all or part of the functions of the application server. Wherein the application server sends a first session establishment request message to a first multicast/broadcast session management network element located in a first PLMN of the MOCN, the first session establishment request message including identification information of a first multicast/broadcast service; the application server sending a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN, the second session establishment request message including identification information of the first multicast/broadcast service; wherein the first PLMN is different from the second PLMN.

In the method, the application server can send the identification information of the first multicast/broadcast service to the multicast/broadcast session management network elements in different PLMNs of the MOCN, and then send the indication information to the multicast/broadcast user plane function network elements respectively corresponding to the multicast/broadcast session management network elements in different PLMNs, thereby being beneficial to enabling the multicast/broadcast user plane function network elements in different PLMNs to simultaneously receive the data of the first multicast/broadcast service from the application server and synchronously updating the serial numbers of the data aiming at the first multicast/broadcast service, and further being beneficial to realizing data synchronization.

In a possible implementation manner, the first session request message further includes an identification of the first PLMN and/or a start value of a first sequence number corresponding to data of the first multicast/broadcast service in the first PLMN; the second session request message further includes an identification of the second PLMN and/or a start value of a second sequence number corresponding to the data of the first multicast/broadcast service in the second PLMN; wherein the start value of the first sequence number is the same as the start value of the second sequence number.

In this method, the application server may also directly indicate the start value of the first sequence number and the start value of the second sequence number, and the start value of the first sequence number is the same as the start value of the second sequence number, and since the policies of updating the first sequence number and the second sequence number are consistent (for example, the sequence number is increased by 1 as long as data is received), the sequence numbers of the data of different PLMNs for the same multicast/broadcast service may be synchronized.

In a sixth aspect, the present application provides a sixth communication method, where the method is performed by an application server, or may be performed by a component (such as a processor, a chip, or a system-on-chip) of the application server, or may be implemented by a logic module or software that can implement all or part of the functions of the application server. The application server generates a session establishment request message, wherein the session establishment request message comprises an identifier of a main Public Land Mobile Network (PLMN) and identifier information of a first multicast/broadcast service in a multi-operator core network (MOCN); the application server sends the session establishment request message to the multicast/broadcast session management network element. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN by the multicast/broadcast session management network element, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

In a possible implementation, the multicast/broadcast session management network element is located in the main PLMN, or the multicast/broadcast session management network element is located in a PLMN other than the main PLMN in the MOCN.

In the above method, the application server may designate a PLMN in the MOCN as a main PLMN (abbreviated as a main PLMN), so that the access network device in the MOCN and the multicast/broadcast user plane functional network element of the main PLMN all establish a shared transmission channel, so that the multicast/broadcast user plane functional network element of the main PLMN uses the same sequence number for the data of the same multicast/broadcast service, thereby realizing that the sequence numbers of the data of the same multicast/broadcast service are synchronized in different PLMNs, and being beneficial to realizing data synchronization.

In a seventh aspect, the present application provides a seventh communication method, where the method is performed by a multicast/broadcast session management network element, or may be performed by a component (such as a processor, a chip, or a system-on-a-chip) of the multicast/broadcast session management network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the multicast/broadcast session management network element. For example by a first multicast/broadcast session management network element in the multi-operator network. The method comprises the steps that a first multicast/broadcast session management network element receives a session establishment request message from an application server, wherein the session establishment request message comprises an identifier of a main Public Land Mobile Network (PLMN) in a multi-operator core network (MOCN) and identifier information of a first multicast/broadcast service; the first multicast/broadcast session management network element sends a multicast/broadcast service session context to the first session management network element, the multicast/broadcast service session context comprising an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identification of the main PLMN and the identification information of the first multicast/broadcast service are used for the first multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

In a possible implementation, the first multicast/broadcast session management network element and the first session management network element are located in the main PLMN.

In the above method, when the first session management network element corresponding to the first multicast/broadcast session management network element requests to acquire the multicast/broadcast service session context, the first multicast/broadcast session management network element may send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the first session management network element, so that the first session management network element triggers to establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, so that the multicast/broadcast user plane function network element of the main PLMN uses the same sequence number for the data of the same multicast/broadcast service, thereby implementing synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs, and being beneficial to implementing data synchronization.

In an eighth aspect, the present application provides an eighth communication method, where the method is performed by a multicast/broadcast session management network element, or may be performed by a component (such as a processor, a chip, or a system-on-a-chip) of the multicast/broadcast session management network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the multicast/broadcast session management network element. For example by a second multicast/broadcast session management network element in the multi-operator network. The second multicast/broadcast session management network element receives a session establishment request message from the application server, wherein the session establishment request message comprises an identifier of a main Public Land Mobile Network (PLMN) in a multi-operator core network (MOCN) and identifier information of a first multicast/broadcast service; the second multicast/broadcast session management network element sends a multicast/broadcast service session context to the second session management network element, the multicast/broadcast service session context comprising an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for the second multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device of the MOCN and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

In a possible implementation, the second multicast/broadcast session management network element and the second session management network element are located in a PLMN other than the main PLMN in the MOCN.

In the above method, when the second session management network element corresponding to the second multicast/broadcast session management network element requests to acquire the multicast/broadcast service session context, the second multicast/broadcast session management network element may send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the second session management network element, so that the second session management network element triggers to establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN, so that the multicast/broadcast user plane functional network element of the main PLMN uses the same sequence number for the data of the same multicast/broadcast service, thereby implementing synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs, and being beneficial to implementing data synchronization.

In a ninth aspect, the present application provides a ninth communication method, where the method is performed by a session management network element, or may be performed by a component (such as a processor, a chip, or a system on a chip) of the session management network element, or may be implemented by a logic module or software capable of implementing all or part of the functions of the session management network element. For example by a second session management network element in a second PLMN. The second session management network element receives a multicast session request message from the terminal device, wherein the multicast session request message comprises an identifier of a multicast session; the second session management network element sends a multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the multicast session identifier according to the multicast session identifier; the second session management network element receives a multicast/broadcast service session context from the multicast/broadcast session management network element, the multicast/broadcast service session context comprising an identification of the primary public land mobile network PLMN and identification information of the first multicast/broadcast service. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device accessed by the terminal device and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

In a possible implementation manner, the second session management network element sends the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the access network device in the multi-operator core network.

In the above method, when the second session management network element receives the multicast session request message of the terminal device, the second session management network element may request the multicast/broadcast session management network element corresponding to the identifier of the multicast session to acquire the session context of the multicast/broadcast service, thereby acquiring the identifier of the main PLMN and the identifier information of the first multicast/broadcast service, thereby triggering and establishing the shared transmission channel between the access network device accessed by the terminal device and the multicast/broadcast user plane functional network element corresponding to the identifier of the main PLMN, which is beneficial to making the multicast/broadcast user plane functional network element of the main PLMN use the same sequence number for the data of the same multicast/broadcast service, thereby realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs and being beneficial to realizing the data synchronization.

In a tenth aspect, the present application provides a tenth communication method, where the method is performed by the access network device, may be performed by a component of the access network device (e.g. a processor, a chip, or a system on a chip, etc.), or may be implemented by a logic module or software that is capable of implementing all or part of the functions of the access network device. For example by the first access network device. The method comprises the steps that first access network equipment receives a first N2 protocol data unit session resource message from a first session management network element, wherein the first N2 protocol data unit session resource message comprises identification of a main Public Land Mobile Network (PLMN) and identification information of a first multicast/broadcast service in a multi-operator core network (MOCN), and the first access network equipment is located in the MOCN; the first access network device sends a first N2 multicast session request message to a multicast/broadcast session management network element in the primary PLMN, the first N2 multicast session request message including identification information of the first multicast/broadcast service.

In the method, the access network device can request the multicast/broadcast session management network element of the main PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN based on the identification of the main PLMN, thereby being beneficial to enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service, realizing the synchronization of the serial numbers of the data of the same multicast/broadcast service in different PLMNs, and being beneficial to realizing the data synchronization.

In a possible implementation manner, when the first access network device does not establish the shared transmission channel, the first access network device sends the identification information of the first multicast/broadcast service to a multicast/broadcast session management network element in the main PLMN; the first access network device establishes a shared transmission channel with the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

In the method, assuming that the first access network device does not establish a shared transmission channel, the first access network device can request to establish the shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN from the multicast/broadcast session management network element of the main PLMN based on the identifier of the main PLMN, thereby being beneficial to enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service and being beneficial to realizing data synchronization.

In a possible implementation manner, the first access network device receives a second N2 protocol data unit session resource message from a second session management network element, where the second N2 protocol data unit session resource message includes an identifier of the main PLMN and identifier information of the first multicast/broadcast service; when the first access network equipment establishes a shared transmission channel, the first access network equipment discards the second N2 protocol data unit session resource message; or the first access network device sends third indication information to the second session management network element, where the third indication information is used to indicate that the shared transmission channel is established. Wherein the first session management network element is located in the main PLMN, and the second session management network element is located in PLMNs other than the main PLMN in the MOCN; or the first session management network element is located in a PLMN other than the main PLMN in the MOCN, and the second session management network element is located in the main PLMN.

In the method, assuming that the first access network device has established the shared transmission channel, the first access network device may discard the identifier of the main PLMN and the identifier information of the first multicast/broadcast service, or send third indication information to the second session management network element in the second PLMN, where the third indication information is used to indicate that the shared transmission channel has been established. That is, if the first access network device cannot be shared by all PLMNs of the MOCN, the first access network device may establish the shared transmission channel by itself without using the identity of the main PLMN.

In a possible implementation manner, the first access network device sends a handover request message to the second access network device, where the handover request message includes an identifier of the main PLMN and identifier information of the first multicast/broadcast service; the identity of the main PLMN and the identity information of the first multicast/broadcast service are used to trigger the establishment of a shared transmission channel between the second access network device and the multicast/broadcast user plane functional network element in the main PLMN, where the shared transmission channel is used to transmit the data of the first multicast/broadcast service.

In the method, if the terminal equipment belonging to the first access network equipment needs to be switched to the second access network equipment, the first access network equipment can send the identifier of the main PLMN to the second access network equipment, which is favorable for enabling the second access network equipment to request the multicast/broadcast session management network element of the main PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN based on the identifier of the main PLMN, thereby being favorable for enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service and being favorable for realizing data synchronization.

In an eleventh aspect, the present application provides an eleventh communication method, where the method is performed by the access network device, may also be performed by a component (such as a processor, a chip, or a chip system) of the access network device, and may also be implemented by a logic module or software that can implement all or part of the functions of the access network device. For example by the first access network device. Wherein the first access network device receives identification information of a first multicast/broadcast service; the first access network device sends an Xn interface message to the second access network device, where the Xn interface message includes identification information of a first multicast/broadcast service and an identification of a first public land mobile network PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The identifier of the first PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a second shared transmission channel between the second access network device and the multicast/broadcast user plane function network element in the first PLMN, where the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

In a possible implementation, the first access network device and the second access network device are located in a multi-operator core network MOCN, and the first PLMN belongs to the MOCN.

In the method, the identification information of the multicast/broadcast service and the identification of the PLMN can be interacted through the Xn interface between the access network devices which are positioned in the MOCN and have the Xn interface, so that the access network devices in the MOCN with the Xn interface can all establish a shared transmission channel with the same multicast/broadcast user plane function network element, thereby being beneficial to realizing data synchronization.

In a twelfth aspect, the present application provides the twelfth communication method, where the method is performed by the access network device, may also be performed by a component (such as a processor, a chip, or a chip system) of the access network device, and may also be implemented by a logic module or software that can implement all or part of the functions of the access network device. For example by the second access network device. The second access network device receives an Xn interface message from the first access network device, where the Xn interface message includes identification information of a first multicast/broadcast service and an identification of a first public land mobile network PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service; the second access network device receives the identification information of the second multicast/broadcast service, and establishes a second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN, the identification information of the first multicast/broadcast service and the identification information of the second multicast/broadcast service, wherein the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service and the data of the second multicast/broadcast service. Wherein the first access network device and the second access network device are located in a MOCN, and the first PLMN belongs to the MOCN.

In the method, the second access network equipment which is positioned in the MOCN and is provided with the Xn interface can receive the identification information of the multicast/broadcast service of other access network equipment and the identification of the PLMN to which the second access network equipment belongs through the Xn interface, so that the access network equipment in the MOCN with the Xn interface can establish a shared transmission channel with the multicast/broadcast user plane function network element in the PLMN, and the realization of data synchronization is facilitated.

In a possible implementation manner, when the types of the first multicast/broadcast service and the second multicast/broadcast service are the same, the second access network device sends a shared transmission channel establishment request message to a multicast/broadcast user plane function network element in the first PLMN; or when the multicast network address corresponding to the identification information of the first multicast/broadcast service is the same as the multicast network address corresponding to the identification information of the second multicast/broadcast service, the second access network device sends a shared transmission channel establishment request message to the multicast/broadcast user plane function network element in the first PLMN.

In the method, when the second multicast/broadcast service of the second access network device is the same as the first multicast/broadcast service of the first access network device and the first access network device establishes the shared transmission channel aiming at the same multicast/broadcast service, the second access network device tries to establish the shared transmission channel to the first PLMN, which is beneficial to realizing data synchronization.

In a thirteenth aspect, the present application provides a thirteenth communication method, where the method is performed by the access network device, may also be performed by a component (such as a processor, a chip, or a chip system) of the access network device, and may also be implemented by a logic module or software that can implement all or part of the functions of the access network device. For example by the first access network device. The first access network device sends a switching request message to the second access network device, where the switching request message includes an identifier of a first public land mobile network PLMN and identifier information of a first multicast/broadcast service in a multi-operator core network MOCN, the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The first access network equipment receives a switching response message from the second access network equipment, wherein the switching response message comprises an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a second shared transmission channel with the second access network equipment belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs to the first PLMN; wherein the first access network device and the second access network device are located in the MOCN, and the first PLMN and the second PLMN are different.

In the method, if the terminal equipment belonging to the first access network equipment needs to be switched to the second access network equipment, the first access network equipment can send the identifier of the first PLMN to which the first access network equipment belongs to the second access network equipment, which is favorable for enabling the second access network equipment to request the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN based on the identifier of the first PLMN, thereby transmitting the data of the same multicast/broadcast service through the same shared transmission channel and being favorable for realizing data synchronization.

In a possible implementation manner, the first access network device forwards the data of the first multicast/broadcast service to the second access network device according to the identifier of the second PLMN or fourth indication information.

In the method, if the second access network device feeds back to the first access network device that the second access network device has established a shared transmission channel with the multicast/broadcast user plane function network elements in other PLMNs, the first access network device may transmit, to the second access network device, data of the multicast/broadcast service that is currently being transmitted by part of the first access network device within a certain time (e.g., based on a timer, etc.), so that the problem of packet loss may be partially alleviated.

In a possible implementation manner, the first access network device receives a first N2 protocol data unit session resource message, where the first N2 protocol data unit session resource message includes an identifier of a first PLMN and identifier information of a first multicast/broadcast service; the first access network device establishes a first shared transmission channel with a multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN and the identification information of the first multicast/broadcast service.

In the method, the first access network device can request the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN based on the identification of the first PLMN and the identification information of the first multicast/broadcast service, thereby being beneficial to enabling the multicast/broadcast user plane function network element of the first PLMN to use the same serial number for the data of the same multicast/broadcast service and being beneficial to realizing data synchronization.

In a possible implementation manner, the handover request message is used for requesting handover of the terminal device from the first access network device to the second access network device, and the handover request message further includes an identifier of a PLMN to which the terminal device belongs.

In the method, the first access network device can also send the identifier of the PLMN to which the terminal device belongs to the second access network device, which is favorable for the second access network device to take the multicast/broadcast user plane function network element of the PLMN to which the terminal device belongs as the suboptimal choice for establishing the shared transmission channel.

In a fourteenth aspect, the present application provides a fourteenth communication method, where the method is performed by an access network device, may also be performed by a component of the access network device (e.g., a processor, a chip, or a system-on-chip, etc.), and may also be implemented by a logic module or software that is capable of implementing all or part of the functions of the access network device. For example by the second access network device. The second access network device receives a handover request message from the first access network device, where the handover request message includes an identifier of a first public land mobile network PLMN and identifier information of a first multicast/broadcast service in a multi-operator core network MOCN, the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The second access network equipment sends a switching response message to the first access network equipment, wherein the switching response message comprises an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a second shared transmission channel with the second access network equipment belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs to the first PLMN; wherein the first access network device and the second access network device are located in the MOCN, the first PLMN and the second PLMN being different.

In the method, if the terminal equipment belonging to the first access network equipment needs to be switched to the second access network equipment, the second access network equipment can receive the identifier of the first PLMN to which the first access network equipment belongs, so that the second access network equipment requests the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane functional network element of the first PLMN based on the identifier of the first PLMN, and the data of the same multicast/broadcast service is transmitted through the same shared transmission channel, thereby being beneficial to realizing data synchronization.

In a possible implementation manner, when the second access network device does not establish the second shared transmission channel for transmitting the data of the first multicast/broadcast service, the second access network device establishes the second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN and the identification information of the first multicast/broadcast service.

In the method, if the second access network device does not establish the shared transmission channel for transmitting the data of the same multicast/broadcast service, the second access network device can attempt to establish the shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN, so that the data of the same multicast/broadcast service are transmitted through the same shared transmission channel, which is beneficial to realizing data synchronization.

In a possible implementation manner, when the second access network device has established a second shared transmission channel for transmitting data of the first multicast/broadcast service, the handover response message includes an identifier of a PLMN corresponding to the second shared transmission channel, or the handover response message includes the fourth indication information.

In a possible implementation manner, when the identifier of the PLMN corresponding to the second shared transmission channel is different from the identifier of the first PLMN, the second access network device receives data of the first multicast/broadcast service from the first access network device; the second access network device forwards the data of the first multicast/broadcast service using a unicast mode.

In the method, if the second access network device feeds back to the first access network device that the second access network device has established a shared transmission channel with the multicast/broadcast user plane function network elements in other PLMNs, the second access network device may receive, in a certain time (e.g., based on a timer, etc.), data of the multicast/broadcast service that is currently being sent by part of the first access network device, so that the problem of packet loss may be partially alleviated.

In the method, the second access network device may also receive the identifier of the PLMN to which the terminal device belongs, so that the second access network device may use the multicast/broadcast user plane function network element of the PLMN to which the terminal device belongs as a suboptimal choice for establishing the shared transmission channel.

In a possible implementation manner, the second access network device establishes a second shared transmission channel according to the identifier of the first PLMN, or the identifier of the second PLMN, or the identifier of the PLMN to which the terminal device belongs.

In a fifteenth aspect, the present application provides a fifteenth communication method implemented by an interaction between a multicast/broadcast session management network element, a multicast/broadcast user plane function network element, an application server. Wherein the application server sends a first session establishment request message to a first multicast/broadcast session management network element located in a first public land mobile network PLMN of the multi-operator core network MOCN, the first session establishment request message comprising identification information of a first multicast/broadcast service; the application server sends a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN, the second session establishment request message including identification information of the first multicast/broadcast service. The first multicast/broadcast session management network element sends first indication information to the first multicast/broadcast user plane function network element according to the first session establishment request message, wherein the first indication information is used for indicating the first multicast/broadcast user plane function network element to increment a first serial number corresponding to data of a first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data; wherein the first multicast/broadcast session management network element and the first multicast/broadcast user plane function network element are located in a first PLMN. The second multicast/broadcast session management network element sends second indication information to the second multicast/broadcast user plane function network element according to the second session establishment request message, wherein the second indication information is used for indicating the second multicast/broadcast user plane function network element to increment a second serial number corresponding to the data when the second multicast/broadcast user plane function network element receives the data of the first multicast/broadcast service; wherein the second multicast/broadcast session management network element and the second multicast/broadcast user plane function network element are located in a second PLMN. The application server transmits data of the first multicast/broadcast service to the first multicast/broadcast user plane function network element and the second multicast/broadcast user plane function network element. The first multicast/broadcast user plane function network element increases a first serial number corresponding to the data of the first multicast/broadcast service according to the first indication information. And the second multicast/broadcast user plane functional network element increases the second serial number corresponding to the data of the first multicast/broadcast service according to the second indication information.

In the method, the application server can request a plurality of PLMNs in the MOCN to perform special user plane configuration in advance, so that each PLMN synchronously updates the sequence number of the data of the same multicast/broadcast service (for example, updates the sequence number of the data when receiving the data), thereby enabling different multicast/broadcast user plane functional network elements to set the same sequence number for the data of the same multicast/broadcast service, and being beneficial to realizing the synchronization of the data.

In a possible implementation manner, the steps of interaction between the multicast/broadcast session management network element, the multicast/broadcast user plane function network element, and the application server may refer to the first aspect to the fifth aspect, and any possible implementation manner of the first aspect to the fifth aspect is not described herein.

In a sixteenth aspect, the present application provides a sixteenth communication method implemented by an interaction between a multicast/broadcast session management network element, a multicast/broadcast user plane function network element, a session management network element, an application server, an access network device. Wherein the application server generates a session establishment request message comprising an identification of the primary PLMN in the multi-operator core network MOCN and identification information of the first multicast/broadcast service. The application server sends the session establishment request message to the first multicast/broadcast session management network element and the second multicast/broadcast session management network element, respectively. The first multicast/broadcast session management network element sends a multicast/broadcast service session context to the first session management network element, the multicast/broadcast service session context including an identity of the primary PLMN and identity information of the first multicast/broadcast service; the identity of the main PLMN and the identity information of the first multicast/broadcast service are used by the first multicast/broadcast session management network element to trigger the establishment of a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN, where the shared transmission channel is used to transmit data of the first multicast/broadcast service. Wherein the first multicast/broadcast session management network element and the first session management network element are located in the primary PLMN. The second multicast/broadcast session management network element sends a multicast/broadcast service session context to the second session management network element, wherein the multicast/broadcast service session context comprises an identifier of the main PLMN and identifier information of the first multicast/broadcast service; the identifier of the main PLMN and the identifier information of the multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device of the MOCN and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN by the second multicast/broadcast session management network element, and the shared transmission channel is used for transmitting the data of the first multicast/broadcast service; wherein the second multicast/broadcast session management network element and the second session management network element are located in a PLMN other than the main PLMN in the MOCN. The second session management network element receives a multicast session request message from the terminal device, wherein the multicast session request message comprises an identifier of a multicast session; and the second session management network element sends a multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the identifier of the multicast session according to the identifier of the multicast session. The second session management network element receives a multicast/broadcast service session context from the multicast/broadcast session management network element, the multicast/broadcast service session context including an identity of the main PLMN and identity information of the first multicast/broadcast service; the second session management network element sends the identity of the primary PLMN and the identity information of the first multicast/broadcast service to the first access network device in the MOCN. A first access network device in the MOCN receives the identification of the main PLMN and the identification information of the first multicast/broadcast service; the first access network device sends an N2 multicast session request message to a multicast/broadcast session management network element in the primary PLMN.

In the method, the shared transmission channel establishment flow of the access network equipment in the MOCN is enhanced, so that the access network equipment in the MOCN and the multicast/broadcast user plane function network elements of the main PLMN are both established with the shared transmission channel, thereby avoiding the situation that a plurality of multicast/broadcast user plane function network elements generate different serial numbers and being beneficial to realizing the synchronization of data.

In a possible implementation manner, the steps of interaction between the multicast/broadcast session management network element, the multicast/broadcast user plane function network element, the application server, and the access network device may refer to the sixth aspect to the tenth aspect, and any possible implementation manner of the sixth aspect to the tenth aspect is not described herein.

In a seventeenth aspect, the present application provides a seventeenth method of communication implemented by interactions between a plurality of access network devices in a MOCN in which an Xn interface is present. Wherein the first access network device receives identification information of a first multicast/broadcast service; the method comprises the steps that first access network equipment sends Xn interface information to second access network equipment, the Xn interface information comprises identification information of a first multicast/broadcast service and identification of a first Public Land Mobile Network (PLMN), the first PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a first shared transmission channel with the first access network equipment belongs, and the first shared transmission channel is used for transmitting data of the first multicast/broadcast service; the identification of the first PLMN and the identification information of the first multicast/broadcast service are used for triggering and establishing a second shared transmission channel between the second access network equipment and the multicast/broadcast user plane functional network element in the first PLMN, wherein the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service; wherein the first access network device and the second access network device are located in a multi-operator core network MOCN, and the first PLMN belongs to the MOCN. The second access network equipment receives the identification information of the second multicast/broadcast service; the second access network device establishes a second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN, the identification information of the first multicast/broadcast service and the identification information of the second multicast/broadcast service, wherein the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service and the data of the second multicast/broadcast service; wherein the first access network device and the second access network device are located in a MOCN.

In the method, a shared transmission channel can be established between a plurality of access network devices with Xn interfaces in the MOCN and the same multicast/broadcast user plane functional network element, thereby being beneficial to realizing synchronization.

In a possible implementation manner, the steps of interaction between the multicast/broadcast session management network element, the multicast/broadcast user plane function network element, and the access network device in the MOCN may refer to the eleventh aspect and the twelfth aspect, and any possible implementation manner of the eleventh aspect and the twelfth aspect is not described herein.

In an eighteenth aspect, the present application provides an eighteenth communication method implemented by interactions between a plurality of access network devices in a MOCN. The first access network device sends a switching request message to the second access network device, where the switching request message includes an identifier of a first public land mobile network PLMN and identifier information of a first multicast/broadcast service in a multi-operator core network MOCN, the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The second access network equipment sends a switching response message to the first access network equipment, wherein the switching response message comprises an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a second shared transmission channel with the second access network equipment belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs to the first PLMN; wherein the first access network device and the second access network device are located in the MOCN, and the first PLMN and the second PLMN are different.

In a possible implementation manner, the step of interaction between the first access network device and the second access network device may refer to the thirteenth aspect and the fourteenth aspect, and any one of the possible implementation manners of the thirteenth aspect and the fourteenth aspect, which are not described herein.

In a nineteenth aspect, the present application provides a first communication device, which may be a multicast/broadcast session management network element, a device in a multicast/broadcast session management network element, or a device that can be used in cooperation with a multicast/broadcast session management network element. In a possible implementation manner, the communication apparatus may include modules that perform the methods/operations/steps/actions as described in the first aspect, the second aspect, the seventh aspect, the eighth aspect, and any one of the possible implementation manners of the first aspect, the second aspect, the seventh aspect, and the eighth aspect, where the modules may be hardware circuits, or software, or a combination of hardware circuits and software implementation. In a possible embodiment, the communication device may comprise a processing unit and a communication unit.

For a specific description of the method performed by the multicast/broadcast session management network element, reference may be made to the above first aspect, second aspect, seventh aspect, and eighth aspect, and corresponding descriptions in any possible implementation manner of the first aspect, second aspect, seventh aspect, and eighth aspect, which are not repeated herein. It will be appreciated that the communication device may also achieve the effects as may be achieved in the first, second, seventh, eighth aspects and any of the possible embodiments of the first, second, seventh, eighth aspects.

In a twentieth aspect, the present application provides a second communication device, which may be a multicast/broadcast user plane function network element, a device in a multicast/broadcast user plane function network element, or a device capable of being used in cooperation with a multicast/broadcast user plane function network element. In a possible implementation manner, the communication apparatus may include modules that perform the methods/operations/steps/actions as described in the third aspect and the fourth aspect and any possible implementation manner of the third aspect and the fourth aspect, where the modules may be hardware circuits, software, or a combination of hardware circuits and software implementation. In a possible embodiment, the communication device may comprise a processing unit and a communication unit.

For a specific description of the method performed by the multicast/broadcast user plane functional network element, reference may be made to the foregoing third aspect and the fourth aspect, and corresponding descriptions in any possible implementation manners of the third aspect and the fourth aspect, which are not repeated herein. It will be appreciated that the communication device may also achieve the effects as may be achieved in any of the possible embodiments of the third and fourth aspects.

In a twenty-first aspect, the present application provides a third communication device, which may be an application server, a device in an application server, or a device that can be used in a matching manner with the application server. In a possible implementation manner, the communication apparatus may include modules that perform the methods/operations/steps/actions as described in the fifth aspect and the sixth aspect and any possible implementation manner of the fifth aspect and the sixth aspect, where the modules may be hardware circuits, or software, or a combination of hardware circuits and software implementation. In a possible embodiment, the communication device may comprise a processing unit and a communication unit.

The specific description of the method executed by the application server may refer to the fifth aspect and the sixth aspect, and corresponding descriptions in any possible implementation manners of the fifth aspect and the sixth aspect, which are not repeated herein. It will be appreciated that the communication device may also achieve the effects as may be achieved in the fifth and sixth aspects and any of the possible embodiments of the fifth and sixth aspects.

In a twenty-second aspect, the present application provides a fourth communication device, which may be a session management network element, a device in a session management network element, or a device that can be used in cooperation with a session management network element. In a possible implementation manner, the communication apparatus may include modules that perform the method/operation/step/action described in any one of the possible implementation manners of the ninth aspect and the ninth aspect, where the modules may be hardware circuits, or software, or a combination of hardware circuits and software implementation. In a possible embodiment, the communication device may comprise a processing unit and a communication unit.

For a specific description of the method performed by the session management network element, reference may be made to the foregoing ninth aspect and corresponding descriptions in any possible implementation manner of the ninth aspect, which are not described herein. It will be appreciated that the communication device may also achieve the effects as may be achieved in any of the possible embodiments of the ninth and ninth aspects.

In a twenty-third aspect, the present application provides a fifth communication apparatus, which may be an access network device, or an apparatus in an access network device, or an apparatus that can be used in a matching manner with an access network device. In a possible implementation manner, the communication apparatus may include modules that perform the methods/operations/steps/actions described in the tenth aspect to the fourteenth aspect and any one of the possible implementation manners of the tenth aspect to the fourteenth aspect, where the modules may be hardware circuits, or software, or a combination of hardware circuits and software implementation. In a possible embodiment, the communication device may comprise a processing unit and a communication unit.

It will be appreciated that the communication device may also achieve the effects as may be achieved in the tenth to fourteenth aspects and any one of the possible embodiments of the tenth to fourteenth aspects.

In a twenty-fourth aspect, the present application provides a communication apparatus comprising: a processor and a memory for storing instructions which, when executed by the processor, cause the communication device to carry out the method of the first to fourteenth aspects and any one of the possible implementation manners of the first to fourteenth aspects. In the alternative, the processor and memory are coupled.

In a twenty-fifth aspect, the present application provides a computer-readable storage medium having instructions stored thereon, which when run on a computer, cause the computer to perform the first to fourteenth aspects, and the method of any one of the possible implementations of the first to fourteenth aspects.

In a twenty-sixth aspect, the present application provides a chip system, the chip system comprising a processor and an interface, and may further comprise a memory, for implementing the method of the first aspect to the fourteenth aspect and any one of the possible implementation manners of the first aspect to the fourteenth aspect. The chip system may be formed of a chip or may include a chip and other discrete devices.

In a twenty-seventh aspect, the present application provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the first to fourteenth aspects and any one of the possible implementation manners of the first to fourteenth aspects.

In a twenty-eighth aspect, the present application provides a communication system, which may comprise one or more of the communication devices described in the nineteenth to twenty-fourth aspects above, implementing the first to fourteenth aspects and the method in any one of the possible implementation manners of the first to fourteenth aspects.

Drawings

FIG. 1 is a schematic diagram of a communication system;

fig. 2 is a schematic diagram of a device for sharing access networks by different PLMNs in a MOCN;

fig. 3a and fig. 3b are schematic flow diagrams of a communication method according to the present application;

FIG. 4 is a flow chart of another communication method according to the present application;

FIG. 5 is a flow chart of another communication method according to the present application;

FIG. 6 is a flow chart of another communication method according to the present application;

FIG. 7 is a schematic diagram of a communication device according to the present application;

Fig. 8 is a schematic diagram of another communication device provided by the present application.

Detailed Description

In the present application, "/" may indicate that the related objects are an "or" relationship, for example, a/B may indicate a or B; "and/or" may be used to describe that there are three relationships associated with an object, e.g., a and/or B, which may represent: there are three cases, a alone, a and B together, and B alone, wherein a, B may be singular or plural. In order to facilitate the description of the technical solution of the present application, in the present application, the words "first", "second", etc. may be used to distinguish between technical features that are functionally the same or similar. The terms "first," "second," and the like do not necessarily denote any order of quantity or order of execution, nor do the terms "first," "second," and the like. In the present disclosure, the word "exemplary" or "such as" is used to mean an example, instance, or illustration, and any embodiment or design described as "exemplary" or "such as" should not be construed as preferred or advantageous over other embodiments or designs. The use of the word "exemplary" or "such as" is intended to present the relevant concepts in a concrete fashion to facilitate understanding.

The technical scheme of the present application will be described below with reference to the accompanying drawings.

In order to solve the problem that the network elements with different multicast/broadcast user plane functions generate different serial numbers aiming at the same multicast service, thereby causing confusion of the access network equipment to the cognition of the serial numbers of the data; the application provides a plurality of communication methods, which can realize the synchronization of the serial numbers of different access network devices in the multi-operator core network scene and realize the synchronization of data transmission.

The communication method provided by the application can be applied to a communication system, in particular to a multi-operator core network (MOCN) system. For example, to the communication system shown in fig. 1.

Fig. 1 is a schematic diagram of a communication system including two parts, a radio access network and a MOCN. Wherein the radio access network is used for realizing the radio access related function. The MOCN mainly comprises the following key logical network elements: multicast/broadcast session management network elements (multicast/broadcast-session management function, MB-SMF), multicast/broadcast user plane function network elements (multicast/broadcast-user plane function, MB-UPF), application servers (application server, AS). Optionally, the communication system further comprises network elements not shown in fig. 1, such as access and mobility management functions (ACCESS AND mobility management function, AMF), session management functions (session management function, SMF), user plane functions (user plane function, UPF), policy control functions (policy control function, PCF), unified data management (unified DATA MANAGEMENT, UDM) network elements, network storage functions (network repository function, NRF), etc., the application is not limited. The application server in the present application may also be referred to as an application function (application function) network element.

The communication systems mentioned in the present application include, but are not limited to: three major application scenarios of narrowband internet of things (NB-IoT), global system for mobile communications (global system for mobile communications, GSM), enhanced data rates for GSM evolution (ENHANCED DATA RATE for GSM evolution, EDGE), wideband code division multiple access (wideband code division multiple access, WCDMA), code division multiple access 2000 (code division multiple access, CDMA 2000), time division synchronous code division multiple access (time division-synchronization code division multiple access, TD-SCDMA), long term evolution (long term evolution, LTE) and 5G mobile communication systems enhance mobile broadband (enhanced mobility broad band, eMBB), ultra high reliability and low latency communications (ultra-reliable and low latency communications, URLLC) and enhanced machine type communications (ENHANCED MACHINE-type communication, eMTC) and future communication systems (e.g., 6G/7G, etc.).

A terminal device, also called User Equipment (UE), mobile Station (MS), mobile Terminal (MT), etc., is a device that provides voice and/or data connectivity to a user. Such as a handheld device, an in-vehicle device, etc., having a wireless connection function. Currently, examples of some terminal devices are: a mobile phone, a tablet, a notebook, a palm, a mobile internet device (mobile INTERNET DEVICE, MID), a wearable device, an unmanned aerial vehicle, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in an industrial control (industrial control), a wireless terminal in an unmanned (SELF DRIVING), a wireless terminal in a teleoperation (remote medical surgery), a wireless terminal in a smart grid (SMART GRID), a wireless terminal in a transportation security (transportation safety), a wireless terminal in a smart city (SMART CITY), a wireless terminal in a smart home (smart home), a terminal in a 5G network, a terminal in a future evolved public land mobile network (publiclandmobilenetwork, PLMN), or a terminal in a future communication system, and the like.

An access network device refers to a radio access network (radio access network, RAN) node (or device), also referred to as a base station, that accesses a terminal device to a wireless network. That is, the satellite in the present application may access the terminal device to the RAN, which may also be referred to as a satellite base station. Examples of some RAN nodes are, for example: a further evolved Node B (gcb), a transmission reception point (transmission reception point, TRP), an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a baseband unit (BBU), or a wireless fidelity (WIRELESS FIDELITY, wifi) access point (access point, AP), a satellite in a satellite communication system, a radio controller in a cloud radio access network (cloud radio access network, CRAN) scenario, a wearable device, an unmanned aerial vehicle, or a device in the internet of vehicles (e.g., internet of vehicles (vehicle to everything, V2X)), or a communication device in inter-device (device to device, D2D) communication, etc. In addition, in one network architecture, the access network device may include a centralized unit (centralized unit, CU) node, or a Distributed Unit (DU) node, or a RAN device including a CU node and a DU node. The RAN equipment comprising CU nodes and DU nodes splits the protocol layers of the eNB in the long term evolution (long term evolution, LTE) system, functions of part of the protocol layers are put in CU centralized control, and functions of the rest part or all of the protocol layers are distributed in DUs, which are centralized control by the CU.

The MB-SMF, similar to the SMF, is mainly responsible for session management in the mobile network, such as session establishment, modification, release, e.g. allocation of IP addresses to users, selection of UPFs providing message forwarding functions, etc. MB-UPF has similar functions to UPF and is mainly responsible for processing user messages, such as forwarding and charging.

1. The related concepts related to the present application:

1. Scene of MOCN:

The current standard protocols are discussing different operator network sharing base stations, mainly focusing on network optimization schemes for multi-operator core network (MOCN) network sharing. For example, fig. 2 is a schematic diagram of a device for sharing access networks by different PLMNs in a MOCN. The terminal device, the access network device and the PLMN are shown in the MOCN, and optionally, other devices or network elements not shown may refer to specific examples of existing MOCNs, and the present application is not limited thereto. It is assumed that there are two PLMNs (e.g., PLMN a and PLMN b in fig. 2), and that PLMN a and PLMN b have a common access network device (e.g., next generation radio access network (nextgenerationradioaccessnetwork, NG-RAN) in fig. 2). Currently, for the NG-RAN, when PLMN a and PLMN b send the same multicast/broadcast service data to the NG-RAN, the NG-RAN needs to send two data on the air interface, which results in waste of air interface resources. The communication method provided by the application can enable the access network equipment to identify the same service when different operators request to establish the multicast/broadcast session, thereby reusing the resources of the air interface (i.e. the sessions of different operators of the same service use the same air interface resource), and further improving the transmission efficiency of the air interface.

2. Unicast-based multicast techniques:

The multicast technology based on unicast aims at solving the following problems: how to further save network resources based on reusing the existing unicast flow as much as possible. Among other things, multicast techniques may also be referred to as multicast techniques. For example, the user plane function network element only sends one part (for example, from the UPF to the access network) for the data flow of the same service sent to different terminal devices in the group, so as to improve the use efficiency of the air interface resource and the core network resource. For example, a joining procedure for a unicast-based multicast technique includes the steps of:

Step 1: the terminal device sends a join request message to the SMF. For example, the UE may request a session modification request by a non-access stratum (NAS) message (e.g., a protocol data unit (protocol data unit, PDU) or a PDU session establishment request), or a join request message of the user plane (e.g., an internet group management protocol join (Internet group management protocol join, igmp join) message). The join request message contains multicast group information (which may also be referred to as multicast session information, which is used to send data corresponding to the multicast group).

Step 2: after receiving the join request message of the terminal device, the SMF acquires multicast information. For example, the SMF may acquire multicast information from the MB-SMF or UDR according to multicast group information/multicast session information, and generate multicast context information corresponding to the multicast according to the multicast information. Optionally, the SMF may also generate information of unicast quality of service Flow (quality of serviceflow, qoS Flow) corresponding to the multicast.

Step 3: the SMF sends a request message to the access network device, where the request message includes the information generated in step 2.

Step 4: the access network device establishes or modifies multicast context information corresponding to the multicast according to the request message of the SMF. Optionally, the access network device may further establish unicast context information.

3. Service continuity mechanism of multicast scheme:

Currently, there is only one anchor point (e.g., MB-UPF) for a multicast session of a PLMN. The MB-UPF inserts a Sequence Number (SN) when sending downlink multicast data, and since there is only one MB-UPF, all access network devices in the PLMN have the same understanding of the sequence number (the data corresponding to the same sequence number is the same). The different access network devices then generate packet data convergence protocol (PACKET DATA convergence protocol, PDCP) sequence numbers based on the sequence numbers of the multicast data and transmit the data over the air interface.

Optionally, if there is a need for the terminal device to switch from the source access network device (S-RAN for short) to the target access network device (T-RAN for short), during the switching phase, when both the S-RAN and the T-RAN support the multicast/broadcast service (multicast and broadcast service, MBS), the S-RAN and the T-RAN exchange information (e.g. exchange SN sequence numbers and/or PDCP sequence numbers), and the S-RAN decides when to stop forwarding according to the SN sequence numbers provided by the T-RAN. For example, the S-RAN will stop forwarding data when forwarding to a certain SN sequence number.

2. The communication method provided by the application comprises the following steps:

Example one: fig. 3a and fig. 3b are schematic flow diagrams of a communication method according to the present application. The communication method is applied to the communication system shown in fig. 1. For example, the communication method may be implemented by an interaction between an application server, a multicast/broadcast session management network element, a multicast/broadcast user plane function network element, comprising the steps of:

S101, the application server sends a first session establishment request message to a first multicast/broadcast session management network element located in a first PLMN of the MOCN.

Here, the first PLMN located in the MOCN may refer to that the first PLMN and the other PLMNs are both connected to a certain access network device or devices. For example, in the MOCN network sharing architecture of the present application, only the RAN is shared. 5G MOCN (including UE, RAN and AMF) for 5G systems supports the ability of operators to use multiple PLMN IDs.

Wherein the first session establishment request message may include identification information of the first multicast/broadcast service.

Wherein the identification information of the multicast/broadcast service is used to identify the multicast/broadcast service. In particular, the identification information of the multicast/broadcast service is used to identify the multicast/broadcast service with a globally unique identifier, e.g. by which the service can be identified in different PLMNs. For example, the identification information of the multicast/broadcast service may be an associated session identification (associated session identifier) that enables the shared NG-RAN node to determine that multiple MBS sessions are transmitting the same content of the same MBS service. Wherein the associated session identification may be a multicast address (source specific multicast address, SSM) of a particular source. For another example, the identification information of the multicast/broadcast service may be a temporary multicast group identification (temporary multicast group identifier, TMGI) list, indicating that the multicast/broadcast service is shared in the TMGI list.

Optionally, a MOCN identification (abbreviated as MOCN ID) is used to identify the MOCN. Wherein the MOCN ID may be an IP multicast address.

Optionally, the first session establishment request message further includes, but is not limited to, one or more of the following information: the type of the first multicast/broadcast service, the identification information of the multicast session, or the identification of the PLMN, etc.

Wherein the type of multicast/broadcast service is used to indicate the type of the first multicast/broadcast service, e.g. multicast service or broadcast service. Further, when the type of the first multicast/broadcast service is a multicast service, it indicates that the first multicast/broadcast service has a shared requirement, that is, the first multicast/broadcast service may be shared in different PLMNs.

The identification information of the multicast session is used to identify the multicast session, which may be, for example, a TMGI corresponding to the multicast session, and the multicast session is used to transmit data of the first multicast/broadcast service. The TMGI may be a TMGI corresponding to the first multicast/broadcast service in the first PLMN of the MOCN. As another example of this, and as another example,

The identity of the PLMN is used to identify the PLMN, e.g., PLMN ID.

Optionally, the first session establishment request message is sent by the application server directly to the first multicast/broadcast session management network element, or by the application server through a network presence function (network exposure function, NEF) network element to the first multicast/broadcast session management network element, which is not limited by the present application.

S102, the application server sends a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN.

Wherein the second session establishment request message may include identification information of the first multicast/broadcast service. The identification information may be the same as or different from the identification information of the first multicast/broadcast service in step S101, and is not limited.

The functional description of the identification information of the multicast/broadcast service may refer to step S101, which is not described herein.

For example, when the second session establishment request message carries the identification information of the first multicast/broadcast service, it may indicate that the first multicast/broadcast service is shared in different PLMNs.

Optionally, the second session establishment request message further includes a type of the first multicast/broadcast service, identification information of the multicast session, network sharing identification information, an identification of the PLMN, etc., and the description of the above information may refer to a corresponding description in example one, which is not repeated herein.

Alternatively, S101 and S102 may be executed sequentially or simultaneously. For example, S101 may be performed first, and S102 may be performed later; s102 may be executed first, and S101 may be executed later; s101 and S102 may also be performed simultaneously, and the present embodiment is not limited.

S103, the first multicast/broadcast session management network element sends first indication information to the first multicast/broadcast user plane function network element according to the first session establishment request message.

The first indication information may be used to indicate the first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data of the first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data.

Wherein the first multicast/broadcast session management network element and the first multicast/broadcast user plane function network element are located in a first PLMN.

The specific implementation manner of the first indication information may include, but is not limited to, the following cases:

Case one: the first indication information is provided as a separate cell. For example, by setting a specific bit value for an existing cell, or by a newly added cell, without limitation. For example, the cell is carried in an N4mb session setup/session modification message sent by the first multicast/broadcast session management network element to the first multicast/broadcast user plane function network element.

It should be noted that, the increment in the present application refers to an increment process of the sequence number, where the increment process may be an increment based on the sequence number, and the increment may be performed by a fixed step, for example, by a fixed step size, and the fixed step size may be1 or greater than 1. The amplitude may be varied, for example, increased in an arithmetic progression, for example, sequentially increased by values of 1,3, 5, etc., and the present embodiment is not limited thereto.

It should be noted that, even if the first multicast/broadcast user plane functional network element does not send the data to the access network device, the first multicast/broadcast user plane functional network element may increment the sequence number corresponding to the data.

And a second case: the first indication information is implemented by a combination of a plurality of cells. For example, in the forwarding behavior rules (forwarding action rule, FAR), it is defined to send data to a particular destination (e.g., a particular specified IP address), or it is defined to discard data before sending (i.e., not send data). In the case of FAR implementation, the first indication information can also enable the first multicast/broadcast user plane functional network element to process the data of the first multicast/broadcast service, which is the same as the other multicast/broadcast user plane functional network elements to process the data of the first multicast/broadcast service, so that the data synchronization is also facilitated.

Optionally, after receiving the first session establishment request message, the first multicast/broadcast session management network element may trigger a remaining session establishment step, for example, the first multicast/broadcast session management network element performs a step of generating multicast policy information by interacting with the PCF, and the specific implementation manner may refer to a corresponding description in the existing protocol standard, which is not described herein again.

Optionally, in step S103, the first multicast/broadcast session management network element sends the first indication information to the first multicast/broadcast user plane function network element according to the type of the multicast/broadcast service and/or the identification information of the first multicast/broadcast service in the first session establishment request message. For example, when the type of the first multicast/broadcast service is a multicast service and the first session establishment request message carries identification information of the first multicast/broadcast service (which indicates that the first multicast/broadcast service has a shared requirement, that is, the first multicast/broadcast service may be shared in different PLMNs), the first multicast/broadcast session management network element sends the first indication information to the first multicast/broadcast user plane functional network element, so that the first multicast/broadcast user plane functional network element may synchronously update the sequence number of the data of the first multicast/broadcast service, so as to realize that the sequence number of the data of the first multicast/broadcast service is synchronized in different PLMNs.

Optionally, the first indication information further includes a start value of the first sequence number. For example, the start value of the first sequence number is 0. In this embodiment, it is assumed that the starting values of the sequence numbers of the data of different PLMNs for the same multicast/broadcast service in the MOCN are the same, so that synchronization of the sequence numbers of the data of different PLMNs for the same multicast/broadcast service is facilitated.

And S104, the second multicast/broadcast session management network element sends second indication information to the second multicast/broadcast user plane function network element according to the second session establishment request message.

The second indication information may be used to indicate the second multicast/broadcast user plane function network element to increment the second sequence number corresponding to the data of the first multicast/broadcast service when receiving the data.

Wherein the second multicast/broadcast session management network element and the second multicast/broadcast user plane function network element are located in a second PLMN. The description of the second session establishment request message may refer to the corresponding description in S102, and will not be repeated here.

The specific implementation of the second indication information may refer to the specific implementation of the first indication information, for example, the second indication information is implemented as an independent cell by setting a specific bit value for an existing cell, or implemented by a newly added cell, for example, the cell is carried in an N4mb session establishment/session modification message sent by the second multicast/broadcast session management network element to the second multicast/broadcast user plane functional network element, or implemented by a combination of one or more existing cells, which are not described herein.

Optionally, after receiving the second session establishment request message, the second multicast/broadcast session management network element may trigger a remaining session establishment step, for example, the second multicast/broadcast session management network element performs a step of interacting with the PCF to generate the multicast policy information, and the specific implementation manner may refer to a corresponding description in the existing protocol standard, which is not described herein again.

Optionally, in step S104, the second multicast/broadcast session management network element sends second indication information to the second multicast/broadcast user plane function network element according to the type of the multicast/broadcast service and/or the identification information of the first multicast/broadcast service in the second session establishment request message. For a specific implementation, reference may be made to the implementation in S103, which is not described herein. The second multicast/broadcast session management network element sends second indication information to the second multicast/broadcast user plane function network element, so that the second multicast/broadcast user plane function network element can synchronously update the sequence number of the data of the first multicast/broadcast service.

Optionally, the second indication information further comprises a start value of the second sequence number. For example, the start value of the second sequence number is 0. Wherein the start value of the first sequence number may be the same as the start value of a second sequence number corresponding to the data of the first multicast/broadcast service in the second PLMN of the MOCN. In the case where the starting values of the first sequence number in the first PLMN and the second sequence number in the second PLMN of the MOCN are the same for the data of the first multicast/broadcast service, the strategy of performing the increment processing on the sequence numbers is also the same (for example, when the data of the first multicast/broadcast service is received, the sequence number is added by 1), the sequence number of the data of the first multicast/broadcast service can be kept the same in the first PLMN and the second PLMN.

Alternatively, S103 and S104 may be executed sequentially or simultaneously. For example, S103 may be performed first, and S104 may be performed later; s104 may be executed first, and S103 may be executed later; s103 and S104 may also be performed simultaneously, and the present embodiment is not limited.

It can be seen that, by executing the above S101-S104, the application server may request, in advance, a plurality of PLMNs in the MOCN (for example, the first PLMN and the second PLMN in this embodiment) to perform special user plane configuration, so that each PLMN synchronously updates the sequence number of the data of the same multicast/broadcast service (for example, updates the sequence number of the data when receiving the data), thereby enabling different multicast/broadcast user plane functional network elements to set the same sequence number for the data of the same multicast/broadcast service, which is beneficial to implementing synchronization of the data.

Optionally, the method further comprises the following steps, as shown in fig. 3 b:

s105, the application server sends the data of the first multicast/broadcast service to the first multicast/broadcast user plane function network element and the second multicast/broadcast user plane function network element.

It is noted that before the application server sends the data of the first multicast/broadcast service to the first multicast/broadcast user plane function network element and the second multicast/broadcast user plane function network element, an MBS session for transmitting the data of the first multicast/broadcast service may have been established in advance.

And S106, the first multicast/broadcast user plane functional network element increases the first serial number corresponding to the data of the first multicast/broadcast service according to the first indication information.

The incrementing may refer to the description in step S103, for example, when the first multicast/broadcast user plane function network element receives the data of the first multicast/broadcast service, the first sequence number corresponding to the data of the first multicast/broadcast service is incremented by 1.

In one example, when the first indication information includes a start value of the first sequence number, the first multicast/broadcast user plane function network element adds 1 to the start value of the first sequence number according to the first indication information, and the value added with 1 is the value of the first sequence number corresponding to the data of the first multicast/broadcast service.

In another example, when the first indication information is FAR, the first multicast/broadcast user plane function network element sends the data of the first multicast/broadcast service to the specified IP address according to the first indication information.

And S107, the second multicast/broadcast user plane functional network element increases the second serial number corresponding to the data of the first multicast/broadcast service according to the second indication information.

The incrementing may refer to the description in step S103, for example, when the second multicast/broadcast user plane function network element receives the data of the first multicast/broadcast service, the second sequence number corresponding to the data of the first multicast/broadcast service is incremented by 1.

In an exemplary embodiment, when the second indication information includes a start value of the second sequence number, the second multicast/broadcast user plane function network element adds 1 to the start value of the second sequence number according to the second indication information, and the value obtained by adding 1 is the value of the second sequence number corresponding to the data of the second multicast/broadcast service.

And when the second indication information is FAR, the second multicast/broadcast user plane function network element sends the data of the second multicast/broadcast service to the appointed IP address according to the second indication information. The designated IP address is the same as the IP address that the first multicast/broadcast user plane function network element sends the data of the first multicast/broadcast service to in S106.

Thus, the first sequence number and the second sequence number may remain synchronized. If there is an access network device that can be connected to the first multicast/broadcast user plane function network element and the second multicast/broadcast user plane function network element at the same time, when the access network device receives data of the first multicast/broadcast service from the first multicast/broadcast user plane function network element and data of the first multicast/broadcast service from the second multicast/broadcast user plane function network element, the access network device can identify that the data from the two devices are data of the same multicast/broadcast service. Or the data of the same first multicast/broadcast service can be sent to the access network device only by the first multicast/broadcast user plane function network element or sent to the access network device only by the second multicast/broadcast user plane function network element, which is beneficial to reducing the consumption of air interface resources.

Alternatively, S106 and S107 may be executed sequentially or simultaneously. For example, S106 may be performed first, and S107 may be performed later; s107 may be executed first, and S106 may be executed later; s106 and S107 may also be performed simultaneously, and the present embodiment is not limited.

Alternatively, the message names in the present application are only examples, and the present application is not limited to the names of the messages between the network elements or devices, and the names of the messages may refer to descriptions in standard protocols.

Example two: fig. 4 is a flow chart of another communication method provided by the present application. The communication method is applied to the communication system shown in fig. 1. For example, the communication method may be implemented by interaction between an application server, a multicast/broadcast session management network element, a multicast/broadcast user plane function network element, a session management network element, an access network device, and a terminal device, including the following steps:

S201, the application server generates a session establishment request message.

The session establishment request message may include an identifier of the main PLMN in the MOCN, and further may further include identifier information of the first multicast/broadcast service.

The primary PLMN may also be referred to as a primary PLMN, and the MB-UPF in the primary PLMN may be referred to as a primary MB-UPF.

Illustratively, the session establishment request message includes an identification of the primary PLMN, which primary MB-UPF may be used for uniformly routing data of multicast/broadcast services in the MOCN, i.e. may not be limited to a specific service.

Illustratively, the session establishment request message includes identification information of the first multicast/broadcast service and an identification of a main PLMN, and the main MB-UPF may be used to uniformly route data of the first multicast/broadcast service in the MOCN, that is, access network devices in the MOCN may each establish a shared transmission channel with the main MB-UPF to implement forwarding of the data of the first multicast/broadcast service.

The description of the PLMN identification and the identification information of the multicast/broadcast service may refer to the corresponding description in example one, and will not be repeated herein.

S202, the application server sends the session establishment request message to the first multicast/broadcast session management network element and the second multicast/broadcast session management network element respectively.

Specifically, the application server can select one PLMN from PLMNs needing to transmit data of multicast/broadcast service in the MOCN as a main PLMN, and the access network equipment establishes a shared transmission channel with the MB-UPF of the main PLMN, namely, the access network equipment establishes the shared transmission channel with the same MB-UPF, thereby avoiding the condition that a plurality of MB-UPFs generate different serial numbers and solving the problem of asynchronous serial numbers.

For example, assume that there are 3 PLMNs in the MOCN, a first PLMN, a second PLMN, and a third PLMN, respectively, each of which 3 PLMNs can transmit data of a multicast/broadcast service (e.g., data of a first multicast/broadcast service). The application server selects the first PLMN as a main PLMN, and the access network device establishes a shared transmission channel with the MB-UPF of the first PLMN to transmit data of the first multicast/broadcast service.

Optionally, the session establishment request message further includes, but is not limited to, one or more of the following information: the type of multicast/broadcast service, the identification information of the multicast session, or the network sharing identification information, etc. The description of the above information may refer to the corresponding description in example one, and will not be repeated here.

Alternatively, the session establishment request message may be directly sent by the application server to the first multicast/broadcast session management network element or the second multicast/broadcast session management network element, or may be sent by the application server to the first multicast/broadcast session management network element or the second multicast/broadcast session management network element through the NEF, which is not limited by the present application.

It should be noted that the session establishment request messages sent to the first multicast/broadcast session management network element and the second multicast/broadcast session management network element in S202 may be slightly different, and are not limited.

In addition, steps S201-S202 may be replaced with: the application server sends the identification of the main PLMN to the first multicast/broadcast session management network element and the second multicast/broadcast session management network element respectively, and further, may also send the identification information of the first multicast/broadcast service, without limitation.

S203, the first multicast/broadcast session management network element sends the multicast/broadcast service session context to the first session management network element.

Wherein the multicast/broadcast service session context may include an identification of the primary PLMN and identification information of the first multicast/broadcast service.

The identification of the main PLMN and the identification information of the first multicast/broadcast service may be used for the first multicast/broadcast session management network element to trigger establishment of a shared transmission channel between the access network device and the multicast/broadcast user plane function network element in the main PLMN. Wherein the shared transmission channel is used for transmitting data of the first multicast/broadcast service. For example, assuming that the primary PLMN is the first PLMN, the first multicast/broadcast session management network element triggers the access network device in the MOCN (e.g., the access network device in the second PLMN) to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN after receiving the multicast/broadcast service session context.

The first multicast/broadcast session management network element and the first session management network element are located in the same PLMN, for example, may be located in the second PLMN or may be located in the first PLMN, and are not limited.

Optionally, the first multicast/broadcast session management network element triggers to establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, where "triggering" may be understood as: the first multicast/broadcast session management network element includes an identity of the primary PLMN in a multicast/broadcast service session context, and is ultimately sent to the access network device in the MOCN via the first session management network element. When the access network equipment in the MOCN has not established a transmission channel with the multicast/broadcast user plane function network element for the multicast/broadcast service, the access network equipment in the MOCN establishes a shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN.

Optionally, if the multicast/broadcast service session context further includes identification information of other multicast/broadcast services (for example, further includes identification information of a second multicast/broadcast service), the identification of the primary PLMN and the identification information of the second multicast/broadcast service are used by the first multicast/broadcast session management network element to trigger establishment of a second shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane functional network element in the primary PLMN, where the second shared transmission channel is used to transmit data of the second multicast/broadcast service.

Optionally, before performing S203, the first multicast/broadcast session management network element may further perform the following steps:

(1) The first multicast/broadcast session management network element, after receiving the session establishment request message, stores the identity of the primary PLMN (also referred to as PRIMARY PLMN ID) and the identity information of the first multicast/broadcast service in the MBS session context.

(2) After the first multicast/broadcast session management network element receives the session establishment request message, the rest of session establishment steps are triggered, for example, the first multicast/broadcast session management network element performs a step of generating multicast policy information by interaction with the PCF, the first multicast/broadcast session management network element performs a step of configuring the first multicast/broadcast user plane function network element, etc., and specific implementation manners may refer to corresponding descriptions in the existing protocol standard and are not repeated herein.

S204, the second multicast/broadcast session management network element sends the multicast/broadcast service session context to the second session management network element.

The multicast/broadcast service session context includes an identifier of a main PLMN in the MOCN, and further may further include identification information of the first multicast/broadcast service.

The identifier of the main PLMN and the identifier information of the first multicast/broadcast service may be used by the second multicast/broadcast session management network element to trigger establishment of a shared transmission channel between the access network device and the multicast/broadcast user plane function network element in the main PLMN. Wherein the shared transmission channel is used for transmitting data of the first multicast/broadcast service. For example, assuming that the primary PLMN is the first PLMN, the second multicast/broadcast session management network element triggers the access network device in the MOCN (e.g., the access network device in the second PLMN) to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN after receiving the multicast/broadcast service session context.

The second multicast/broadcast session management network element and the second session management network element are located in the same PLMN, for example, may be located in the second PLMN or may be located in the first PLMN, and are not limited.

Optionally, the second multicast/broadcast session management network element triggers the establishment of a shared transmission channel between the access network device of the MOCN and the multicast/broadcast user plane function network element corresponding to the identity of the main PLMN, where "triggering" may be understood as: the second multicast/broadcast session management network element includes an identification of the primary PLMN in the multicast/broadcast service session context, and is eventually sent to the access network device in the MOCN via the second session management network element. When the access network equipment in the MOCN has not established a transmission channel with the multicast/broadcast user plane function network element for the multicast/broadcast service, the access network equipment in the MOCN establishes a shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN.

Optionally, if the multicast/broadcast service session context further includes identification information of other multicast/broadcast services (for example, further includes identification information of a second multicast/broadcast service), the identification of the primary PLMN and the identification information of the second multicast/broadcast service are used by the second multicast/broadcast session management network element to trigger establishment of a second shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the primary PLMN, where the second shared transmission channel is used to transmit data of the second multicast/broadcast service.

Optionally, the second multicast/broadcast session management network element may further perform the following steps before performing S204:

(1) After receiving the session establishment request message, the second multicast/broadcast session management network element stores the identity of the primary PLMN (also referred to as PRIMARY PLMN ID) and the identity information of the first multicast/broadcast service in the MBS session context (i.e., stores them as part of the MBS session context).

(2) After receiving the session establishment request message, the second multicast/broadcast session management network element triggers the rest of session establishment steps, for example, the second multicast/broadcast session management network element performs a step of generating multicast policy information by interacting with the PCF, and the second multicast/broadcast session management network element performs a step of configuring a second multicast/broadcast user plane function network element, which may be specifically described with reference to the corresponding description in the existing protocol standard, and will not be repeated herein.

Alternatively, S203 and S204 may be executed sequentially or simultaneously. For example, S203 may be performed first, and S204 may be performed later; s204 may be performed first, and S203 may be performed later; s203 and S204 may also be performed simultaneously, and the present embodiment is not limited.

It can be seen that by executing the above steps S201-S204, the shared transmission channel establishment procedure of the access network device in the MOCN may be enhanced, so that the access network device in the MOCN and the multicast/broadcast user plane function network element of the main PLMN all establish a shared transmission channel, thereby avoiding the situation that multiple multicast/broadcast user plane function network elements generate different sequence numbers, and being beneficial to implementing data synchronization.

Optionally, example two may further include the following steps:

s205, the terminal device sends a multicast session request message to the second session management network element in the second PLMN.

Wherein the multicast session request message includes an identification of the multicast/broadcast service session.

S206, the second session management network element sends the multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the identifier of the multicast/broadcast service session according to the identifier of the multicast/broadcast service session.

The multicast session identifier may include information such as TMGI or IP multicast address. For example, if the terminal device requests to join the multicast group for a certain period of time, and sends a multicast session request message to the second session management network element.

In particular, the multicast session request message may be a PDU session establishment request (PDUSessionEstablishmentrequest) message or a PDU session modification request (PDUSessionModificationrequest) message.

And the second session management network element sends a multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the identifier of the multicast session according to the identifier of the multicast session, wherein the multicast/broadcast service session context request message is used for requesting to acquire the MBS session context corresponding to the multicast/broadcast service session. In particular, the multicast/broadcast service session context request message may be an interface-multicast broadcast session context status subscription request (Nmbsmf _ MBSSession _ ContextStatusSubscribe request) message provided by the MB-SMF.

S207, the multicast/broadcast session management network element corresponding to the multicast session identification sends the multicast/broadcast service session context to the second session management network element.

Wherein the multicast/broadcast service session context includes an identification of the primary PLMN and identification information of the first multicast/broadcast service.

S208, the second session management network element sends an N2 protocol data unit session resource message to the first access network device in the MOCN.

The N2 protocol data unit session resource message may include an identifier of the main PLMN and identifier information of a first multicast/broadcast service, where the first access network device is an access network device accessed by a terminal device joining the first multicast/broadcast service.

S209, the first access network device sends a first N2 multicast session request message to the multicast/broadcast session management network element in the main PLMN.

The first N2 multicast session request message is used for requesting to establish a shared transmission channel between the first access network and a multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

Illustratively, the first N2 multicast session request message may be a multicast broadcast and traffic distribution setup request transmission (MBS Distribution Setup Request Transfer) message. The message may be further included in a distribution setup request (DISTRIBUTION SETUP REQUEST) message sent by the first access network device to the AMF and sent by the AMF to a multicast/broadcast session management network element in the primary PLMN.

Optionally, the first N2 multicast session request message includes identification information of the first multicast/broadcast service. For example, if the identification of the first multicast/broadcast service is an IP multicast address, the first access network provides the entire content of the identification information of the first multicast/broadcast service to the MB-SMF. Specifically, the first access network device may first select a corresponding AMF according to the identifier of the main PLMN, and then the AMF finds a corresponding MB-SMF through NRF according to the IP multicast address. For another example, if the identifier of the first multicast/broadcast service is a TMGI list, the first access network device may find a corresponding TMGI from the TMGI list according to the identifier of the main PLMN (e.g., find a corresponding TMGI according to a PLMN ID field included in the TMGI). In this case, the first access network device only needs to provide part of the content of the identification information of the first multicast/broadcast service (e.g. to provide the TMGI corresponding to the main PLMN in the TMGI list).

Alternatively, the specific implementation of S209 may include the following two cases:

Case one: when the first access network device does not establish a shared transmission channel, the first access network device sends a first N2 multicast session request message to a multicast/broadcast session management network element in the main PLMN, and establishes a shared transmission channel with a multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

For example, assuming that the first access network device does not establish a shared transmission channel, and assuming that the main PLMN is the first PLMN, the first access network device may request, from a multicast/broadcast session management network element of the first PLMN, to establish a shared transmission channel with a multicast/broadcast user plane function network element of the first PLMN based on an identifier of the first PLMN, thereby facilitating the multicast/broadcast user plane function network element of the first PLMN to use the same sequence number for data of the first multicast/broadcast service, and facilitating data synchronization.

And a second case: when the first access network equipment establishes a shared transmission channel, the first access network equipment discards the N2 protocol data unit session resource message; or the first access network device sends third indication information to the second session management network element, wherein the third indication information is used for indicating that the shared transmission channel is established; or the first access network device sends a response message of the N2 protocol data unit session resource message to the second session management network element, which indicates that the first access network device has successfully received the N2 protocol data unit session resource message. The N2 protocol data unit session resource message may be an NGAP PDU session resource setup (NGAP PDU Session resource establishment) message or an NGAP PDU session resource modification (NGAP PDU Session resource modify) message, for example.

For example, assuming that the first access network device has established a shared transmission channel, assuming that the primary PLMN is the first PLMN, the first access network device may discard the identity of the first PLMN and the identity information of the first multicast/broadcast service, or send third indication information to the second session management network element, where the third indication information is used to indicate that the shared transmission channel has been established. That is, if the first access network device cannot be shared by all PLMNs of the MOCN, the first access network device may not use the identity of the main PLMN, but rather may establish a shared transmission channel by itself to transmit data of the first multicast/broadcast service.

Optionally, after the shared transmission channel is established, the first access network device may configure a radio resource control (radio resource control, RRC) connection of the terminal device. The specific implementation may refer to the corresponding description in the existing protocol standard, and will not be described herein.

S210, the first access network equipment sends a switching request message to the second access network equipment.

Wherein the handover request message includes an identification of the primary PLMN and identification information of the first multicast/broadcast service.

If the first access network device (i.e. S-RAN) determines to switch the terminal device, the first access network device may send a switch request message to the second access network device (i.e. T-RAN). The identification of the first PLMN and the identification information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the second access network device and the multicast/broadcast user plane function network element in the first PLMN, wherein the shared transmission channel is used for transmitting the data of the first multicast/broadcast service. Wherein the identity of the first public land mobile network refers to which PLMN MB-SMF the UE receives in the S-RAN the multicast session is managed by, which may not be the same as the registered PLMN ID of the UE.

S211, the second access network device sends a second N2 multicast session request message to the multicast/broadcast session management network element in the primary PLMN.

The second N2 multicast session request message includes identification information of the first multicast/broadcast service, and is used for requesting to establish a shared transmission channel between the second access network and the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service. The second N2 multicast session request message may be, for example, a multicast broadcast and traffic distribution setup request transmission (MBS Distribution Setup Request Transfer) message. It may be further included in a distribution setup request (DISTRIBUTION SETUP REQUEST) message sent by the second access network device to the AMF and sent by the AMF to the multicast/broadcast session management network element in the first PLMN.

Alternatively, the second N2 multicast session request message may include all or part of the content of the identification information of the first multicast/broadcast service. The specific implementation may refer to the description of the first N2 multicast session request message, which is not described herein.

Alternatively, the specific implementation of S211 may include the following two cases:

Case one: when the second access network device does not establish a shared transmission channel, the second access network device sends a second N2 multicast session request message to the multicast/broadcast session management network element in the main PLMN, and establishes a shared transmission channel with the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used to transmit data of the first multicast/broadcast service.

For example, assuming that the second access network device does not establish a shared transmission channel, the second access network device also establishes a shared transmission channel with the multicast/broadcast user plane function network element in the main PLMN, thereby facilitating the multicast/broadcast user plane function network element of the main PLMN to use the same sequence number for the data of the first multicast/broadcast service, and facilitating the data synchronization.

And a second case: the second access network device may, based on configuration reasons, not use the identity of the main PLMN, but rather establish the shared transmission channel through an existing procedure. For example, assuming that the second access network device cannot be shared by the PLMN, the second access network device establishes a shared transmission path with the multicast/broadcast user plane function network element of the second PLMN when the second access network device can only connect to the second PLMN.

Example three: fig. 5 is a flow chart of another communication method provided by the present application. The communication method is applied to the communication system shown in fig. 1. For example, the communication method may be implemented by interaction between a multicast/broadcast session management network element, a multicast/broadcast user plane function network element, a session management network element, an access network device, and a terminal device, including the steps of:

S301, the first access network device receives identification information of the first multicast/broadcast service.

The description of the identification information of the first multicast/broadcast service may refer to the corresponding description in example one, and will not be described herein.

Optionally, the step S301 further includes the following steps:

(1) The terminal device sends a multicast session request message to the first session management network element, the multicast session request message comprising an identification of the multicast session. In particular, the multicast session request message may be a PDU session establishment request (PDUSessionEstablishmentrequest) message or a PDU session modification request (PDUSessionModificationrequest) message.

(2) And the first session management network element sends a multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the identifier of the multicast session according to the identifier of the multicast session. In particular, the multicast/broadcast service session context request message may be an interface-multicast broadcast session context status subscription request t (Nmbsmf _ MBSSession _ ContextStatusSubscribereques) message provided by MB-SMF.

The multicast session identifier may include information such as TMGI or IP multicast address.

(3) The multicast/broadcast session management network element corresponding to the identification of the multicast session sends a multicast/broadcast service session context to the first session management network element, where the multicast/broadcast service session context includes identification information of the first multicast/broadcast service.

(4) The first session management network element sends identification information of the first multicast/broadcast service to the first access network device. Correspondingly, the first access network device receives identification information of a first multicast/broadcast service from the first session management network element.

The specific implementation manner of the steps (1) to (4) may refer to the corresponding description in the second example, and will not be repeated here.

Optionally, when the first access network device receives the identification information of the first multicast/broadcast service, the first access network device may trigger a process of establishing the shared transmission channel, and the specific implementation manner may refer to a corresponding process in the existing standard protocol, which is not described herein again.

S302, the first access network device sends an Xn interface message to the second access network device, wherein the Xn interface message comprises the identification information of the first multicast/broadcast service and the identification of the first PLMN.

The Xn interface message may be, for example, an NG-RAN node configuration update (NG-RAN node Configuration Update) request message, a resource status report (Resource Status Reporting) message, or a new design message, which is not limited by the present application.

The first PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a first shared transmission channel with a first access network device belongs, where the first shared transmission channel is used for transmitting data of a first multicast/broadcast service. For example, in this embodiment, it is assumed that the first access network device and the second access network device are located in the MOCN, and the first PLMN belongs to the MOCN, and both the first access network device and the second access network device have an Xn interface, and then the first access network may send, through the Xn interface, identification information of the first multicast/broadcast service and the identification of the first PLMN to the second access network device.

The identifier of the first PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a second shared transmission channel between the second access network device and the multicast/broadcast user plane function network element in the first PLMN, where the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service. For example, after the second access network device receives the identifier of the first PLMN and the identifier information of the first multicast/broadcast service, if the second access network device needs to establish a shared transmission channel later, the second access network device preferentially selects to establish a second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN, so that the second access network device and the first access network device both establish a shared transmission channel to the same PLMN, which is beneficial to realizing synchronization of data transmission.

Optionally, after the second access network device receives the Xn interface message, the second access network device does not immediately establish the shared transmission channel, but waits until the terminal device having the same identification information of the first multicast/broadcast service subsequently joins the second access network device, and the second access network device establishes the corresponding shared transmission channel.

Optionally, example three further includes the steps of:

S303, the second access network equipment receives the identification information of the second multicast/broadcast service.

The identification information of the second multicast/broadcast service and the identification information of the first multicast/broadcast service are similar, and the description of the identification information of the second multicast/broadcast service may refer to the description of the identification information of the first multicast/broadcast service in example one, which is not repeated herein.

Optionally, the step S303 further includes the following steps:

(5) After a period of time, the other terminal device sends a multicast session request message to the second session management network element, where the multicast session request message includes an identifier of the multicast session.

(6) And the second session management network element sends a multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the identifier of the multicast session according to the identifier of the multicast session.

(7) The multicast/broadcast session management network element corresponding to the identifier of the multicast session sends a multicast/broadcast service session context to the second session management network element, where the multicast/broadcast service session context includes identifier information of the second multicast/broadcast service.

(8) The second session management network element sends identification information of the second multicast/broadcast service to the second access network device. Correspondingly, the second access network device receives the identification information of the second multicast/broadcast service from the second session management network element.

The specific implementation manner of the steps (5) to (8) may refer to the corresponding description in the second example, and will not be repeated here. Alternatively, the second session management network element in the steps (5) to (8) may be replaced by the first session management network element, that is, the terminal device may request to join the multicast group in the same PLMN, or may request to join the multicast group in another PLMN.

S304, the second access network equipment establishes a second shared transmission channel with the multicast/broadcast user plane functional network element in the first PLMN according to the identification of the first PLMN, the identification information of the first multicast/broadcast service and the identification information of the second multicast/broadcast service.

Wherein the second shared transmission channel is used for transmitting data of the first multicast/broadcast service and data of the second multicast/broadcast service.

The specific implementation manner of S304 includes the following cases:

case one: when the types of the first multicast/broadcast service and the second multicast/broadcast service are the same, the second access network device sends a shared transmission channel establishment request message to the multicast/broadcast user plane function network element in the first PLMN.

For example, the type information of the first multicast/broadcast service may be included in the identification information of the first multicast/broadcast service, and the type information of the second multicast/broadcast service may be included in the identification information of the second multicast/broadcast service, and specifically, a certain field in the identification information carries the type information.

And a second case: when the multicast network address corresponding to the identification information of the first multicast/broadcast service is the same as the multicast network address corresponding to the identification information of the second multicast/broadcast service, the second access network device sends a shared transmission channel establishment request message to the multicast/broadcast user plane function network element in the first PLMN.

For example, the multicast network address corresponding to the first multicast/broadcast service may be included in the identification information of the first multicast/broadcast service, and the multicast network address corresponding to the second multicast/broadcast service may be included in the identification information of the second multicast/broadcast service, and specifically, a certain field in the identification information carries the multicast network address corresponding to the multicast/broadcast service.

And a third case: when the identification information of the first multicast/broadcast service is the same as the identification information of the second multicast/broadcast service, the second access network device sends a shared transmission channel establishment request message to the multicast/broadcast user plane function network element in the first PLMN.

In summary, if the second access network device finds that a shared transmission channel has been established by an access network device (e.g., the first access network device) in the vicinity, the second access network device will attempt to establish the shared transmission channel to the same PLMN, which is beneficial to achieve synchronization of data transmission.

Example four: fig. 6 is a flow chart of another communication method provided by the present application. The communication method is applied to the communication system shown in fig. 1. For example, the communication method may be implemented by interaction between an application server, a multicast/broadcast session management network element, a multicast/broadcast user plane function network element, a session management network element, an access network device, and a terminal device, including the following steps:

s401, the first access network device sends a switching request message to the second access network device.

Wherein the handover request message includes an identification of the first PLMN in the MOCN and identification information of the first multicast/broadcast service.

The first PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a first shared transmission channel with a first access network device belongs, where the first shared transmission channel is used for transmitting data of a first multicast/broadcast service.

The description of the identification information of the first PLMN and the first multicast/broadcast service may refer to the corresponding description in example one, and will not be repeated herein.

For example, if the terminal device belonging to the first access network device needs to be switched to the second access network device, the first access network device sends the identifier of the first PLMN and the identifier information of the first multicast/broadcast service to the second access network device.

Optionally, the handover request message further includes an identification of the PLMN to which the terminal device belongs. For example, the first access network device may further send an identifier of the PLMN to which the terminal device belongs to the second access network device, so that the second access network device uses a multicast/broadcast user plane function network element of the PLMN to which the terminal device belongs as a suboptimal choice for establishing the shared transmission channel.

Optionally, S401 further includes the following steps:

(1) The application server sends a first session setup request message to a first multicast/broadcast session management network element located in a first PLMN of the MOCN. Wherein the first session establishment request message includes identification information of the first multicast/broadcast service and an identification of the first PLMN.

(2) The application server sends a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN. Wherein the second session establishment request message includes an identification of the second PLMN and identification information of the first multicast/broadcast service.

Optionally, after the second multicast/broadcast session management network element receives the second session establishment request message, the second multicast/broadcast session management network element may trigger the remaining session establishment steps, for example, the second multicast/broadcast session management network element performs a step of generating multicast policy information by interaction with the PCF, and the specific implementation manner may refer to the corresponding description in the existing protocol standard, which is not described herein again.

(3) The terminal device sends a multicast session request message to a first session management network element in the first PLMN, the multicast session request message comprising an identification of the multicast session.

(4) And the first session management network element sends a multicast/broadcast service session context request message to the multicast/broadcast session management network element corresponding to the identifier of the multicast session according to the identifier of the multicast session.

(5) The multicast/broadcast session management network element corresponding to the identification of the multicast session sends a multicast/broadcast service session context to the first session management network element, where the multicast/broadcast service session context includes identification information of the first multicast/broadcast service.

(6) The first session management network element sends identification information of the first multicast/broadcast service to the first access network device. Correspondingly, the first access network device receives identification information of a first multicast/broadcast service from the first session management network element.

The specific implementation manner of the steps (1) and (6) may refer to the corresponding description in the second example or the third example, which is not repeated herein.

Optionally, after the establishment of the shared transmission channel is completed, the first access network device may configure RRC connection of the terminal device. The specific implementation may refer to the corresponding description in the existing protocol standard, and will not be described herein.

S402, the second access network equipment sends a switching response message to the first access network equipment.

Wherein the handover response message includes an identification of the second PLMN or fourth indication information.

The second PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a second shared transmission channel with the second access network device belongs. Optionally, the second PLMN is different from the first PLMN, which means that the second access network device establishes the shared transmission channel using a different PLMN identity than the first access network device. Or the second PLMN may be the first PLMN, that is, the PLMN to which the shared transmission channel established by the second access network device points is the first PLMN, which indicates that the second access network device multiplexes the first PLMN.

The fourth indication information is used for indicating that the multicast/broadcast user plane function network element establishing the second shared transmission channel with the second access network device belongs to the first PLMN. That is, the PLMN to which the shared transmission channel established by the second access network device points is the first PLMN, which means that the second access network device multiplexes the first PLMN.

The specific implementation of S402 may include the following cases:

Case one: when the second access network device does not establish a second shared transmission channel for transmitting the data of the first multicast/broadcast service, the second access network device establishes a second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN and the identification information of the first multicast/broadcast service.

For example, if the second access network device does not establish a shared transmission channel for transmitting the data of the first multicast/broadcast service, the second access network device may attempt to establish the shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN, so that the data of the first multicast/broadcast service is transmitted through the same shared transmission channel, which is beneficial for implementing data synchronization. In this case, the second PLMN identity included in the handover response message sent by the second access network device to the first access network device is the first PLMN identity; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that the multicast/broadcast user plane function network element that establishes the second shared transmission channel with the second access network device belongs to the first PLMN. That is, the PLMN to which the shared transmission channel established by the second access network device points is the first PLMN, which means that the second access network device multiplexes the first PLMN.

And a second case: when the second access network device has established a second shared transmission channel for transmitting data of the first multicast/broadcast service, the handover response message fed back by the second access network device to the first access network device includes an identification of the second PLMN or fourth indication information.

For example, if the second access network device has established a shared transmission channel for transmitting data of the first multicast/broadcast service, and the shared transmission channel points to a PLMN with the same identifier as the first PLMN, that is, the PLMN to which the shared transmission channel has been established by the second access network device points is the first PLMN, which means that the second access network device multiplexes the first PLMN, the handover response message fed back by the second access network device to the first access network device includes fourth indication information, where the fourth indication information is used to indicate that the multicast/broadcast user plane function network element that establishes the second shared transmission channel with the second access network device belongs to the first PLMN; or the second PLMN included in the handover response message is identified as the first PLMN.

For another example, if the second access network device has established a shared transmission channel for transmitting data of the first multicast/broadcast service, and the shared transmission channel points to a PLMN different from the first PLMN identifier, the handover response message fed back by the second access network device to the first access network device includes the identifier of the second PLMN, where the second PLMN is different from the first PLMN.

Optionally, when the second access network device has established a second shared transmission path for transmitting data of the first multicast/broadcast service, the second access network device may not feed back information to the first access network device.

Optionally, S402 further includes the following steps:

(7) And the first access network equipment forwards the data of the first multicast/broadcast service to the second access network equipment according to the identification of the second PLMN or the fourth indication information.

Optionally, the first access network device may forward the data of the first multicast/broadcast service to the second access network device in a preset period of time, so that the problem of packet loss may be partially alleviated, but more forwarding resources may not be occupied.

For example, if the second access network device feeds back to the first access network device that it has established a shared transmission channel with the multicast/broadcast user plane function network element in the other PLMN, the first access network device may transmit, to the second access network device, data of the multicast/broadcast service that is being sent by part of the first access network device at a certain time (e.g. based on a timer, etc.), so that the problem of packet loss may be partially alleviated. In this case, the second access network device forwards the data of the first multicast/broadcast service using unicast.

Optionally, when the identifier of the PLMN corresponding to the second shared transmission channel is different from the identifier of the first PLMN, the first access network device may stop forwarding the data of the first multicast/broadcast service to the second access network device.

To implement the functions of the method provided by the present application, the apparatus or device provided by the present application may include a hardware structure and/or a software module, where the functions are implemented in the form of a hardware structure, a software module, or a hardware structure plus a software module. Some of the functions described above are performed in a hardware configuration, a software module, or a combination of hardware and software modules, depending on the specific application of the solution and design constraints. The division of the modules in the present application is illustrative, and is merely a logic function division, and there may be another division manner in actual implementation. In addition, each functional module in the embodiments of the present application may be integrated in one processor, or may exist alone physically, or two or more modules may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules.

Fig. 7 is a schematic diagram of a communication device provided by the present application. The apparatus may comprise modules, which may be hardware circuits, software, or a combination of hardware circuits and software implementations, that perform the methods/operations/steps/actions described in connection with any of the embodiments shown in figures 3a through 6.

The apparatus 700 comprises a communication unit 701 and a processing unit 702 for implementing the methods performed by the respective network elements or devices in the foregoing embodiments.

In a possible implementation, the apparatus is or is located in a multicast/broadcast session management network element. Specifically, the communication unit 701 is configured to receive a first session establishment request message from an application server, where the first session establishment request message includes identification information of a first multicast/broadcast service and an identification of a first PLMN in the MOCN. The processing unit 702 is configured to send, according to the first session establishment request message, first indication information to the first multicast/broadcast user plane function network element through the communication unit 701, where the first indication information is used to instruct the first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data of the first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data; wherein the first multicast/broadcast session management network element and the first multicast/broadcast user plane function network element are located in a first PLMN.

Optionally, the first sequence number is used for the access network device in the MOCN to identify data of the first multicast/broadcast service from the first PLMN.

Optionally, the first session establishment request message further comprises a type of the multicast/broadcast service. When the type of the first multicast/broadcast service is a multicast service, the communication unit 701 is further configured to send first indication information to the first multicast/broadcast user plane function network element.

Optionally, the first session establishment request message further includes network sharing identification information; the network share identification information is used to indicate that the first multicast/broadcast service is shared in a temporary multicast group identification, TMGI, list of a second PLMN of the MOCN, the second PLMN being different from the first PLMN. The communication unit 701 is further configured to send first indication information to a first multicast/broadcast user plane function network element according to the network sharing identification information.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method implemented by the apparatus may instruct the corresponding first multicast/broadcast user plane function network element to perform special configuration, for example, instruct the first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data of the first multicast/broadcast service when the data is received (for example, add 1 to the first sequence number). Therefore, the first multicast/broadcast user plane function network element synchronously updates the sequence numbers of the data of the same multicast/broadcast service according to the indication of the first multicast/broadcast session management network element, and is beneficial to realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation, the apparatus is or is located in a multicast/broadcast session management network element. Specifically, the communication unit 701 is configured to receive a second session establishment request message from the application server, where the second session establishment request message includes identification information of the first multicast/broadcast service and an identification of the second PLMN in the MOCN. The processing unit 702 is configured to send, according to the second session establishment request message, second indication information to the second multicast/broadcast user plane function network element through the communication unit 701, where the second indication information is used to instruct the second multicast/broadcast user plane function network element to increment a second sequence number corresponding to the data of the first multicast/broadcast service when the second multicast/broadcast user plane function network element receives the data; wherein the second multicast/broadcast session management network element and the second multicast/broadcast user plane function network element are located in a second PLMN.

Optionally, the second sequence number is used for the access network device in the MOCN to identify data of the first multicast/broadcast service from the second PLMN.

Optionally, the first indication information includes a start value of a first sequence number, and the second indication information includes a start value of a second sequence number, where the start value of the first sequence number is the same as a start value of a second sequence number corresponding to the data of the first multicast/broadcast service in the second PLMN of the MOCN.

Optionally, the second session establishment request message further comprises a type of the multicast/broadcast service. When the type of the first multicast/broadcast service is a multicast service, the communication unit 701 is further configured to send first indication information to the second multicast/broadcast user plane function network element.

Optionally, the second session establishment request message further includes network sharing identification information; the network share identification information is used to indicate that the first multicast/broadcast service is shared in a temporary multicast group identification, TMGI, list of a second PLMN of the MOCN, the second PLMN being different from the first PLMN. The communication unit 701 is further configured to send second indication information to a second multicast/broadcast user plane function network element according to the network sharing identification information.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method implemented by the device may instruct the corresponding second multicast/broadcast user plane function network element to perform special configuration, for example, instruct the second multicast/broadcast user plane function network element to increment a second sequence number corresponding to the data (for example, add 1 to the second sequence number) when the second multicast/broadcast user plane function network element receives the data of the first multicast/broadcast service. Therefore, the second multicast/broadcast user plane function network element synchronously updates the sequence numbers of the data of the same multicast/broadcast service according to the indication of the second multicast/broadcast session management network element, thereby realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation, the apparatus is or is located in a multicast/broadcast user plane function network element. Specifically, the communication unit 701 is configured to receive first indication information from a multicast/broadcast session management network element, where the first indication information is configured to instruct a first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data of a first multicast/broadcast service when the data is received. The communication unit 701 is further configured to receive data of a first multicast/broadcast service from an application server; the processing unit 702 is configured to increment a first sequence number corresponding to the data according to the first indication information.

Optionally, the communication unit 701 is further configured to send data of the first multicast/broadcast service and the first sequence number corresponding to the data to an access network device in the MOCN, where the first multicast/broadcast user plane function network element is located in a first PLMN of the MOCN, and the first sequence number is used for identifying, by the access network device, the data of the first multicast/broadcast service from the first PLMN.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method implemented by the apparatus may be specifically configured according to the indication to process the user plane, for example, to increment the first sequence number corresponding to the data of the first multicast/broadcast service when the data is received, whether or not the data is to be transmitted to the access network device. Therefore, the first multicast/broadcast user plane function network element can synchronously update the sequence numbers of the data of the same multicast/broadcast service, and realize the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation, the apparatus is or is located in a multicast/broadcast user plane function network element. Specifically, the communication unit 701 receives second indication information from the second multicast/broadcast session management network element, where the second indication information is used to instruct the second multicast/broadcast user plane function network element to increment a second sequence number corresponding to the data when receiving the data of the first multicast/broadcast service. The communication unit 701 is further configured to receive data of a first multicast/broadcast service from an application server; the processing unit 702 is configured to increment a second serial number corresponding to the data according to the second indication information.

Optionally, the communication unit 701 is further configured to send data of the first multicast/broadcast service and a second sequence number corresponding to the data to an access network device in the MOCN, where the second multicast/broadcast user plane function network element is located in a second PLMN of the MOCN, and the second sequence number is used for identifying the data of the first multicast/broadcast service from the second PLMN by the access network device.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method implemented by the apparatus may be specifically configured according to the indication to process the user plane, for example, to increment the second sequence number corresponding to the data of the first multicast/broadcast service when the data is received, regardless of whether the data is to be transmitted to the access network device. Therefore, the second multicast/broadcast user plane function network element can synchronously update the sequence numbers of the data of the same multicast/broadcast service, and realize the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation, the device is an application server, or is located in an application server. Specifically, the communication unit 701 is configured to send a first session establishment request message to a first multicast/broadcast session management network element located in a first PLMN of the MOCN, where the first session establishment request message includes an identification of the first PLMN and identification information of a first multicast/broadcast service. The communication unit 701 is further configured to send a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN, where the second session establishment request message includes an identifier of the second PLMN and identifier information of the first multicast/broadcast service; wherein the first PLMN is different from the second PLMN. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, the first session request message further includes a start value of a first sequence number corresponding to data of the first multicast/broadcast service in the first PLMN; the second session request message further includes a start value of a second sequence number corresponding to data of the first multicast/broadcast service in the second PLMN; wherein the start value of the first sequence number is the same as the start value of the second sequence number.

The specific execution flow of the communication unit 701 in this embodiment may refer to the corresponding description in the foregoing method embodiment, which is not repeated here. The communication method realized by the device can send the identification information of the first multicast/broadcast service to the multicast/broadcast session management network elements in different PLMNs of the MOCN, and then send the indication information to the multicast/broadcast user plane function network elements respectively corresponding to the multicast/broadcast session management network elements in different PLMNs, thereby being beneficial to enabling the multicast/broadcast user plane function network elements in different PLMNs to simultaneously receive the data of the first multicast/broadcast service from the application server and synchronously updating the serial numbers of the data aiming at the first multicast/broadcast service, and further being beneficial to realizing data synchronization.

In a possible implementation, the device is an application server, or is located in an application server. Specifically, the processing unit 702 is configured to generate a session establishment request message, where the session establishment request message includes an identifier of a main PLMN and identifier information of a first multicast/broadcast service in the MOCN. The communication unit 701 is configured to send the session establishment request message to a multicast/broadcast session management network element. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN by the multicast/broadcast session management network element, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

Optionally, the multicast/broadcast session management network element is located in the main PLMN, or the multicast/broadcast session management network element is located in a PLMN other than said main PLMN in the MOCN.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method implemented by the device can designate a certain PLMN in the MOCN as a main PLMN (called main PLMN for short), so that the access network equipment in the MOCN and the multicast/broadcast user plane function network element of the main PLMN establish a shared transmission channel, and the multicast/broadcast user plane function network element of the main PLMN uses the same serial number for the data of the same multicast/broadcast service, thereby being beneficial to realizing data synchronization.

In a possible implementation, the apparatus is or is located in a multicast/broadcast session management network element. Specifically, the communication unit 701 is configured to receive a session establishment request message from an application server, where the session establishment request message includes an identifier of a main PLMN in the MOCN and identifier information of a first multicast/broadcast service. The communication unit 701 is further configured to send a multicast/broadcast service session context to the first session management network element, where the multicast/broadcast service session context includes an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identification of the main PLMN and the identification information of the first multicast/broadcast service are used for the first multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, the first multicast/broadcast session management network element and the first session management network element are located in a main PLMN.

The specific execution flow of the communication unit 701 in this embodiment may refer to the corresponding description in the foregoing method embodiment, which is not repeated here. The communication method implemented by the device can send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the first session management network element, so that the first session management network element triggers the establishment of a shared transmission channel between the access network equipment in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN, thereby enabling the multicast/broadcast user plane functional network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service, and being beneficial to realizing data synchronization.

In a possible implementation, the apparatus is or is located in a multicast/broadcast session management network element. Specifically, the communication unit 701 is configured to receive a session establishment request message from an application server, where the session establishment request message includes an identifier of a main PLMN in the MOCN and identifier information of a first multicast/broadcast service. The communication unit 701 is further configured to send a multicast/broadcast service session context to the second session management network element, where the multicast/broadcast service session context includes an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for the second multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device of the MOCN and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, the second multicast/broadcast session management network element and the second session management network element are located in a PLMN other than the main PLMN in the MOCN.

The specific execution flow of the communication unit 701 in this embodiment may refer to the corresponding description in the foregoing method embodiment, which is not repeated here. The communication method implemented by the device can send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the second session management network element, so that the second session management network element triggers the establishment of a shared transmission channel between the access network equipment in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN, thereby enabling the multicast/broadcast user plane functional network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service, and being beneficial to realizing data synchronization.

In a possible implementation manner, the device is a session management network element, or is located in the session management network element. Specifically, the communication unit 701 is configured to receive a multicast session request message from a terminal device, where the multicast session request message includes an identifier of a multicast session. The processing unit 702 is configured to send, according to the identifier of the multicast session, a multicast/broadcast service session context request message to a multicast/broadcast session management network element corresponding to the identifier of the multicast session through the communication unit 701. The communication unit 701 is further configured to receive a multicast/broadcast service session context from a multicast/broadcast session management network element, where the multicast/broadcast service session context includes an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device accessed by the terminal device and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

Optionally, the communication unit 701 is further configured to send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to an access network device in the multi-operator core network.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method realized by the device can request the multicast/broadcast session management network element corresponding to the identifier of the multicast session to acquire the session context of the multicast/broadcast service, thereby acquiring the identifier of the main PLMN and the identifier information of the first multicast/broadcast service, triggering the establishment of a shared transmission channel between the access network device accessed by the terminal device and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, and being beneficial to enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service and being beneficial to realizing the data synchronization.

In a possible implementation manner, the device is an access network device or is located in the access network device. Specifically, the communication unit 701 is configured to receive a first N2 protocol data unit session resource message from a first session management network element, where the first N2 protocol data unit session resource message includes an identifier of a main PLMN in a MOCN and identifier information of a first multicast/broadcast service, and the first access network device is located in the MOCN. The communication unit 701 is further configured to send a first N2 multicast session request message to a multicast/broadcast session management network element in the primary PLMN, where the first N2 multicast session request message includes identification information of the first multicast/broadcast service. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, when the first access network device does not establish the shared transmission channel, the communication unit 701 is further configured to send identification information of the first multicast/broadcast service to a multicast/broadcast session management network element in the main PLMN. The processing unit 702 is configured to establish a shared transmission channel with a multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

Optionally, the communication unit 701 is further configured to receive a second N2 protocol data unit session resource message from a second session management network element, where the second N2 protocol data unit session resource message includes an identifier of the main PLMN and identifier information of the first multicast/broadcast service. The processing unit 702 is configured to discard the second N2 protocol data unit session resource message when the first access network device has established the shared transmission channel; or the communication unit 701 is further configured to send third indication information to the second session management network element, where the third indication information is used to indicate that the shared transmission channel is established. Wherein the first session management network element is located in the main PLMN, and the second session management network element is located in PLMNs other than the main PLMN in the MOCN; or the first session management network element is located in a PLMN other than the main PLMN in the MOCN, and the second session management network element is located in the main PLMN.

Optionally, the communication unit 701 is further configured to send a handover request message to the second access network device, where the handover request message includes an identifier of the main PLMN and identifier information of the first multicast/broadcast service. The identity of the main PLMN and the identity information of the first multicast/broadcast service are used to trigger the establishment of a shared transmission channel between the second access network device and the multicast/broadcast user plane functional network element in the main PLMN, where the shared transmission channel is used to transmit the data of the first multicast/broadcast service.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method realized by the device can request the multicast/broadcast session management network element of the main PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN based on the identification of the main PLMN, thereby being beneficial to enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service and being beneficial to realizing data synchronization.

In a possible implementation manner, the device is an access network device or is located in the access network device. Specifically, the communication unit 701 is configured to receive identification information of a first multicast/broadcast service. The communication unit 701 is further configured to send an Xn interface message to the second access network device, where the Xn interface message includes identification information of a first multicast/broadcast service and an identification of a first public land mobile network PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The identifier of the first PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a second shared transmission channel between the second access network device and the multicast/broadcast user plane function network element in the first PLMN, where the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, the first access network device and the second access network device are located in a multi-operator core network MOCN, and the first PLMN belongs to the MOCN.

In this embodiment, the specific execution flow of the communication unit 701 may refer to the corresponding description in the foregoing method embodiment, which is not repeated here. The communication method realized by the device enables the access network equipment which is positioned in the MOCN and has the Xn interface to interact the identification information of the multicast/broadcast service and the identification of the PLMN to which the access network equipment belongs through the Xn interface, thereby enabling the access network equipment in the MOCN with the Xn interface to establish a shared transmission channel with the same multicast/broadcast user plane function network element and being beneficial to realizing data synchronization.

In a possible implementation manner, the device is an access network device or is located in the access network device. Specifically, the communication unit 701 is configured to receive an Xn interface message from a first access network device, where the Xn interface message includes identification information of a first multicast/broadcast service, and an identification of a first PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The communication unit 701 is further configured to receive identification information of the second multicast/broadcast service. The processing unit 702 is configured to establish a second shared transmission channel with a multicast/broadcast user plane function network element in the first PLMN according to the identifier of the first PLMN, the identifier information of the first multicast/broadcast service, and the identifier information of the second multicast/broadcast service, where the second shared transmission channel is used for transmitting data of the first multicast/broadcast service and data of the second multicast/broadcast service. Wherein the first access network device and the second access network device are located in a MOCN, and the first PLMN belongs to the MOCN.

Optionally, when the types of the first multicast/broadcast service and the second multicast/broadcast service are the same, the communication unit 701 is configured to send a shared transmission channel establishment request message to a multicast/broadcast user plane function network element in the first PLMN; or when the multicast network address corresponding to the identification information of the first multicast/broadcast service is the same as the multicast network address corresponding to the identification information of the second multicast/broadcast service, the communication unit 701 is configured to send a shared transmission channel establishment request message to the multicast/broadcast user plane function network element in the first PLMN.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method realized by the device enables the second access network equipment which is positioned in the MOCN and is provided with the Xn interface to receive the identification information of the multicast/broadcast service of other access network equipment and the identification of the affiliated PLMN through the Xn interface, thereby enabling the access network equipment in the MOCN provided with the Xn interface to establish a shared transmission channel with the multicast/broadcast user plane function network element in the PLMN, and being beneficial to realizing data synchronization.

In a possible implementation manner, the device is an access network device or is located in the access network device. Specifically, the communication unit 701 is configured to send a handover request message to a second access network device, where the handover request message includes an identifier of a first PLMN in the MOCN and identifier information of a first multicast/broadcast service, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The communication unit 701 is further configured to receive a handover response message from a second access network device, where the handover response message includes an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that the multicast/broadcast user plane function network element that establishes the second shared transmission channel with the second access network device belongs to the first PLMN. Wherein the first access network device and the second access network device are located in the MOCN, and the first PLMN and the second PLMN are different. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, the communication unit 701 is further configured to forward the data of the first multicast/broadcast service to the second access network device according to the identifier of the second PLMN or fourth indication information.

Optionally, the communication unit 701 is further configured to receive a first N2 protocol data unit session resource message, where the first N2 protocol data unit session resource message includes an identification of the first PLMN and identification information of the first multicast/broadcast service. The processing unit 702 is configured to establish a first shared transmission channel with a multicast/broadcast user plane function network element in the first PLMN according to the identifier of the first PLMN and the identifier information of the first multicast/broadcast service.

Optionally, the handover request message is used for requesting handover of the terminal device from the first access network device to the second access network device, and the handover request message further includes an identifier of a PLMN to which the terminal device belongs.

In this embodiment, the specific execution flow of the communication unit 701 may refer to the corresponding description in the foregoing method embodiment, which is not repeated here. The communication method realized by the device can send the identifier of the first PLMN to which the first access network device belongs to the second access network device, which is beneficial to enabling the second access network device to request the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN based on the identifier of the first PLMN, thereby enabling the data of the same multicast/broadcast service to be transmitted through the same shared transmission channel and being beneficial to realizing data synchronization.

In a possible implementation manner, the device is an access network device or is located in the access network device. Specifically, the communication unit 701 is configured to receive a handover request message from a first access network device, where the handover request message includes an identifier of a first PLMN and identifier information of a first multicast/broadcast service in the MOCN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The communication unit 701 is further configured to send a handover response message to the first access network device, where the handover response message includes an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that the multicast/broadcast user plane function network element that establishes the second shared transmission channel with the second access network device belongs to the first PLMN. Wherein the first access network device and the second access network device are located in the MOCN, the first PLMN and the second PLMN being different. It should be noted that in this embodiment, the processing unit 702 is optional and is not limited.

Optionally, when the second access network device does not establish the second shared transmission channel for transmitting the data of the first multicast/broadcast service, the processing unit 702 is configured to establish the second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identifier of the first PLMN and the identifier information of the first multicast/broadcast service.

Optionally, when the second access network device has established a second shared transmission channel for transmitting data of the first multicast/broadcast service, the handover response message includes an identifier of a PLMN corresponding to the second shared transmission channel, or the handover response message includes the fourth indication information.

Optionally, when the identifier of the PLMN corresponding to the second shared transmission channel is different from the identifier of the first PLMN, the communication unit 701 is configured to receive data of the first multicast/broadcast service from the first access network device. The processing unit 702 is configured to forward data of the first multicast/broadcast service using a unicast mode.

Optionally, the processing unit 702 is configured to establish a second shared transmission channel according to the identifier of the first PLMN, or the identifier of the second PLMN, or the identifier of the PLMN to which the terminal device belongs.

In this embodiment, the specific execution flow of the communication unit 701 and the processing unit 702 may refer to the corresponding descriptions in the foregoing method embodiments, which are not repeated herein. The communication method realized by the device can receive the identifier of the first PLMN to which the first access network equipment belongs, so that the second access network equipment requests the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN based on the identifier of the first PLMN, and the data of the same multicast/broadcast service is transmitted through the same shared transmission channel, thereby being beneficial to realizing data synchronization.

Fig. 8 is a schematic diagram of another communication apparatus according to the present application, for implementing the communication method in the above-mentioned method embodiments. The apparatus 800 may also be a system-on-chip, or may be a network element or device as described in the above method embodiments.

Wherein the apparatus 800 comprises a communication interface 801 and a processor 802. The communication interface 801 may be, for example, a transceiver, an interface, a bus, a circuit, or a device capable of implementing a transceiving function. Wherein the communication interface 801 is for communicating with other apparatus over a transmission medium so that the apparatus 800 may communicate with other apparatus. The processor 802 is configured to perform process-related operations.

In a possible implementation manner, the apparatus 800 may be or may be located in a multicast/broadcast session management network element, and in particular, the communication interface 801 is configured to receive a first session establishment request message from an application server, where the first session establishment request message includes identification information of a first multicast/broadcast service and an identification of a first PLMN in the MOCN. The processor 802 is configured to send, according to a first session establishment request message, first indication information to a first multicast/broadcast user plane function network element through the communication interface 801, where the first indication information is used to instruct the first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data of a first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data; wherein the first multicast/broadcast session management network element and the first multicast/broadcast user plane function network element are located in a first PLMN.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method implemented by the device may instruct the corresponding first multicast/broadcast user plane functional network element to perform special configuration, for example, instruct the first multicast/broadcast user plane functional network element to increment a first sequence number corresponding to data of the first multicast/broadcast service when the data is received (for example, add 1 to the first sequence number). Therefore, the first multicast/broadcast user plane function network element synchronously updates the sequence numbers of the data of the same multicast/broadcast service according to the indication of the first multicast/broadcast session management network element, and is beneficial to realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the apparatus 800 may be or may be located in a multicast/broadcast session management network element, and in particular, the communication interface 801 is configured to receive a second session establishment request message from the application server, where the second session establishment request message includes identification information of the first multicast/broadcast service and an identification of the second PLMN in the MOCN. The processor 802 is configured to send second indication information to a second multicast/broadcast user plane function network element through the communication interface 801 according to the second session establishment request message, where the second indication information is used to instruct the second multicast/broadcast user plane function network element to increment a second sequence number corresponding to the data of the first multicast/broadcast service when the second multicast/broadcast user plane function network element receives the data; wherein the second multicast/broadcast session management network element and the second multicast/broadcast user plane function network element are located in a second PLMN.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method implemented by the device may instruct the corresponding second multicast/broadcast user plane functional network element to perform a special configuration, for example, instruct the second multicast/broadcast user plane functional network element to increment a second sequence number corresponding to the data (for example, add 1 to the second sequence number) when the second multicast/broadcast user plane functional network element receives the data of the first multicast/broadcast service. Therefore, the second multicast/broadcast user plane function network element synchronously updates the sequence numbers of the data of the same multicast/broadcast service according to the indication of the second multicast/broadcast session management network element, thereby realizing the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the apparatus 800 may be a multicast/broadcast user plane function network element, or may be located in a multicast/broadcast user plane function network element, and specifically, the communication interface 801 is configured to receive first indication information from a multicast/broadcast session management network element, where the first indication information is used to instruct the first multicast/broadcast user plane function network element to increment a first sequence number corresponding to data when the first multicast/broadcast service data is received. The communication interface 801 is also for receiving data of a first multicast/broadcast service from an application server; the processor 802 is configured to increment a first sequence number corresponding to the data according to the first indication information.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method implemented by the device may specifically configure the processing of the user plane according to the indication, e.g. increment the first sequence number corresponding to the data of the first multicast/broadcast service when the data is received, whether or not the data is to be sent to the access network device. Therefore, the first multicast/broadcast user plane function network element can synchronously update the sequence numbers of the data of the same multicast/broadcast service, and realize the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the apparatus 800 may be a multicast/broadcast user plane function network element, or may be located in a multicast/broadcast user plane function network element, and specifically, the communication interface 801 is configured to receive second indication information from a second multicast/broadcast session management network element, where the second indication information is configured to instruct the second multicast/broadcast user plane function network element to increment a second sequence number corresponding to data when the second multicast/broadcast user plane function network element receives the data of the first multicast/broadcast service. The communication interface 801 is also for receiving data of a first multicast/broadcast service from an application server; the processor 802 is configured to increment a second serial number corresponding to the data according to the second indication information.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method implemented by the device may indicate that the processing of the user plane is specifically configured, e.g. the second sequence number corresponding to the data of the first multicast/broadcast service is incremented upon receipt of the data, whether or not the data is to be sent to the access network device. Therefore, the second multicast/broadcast user plane function network element can synchronously update the sequence numbers of the data of the same multicast/broadcast service, and realize the synchronization of the sequence numbers of the data of the same multicast/broadcast service in different PLMNs.

In a possible implementation manner, the apparatus 800 may be an application server or may be located in an application server, and in particular, the processor 802 is configured to send, through the communication interface 801, a first session establishment request message to a first multicast/broadcast session management network element located in a first PLMN of the MOCN, where the first session establishment request message includes an identification of the first PLMN and identification information of the first multicast/broadcast service. The processor 802 is further configured to send a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN through the communication interface 801, the second session establishment request message including an identification of the second PLMN and identification information of the first multicast/broadcast service; wherein the first PLMN is different from the second PLMN.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the method executed by the communication unit in the embodiment of fig. 7, and the description in the foregoing method embodiment will not be repeated here. The communication method realized by the device can send the identification information of the first multicast/broadcast service to the multicast/broadcast session management network elements in different PLMNs of the MOCN, and then send the indication information to the multicast/broadcast user plane function network elements respectively corresponding to the multicast/broadcast session management network elements in different PLMNs, thereby being beneficial to enabling the multicast/broadcast user plane function network elements in different PLMNs to simultaneously receive the data of the first multicast/broadcast service from the application server and synchronously updating the serial numbers of the data aiming at the first multicast/broadcast service, and further being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be an application server or may be located in an application server, and in particular, the processor 802 is configured to generate a session establishment request message, where the session establishment request message includes an identifier of a main PLMN in the MOCN and identifier information of the first multicast/broadcast service. The communication interface 801 is used to send the session establishment request message to a multicast/broadcast session management network element. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane functional network element in the main PLMN by the multicast/broadcast session management network element, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method implemented by the device can designate a certain PLMN in the MOCN as the main PLMN, so that the access network device in the MOCN and the multicast/broadcast user plane function network element of the main PLMN establish a shared transmission channel, and the multicast/broadcast user plane function network element of the main PLMN uses the same serial number for the data of the same multicast/broadcast service, thereby being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be or may be located in a multicast/broadcast session management network element, and specifically, the communication interface 801 is configured to receive a session establishment request message from an application server, where the session establishment request message includes an identifier of a main PLMN in the MOCN and identifier information of a first multicast/broadcast service. The processor 802 is configured to send a multicast/broadcast service session context to the first session management network element via the communication interface 801, the multicast/broadcast service session context comprising an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identification of the main PLMN and the identification information of the first multicast/broadcast service are used for the first multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the method executed by the communication unit in the embodiment of fig. 7, and the description in the foregoing method embodiment will not be repeated here. The communication method implemented by the device can send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the first session management network element, so that the first session management network element triggers the establishment of a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, thereby enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service, and being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be or may be located in a multicast/broadcast session management network element, and specifically, the communication interface 801 is configured to receive a session establishment request message from an application server, where the session establishment request message includes an identifier of a main PLMN in the MOCN and identifier information of a first multicast/broadcast service. The processor 802 is configured to send a multicast/broadcast service session context to the second session management network element via the communication interface 801, the multicast/broadcast service session context comprising an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for the second multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device of the MOCN and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the method executed by the communication unit in the embodiment of fig. 7, and the description in the foregoing method embodiment will not be repeated here. The communication method implemented by the device can send the identifier of the main PLMN and the identifier information of the first multicast/broadcast service to the second session management network element, so that the second session management network element triggers the establishment of a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, thereby enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service, and being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be a session management network element or may be located in a session management network element, and in particular, the communication interface 801 is configured to receive a multicast session request message from a terminal device, where the multicast session request message includes an identifier of a multicast session. The processor 802 is configured to send a multicast/broadcast service session context request message to a multicast/broadcast session management network element corresponding to the identifier of the multicast session through the communication interface 801 according to the identifier of the multicast session. The communication interface 801 is further configured to receive a multicast/broadcast service session context from a multicast/broadcast session management network element, the multicast/broadcast service session context comprising an identity of the primary PLMN and identity information of the first multicast/broadcast service. The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device accessed by the terminal device and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method realized by the device can request the multicast/broadcast session management network element corresponding to the identifier of the multicast session to acquire the session context of the multicast/broadcast service, thereby acquiring the identifier of the main PLMN and the identifier information of the first multicast/broadcast service, triggering the establishment of a shared transmission channel between the access network device accessed by the terminal device and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, and being beneficial to enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service and being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be an access network device or may be located in an access network device, and in particular, the communication interface 801 is configured to receive a first N2 protocol data unit session resource message from a first session management network element, where the first N2 protocol data unit session resource message includes an identifier of a main PLMN in a MOCN and identifier information of a first multicast/broadcast service, and the first access network device is located in the MOCN. The processor 802 is configured to send a first N2 multicast session request message to a multicast/broadcast session management network element in the primary PLMN via the communication interface 801, the first N2 multicast session request message comprising identification information of the first multicast/broadcast service.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method realized by the device can request the multicast/broadcast session management network element of the main PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the main PLMN based on the identification of the main PLMN, thereby being beneficial to enabling the multicast/broadcast user plane function network element of the main PLMN to use the same serial number for the data of the same multicast/broadcast service and being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be an access network device, or may be located in an access network device, and specifically, the communication interface 801 is configured to receive identification information of the first multicast/broadcast service. The processor 802 is configured to send an Xn interface message to the second access network device through the communication interface 801, where the Xn interface message includes identification information of a first multicast/broadcast service and an identification of a first public land mobile network PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The identifier of the first PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a second shared transmission channel between the second access network device and the multicast/broadcast user plane function network element in the first PLMN, where the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the method executed by the communication unit in the embodiment of fig. 7, and the description in the foregoing method embodiment will not be repeated here. The communication method realized by the device enables the access network devices which are positioned in the MOCN and provided with the Xn interface to interact the identification information of the multicast/broadcast service and the identification of the PLMN to which the access network devices belong through the Xn interface, thereby enabling the access network devices in the MOCN provided with the Xn interface to establish a shared transmission channel with the same multicast/broadcast user plane function network element and being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be an access network device or may be located in an access network device, and specifically, the communication interface 801 is configured to receive an Xn interface message from a first access network device, where the Xn interface message includes identification information of a first multicast/broadcast service, and an identification of a first PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The communication interface 801 is also used for receiving identification information of the second multicast/broadcast service. The processor 802 is configured to establish a second shared transmission channel with a multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN, the identification information of the first multicast/broadcast service, and the identification information of the second multicast/broadcast service, where the second shared transmission channel is used for transmitting data of the first multicast/broadcast service and data of the second multicast/broadcast service. Wherein the first access network device and the second access network device are located in a MOCN, and the first PLMN belongs to the MOCN.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method realized by the device enables the second access network device which is positioned in the MOCN and has the Xn interface to receive the identification information of the multicast/broadcast service of other access network devices and the identification of the affiliated PLMN through the Xn interface, thereby enabling the access network device in the MOCN with the Xn interface to establish a shared transmission channel with the multicast/broadcast user plane function network element in the PLMN, and being beneficial to realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be an access network device or may be located in an access network device, and specifically, the processor 802 is configured to send a handover request message to a second access network device through the communication interface 801, where the handover request message includes an identifier of a first PLMN in the MOCN and identifier information of a first multicast/broadcast service, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device, where the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The communication interface 801 is further configured to receive a handover response message from a second access network device, where the handover response message includes an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that the multicast/broadcast user plane function network element that establishes the second shared transmission channel with the second access network device belongs to the first PLMN. Wherein the first access network device and the second access network device are located in the MOCN, and the first PLMN and the second PLMN are different.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the method executed by the communication unit in the embodiment of fig. 7, and the description in the foregoing method embodiment will not be repeated here. The communication method realized by the device can send the identifier of the first PLMN to which the first access network device belongs to the second access network device, which is favorable for enabling the second access network device to request the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN based on the identifier of the first PLMN, thereby transmitting the data of the same multicast/broadcast service through the same shared transmission channel and being favorable for realizing data synchronization.

In a possible implementation manner, the apparatus 800 may be an access network device, or may be located in an access network device, and specifically, the communication interface 801 is configured to receive a handover request message from a first access network device, where the handover request message includes an identifier of a first PLMN in the MOCN and identification information of a first multicast/broadcast service, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device, where the first shared transmission channel is used to transmit data of the first multicast/broadcast service. The processor 802 is configured to send a handover response message to the first access network device through the communication interface 801, where the handover response message includes an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that the multicast/broadcast user plane function network element that establishes the second shared transmission channel with the second access network device belongs to the first PLMN. Wherein the first access network device and the second access network device are located in the MOCN, the first PLMN and the second PLMN being different.

The specific execution flow of the communication interface 801 and the processor 802 in this embodiment may refer to the methods executed by the communication unit and the processing unit in the embodiment of fig. 7, and the descriptions in the foregoing method embodiments are not repeated herein. The communication method implemented by the device can receive the identifier of the first PLMN to which the first access network device belongs, so that the second access network device requests the multicast/broadcast session management network element of the first PLMN to establish a shared transmission channel with the multicast/broadcast user plane function network element of the first PLMN based on the identifier of the first PLMN, and the data of the same multicast/broadcast service is transmitted through the same shared transmission channel, thereby being beneficial to realizing data synchronization.

Optionally, the apparatus 800 may further comprise at least one memory 803 for storing program instructions and/or data. In one embodiment, the memory is coupled to the processor. The coupling in the present application is an indirect coupling or communication connection between devices, units or modules, which may be in electrical, mechanical or other form for the exchange of information between the devices, units or modules. The processor may operate in conjunction with the memory. The processor may execute program instructions stored in the memory. The at least one memory and the processor are integrated.

The specific connection medium between the communication interface, the processor, and the memory is not limited in the present application. For example, the memory, the processor, and the communication interface are connected by a bus, and the bus 804 is shown in fig. 8 with a thick line, and the connection between other components is merely schematically illustrated and not limited thereto. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 8, but not only one bus or one type of bus.

In the present application, the processor may be a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or perform the methods, steps, and logic blocks disclosed in the present application. The general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the present application may be embodied directly in a hardware processor for execution, or in a combination of hardware and software modules in a processor for execution.

In the present application, the memory may be a nonvolatile memory such as a hard disk (HARD DISK DRIVE, HDD) or a Solid State Disk (SSD), or may be a volatile memory (RAM) such as a random-access memory (RAM). The memory is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such. The memory of the present application may also be circuitry or any other device capable of performing the function of storing program instructions and/or data.

The present application provides a communications device comprising a processor coupled to a memory for reading and executing computer instructions stored in the memory to implement a communications method in any of the embodiments shown in figures 3a to 6.

The present application provides a communication system comprising one or more of the individual network elements or devices of any of the embodiments shown in fig. 3a to 6.

The application provides a computer readable storage medium. The computer-readable storage medium stores a program or instructions. The program or instructions, when run on a computer, cause the computer to perform the communication method in any of the embodiments shown in fig. 3a to 6.

A computer program product is provided in the present application. The computer program product includes instructions. The instructions, when executed on a computer, cause the computer to perform the communication method of any of the embodiments shown in fig. 3a to 6.

The present application provides a chip or chip system comprising at least one processor and an interface, the interface and the at least one processor being interconnected by wires, the at least one processor being adapted to run a computer program or instructions to perform a communication method as in any of the embodiments shown in fig. 3a to 6.

The interface in the chip may be an input/output interface, a pin, a circuit, or the like.

The above-mentioned chip system may be a System On Chip (SOC) or a baseband chip, etc., where the baseband chip may include a processor, a channel encoder, a digital signal processor, a modem, an interface module, etc.

In one implementation, the chip or chip system described above further includes at least one memory having instructions stored therein. The memory may be a memory unit within the chip, such as a register, a cache, etc., or may be a memory unit of the chip (e.g., a read-only memory, a random access memory, etc.).

The technical scheme provided by the application can be realized in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions in accordance with the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a network device, a terminal device, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital video disc (digital video disc, DVD)), or a semiconductor medium, etc.

In the present application, embodiments may be referred to each other, e.g., methods and/or terms between method embodiments may be referred to each other, e.g., functions and/or terms between apparatus embodiments and method embodiments may be referred to each other, without logical contradiction.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A method of communication, comprising:

the method comprises the steps that a first multicast/broadcast session management network element receives a first session establishment request message from an application server, wherein the first session establishment request message comprises identification information of a first multicast/broadcast service;

The first multicast/broadcast session management network element sends first indication information to a first multicast/broadcast user plane function network element according to the first session establishment request message, wherein the first indication information is used for indicating the first multicast/broadcast user plane function network element to increment a first serial number corresponding to data of the first multicast/broadcast service when receiving the data;

Wherein the first multicast/broadcast session management network element and the first multicast/broadcast user plane function network element are located in a first public land mobile network PLMN of a multi-operator core network MOCN.

2. The method of claim 1, wherein the first session establishment request message further comprises an identification of the first PLMN;

The first sequence number is used for an access network device in the MOCN to identify data of the first multicast/broadcast service from the first PLMN.

3. A method of communication, comprising:

a second multicast/broadcast session management network element receives a second session establishment request message from an application server, wherein the second session establishment request message comprises identification information of a first multicast/broadcast service;

The second multicast/broadcast session management network element sends second indication information to a second multicast/broadcast user plane function network element according to the second session establishment request message, wherein the second indication information is used for indicating the second multicast/broadcast user plane function network element to increment a second serial number corresponding to the data when receiving the data of the first multicast/broadcast service;

Wherein the second multicast/broadcast session management network element and the second multicast/broadcast user plane function network element are located in a second public land mobile network PLMN of a multi-operator core network MOCN.

4. A method according to claim 3, wherein the second session establishment request message further comprises an identification of the second PLMN;

The second sequence number is used for an access network device in the MOCN to identify data of the first multicast/broadcast service from the second PLMN.

5. A method of communication, comprising:

The method comprises the steps that a first multicast/broadcast user plane function network element receives first indication information from a multicast/broadcast session management network element, wherein the first indication information is used for indicating the first multicast/broadcast user plane function network element to increment a first serial number corresponding to data of a first multicast/broadcast service when the first multicast/broadcast user plane function network element receives the data;

The first multicast/broadcast user plane function network element receives data of the first multicast/broadcast service from an application server;

And the first multicast/broadcast user plane functional network element increases the first serial number corresponding to the data according to the first indication information.

6. The method of claim 5, wherein the method further comprises:

The first multicast/broadcast user plane functional network element sends the data of the first multicast/broadcast service and the first serial number corresponding to the data to an access network device in a multi-operator core network MOCN,

The first multicast/broadcast user plane function network element is located in a first PLMN of the MOCN, the first sequence number being used by the access network device to identify data of the first multicast/broadcast service from the first PLMN.

7. A method of communication, comprising:

The second multicast/broadcast user plane function network element receives second indication information from a second multicast/broadcast session management network element, wherein the second indication information is used for indicating the second multicast/broadcast user plane function network element to increment a second serial number corresponding to data when receiving the data of the first multicast/broadcast service;

the second multicast/broadcast user plane function network element receives data of the first multicast/broadcast service from an application server;

and the second multicast/broadcast user plane functional network element increases the second serial number corresponding to the data according to the second indication information.

8. The method of claim 7, wherein the method further comprises:

The second multicast/broadcast user plane functional network element sends the data of the first multicast/broadcast service and the second serial number corresponding to the data to an access network device in a multi-operator core network MOCN,

The second multicast/broadcast user plane function network element is located in a second PLMN of the MOCN, the second sequence number being used by the access network device to identify data of the first multicast/broadcast service from the second PLMN.

9. The method of claim 1, wherein the first session establishment request message further comprises a type of the multicast/broadcast service;

The first multicast/broadcast session management network element sends first indication information to a first multicast/broadcast user plane function network element according to the first session establishment request message, including:

and when the type of the first multicast/broadcast service is multicast service, the first multicast/broadcast session management network element sends the first indication information to the first multicast/broadcast user plane function network element.

10. The method of claim 1, wherein the first session establishment request message further comprises network sharing identification information; the network sharing identification information is used for indicating that the first multicast/broadcast service is shared in a Temporary Multicast Group Identification (TMGI) list of a second PLMN of the MOCN, wherein the second PLMN is different from the first PLMN;

And the first multicast/broadcast session management network element sends the first indication information to the first multicast/broadcast user plane function network element according to the network sharing identification information.

11. The method of claim 1, wherein the first indication information comprises a start value of the first sequence number that is the same as a start value of a corresponding second sequence number of the data of the first multicast/broadcast service in a second PLMN of the MOCN.

12. A method of communication, comprising:

The application server sends a first session establishment request message to a first multicast/broadcast session management network element located in a first public land mobile network PLMN of a multi-operator core network MOCN, the first session establishment request message comprising identification information of a first multicast/broadcast service;

The application server sending a second session establishment request message to a second multicast/broadcast session management network element located in a second PLMN of the MOCN, the second session establishment request message including identification information of the first multicast/broadcast service;

wherein the first PLMN is different from the second PLMN.

13. The method according to claim 12, wherein the first session request message further comprises an identification of the first PLMN and/or a start value of a first sequence number corresponding to data of the first multicast/broadcast service in the first PLMN;

The second session request message further includes an identifier of the second PLMN and/or a start value of a second sequence number corresponding to the data of the first multicast/broadcast service in the second PLMN;

wherein the start value of the first sequence number is the same as the start value of the second sequence number.

14. A method of communication, comprising:

The application server generates a session establishment request message, wherein the session establishment request message comprises an identifier of a main Public Land Mobile Network (PLMN) and identifier information of a first multicast/broadcast service in a multi-operator core network (MOCN);

the application server sends the session establishment request message to a multicast/broadcast session management network element;

The identification of the main PLMN and the identification information of the first multicast/broadcast service are used for the multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, wherein the shared transmission channel is used for transmitting the data of the first multicast/broadcast service;

the multicast/broadcast session management network element is located in the home PLMN or in a PLMN other than the home PLMN in the MOCN.

15. A method of communication, comprising:

The method comprises the steps that a first multicast/broadcast session management network element receives a session establishment request message from an application server, wherein the session establishment request message comprises an identifier of a main Public Land Mobile Network (PLMN) in a multi-operator core network (MOCN) and identifier information of a first multicast/broadcast service;

The first multicast/broadcast session management network element sends a multicast/broadcast service session context to the first session management network element, wherein the multicast/broadcast service session context comprises an identifier of the main PLMN and identifier information of the first multicast/broadcast service;

The identification of the main PLMN and the identification information of the first multicast/broadcast service are used for the first multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device in the MOCN and the multicast/broadcast user plane function network element in the main PLMN, wherein the shared transmission channel is used for transmitting the data of the first multicast/broadcast service;

wherein the first multicast/broadcast session management network element and the first session management network element are located in the primary PLMN.

16. A method of communication, comprising:

The second multicast/broadcast session management network element receives a session establishment request message from an application server, wherein the session establishment request message comprises an identifier of a main Public Land Mobile Network (PLMN) in a multi-operator core network (MOCN) and identifier information of a first multicast/broadcast service;

the second multicast/broadcast session management network element sends a multicast/broadcast service session context to the second session management network element, wherein the multicast/broadcast service session context comprises an identifier of the main PLMN and identifier information of the first multicast/broadcast service;

The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for the second multicast/broadcast session management network element to trigger and establish a shared transmission channel between the access network device of the MOCN and the multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, where the shared transmission channel is used for transmitting the data of the first multicast/broadcast service;

wherein the second multicast/broadcast session management network element and the second session management network element are located in PLMNs of the MOCN other than the primary PLMN.

17. A method of communication, comprising:

the second session management network element receives a multicast session request message from the terminal equipment, wherein the multicast session request message comprises an identifier of a multicast session;

the second session management network element sends a multicast/broadcast service session context request message to a multicast/broadcast session management network element corresponding to the identifier of the multicast session according to the identifier of the multicast session;

The second session management network element receives a multicast/broadcast service session context from the multicast/broadcast session management network element, wherein the multicast/broadcast service session context comprises an identifier of a main PLMN and identifier information of a first multicast/broadcast service;

The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the access network device accessed by the terminal device and a multicast/broadcast user plane function network element corresponding to the identifier of the main PLMN, wherein the shared transmission channel is used for transmitting data of the first multicast/broadcast service;

wherein the second session management network element is located in a PLMN of the MOCN other than the main PLMN.

18. The method of claim 17, wherein the method further comprises:

the second session management network element sends the identification of the main PLMN and the identification information of the first multicast/broadcast service to an access network device in a multi-operator core network.

19. A method of communication, comprising:

A first access network device receives a first N2 protocol data unit session resource message from a first session management network element, wherein the first N2 protocol data unit session resource message comprises an identifier of a main Public Land Mobile Network (PLMN) and identifier information of a first multicast/broadcast service in a multi-operator core network (MOCN), and the first access network device is positioned in the MOCN;

the first access network device sends a first N2 multicast session request message to a multicast/broadcast session management network element in the main PLMN, where the first N2 multicast session request message includes identification information of the first multicast/broadcast service.

20. The method of claim 19, wherein the first access network device sending an N2 multicast session request message to a multicast/broadcast session management network element in the primary PLMN comprises:

when the first access network device does not establish a shared transmission channel, the first access network device sends identification information of the first multicast/broadcast service to a multicast/broadcast session management network element in the main PLMN;

The first access network device establishes a shared transmission channel with the multicast/broadcast user plane function network element in the main PLMN, where the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

21. The method according to claim 19 or 20, characterized in that the method further comprises:

the first access network device receives a second N2 protocol data unit session resource message from a second session management network element, wherein the second N2 protocol data unit session resource message comprises an identifier of the main PLMN and identifier information of the first multicast/broadcast service;

When the first access network equipment establishes a shared transmission channel, the first access network equipment discards the second N2 protocol data unit session resource message; or the first access network device sends third indication information to the second session management network element, wherein the third indication information is used for indicating that the shared transmission channel is established;

Wherein the first session management network element is located in the main PLMN, and the second session management network element is located in a PLMN other than the main PLMN in the MOCN; or the first session management network element is located in a PLMN other than the main PLMN in the MOCN, and the second session management network element is located in the main PLMN.

22. The method of claim 19, wherein the method further comprises:

The first access network device sends a switching request message to the second access network device, wherein the switching request message comprises the identification of the main PLMN and the identification information of the first multicast/broadcast service;

The identifier of the main PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a shared transmission channel between the second access network device and a multicast/broadcast user plane function network element in the main PLMN, and the shared transmission channel is used for transmitting data of the first multicast/broadcast service.

23. A method of communication, comprising:

The first access network equipment receives the identification information of the first multicast/broadcast service;

The first access network device sends an Xn interface message to the second access network device, where the Xn interface message includes identification information of the first multicast/broadcast service and an identification of a first public land mobile network PLMN, where the first PLMN is a PLMN to which a multicast/broadcast user plane function network element that establishes a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used to transmit data of the first multicast/broadcast service;

The identifier of the first PLMN and the identifier information of the first multicast/broadcast service are used for triggering and establishing a second shared transmission channel between the second access network device and the multicast/broadcast user plane function network element in the first PLMN, wherein the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service;

Wherein the first access network device and the second access network device are located in a multi-operator core network MOCN, and the first PLMN belongs to the MOCN.

24. A method of communication, comprising:

The method comprises the steps that a second access network device receives an Xn interface message from a first access network device, wherein the Xn interface message comprises identification information of a first multicast/broadcast service and identification of a first Public Land Mobile Network (PLMN), the first PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used for transmitting data of the first multicast/broadcast service;

the second access network equipment receives the identification information of a second multicast/broadcast service;

The second access network device establishes a second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN, the identification information of the first multicast/broadcast service and the identification information of the second multicast/broadcast service, wherein the second shared transmission channel is used for transmitting the data of the first multicast/broadcast service and the data of the second multicast/broadcast service;

Wherein the first access network device and the second access network device are located in a MOCN, and the first PLMN belongs to the MOCN.

25. The method of claim 24, wherein the second access network device establishes a second shared transmission channel with a multicast/broadcast user plane function network element in the first PLMN based on the identification of the first PLMN, the identification information of the first multicast/broadcast service, and the identification information of the second multicast/broadcast service, comprising:

When the types of the first multicast/broadcast service and the second multicast/broadcast service are the same, the second access network device sends a shared transmission channel establishment request message to a multicast/broadcast user plane function network element in the first PLMN; or alternatively

And when the multicast network address corresponding to the identification information of the first multicast/broadcast service is the same as the multicast network address corresponding to the identification information of the second multicast/broadcast service, the second access network device sends a shared transmission channel establishment request message to the multicast/broadcast user plane function network element in the first PLMN.

26. A method of communication, comprising:

A first access network device sends a switching request message to a second access network device, wherein the switching request message comprises an identifier of a first Public Land Mobile Network (PLMN) and identifier information of a first multicast/broadcast service in a multi-operator core network (MOCN), the first PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used for transmitting data of the first multicast/broadcast service;

The first access network device receives a switching response message from the second access network device, wherein the switching response message comprises an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a second shared transmission channel with the second access network device belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs to the first PLMN;

wherein the first access network device and the second access network device are located in the MOCN, the first PLMN and the second PLMN being different.

27. The method of claim 26, wherein the method further comprises:

and the first access network equipment forwards the data of the first multicast/broadcast service to the second access network equipment according to the identification of the second PLMN or the fourth indication information.

28. The method of claim 26, wherein before the first access network device sends the handover request message to the second access network device, the method further comprises:

The first access network device receives a first N2 protocol data unit session resource message, where the first N2 protocol data unit session resource message includes an identifier of the first PLMN and identifier information of the first multicast/broadcast service;

The first access network device establishes the first shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN and the identification information of the first multicast/broadcast service.

29. A method of communication, comprising:

A second access network device receives a switching request message from a first access network device, wherein the switching request message comprises an identifier of a first Public Land Mobile Network (PLMN) and identifier information of a first multicast/broadcast service in a multi-operator core network (MOCN), the first PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a first shared transmission channel with the first access network device belongs, and the first shared transmission channel is used for transmitting data of the first multicast/broadcast service;

The second access network device sends a switching response message to the first access network device, wherein the switching response message comprises an identifier of a second PLMN, and the second PLMN is a PLMN to which a multicast/broadcast user plane function network element establishing a second shared transmission channel with the second access network device belongs; or the handover response message includes fourth indication information, where the fourth indication information is used to indicate that a multicast/broadcast user plane function network element that establishes a second shared transmission channel with the second access network device belongs to the first PLMN;

30. The method of claim 29, wherein before the second access network device sends a handoff response message to the first access network device, the method further comprises:

When the second access network device does not establish a second shared transmission channel for transmitting the data of the first multicast/broadcast service, the second access network device establishes the second shared transmission channel with the multicast/broadcast user plane function network element in the first PLMN according to the identification of the first PLMN and the identification information of the first multicast/broadcast service.

31. The method according to claim 29, wherein when the second access network device has established a second shared transmission channel for transmitting data of the first multicast/broadcast service, the handover response message comprises an identification of a PLMN corresponding to the second shared transmission channel, or the handover response message comprises the fourth indication information.

32. The method of claim 31, further comprising:

When the identifier of the PLMN corresponding to the second shared transmission channel is different from the identifier of the first PLMN, the second access network device receives the data of the first multicast/broadcast service from the first access network device;

the second access network device forwards the data of the first multicast/broadcast service in a unicast mode.

33. A communication device comprising a processing unit and a communication unit for performing the method of any of claims 1 to 32.

34. A communication device, comprising: a processor and a memory for storing instructions that, when executed by the processor, cause the communication device to perform the method of any one of claims 1 to 32.

35. A computer readable storage medium having instructions stored thereon which, when run on a computer, cause the computer to perform the method of any of claims 1 to 32.

36. A chip system comprising a processor, a memory and an interface for performing the method of any of claims 1 to 32.

37. A communication system comprising communication means for performing the method of any of claims 1 to 32.

38. A computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any one of claims 1 to 32.