WO2022041156A1

WO2022041156A1 - Multicast group communication method, device, and system

Info

Publication number: WO2022041156A1
Application number: PCT/CN2020/112291
Authority: WO
Inventors: 王亚鑫; 李岩; 潘奇
Original assignee: 华为技术有限公司
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2022-03-03

Abstract

Disclosed are a multicast group communication method, device, and system, related to the field of communications, for reducing the latency of a terminal device joining a multicast group. The multicast group communication method comprises: a first user plane function network element receives a first message from a terminal device, the first message comprising an identifier of a first multicast group, and the first message being used for requesting the joining of the terminal device to the first multicast group; the first user plane function network element transmits first indication information to a session management function network element on the basis of the first message, the first indication information being used for indicating the joining of the terminal device to the first multicast group; the first user plane function network element receives second activation information from the session management function network element, the second activation information being used for indicating whether a data stream corresponding to the first multicast group is being transmitted on a network element of an access network; and if the second activation information indicates that the data stream corresponding to the first multicast group is being transmitted on the network element of the access network, then the first user plane function network element transmits the first indication information to the network element of the access network.

Description

Multicast group communication method, apparatus and system

technical field

The present application relates to the field of communication, and in particular, to a method, apparatus and system for multicast group communication.

Background technique

When transmitting a multicast service (eg, live broadcast) through a wireless communication system, a terminal device can choose to receive different multicast services by accessing different multicast groups. When joining a multicast group, the user plane network element on the network side obtains a new multicast group from the signaling plane network element. The interaction delay makes the switching time longer, which cannot meet the delay-sensitive scenarios (such as virtual reality (virtual reality). , VR) live broadcast) delay requirements.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a method, apparatus, and system for multicast group communication, which are used to reduce the delay for a terminal device to join a multicast group.

To achieve the above object, the embodiments of the present application adopt the following technical solutions:

A first aspect provides a multicast group communication method, including: a first user plane function network element receives a first message from a terminal device, the first message includes an identifier of the first multicast group, and the first message It is used to request to add the terminal device to the first multicast group; the first user plane function network element sends first indication information to the session management function network element according to the first message, and the first indication information is used to instruct the terminal device to be added to the first multicast group. Multicast group; the first user plane function network element receives second activation information from the session management function network element, and the second activation information is used to indicate whether the data stream corresponding to the first multicast group is already on the access network element is sent; if the second activation information indicates that the data stream corresponding to the first multicast group has been sent on the access network element, the first user plane function network element sends the first indication information to the access network element.

In the multicast group communication method provided by the embodiment of the present application, when a terminal device requests to join the first multicast group, the UPF network element instructs the RAN network element to add the terminal device to the first multicast group through a user plane message, without having to The RAN network element is instructed to join the terminal device to the first multicast group through the control plane message, thereby reducing the delay for the terminal device to join the multicast group.

In a possible implementation manner, the method further includes: the first user plane function network element receives a second message from the terminal device, where the second message includes an identifier of the second multicast group, the second multicast group is one of the associated multicast groups of the first multicast group, and the second message is used to request to withdraw the terminal device from the second multicast group; the first user plane function network element reports to the session management function network element according to the second message. The element sends second indication information, where the second indication information is used to indicate that the terminal device has left the second multicast group. This embodiment is used to further indicate which multicast group the terminal device has left.

In a possible implementation manner, the first indication information sent by the first user plane function network element to the access network element is carried in the packet header of the data stream. That is, the first indication information is transmitted to the network element of the access network through a user plane message.

A second aspect provides a multicast group communication method, comprising: a second user plane function network element receiving a third message and first indication information from a session management function network element, where the third message includes the first multicast group The identifier of the first multicast group, and the identifier of the associated multicast group of the first multicast group; the first indication information is used to instruct the terminal device to join the first multicast group; the second user plane function network element receives the first multicast group from the application server. a multicast group and a data stream corresponding to the associated multicast group; the second user plane function network element sends the first indication information and the data stream corresponding to the first multicast group to the access network element; the second user The plane function network element sends third activation information to the session management function network element, where the third activation information is used to indicate whether the first multicast group and the data stream corresponding to the associated multicast group have been sent on the access network element .

In a possible implementation manner, the method further includes: the second user plane function network element receives, from the session management function network element, a port of the access network element corresponding to the first multicast group and the associated multicast group information, and the port information is used to establish a tunnel for transmitting data flow between the network element of the second user plane function and the network element of the access network. The second user plane function network element may establish a tunnel for transmitting data flow between the second user plane function network element and the access network element according to the port information.

In a possible implementation manner, the method further includes: the second user plane function network element receives third indication information from the session management function network element, where the third indication information is used to instruct the terminal device to withdraw from the second multicast group , the second multicast group is one of the associated multicast groups; the second user plane function network element sends third indication information to the access network element. This embodiment is used to further instruct the terminal device which multicast group to leave.

In a possible implementation manner, the method further includes: the second user plane function network element stops sending the data stream corresponding to the second multicast group to the access network element. The transmission bandwidth between the network element of the second user plane function and the network element of the access network can be saved.

In a possible implementation manner, the first indication information sent by the second user plane function network element to the access network element is carried in the packet header of the data stream. That is, the first indication information is transmitted to the network element of the access network through a user plane message.

A third aspect provides a multicast group communication method, comprising: a session management function network element receiving first indication information from a first user plane function network element, where the first indication information is used to add a terminal device to the first multicast group; the session management function network element obtains the identifier of the first multicast group from the unified data repository, and the identifier of the associated multicast group of the first multicast group; the session management function network element reports to the first user plane The functional network element sends first activation information, where the first activation information is used to indicate whether the data stream corresponding to the first multicast group and the associated multicast group has been sent on the access network element; The second user plane function network element sends a third message and the first indication information, where the third message includes the identifier of the first multicast group and the identifier of the associated multicast group; the session management function network element is sent from the second user plane function network element. element receives third activation information, the third activation information is used to indicate whether the data stream corresponding to the first multicast group and the associated multicast group has been sent on the access network element, and the third activation information is also used to update First activation information.

In the multicast group communication method provided by the embodiment of the present application, the session management function network element indicates whether the data flow corresponding to the first multicast group of the first user plane function network element and the associated multicast group is already in the access network element If the data stream corresponding to the first multicast group has been sent on the access network element, the first user plane function network element instructs the access network element to add the terminal device to the first multicast group , that is, the network element of the access network directly sends the data stream corresponding to the first multicast group to the terminal device, thereby reducing the time delay for the terminal device to join the multicast group.

In a possible implementation manner, the method further includes: the session management function network element sends the identification of the first multicast group and the identification of the associated multicast group to the access network element; the session management function network element receives the The incoming network element receives port information of the access network element that corresponds to the first multicast group and the associated multicast group, and the port information is used to establish transmission between the second user plane function network element and the access network element The tunnel of the data flow; the session management function network element sends port information to the second user plane function network element. The second user plane function network element may establish a tunnel for transmitting data flow between the second user plane function network element and the access network element according to the port information.

In a possible implementation manner, the method further includes: the session management function network element receives second indication information from the first user plane function network element, where the second indication information is used to indicate that the terminal device has left the second multicast group , the second multicast group is one of the associated multicast groups; the session management function network element sends third indication information to the second user plane function network element, and the third indication information is used to instruct the terminal device to exit the second broadcast group. This embodiment is used to further instruct the terminal device which multicast group to leave.

In a fourth aspect, a multicast group communication method is provided, comprising: an access network element receiving first indication information from a first user plane function network element or a second user plane function network element, wherein the first indication information It is used to add terminal equipment to the first multicast group, the first user plane function network element is used to transmit unicast data streams, and the second user plane network element is used to transmit multicast data streams; The user plane function network element receives the data stream corresponding to the first multicast group; the access network network element sends the data stream to the terminal device.

In a possible implementation manner, the method further includes: the access network element receiving the identifier of the first multicast group from the session management function network element, and, the identification of the associated multicast group of the first multicast group. Identification; the access network element sends the port information of the access network element corresponding to the first multicast group and the associated multicast group to the session management function network element, and the port information is used to establish the second user plane function network element A tunnel for transporting data streams with network elements of the access network. The second user plane function network element may establish a tunnel for transmitting data flow between the second user plane function network element and the access network element according to the port information.

In a possible implementation manner, the method further includes: the access network element receives third indication information from the first user plane function network element or the second user plane function network element, where the third indication information is used to instruct the terminal The device exits the second multicast group, and the second multicast group is one of the associated multicast groups of the first multicast group; the access network element stops sending the terminal device corresponding to the second multicast group. data flow. The transmission bandwidth between the network element of the access network and the terminal device can be saved.

In a possible implementation manner, the third indication information is carried in the packet header of the data stream. That is, the third indication information is transmitted to the network element of the access network through the user plane message.

In a possible implementation manner, the first indication information is carried in a packet header of the data stream. That is, the first indication information is transmitted to the network element of the access network through a user plane message.

A fifth aspect provides a multicast group communication method, including: a first network element acquiring multicast group information, an identifier of the first multicast group, and an identifier of an associated multicast group of the first multicast group Identification; the multicast group information includes the first Internet Protocol IP multicast address corresponding to the identification of the first multicast group, the first IP multicast address corresponding to the identification of the associated multicast group, and the first IP multicast address corresponding to the identification of the first multicast group. The universal tunnel endpoint identifier C-TEID, and the C-TEID corresponding to the associated multicast group; the first network element receives first indication information from the second network element, and the first indication information is used to add the terminal device to the first The first network element sends the multicast group information to the second network element according to the first indication information; wherein, the first network element is a network element with multicast broadcast session management function, and the second network element is a multicast access network element and a mobility management function network element; or, the first network element is a multicast access and mobility management function network element, and the second network element is an access network element.

In the multicast group communication method provided by the embodiment of the present application, when the terminal device joins the first multicast group, the RAN network element obtains the corresponding multicast group associated with the first multicast group from the MB-SMF network element in advance. The first IP multicast address and C-TEID of the associated multicast group, so that when the terminal device joins the associated multicast group, the RAN network element does not need to obtain the first IP multicast group corresponding to the associated multicast group from the M-AMF network element and the MB-SMF network element in turn. An IP multicast address and C-TEID, thereby reducing the delay for terminal equipment to join a multicast group.

In a possible implementation manner, the first network element is a multicast broadcast session management function network element, and the first network element obtains the multicast group information, including: the first network element receives from the multicast broadcast user plane function network element Multicast group information. This embodiment provides a possible way for the first network element to acquire multicast group information.

In a possible implementation manner, the first network element is a multicast access and mobility management function network element, and the first network element obtains the multicast group information, including: the first network element obtains the multicast group information from the multicast broadcast session management function network element. Meta receives multicast group information. This embodiment provides another possible way for the first network element to acquire multicast group information.

In a sixth aspect, a method for multicast group communication is provided, including: a second network element sending first indication information to a first network element, where the first indication information is used to add a terminal device to the first multicast group; The second network element receives the multicast group information from the first network element. The multicast group information includes the first Internet Protocol IP multicast address corresponding to the identifier of the first multicast group, and the first IP multicast address corresponding to the identifier of the associated multicast group. An IP multicast address, the C-TEID corresponding to the general tunnel endpoint of the first multicast group, and the C-TEID corresponding to the associated multicast group. Wherein, the first network element is a multicast broadcast session management function network element, and the second network element is a multicast access and mobility management function network element; or, the first network element is a multicast access and mobility management function network element, The second network element is an access network element.

In a seventh aspect, a communication device is provided, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to the first aspect and any one of the embodiments thereof.

In an eighth aspect, a communication device is provided, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to the second aspect and any one of the embodiments thereof.

In a ninth aspect, a communication device is provided, comprising: a processing module and a transceiving module; the processing module and the transceiving module are configured to execute the method according to the third aspect and any one of the embodiments thereof.

In a tenth aspect, a communication device is provided, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to the fourth aspect and any one of the embodiments thereof.

In an eleventh aspect, a communication device is provided, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to the fifth aspect and any one of the embodiments thereof.

A twelfth aspect provides a communication device, comprising: a processing module and a transceiving module; the processing module and the transceiving module are configured to execute the method of the sixth aspect.

A thirteenth aspect provides a communication device, the communication device includes a processor, a memory and a communication interface, the processor is coupled to the memory, when the processor controls the communication interface to execute a computer program or instruction in the memory, as in the first aspect and The method of any of its embodiments is performed.

A fourteenth aspect provides a communication device, the communication device includes a processor, a memory and a communication interface, the processor is coupled with the memory, when the processor controls the communication interface to execute a computer program or instruction in the memory, as in the second aspect and The method of any embodiment thereof is performed.

A fifteenth aspect provides a communication device, the communication device includes a processor, a memory and a communication interface, the processor is coupled with the memory, when the processor controls the communication interface to execute a computer program or instruction in the memory, as in the third aspect and The method of any of its embodiments is performed.

A sixteenth aspect provides a communication device, the communication device includes a processor, a memory and a communication interface, the processor is coupled to the memory, when the processor controls the communication interface to execute a computer program or instruction in the memory, as in the fourth aspect and The method of any of its embodiments is performed.

A seventeenth aspect provides a communication device, the communication device includes a processor, a memory and a communication interface, the processor is coupled with the memory, when the processor controls the communication interface to execute the computer program or instructions in the memory, as shown in the fifth The method of the aspect and any embodiment thereof is performed.

An eighteenth aspect provides a communication device, the communication device includes a processor, a memory, and a communication interface, the processor is coupled to the memory, and when the processor controls the communication interface to execute a computer program or instruction in the memory, as shown in the sixth The method of the aspect and any embodiment thereof is performed.

A nineteenth aspect provides a communication system, including the communication device according to the seventh aspect to the tenth aspect and any of the embodiments thereof, or, including the eleventh aspect to the twelfth aspect and any one of the embodiments thereof The communication device according to the embodiment, or, includes the communication device according to the thirteenth aspect to the sixteenth aspect and any one of the embodiments thereof, or includes the seventeenth aspect to the eighteenth aspect and any one of the embodiments thereof. The communication device according to the embodiment.

A twentieth aspect provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, which, when executed on a computer or a processor, causes the computer or processor to execute the first to sixth aspects Aspects and the method of any embodiment thereof.

In a twenty-first aspect, there is provided a computer program product comprising instructions that, when executed on a computer or processor, cause the computer or processor to perform as described in the first to sixth aspects and any one of the embodiments Methods.

For the technical effects of the seventh aspect to the twenty-first aspect, refer to the content of the first aspect to the sixth aspect, which will not be repeated here.

Description of drawings

FIG. 1 is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application;

2 is a schematic diagram of a QoS flow and a PDU session provided by an embodiment of the present application;

3 is a schematic diagram of transmitting multicast services in a manner of sharing a unicast QoS flow according to an embodiment of the present application;

4 is a schematic flowchart of a method for transmitting a multicast service provided by an embodiment of the present application;

5 is a schematic flowchart of another method for transmitting a multicast service provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of a data flow corresponding to multiple views of a multicast service provided by an embodiment of the present application;

7 is a schematic diagram of the core idea of a multicast group communication method provided by an embodiment of the present application;

FIG. 8 provides a schematic flowchart 1 of a method for multicast group communication according to an embodiment of the present application;

FIG. 9 provides a second schematic flowchart of a method for multicast group communication according to an embodiment of the present application;

FIG. 10 provides a third schematic flowchart of a method for multicast group communication according to an embodiment of the present application;

FIG. 11 provides a fourth schematic flowchart of a method for multicast group communication according to an embodiment of the present application;

FIG. 12 provides a fifth schematic flowchart of a method for multicast group communication according to an embodiment of the present application;

FIG. 13 provides a sixth schematic flowchart of a method for multicast group communication according to an embodiment of the present application;

FIG. 14 provides a seventh schematic flowchart of a method for multicast group communication according to an embodiment of the present application;

FIG. 15 provides a schematic structural diagram 1 of a communication device according to an embodiment of the present application;

FIG. 16 provides a second schematic structural diagram of a communication device according to an embodiment of the present application;

FIG. 17 provides a third schematic structural diagram of a communication device according to an embodiment of the present application;

FIG. 18 provides a fourth schematic structural diagram of a communication device according to an embodiment of the present application;

FIG. 19 provides a fifth schematic structural diagram of a communication device according to an embodiment of the present application;

FIG. 20 provides a sixth schematic structural diagram of a communication device according to an embodiment of the present application;

FIG. 21 provides a seventh schematic structural diagram of a communication apparatus according to an embodiment of the present application.

detailed description

The network architecture and service scenarios described in the embodiments of the present application are for the purpose of illustrating the technical solutions of the embodiments of the present application more clearly, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. The evolution of the architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

In the embodiment of the present application, "/" indicates that the two before and after the symbol are "or".

The embodiments of the present application can be applied not only to a time division duplexing (TDD) scenario, but also to a frequency division duplex (frequency division duplexing, FDD) scenario, which is not limited.

The embodiments of this application are described based on the scenario of a 5G network in a wireless communication network. It should be noted that the solutions in the embodiments of this application can also be applied to other wireless communication networks, and the corresponding names can also be used in other wireless communication networks. Substitute the name of the corresponding function.

FIG. 1 provides a communication system architecture, including: a terminal device 101, a radio access network ((radio) access network, (R)AN) network element 102, a user plane function (user plane function, UPF) network element 103, A data network (DN) 104, an access and mobility management function (AMF) network element 105, a session management function (SMF) network element 106, a policy control network element (policy control function, PCF) network element 107, unified data management (UDM) network element 108, application function (application function, AF) network element 109, authentication server function (authentication server function, AUSF) network element 110 and a network slice selection function (NSSF) network element 111, a network exposure function (NEF) network element 112, and a multicast/broadcast service function (MBSF) network element 113.

It should be noted that the name of the interface between each network element in FIG. 1 is just an example, and the name of the interface may be other names in specific implementation, which is not limited. For example, the interface between the terminal device 101 and the AMF network element 105 may be the N1 interface, the interface between the RAN network element 102 and the AMF network element 105 may be the N2 interface, and the interface between the RAN network element 102 and the UPF network element 103 It can be an N3 interface, the interface between the UPF network element 103 and the SMF network element 106 can be an N4 interface, the interface between the PCF network element 107 and the AF network element 109 can be an N5 interface, and the interface between the UPF network element 103 and the DN 104 The interface can be the N6 interface, the interface between the SMF network element 106 and the PCF network element 107 can be the N7 interface, the interface between the AMF network element 105 and the UDM network element 108 can be the N8 interface, the UPF network element 103 and the UPF network element The interface between the elements 103 may be the N9 interface, the interface between the SMF network element 106 and the UDM network element 108 may be the N10 interface, the interface between the AMF network element 105 and the SMF network element 106 may be the N11 interface, and the PCF network element The interface between 107 and the UDM network element 108 can be the N25 interface, the interface between the AMF network element 105 and the AUSF network element 110 can be N12, the interface between the UDM network element 108 and the AUSF network element 110 can be N13, and the AMF network element 110 can be the interface. The interface between the network element 105 and the NSSF network element 111 may be N22, the interface between the NEF network element 112 and the PCF network element 107 may be N30, the interface between the NEF network element 112 and the UDM network element 108 may be N52, The interface between the NEF network element 112 and the AF network element 109 may be N33, and the MBSF network element 113 and the NEF network element 112 may be co-located.

The terminal device 101 may include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem; it may also include subscriber units, cellular phones , smart phone (smart phone), wireless data card, personal digital assistant (personal digital assistant, PDA) computer, tablet computer, wireless modem (modem), handheld device (handheld), laptop computer (laptop computer), cordless Telephone (cordless phone) or wireless local loop (wireless local loop, WLL) station, machine type communication (machine type communication, MTC) terminal, user equipment (user equipment, UE), mobile station (mobile station, MS), terminal device (terminal device) or relay user equipment, etc. The relay user equipment may be a 5G home gateway (residential gateway, RG). For the convenience of description, the devices mentioned above may be collectively referred to as terminal devices.

The RAN network element 102 is a device that provides wireless access for the terminal device 101, including but not limited to gNodeB, wireless fidelity (wireless fidelity, Wi-Fi) access point, world interoperability for microwave access, WiMAX) base station, etc. The RAN network element can be a RAN network element, and the RAN network element is a RAN network element accessing the 5G core network, which can be an NR gNodeB, or an evolved universal terrestrial radio access (E-UTRA) in LTE. ) network element.

The UPF network element 103 is mainly responsible for processing user packets, such as forwarding and charging. The UPF network element may be a unicast UPF network element, a multicast UPF network element, or a multicast/broadcast user plane function (multicast/broadcast user plane function, MB-UPF) network element. The unicast UPF network element and the multicast UPF network element may be the same UPF network element. The unicast UPF network element is functionally the same as the multicast UPF network element, except that the unicast data stream of the current terminal device is transmitted on the unicast UPF network element (the UPF network element can also transmit multicast data streams, such as transmitting other The multicast data stream of the multicast service of the terminal device), the multicast data stream of the current terminal device is transmitted on the multicast UPF network element (the UPF network element can also transmit the unicast data stream). Both unicast UPF network elements and multicast UPF network elements send data streams to RAN network elements in the form of tunnels. The MB-UPF network element is a UPF network element specially used for sending multicast data streams, that is, it is used to transmit the multicast data stream, and sends the multicast data stream to the RAN network element in the form of multicast.

DN 104 refers to a network that provides data transmission services for users, such as IP multimedia services (IP multi-media service, IMS), the Internet (Internet), and the like. The terminal device 101 accesses the DN 104 by establishing a protocol data unit (protocol data unit, PDU) session between the terminal device, the RAN network element 102, the UPF network element 103, and the DN 104.

The AMF network element 105 is mainly responsible for mobility management in the mobile network, such as user location update, user registration in the network, user handover, and the like. The AMF network element 105 may be a multicast access and mobility management function (multicast access and mobility management function, M-AMF) network element. The M-AMF network element is an AMF network element specially used to manage the multicast context. The network element stores the temporary mobile group identity (TMGI) of the multicast service and the first corresponding MB-UPF network element. Internet Protocol (IP) multicast address and common tunnel endpoint identifier (C-TEID).

The SMF network element 106 is mainly responsible for session management in the mobile network, such as session establishment, modification, and release. For example, specific functions include: assigning IP addresses to users, selecting a UPF that provides packet forwarding functions, and the like. The SMF network element 106 may be a multicast/broadcast session management function (MB-SMF) network element, and the MB-SMF network element is an SMF network element specially used for managing multicast contexts. The TMGI of the multicast service and the first IP multicast address and C-TEID of the corresponding MB-UPF network element.

Among them, TMGI is used in multimedia broadcast multicast service (multimedia broadcast multicast service, MBMS) to uniquely identify multicast and broadcast bearer services. The first IP multicast address and the C-TEID are allocated by the MB-SMF network element or the MB-UPF network element. The first IP multicast address is used to identify the multicast service transmitted by the MB-UPF network element, and the C-TEID is used to identify Port of the MB-UPF network element.

The PCF network element 107 is responsible for providing policies, such as QoS policies, slice selection policies, and the like.

The UDM network element 108 is used to store user data, such as subscription information and authentication/authorization information.

The AF network element 109 may also be called a server, and is responsible for providing services to the 3GPP network, such as affecting service routing, interacting with the PCF network element for policy control, and the like.

The AUSF network element 110 is used to authenticate and authorize users.

The NSSF network element 111 is used to centrally manage the slicing function.

The NEF network element 112 is responsible for the isolation of internal and external networks, and is used to open network capabilities, including open monitoring (Monitoring) capabilities, policy/billing capabilities, and analysis and reporting capabilities.

The MBSF network element 113 is used for the server to interact with the MB-SMF network element, to negotiate the path establishment between the multicast service and the MB-UPF network element, and to notify the start/end information of the multicast service.

First, some concepts involved in this application are described:

Multicast service: defined by the 3GPP standard, used for point-to-multipoint unidirectional multimedia services. The multicast service sends multimedia broadcast services to the terminal equipment in the cell through the common resource block on the air interface, or sends the multicast service subscribed by the terminal equipment to the terminal equipment in the cell in a multicast manner, thereby saving air interface resources. In this application, the multicast service also includes the use of a public tunnel for transmission from the UPF network element to the RAN network element in the transmission network, thereby saving transmission network resources.

Multicast group: A group formed by a group of users who receive data streams of the same multicast service at the same time. The multicast group may be represented by an identifier of the multicast group, and the identifier of the multicast group may be, for example, an IP multicast address, TMGI, and the like.

Multicast tree: including the multicast tree of the application server and the multicast tree of the MB-UPF network element:

The multicast tree of the application server: refers to the transmission from the application server to the MB-UPF network element using the multicast protocol, thereby forming a multicast tree. If an MB-UPF network element needs to receive the data stream of a multicast service, the MB-UPF network element needs to join the multicast tree corresponding to the application server through the multicast protocol. This process requires the MB-UPF network element to obtain the corresponding application server. The IP multicast address of the service, which is allocated by the application server, and can generally be obtained by configuring the SMF network element.

Multicast tree of MB-UPF network elements: MB-UPF network elements are UPF plane network elements dedicated to transmitting data streams of multicast services, and multicast protocol is used for transmission between MB-UPF network elements and RAN network elements. Form a multicast tree. If a RAN network element needs to receive the data stream of a multicast service, the RAN network element needs to join the multicast tree corresponding to the MB-UPF network element, that is, the RAN network element obtains the data stream from the MB-SMF network element through the M-AMF network element. The MB-UPF network element is used to transmit the first IP multicast address and the C-TEID corresponding to the multicast service. See the foregoing description for the first IP multicast address and the C-TEID.

The first multicast group: the multicast group that the terminal device requests to join (or switch to), that is, the terminal device requests to obtain the data stream corresponding to the multicast group from the application server.

The associated multicast group of the first multicast group: belongs to the same multicast service as the first multicast group, and each multicast group is used to transmit different data streams of the same multicast service. For example, data streams from different perspectives of the same program in a VR live broadcast.

The second multicast group: the multicast group that the terminal device requests to leave, that is, the terminal device requests to stop acquiring the data stream corresponding to the multicast group from the application server. The second multicast group belongs to one of the associated multicast groups.

Multicast context: Information related to multicast sessions stored on SMF network elements or on RAN network elements. Including the identity of the multicast session, the identity of the multicast group (for example, the second IP multicast address), the identity of the terminal equipment in the multicast group, the identity of the RAN network element and the UPF network element that are transmitting the multicast service, etc. . The second IP multicast address is different from the first IP multicast address, the second IP multicast address is allocated by the application server, and the first IP multicast address is allocated by the MB-SMF network element or the MB-UPF network element.

Access network resources: Refers to the air interface resources corresponding to the data flow sent by the RAN network element to the terminal equipment through the air interface. Including radio bearers and corresponding underlying access network resources.

As shown in FIG. 2 , in the above-mentioned 5G communication system, data can be transmitted through a PDU session between terminal equipment, RAN network elements, and UPF network elements. In the PDU session, the management of QoS differentiation is realized through the quality of service (QoS) flow (QoS Flow). In the 5G communication system, the QoS flow is controlled by the SMF network element, which can be pre-configured or established through the PDU session establishment process or the PDU session modification process. When the QoS flow is transmitted between the terminal equipment and the RAN network element, the QoS flow is mapped to the corresponding access network resources.

For the multicast service, in a possible implementation manner of the prior art, the transmission of multiple data stream of the broadcast service. For the way of sharing the unicast QoS flow, as shown in FIG. 3 , the UPF network element can perform multicast transmission through the common QoS flow (or called shared tunnel).

As shown in FIG. 4 , a method for transmitting a multicast service provided by an embodiment of the present application describes the process of establishing a multicast session, how to establish a shared tunnel, and how a terminal device joins a multicast group and receives multicast services. data flow. The method includes a parallel user plane scheme (S403a-S403b) and a control plane scheme (S404a-S404b). The method includes steps S401-S413:

S401. The application server sends the identifier of the multicast group of the multicast service to the terminal device through the application layer.

Specifically, the application server sends the identifier of the multicast group (for example, the second IP multicast address) corresponding to the multicast service to the application layer of the terminal device through the application layer, so that the terminal device can join the corresponding multicast group in order to receive The data flow of the corresponding multicast service.

S402, the terminal device accesses the network through the registration process and the PDU session establishment process.

The following steps S403a-S403b are optional user plane solutions:

S403a, the terminal device sends a multicast join request message to the unicast UPF network element through a user plane message.

The multicast join request message may be an IGMP join request message or a multicast listener discover (multicast listener discover, MLD) request message.

The multicast join request message includes the identifier of the multicast group that the terminal device requests to join.

S403b, after receiving the multicast join request message, the unicast UPF network element sends a User Plane Event Notify message to the SMF network element.

The message includes the identifier of the multicast group that the terminal device requests to join.

The following steps S404a-S404b are optional control plane solutions:

S404a, the terminal device sends a PDU Session Modification Request (PDU Session Modification Request) message to the AMF network element.

The message includes the identifier of the multicast group that the terminal device requests to join, and the message is used to request to join the multicast group.

S404b, the AMF network element sends a session management context (Nsmf_PDUSession_Update SMContext) message to the SMF network element.

S405, the SMF network element queries the multicast context of the corresponding multicast group in a unified data repository (unified data repository, UDR) by using the identifier of the multicast group.

If the multicast context of the corresponding multicast group is not queried, create a multicast context of the corresponding multicast group, and add the terminal device to the multicast group in the created multicast context. The multicast context in which the multicast group is recorded in the UDR is maintained by the SMF network element.

If the multicast context of the corresponding multicast group is queried, the terminal device is added to the multicast group in the multicast context.

S406, the SMF network element sends an N1N2 message transfer (Namf_Communication N1N2MessageTransfer) message to the AMF network element.

The message includes the unicast session identifier and the multicast session identifier of the terminal device.

Wherein, the multicast session identifier is obtained by the SMF network element through the identifier query configuration of the multicast group. The unicast session identifier is selected and obtained by the SMF network element according to the locally stored context of the terminal device.

S407, the AMF network element sends an N2 session request (N2 Session Request) message to the RAN network element.

The message includes the unicast session identifier and the multicast session identifier of the terminal device, wherein the unicast session identifier is used by the RAN network element to identify the terminal device, and the unicast session identifier and the multicast session identifier are used by the RAN network element to identify the unicast session Associate with a multicast session.

S408, the RAN network element adds the terminal device to the multicast group.

If the service flow corresponding to the multicast group has not been sent, the RAN network element also allocates group RNTI and access network resources; if the service flow corresponding to the multicast group has been sent to other terminal equipment, the terminal equipment Join the multicast group and send the group RNTI to the terminal device.

In addition, the RAN network element detects whether the N3 tunnel has been established with the multicast UPF network element. If the N3 tunnel has not been established, configure the port information of the AN port for the multicast session, and execute the following steps S409-S413. If the N3 tunnel has been established, the following steps S409-S413 are not performed.

S409, the RAN network element sends an N2 session response (N2 Session Response) message to the AMF network element.

The message includes port information of the AN port configured by the RAN element for the multicast session.

S410: The AMF network element sends an update session management context (Nsmf_PDUSession_UpdateSMContext) message to the SMF network element.

S411. The SMF network element sends an N4 Session Modification Request (N4 Session Modification Request) message to the multicast UPF network element.

This message is used to instruct the multicast UPF network element to join the multicast tree of the application server, establish a data transmission path with the application server, and receive the data stream of the multicast service from the application server.

S412, the multicast UPF network element establishes an N3 tunnel with the RAN network element through the AN port.

After receiving the data stream of the multicast service from the application server, the multicast UPF network element sends the data stream of the multicast service to the AN port of the RAN network element through the N3 tunnel.

S413. The RAN network element selects the access network resources according to the local policy, and sends the data stream of the multicast service to the terminal device in the form of unicast or multicast.

In this embodiment, when a terminal device requests to join a multicast group, the UPF network element makes a judgment and notifies the SMF network element to join the multicast group. The session is adjusted and the RAN network element is notified of the adjustment of the multicast context of the multicast group, and the RAN network element notifies the terminal equipment to join the multicast group. This embodiment not only implements joining the multicast group on the user plane, but also implements the exchange of the multicast context of the multicast group between the SMF network element and the RAN network element through the control plane, thus increasing the delay for the terminal device to join the multicast group .

For the multicast service, in another possible implementation manner of the prior art, the multicast session can be managed by the MBSF network element or the application server. When the MBSF network element or the application server starts the multicast service, the MBSF network element or the application server starts the multicast service. The application server sends a multicast session establishment request message to the MB-SMF network element, and the MB-SMF network element configures the IP address and port of the MB-UPF network element for the MBSF network element or the application server, which is used to establish the MB-UPF network element and application The user plane is connected between the servers, and the MB-UPF network element is added to the multicast tree corresponding to the multicast service of the application server, so that the MB-UPF network element can receive the data stream of the multicast service from the application server.

In addition, the terminal device sends the identifier of the multicast group (for example, TMGI) to the RAN network element to request to join the corresponding multicast group, and the RAN network element obtains the multicast group by querying the M-AMF network element and the MB-SMF network element in turn. The first multicast address and C-TEID corresponding to the group are used to establish a user plane connection between the UPF network element and the RAN network element. The RAN network element joins the multicast tree corresponding to the multicast service of the MB-UPF network element , so that the terminal device can receive the data stream of the multicast service.

Specifically, as shown in FIG. 5, another method for transmitting a multicast service provided by an embodiment of the present application includes:

S501. A terminal device acquires information of a multicast service from an MBSF network element or an application server.

The information of the multicast service includes the program content, the identifier of the multicast group corresponding to the multicast service (for example, TMGI), the broadcast time of the program, and the like.

S502, when the MBSF network element or the application server starts the multicast service, send a multicast session establishment request message to the MB-SMF network element.

The message includes an identifier of the multicast group corresponding to the multicast service, and the message is used to request the MB-SMF network element to establish a corresponding session for the multicast group.

S503. The MB-SMF network element sends a multicast broadcast session start (MB Session Start) message to the MB-UPF network element.

The message includes the identifier of the multicast group corresponding to the multicast service. This message is used to request the MB-UPF network element to assign an IP address and port to the multicast group, and the IP address and port are used by the MB-UPF network element to receive the identifier corresponding to the multicast group from the MBSF network element or the application server. The data flow of the multicast service. That is, the data packet carrying the data flow of the multicast service sent by the MBSF network element or the application server to the MB-UPF network element includes the above-mentioned IP address and port.

Optionally, if the first IP multicast address and C-TEID corresponding to the multicast group are also allocated by the MB-UPF network element, the message is also used to request the MB-UPF network element to allocate the IP multicast address for the multicast group. The first IP multicast address and C-TEID. The first IP multicast address and C-TEID corresponding to the multicast group are used by the RAN network element to receive the data stream of the multicast service corresponding to the identifier of the multicast group from the MB-UPF network element. The AMF network element obtains the first IP multicast address and the C-TEID from the MB-SMF network element. The RAN network element sends a multicast group join request message (for example, an internet group management protocol (protocol, IGMP) message, a multicast listener discovery (Multicast Listener Discover, MLD) message to the MB-UPF network element ), to request the transmission of a data stream of a multicast service, the message includes the first IP multicast address and the C-TEID, and the MB-UPF network element receives the message through the port corresponding to the C-TEID, and sends the message to the C-TEID. - The port corresponding to the TEID transmits the data stream of the multicast service corresponding to the first IP multicast address. The MLD message is the ipv6 version of the IGMP message.

Optionally, if the first IP multicast address and C-TEID corresponding to the multicast group are not allocated by the MB-UPF network element, the MB-SMF network element allocates the first IP multicast address and C-TEID corresponding to the multicast group. C-TEID, and send the first IP multicast address and C-TEID corresponding to the multicast group to the MB-UPF network element.

S504, the MB-SMF network element sends the IP address and port allocated by the MB-UPF network element for the multicast group to the MBSF network element or the application server.

Optionally, if the MB-SMF network element also allocates or receives the first IP multicast address and C-TEID corresponding to the multicast group from the MB-UPF network element, the first IP multicast address corresponding to the multicast group The multicast address and C-TEID are stored.

S505 , the terminal device sends an identifier (eg, TMGI) of a multicast group corresponding to a certain multicast service to the RAN network element.

The identifier of the multicast group indicates that the terminal device requests to join the multicast group to receive the data stream of the corresponding multicast service.

S506: If the multicast group has not been allocated the corresponding access network resource, the RAN network element sends the identifier of the multicast group to the M-AMF network element.

If the multicast group has been allocated the corresponding access network resources, the following steps S507-S511 are skipped, and the RAN network element sends the data stream of the multicast service corresponding to the multicast group to the terminal device.

S507. If the M-AMF network element does not have the first IP multicast address and C-TEID corresponding to the multicast group, record the request of the RAN network element to add the terminal device to the multicast group, and report to the MB-SMF network Meta sends the identity of the multicast group.

If the M-AMF network element has the first IP multicast address and C-TEID corresponding to the multicast group, steps S508-S510 are skipped.

S508. If the data stream of the multicast service corresponding to the multicast group has been delivered from the application server, the MB-SMF network element sends a multicast broadcast service (multicast broadcast service, MBS) session start request to the M-AMF network element (MBS Session Start Request) message.

The message includes the first IP multicast address and C-TEID corresponding to the multicast group.

If the data stream of the multicast service corresponding to the multicast group has not been delivered from the application server, the MB-SMF network element waits for the application server to send the multicast service corresponding to the multicast group to the MB-UPF network element.

S509, the M-AMF network element saves the first IP multicast address and the C-TEID corresponding to the multicast group, and sends an MBS Session Start Response (MBS Session Start Response) message to the MB-SMF network element.

S510. The M-AMF network element sends an MBS session start request (MBS Session Start Request) message to the RAN network element.

S511. The RAN network element sends an MBS Session Start Response (MBS Session Start Response) message to the M-AMF network element.

The RAN network element establishes a user plane connection (or downlink data transmission path) with the MB-UPF network element according to the first multicast address and C-TEID corresponding to the multicast group, so as to receive the corresponding The data flow of the multicast service. In addition, the RAN network element allocates access network resources for the multicast service corresponding to the multicast group, and sends the data stream of the multicast service to the terminal device.

In this embodiment, the RAN network element searches for the first multicast address and the C-TEID corresponding to the multicast group from the AMF network element and the SMF network element step by step, which increases the delay for the terminal device to join the multicast group.

Aiming at the delay problem caused by the above two implementations, the embodiment of the present application provides a multicast address communication method, which can be applied to the following scenarios:

Scenario 1: For VR live broadcast services, the application server simultaneously delivers data streams of multiple perspectives, and the data stream of each perspective corresponds to a multicast group. When the terminal device quickly switches the perspective by turning its head, it joins a new multicast group Group.

Scenario 2. Multi-view live broadcast services, such as Spring Festival Gala, sports competitions, etc., there are multiple cameras on-site for shooting. The data stream captured by each camera corresponds to a multicast group, and the terminal device quickly switches between the data streams corresponding to different cameras. When switching, join a new multicast group.

Scenario 3. Other multicast services for fast channel switching.

Exemplarily, for scenario one, taking the field of view vitual reality (FOV VR) live video broadcast using multicast transmission as shown in FIG. 6 as an example, each program includes data streams of multiple viewing angles. , the data stream of each view corresponds to an identifier of a multicast group (for example, a second IP multicast address), and the client of the terminal device selects a different view to watch, that is, selects an identifier of a different multicast group.

During the live broadcast, the application server maintains the association relationship between the different viewing angles of each program and the identifiers of the corresponding multicast groups. For multicast, the address accessed by the client of the terminal device is the second IP multicast address of the multicast group. When the live broadcast starts, the terminal device first requests program information from the application server, and obtains the different perspectives of each program and the corresponding The association of the identifiers of the multicast groups.

For example, the above-mentioned association relationship is shown in Table 1, in which there are two multicast services of program a and program b, each multicast service has 12 views, and each view corresponds to an identifier of a multicast group.

Table 1

When the user is watching program a (that is, the multicast service), when the viewing angle is switched from 0 degrees (corresponding to the second multicast group) to 30 degrees (corresponding to the first multicast group), the terminal device requests The multicast group whose identifier (second IP multicast address) is 235.254.196.1 (ie, the second multicast group) switches to the multicast whose identifier (second IP multicast address) is 235.254.196.2 The group (ie, the first multicast group), that is, the multicast group (ie, the first multicast group) whose identifier (second IP multicast address) for requesting to join the multicast group is 235.254.196.2.

In the multicast group communication method provided by the embodiment of the present application, in addition, if the RAN network element detects that the terminal device requests to join the first multicast group, and the data stream of the first multicast group is already being transmitted to other terminal devices, Then, the terminal can be directly added to the first multicast group, and the corresponding data stream can be sent to the terminal device.

As shown in FIG. 7 , taking a perspective of program a in Table 1 corresponding to each multicast group as an example, the core idea of the multicast group communication method provided by the embodiment of the present application is:

A mapping relationship between the multicast service and the identifier of the first multicast group of the multicast service and the identifier of the associated multicast group is maintained between the application layer of the terminal device and the application layer of the application server. This enables the terminal device to switch between different multicast groups of the same multicast service, corresponding to the data streams of the different perspectives of the program a that the terminal device receives from the application server.

If the terminal equipment requests to join the first multicast group (for example, multicast group 1), for example, the terminal equipment requests to play a data stream of a certain view of the program a, the MBSF network element or AS not only sends the first multicast group to the UPF network element data streams corresponding to the multicast group, and also send the data streams corresponding to the associated multicast groups (such as multicast group 2 to multicast group 12) of the first multicast group to the UPF network element, such as all other data streams of program a View data flow. In addition, not only the identifier of the first multicast group (for example, the identifier of multicast group 1), but also the identifier of the associated multicast group of the first multicast group (for example, the identifier of multicast group 1) is sent to the SMF network element. IDs of multicast group 2 to multicast group 12).

The SMF network element sends the identifier of the first multicast group and the identifier of the associated multicast group to the RAN network element and the UPF network element, so that the UPF network element receives and caches the data stream corresponding to the first multicast group and the associated multicast group. The data streams corresponding to the broadcast group, for example, receive and buffer the data streams of all 12 views of the program a. The RAN network element is caused to allocate group RNTI and access network resources for the first multicast group and the associated multicast group.

The SMF network element sends the first indication information to the UPF network element, which is used to instruct the terminal device to join the first multicast group (that is, instructing the UPF network element to receive and send the data stream corresponding to the first multicast group to the RAN network element) , or, the UPF network element parses the IGMP message (or MLD message) from the terminal device to obtain the first indication information. The UPF network element then instructs the RAN network element first indication information through the user plane (that is, instructing the RAN network element to receive and send the data stream corresponding to the first multicast group to the terminal device).

When the terminal device requests to join a multicast group (such as multicast group 2) in the associated multicast group again, since the UPF network element has already received and buffered the corresponding data stream, it can directly send the data stream to the RAN network element. corresponding data stream. Since the RAN network element has allocated the access network resources to the multicast group, it can directly send the corresponding data stream to the terminal device through the air interface, which realizes the rapid reception of the data stream of the new multicast group, which reduces the The delay for the terminal device to join the multicast group.

For the method for transmitting a multicast service in FIG. 4 , an embodiment of the present application provides a multicast group communication method, including a session establishment process and a multicast group joining process.

In the session establishment process, the terminal device requests the unicast UPF network element to join the first multicast group through the RAN network element, and the SMF network element obtains the identifier of the first multicast group, and the identifier of the first multicast group The identifier of the associated multicast group.

In the process of joining a multicast group, the SMF network element sends the first activation information to the unicast UPF network element, where the first activation information is used to indicate whether the first multicast group and the data stream corresponding to the associated multicast group are already in the Sent on the RAN element. If the terminal device requests the unicast UPF network element to join the first multicast group through the RAN network element, and the first activation information indicates that the data stream corresponding to the first multicast group has been sent on the RAN network element, the unicast The UPF network element can directly instruct the RAN network element to add the terminal device to the first multicast group through a user plane message, instead of instructing the RAN network element to add the terminal device to the first multicast group through a control plane message, thereby reducing the number of terminal devices. The delay for the device to join the multicast group.

In addition, in the process of joining a multicast group, if the data stream corresponding to the first multicast group has not been sent on the RAN network element, the SMF network element sends the first indication information to the multicast UPF network element. The identifier of the multicast group and the identifier of the associated multicast group, and the first indication information is used to add the terminal device to the first multicast group; the multicast UPF network element receives the first multicast group from the application server and the associated multicast group. The data stream corresponding to the multicast group, but only the data stream corresponding to the first multicast group is sent to the RAN network element, and the RAN network element is instructed to add the terminal device to the first multicast group through the user plane message without having to control the The message instructs the RAN network element to add the terminal device to the first multicast group, thereby reducing the delay for the terminal device to join the multicast group.

As shown in FIG. 8 , an embodiment of the present application provides a multicast group communication method. The method may include S801-S809. Wherein, steps S804-S809 may be performed in a loop, that is, step S804 is continued to be performed after step S809 is performed. In addition, step S805 and steps S806-S809 are two optional parallel solutions.

S801. The terminal device sends a first message to a first UPF network element through a RAN network element.

Correspondingly, the first UPF network element receives the first message from the terminal device. The first UPF network element may be a unicast UPF network element, that is, a UPF network element for transmitting a unicast data stream.

Specifically, if the application layer of the terminal device wants to change the multicast group, step S801 may be performed. For example, in the VR live broadcast service, the viewing angle is switched, in the IPTV service, etc., the terminal device sends the first message to the unicast UPF through the RAN network element.

The first message may include an identifier of the first multicast group, and the first message may be used to request that the terminal device be added to the first multicast group. Exemplarily, the first message may be an IGMP Join (Join) request message.

Optionally, the above method further includes: the terminal device sends the second message to the first UPF network element through the RAN network element, and correspondingly, the first UPF network element may also receive the second message from the terminal device.

Wherein, the second message may include the identifier of the second multicast group, the second multicast group is one of the associated multicast groups, and the second message may be used to request the terminal device to exit the second multicast group . Exemplarily, the second message may be an IGMP Leave (Leave) request message.

S802. The first UPF network element sends the first indication information to the SMF network element according to the first message.

Correspondingly, the SMF network element receives the first indication information from the first UPF network element. As mentioned above, the first message can be used to request to add the terminal device to the first multicast group, and correspondingly, the first indication information can be used to add the terminal device to the first multicast group.

Optionally, the above method further includes: the first UPF network element sends the second indication information to the SMF network element according to the second message. As mentioned above, the second message can be used to request to withdraw the terminal device from the second multicast group. correspondingly, the second indication information may be used to indicate that the terminal device has left the second multicast group.

The indication information (the first indication information, the second indication information, and the third indication information hereinafter) involved in the embodiments of the present application may be represented in an implicit manner, that is, one of the indication information is indicated by default. For example, the identification of the multicast group is included in a message without explicit indication.

The indication information involved in this embodiment of the present application may also be expressed in an explicit manner. For example, the indication information occupies a single cell and is paired with the identifier of the multicast group, indicating that the terminal device is added to the paired multicast group ( first indication information), or whether the terminal device has exited the paired multicast group (second indication information), or is the terminal device exited from the paired multicast group (third indication information). For another example, certain indication information may be represented by a specific message (eg, an IGMP join request message, or an IGMP leave request message), and the message includes the identifier of the multicast group.

S803. The SMF network element obtains the identifier of the first multicast group and the identifier of the associated multicast group of the first multicast group from the UDR.

Specifically, the UDR may obtain the identifier of the first multicast group and the identifier of the associated multicast group of the first multicast group from the AF. The associated multicast group of the first multicast group and the first multicast group belong to the same multicast service, for example, different viewing angles of the same live broadcast; Multicast groups belong to associated multicast services, such as live football and basketball. And the number of associated multicast groups is not limited, which can be one or more. Exemplarily, the identifier of the first multicast group or the identifier of the associated multicast group may be the second IP multicast address.

S804: The SMF network element sends the first activation information (which may include the second activation information) to the first UPF network element.

Correspondingly, the first UPF network element receives the first activation information from the SMF network element.

The first activation information may be used to indicate whether data streams corresponding to both the first multicast group and the associated multicast group have been sent on the RAN network element.

The first activation information may include second activation information, and the second activation information may be used to indicate whether the data stream corresponding to the first multicast group has been sent on the RAN network element. Correspondingly, the step S804 may include the SMF network element sending the second activation information to the first UPF network element. Further, the first UPF network element receives the second activation information from the SMF network element.

Exemplarily, the activation information in this embodiment of the present application may be represented by bits, and each multicast group may correspond to one bit. For example, when the bit value is 1, it indicates the data corresponding to the multicast group. The stream has been sent on the RAN network element. When the bit value is 0, it indicates that the data stream corresponding to the multicast group has not been sent on the RAN network element. Alternatively, the SMF network element may send the identifier of the multicast group that is activated (that is, the corresponding data flow has been sent on the RAN network element) to the first UPF network element as the first activation information.

It should be noted that steps S804-S809 may be performed cyclically. Specifically, the first activation information may be used to update the third activation information sent by the second UPF network element to the SMF network element in step S809 of the previous cycle process .

It should be pointed out that in an optional scenario, the SMF network element and the second UPF network element cannot learn the identity of the RAN network element, but can learn the port information of the RAN network element for the multicast session (ie port information of the RAN network element corresponding to the first multicast group and the associated multicast group).

Optionally, the SMF network element may determine the identifier of a unicast session of the terminal device through the identifier of the terminal device, and determine the port information of the RAN network element for the multicast session through the identifier of the unicast session, thereby determining the first activation information.

In a possible implementation, the SMF network element can obtain the relationship between the identifier of the unicast session and the port information of the unicast session performed by the RAN network element (the RAN network element sends a message corresponding to the identifier of the unicast session to the SMF network element. The port information of the RAN network element for the unicast session is associated with the port information of the RAN network element for the multicast session (the IP addresses of the RAN corresponding to the two port information are the same), Therefore, the SMF network element can determine the port information of the RAN network element for the unicast session through the identifier of the unicast session, and determine the port information of the RAN network element for the multicast session through the port information of the RAN network element for the unicast session, so as to determine the first The activation information is sent to the corresponding first UPF network element.

In another possible implementation manner, as described in the following step S902, the SMF network element may associate the port information of the RAN network element corresponding to the first multicast group and the associated multicast group with the identifier of the unicast session Therefore, the SMF network element can also determine the port information of the RAN network element for the multicast session through the identifier of the unicast session, so as to determine the first activation information and send it to the corresponding first UPF network element.

Optionally, if the first activation information (or the second activation information) indicates that the data stream corresponding to the first multicast group has been sent on the RAN network element, step S805 is performed; or alternatively, if the first activation information If the information (or the second activation information) indicates that the data stream corresponding to the first multicast group has not been sent on the RAN network element, the following steps S806-S809 are performed.

S805. The first UPF network element sends the first indication information to the RAN network element.

Correspondingly, the RAN network element receives the first indication information from the first UPF network element. The first indication information sent by the first UPF network element to the RAN network element may be carried in the packet header of the data stream sent by the first UPF network element to the RAN network element, that is, the transmission delay can be reduced by transmitting the indication information on the user plane. Exemplarily, the packet header of the data stream in this embodiment of the present application may refer to the GPRS tunnel protocol user plane (GPRS tunnel protocol-user plane, GTP-U) packet header of the data stream.

Optionally, the above method further includes: the first UPF network element sends third indication information to the RAN network element.

Wherein, the third indication information may be used to withdraw the terminal device from the second multicast group. The third indication information may be carried in the packet header of the data stream sent by the first UPF network element to the RAN network element, and may be sent separately or together with the first indication information.

S806: The SMF network element sends the third message and the first indication information to the second UPF network element.

Correspondingly, the second UPF network element receives the third message and the first indication information from the SMF network element.

The third message may include the identifier of the first multicast group and the identifier of the associated multicast group. Exemplarily, the third message may be an N4 message.

It should be noted that the first indication information may be carried in a third message and sent, and accordingly, step S806 may be replaced by the SMF network element sending a third message to the second UPF network element, where the third message includes the first indication information; Obviously, the first indication information may also be carried in other messages except the third message and sent, which is not limited.

The second UPF network element may be a multicast UPF network element, that is, a UPF network element that transmits a multicast data stream.

Optionally, the above method further includes: the SMF network element sends third indication information to the second UPF network element.

It should be noted that the third indication information may be carried in the third message and sent, or may be carried in other messages except the third message and sent.

S807. The second UPF network element receives the first multicast group and the data stream corresponding to the associated multicast group from the application server.

S808. The second UPF network element sends the first indication information and the data stream corresponding to the first multicast group to the RAN network element.

Correspondingly, the RAN network element receives the first indication information and the data stream corresponding to the first multicast group from the second UPF network element. Wherein, the first indication information may be carried in the packet header of the data stream.

Optionally, the above method further includes: the second UPF network element sends third indication information to the RAN network element, the third indication information may be carried in the packet header of the data stream, and may be sent separately or together with the first indication information.

Optionally, the above method further includes: the second UPF network element stops sending the data stream corresponding to the second multicast group to the RAN network element, for example, the last terminal device of the second multicast group requests to quit the second multicast When requesting to stop receiving the data stream corresponding to the second multicast group, the second UPF network element may stop sending the data stream corresponding to the second multicast group to the RAN network element.

Optionally, the above method further includes: if the RAN network element serves multiple terminal devices, the second UPF network element sends the identifier of the terminal device to the RAN network element, so that the RAN network element knows which terminal device to add to the first multicast group. group, and send the corresponding data stream to the terminal device.

It should be noted that, step S808 and step S805 may alternatively be executed.

S809: The second UPF network element sends third activation information to the SMF network element.

Correspondingly, the SMF network element receives the third activation information from the second user plane function network element.

The third activation information may be used to indicate whether the first multicast group and the data stream corresponding to the associated multicast group have been sent on the RAN network element. The third activation information may be used by the SMF network element to update the first activation information, so as to be subsequently sent to the first UPF network element.

After that, the SMF network element may restart to perform step S804 and subsequent steps, that is, send the updated first activation information to the first UPF network element.

Correspondingly, the first UPF network element may receive the updated first activation information from the SMF network element. Wherein, the updated first activation information may include updated second activation information, that is to say, this step includes that the first UPF network element receives the updated second activation information from the SMF network element, and the updated second activation information The information may be used to indicate whether the data stream corresponding to the first multicast group has been sent on the RAN network element. At this time, in the updated first activation information (or the updated first activation information), the data stream corresponding to the first multicast group has been sent on the RAN network element.

Optionally, the above method further includes: the SMF network element obtains the port information corresponding to the first multicast group and the associated multicast group from the RAN network element, and sends it to the second UPF network element, so that the second UPF network element can Establish a downlink transmission path with the RAN network element.

As shown in FIG. 9, another multicast group communication method is provided. The communication method may be based on the embodiment shown in FIG. 8 , and specifically, further includes steps S901-S903 after steps S801-S803:

S901. The SMF network element sends the identifier of the first multicast group and the identifier of the associated multicast group to the RAN network element.

Accordingly, the RAN network element receives the identification of the first multicast group and the identification of the associated multicast group from the SMF network element. See the foregoing description for the identification of the first multicast group and the identification of the associated multicast group.

S902: The RAN network element sends the port information of the RAN network element corresponding to the first multicast group and the associated multicast group to the SMF network element.

Accordingly, the SMF network element may receive port information of the RAN network element corresponding to the first multicast group and the associated multicast group from the RAN network element. The above port information can be used to establish a tunnel (N3 tunnel) for transmitting data flow between the second UPF network element and the RAN network element. For example, the packet header of the data flow sent by the second UPF network element to the RAN network element includes the above port information. , indicating that the data flow is sent to the above-mentioned port through the above-mentioned tunnel for transmitting the data flow, and the RAN network element parses the data packet corresponding to the data flow from the above-mentioned port.

After receiving the identifier of the first multicast group and the identifier of the associated multicast group, the RAN network element can allocate port information (for example, AN port number), QFI, Access network resources (such as data radio bearers (DRBs)) and group RNTIs.

Each multicast group may correspond to one multicast session, one AN port (that is, one N3 tunnel), one QFI, one DRB, and one RNTI; or, the first multicast group and the associated multicast group correspond to one multicast Session, one AN port (ie, one N3 tunnel), each multicast group corresponds to one QFI, one DRB, and one RNTI.

If each multicast group corresponds to one AN port (ie, one N3 tunnel), the RAN network element may send the association relationship between the port information and the corresponding multicast group to the SMF network element. If the first multicast group and the associated multicast group correspond to one AN port (ie, one N3 tunnel), the RAN network element may send port information to the SMF network element.

After receiving the port information corresponding to the first multicast group and the associated multicast group from the RAN network element, the SMF network element may bind the port information with an identifier of a unicast session of the terminal device. The unicast session can be used by the terminal device to send user plane control messages (eg, IGMP messages) to the multicast UPF network element, and can also be used by the multicast UPF network element to send user plane control messages to the terminal device.

S903: The SMF network element sends the port information of the RAN network element corresponding to the first multicast group and the associated multicast group to the second UPF network element.

Correspondingly, the second UPF network element receives port information of the RAN network element corresponding to the first multicast group and the associated multicast group from the SMF network element.

It should be noted that step S903 and step S806 may be executed together.

For the method for transmitting multicast services in FIG. 5 , the MB-SMF network element acquires multicast group information, the identifier of the first multicast group, and the identifier of the associated multicast group of the first multicast group, and the multicast The group information includes the first IP multicast address corresponding to the identifier of the first multicast group, the first IP multicast address corresponding to the identifier of the associated multicast group of the first multicast group, the first multicast group The corresponding C-TEID, and the C-TEID corresponding to the associated multicast group. When the RAN network element requests to add the terminal device to the first multicast group, the MB-SMF network element sends the multicast group information to the RAN network element through the M-AMF network element. So that when the terminal device requests to join the associated multicast group, the RAN network element does not need to obtain the first IP multicast address and the C-TEID corresponding to the associated multicast group from the M-AMF network element and the MB-SMF network element in turn, Thereby, the delay for the terminal device to join the multicast group is reduced.

As shown in Figure 10, the multicast group communication method includes:

S1001. A first network element acquires multicast group information, an identifier of the first multicast group, and an identifier of an associated multicast group of the first multicast group.

The multicast group information may include the first IP multicast address corresponding to the identifier of the first multicast group, the first IP multicast address corresponding to the identifier of the associated multicast group of the first multicast group, the first multicast group. The C-TEID corresponding to the multicast group, and the C-TEID corresponding to the associated multicast group.

The first network element may be an MB-SMF network element or an MB-AMF network element.

When the first network element is an MB-SMF network element, the first network element may receive the multicast group information from the MB-UPF network element, or the first network element may configure the multicast group information. The first network element may receive an identification of the first multicast group and an identification of an associated multicast group of the first multicast group from the MBSF network element.

When the first network element is an MB-AMF network element, the first network element may receive the multicast group information, the identifier of the first multicast group, and the associated multicast of the first multicast group from the MB-SMF network element The ID of the group.

S1002. The second network element sends first indication information to the first network element.

Correspondingly, the first network element receives the first indication information from the second network element. The first indication information may be used to add the terminal device to the first multicast group.

Optionally, when the first network element is an MB-SMF, the second network element is an MB-AMF network element; when the first network element is an MB-AMF network element, the second network element is a RAN network element.

S1003. The first network element sends multicast group information to the second network element according to the first indication information.

The identifier of the first multicast group can be determined through the first indication information, thereby determining the identifier of the associated multicast group, and the first IP multicast address and C-TEID in the multicast group information are both the same as the first multicast group. The identifier of the multicast group corresponds to the identifier of the associated multicast group, so the corresponding multicast group information can be determined.

The foregoing multicast group communication method will be described below with reference to specific embodiments.

First, for the method shown in FIG. 4 , how the SMF network element obtains the identifier of the first multicast group and the identifier of the associated multicast group, and completes the configuration of the RAN network element and the UPF network element. As shown in Figure 11, the process includes:

S1101. The AF network element generates an AF request (AF Request) message.

The message includes the identifier of the first multicast group corresponding to the multicast service and the identifier of the associated multicast group of the first multicast group, and may also include multicast service information, such as media information (such as the playback content type: audio, video, mpg, etc.), QoS requirements, start time and stop time of multicast services, identification of multicast services (for example, APP identification), etc.

S1102. The AF network element sends an AF request message to the NEF network element.

S1103. The NEF network element stores the multicast context of the first multicast group according to the AF request message.

The NEF network element extracts the identifier of the first multicast group in the AF request message and the identifier of the associated multicast group of the first multicast group, and stores it in the multicast context of the first multicast group in the UDR. The identifications of the multicast service corresponding to the first multicast group and the associated multicast group in the AF request message are stored in the multicast context of the first multicast group of the UDR.

S1104. The NEF network element sends an AF request response (AF Request Response) message to the AF network element.

This message is used to indicate completion of storing the multicast context of the first multicast group.

S1105, the terminal device completes the registration and establishes a unicast session.

S1106: The terminal device sends an IGMP Join (Join) request message to the unicast UPF network element through the unicast session.

The message includes the identifier of the first multicast group (for example, the second IP multicast address), and the message is used to request the terminal device to join the first multicast group in order to receive the data stream corresponding to the first multicast group .

Exemplarily, as described in Scenario 1 above, assuming that the identifier of the first multicast group is the second IP multicast address 235.254.196.2 of program a, it means that the terminal device wants to receive a data stream with a +30 degree viewing angle.

S1107. The unicast UPF network element sends a User Plane Event Notify message to the SMF network element according to the IGMP Join request message.

The message includes the identifier of the first multicast group.

The SMF network element executes the process of adding the terminal device to the first multicast group according to the above message, and the process may be a multicast session establishment process or a multicast session adjustment process of the first multicast group. Specifically, the following steps S1108-S1113 are included.

S1108: After the SMF network element selects the PCF network element, the PCF network element obtains the multicast context of the first multicast group from the UDR through the data management notification (Nudr_DM_Notify) service.

S1109a, the SMF network element obtains the multicast context of the first multicast group and related policies and charging control (policy and charging control, PCC) rules from the PCF network element through the update notification (Npcf_SMPolicyControl_UpdateNotify) service.

Since the multicast context of the first multicast group includes the identifier of the first multicast group and the identifier of the associated multicast group, this step refers to step S803.

S1109b, the SMF network element may also obtain the multicast context of the first multicast group and the related PCC rules from the UDR through a multicast distribution session check (Multicast Distribution Session Check).

S1110. The SMF network element sends an N2 session request (N2 Session Request) message to the RAN network element.

The message includes the identifier of the first multicast group and the identifier of the associated multicast group.

This step refers to step S901.

S1111. The RAN network element sends the port information of the RAN network element corresponding to the first multicast group and the associated multicast group to the SMF network element.

This step refers to step S902.

S1112. The SMF network element sends the port information of the RAN network element corresponding to the first multicast group and the associated multicast group to the multicast UPF network element through an N4 message.

The above-mentioned N4 message may also include the identifier of the first multicast group and the identifier of the associated multicast group, which are used to instruct the multicast UPF network element to establish a data transmission path with the application server, and receive the first multicast group from the application server. group and the data stream of the associated multicast group, but only the data stream corresponding to the first multicast group is sent to the RAN network element.

This step refers to step S903.

The following describes how the unicast UPF network element or the multicast UPF network element sends the first indication information to the RAN network element after receiving the first indication information for adding the terminal device to the first multicast group (that is, adding the terminal device to the first multicast group). broadcast group). As shown in Figure 12, the process includes:

S1201. A terminal device establishes a multicast session with a network element on the network side.

The network elements on the network side include RAN network elements, AMF network elements, SMF network elements, PCF network elements, and multicast UPF network elements. It is assumed that the terminal device receives the data stream of the second multicast group at this time, where the second multicast group is one of the associated multicast groups of the first multicast group.

S1202. The SMF network element sends the first activation information to the unicast UPF network element.

This step refers to step S802.

S1203: The terminal device sends an IGMP Join (Join) request message to the unicast UPF network element through the RAN network element to request to join the first multicast group.

This step refers to step S801.

If the first activation information (or the second activation information) indicates that the data stream corresponding to the first multicast group is to be sent, execute steps S1204-S1205; otherwise, skip step S1204 and execute steps S1205-S1211.

S1204. The unicast UPF network element sends the first indication information and the data stream corresponding to the first multicast group to the RAN network element.

The first indication information may be carried in a GPRS tunneling protocol (GPRS tunneling protocol, GTP-U) header of the data stream.

This step refers to step S805.

S1205. The unicast UPF sends a user plane event notification (User Plane Event Notify) message to the SMF network element according to the IGMP join (Join) request message.

The message includes the identifier of the first multicast group.

This step refers to step S802.

If the unicast UPF network element and the multicast UPF network element are the same UPF network element, steps S1206-S1207 are skipped.

S1206, the SMF network element queries and updates the multicast context.

The multicast context may be stored on other SMF network elements, and this SMF network element may query other SMF network elements for the multicast context. The multicast context includes the multicast group served by the multicast UPF network element and the corresponding activation state (that is, whether the corresponding data stream has been sent on the RAN network element), and also includes the terminal equipment corresponding to each multicast group 's identification.

S1207, the SMF network element sends an N4 message to the multicast UPF network element.

The message includes the identifier of the terminal device and the identifier of the first multicast group. That is, the identifier of the multicast group carried in the default N4 message indicates that the terminal device is to be added to the corresponding multicast group.

Optionally, the message may further include the first indication information, the third indication information and the identifier of the second multicast group. That is, the terminal device is instructed to join or quit the corresponding multicast group through explicit instruction information.

This step refers to step S806.

S1208. The multicast UPF determines the first indication information according to the N4 message or the IGMP join request message.

If the unicast UPF network element and the multicast UPF network element are the same UPF network element, the multicast UPF network element determines the first indication information according to the IGMP join request message. For example, the IGMP join request message includes the identifier of the first multicast group, and the IGMP join request message indicates that the terminal device is added to the corresponding multicast group. Therefore, it can be determined that the first indication information is to add the terminal device to the first multicast group. broadcast group.

Optionally, if the unicast UPF network element and the multicast UPF network element are the same UPF network element, the multicast UPF network element determines the third indication information according to the IGMP leave request message. For example, the IGMP leave request message includes the identifier of the second multicast group, and the IGMP leave request message indicates that the terminal device is to leave the corresponding multicast group. Therefore, it can be determined that the third instruction information is to leave the terminal device to the second multicast group. broadcast group.

If the unicast UPF network element and the multicast UPF network element are not the same UPF network element, the multicast UPF determines the first indication information according to the N4 message.

For example, if there is no indication information in the N4 message, but only the identifier of the terminal device and the identifier of the first multicast group, the corresponding multicast group is activated. If the N4 message includes the first indication information, the third indication information, the identifier of the first multicast group and the identifier of the second multicast group, activate the corresponding identifier of the first multicast group indicated by the first indication information The multicast group corresponding to the identifier of the second multicast group indicated by the third indication information is deactivated.

Optionally, if the unicast UPF network element and the multicast UPF network element are not the same UPF network element, the multicast UPF network element determines the third indication information according to the N4 message.

S1209: The multicast UPF network element receives the first multicast group and the data stream corresponding to the associated multicast group from the application server.

This step refers to step S807.

S1210: The multicast UPF network element sends the identifier of the terminal device, the first indication information, and the data stream corresponding to the first multicast group to the RAN network element.

This step refers to step S808.

S1211. The multicast UPF network element sends an N4 message to the SMF network element.

The message includes third activation information, and this step refers to step S809.

S1212. The SMF network element sends the updated first activation information to the unicast UPF network element.

This step refers to step S809.

S1213. The RAN network element adds the terminal device to the first multicast group according to the identifier of the terminal device and the first indication information.

That is, the RAN network element sends the data stream corresponding to the first multicast group to the terminal device through the access network resource.

Optionally, the RAN network element withdraws the terminal device from the second multicast group according to the identification of the terminal device and the third indication information. That is, the RAN network element stops sending the data stream corresponding to the second multicast group to the terminal device.

The following describes that the RAN network element receives the IGMP join request message from the terminal device, thereby determining to add the terminal device to the first multicast group. The RAN network element does not need to receive the first indication information from the multicast UPF network element; the SMF network element does not need to send the unicast The UPF network element sends the first activation information, and the multicast UPF network element sends the first activation information to the SMF network element. As shown in Figure 13, the process includes:

S1301. A terminal device establishes a multicast session with a network side.

This step refers to step S1201.

S1302: The terminal device sends an IGMP Join (Join) request message to the unicast UPF network element through the RAN network element.

This step refers to step S801.

In addition, when detecting the IGMP join request message, the RAN network element queries the first activation information (or the second activation information) to determine whether the data stream corresponding to the first multicast group has been sent, and if the first multicast group has been sent For the corresponding data stream, steps S1303-S1309 are skipped, and step S1310 is executed. If the data stream corresponding to the first multicast group is not sent, wait for the multicast UPF network element to deliver the data stream corresponding to the first multicast group.

S1303. The unicast UPF sends a User Plane Event Notify message to the SMF network element according to the IGMP Join request message.

This step refers to step S1205.

If the unicast UPF network element and the multicast UPF network element are the same UPF network element, steps S1304-S1305 are skipped.

S1304, the SMF network element queries and updates the multicast context.

This step refers to step S1206.

S1305. The SMF network element sends an N4 message to the multicast UPF network element.

This step refers to step S1207.

S1306. The multicast UPF determines the first indication information according to the N4 message or the IGMP join request message.

This step refers to step S1208.

S1307: The multicast UPF network element receives the first multicast group and the data stream corresponding to the associated multicast group from the application server.

This step refers to step S807.

S1308: The multicast UPF network element sends the data stream corresponding to the first multicast group to the RAN network element.

That is, the multicast UPF network element does not send the first indication information to the RAN network element.

S1309: The multicast UPF network element sends an N4 message to the SMF network element.

This step refers to step S1211.

S1310. The RAN network element adds the terminal device to the first multicast group according to the IGMP join request message.

Because the IGMP Join Request message includes the identifier of the first multicast group, the RAN network element can add the terminal device to the first multicast group according to the identifier of the first multicast group in the IGMP Join Request message.

The following describes how the SMF network element obtains the identifier of the first multicast group and the identifier of the associated multicast group, and completes the configuration of the RAN network element and the UPF network element with respect to the method shown in FIG. 5 . As shown in Figure 14, the process includes:

S1401. A terminal device acquires information of a multicast service from an MBSF network element or an application server.

This step refers to step S501.

S1402: When the MBSF network element or the application server starts the multicast service, send a multicast session establishment request message to the MB-SMF network element.

The message includes the identifier of the first multicast group (eg TMGI) corresponding to the multicast service and the identifier of the associated multicast group (eg TMGI), and the message is used to request the MB-SMF network element to be the first multicast group The group establishes the corresponding session.

In this step, refer to step S1001 that when the first network element is an MB-SMF network element, the first network element obtains the identifier of the first multicast group and the identifier of the associated multicast group of the first multicast group.

S1403. The MB-SMF network element sends a multicast broadcast session start (MB Session Start) message to the MB-UPF network element.

The message includes the identifier of the first multicast group and the identifier of the associated multicast group. This message is used to request the MB-UPF network element to allocate IP addresses and ports for the first multicast group and associated multicast groups. These IP addresses and ports are used by the MB-UPF network element to receive from the MBSF network element or the application server. The first multicast group and the data stream corresponding to the associated multicast group. That is, the data packet carrying the first multicast group and the data stream corresponding to the associated multicast group sent by the MBSF network element or the application server to the MB-UPF network element includes the above IP address and port.

Each multicast group may correspond to one IP address and one port, or the first multicast group and the associated multicast group may correspond to one IP address and one port.

If the multicast group information (first IP multicast address and C-TEID) corresponding to the multicast group is also allocated by the MB-UPF network element, this message is also used to request the MB-UPF network element to be the first multicast Group and multicast group information (first IP multicast address and C-TEID) assigned by the associated multicast group. Each multicast group corresponds to a first IP multicast address and a C-TEID, for the RAN network element to receive the first multicast group and the data stream corresponding to the associated multicast group from the MB-UPF network element.

For this step, refer to step S1001 that when the first network element is an MB-SMF network element, the first network element acquires multicast group information.

S1404. The MB-SMF network element sends the IP address and port allocated by the MB-UPF network element for the first multicast group and the associated multicast group to the MBSF network element or the application server.

If the MB-SMF network element also receives the multicast group information corresponding to the first multicast group and the associated multicast group, the MB-SMF network element sends the corresponding multicast group information to the MBSF network element or the application server .

S1405. The terminal device sends the first indication information to the RAN network element.

The first indication information may be an identification (eg, TMGI) of the first multicast group.

S1406: The RAN network element sends the first indication information to the M-AMF network element.

This step refers to when the first network element is an M-AMF network element and the second network element is a RAN network element in step S1002.

S1407. The AMF network element sends the first indication information to the MB-SMF network element.

And the AMF network element records that the RAN network element is waiting to receive the data stream corresponding to the first multicast group.

For this step, refer to step S1002 when the first network element is an MB-SMF network element and the second network element is an M-AMF network element.

S1408. If the data stream corresponding to the first multicast group has been delivered from the application server, the MB-SMF network element sends an MBS Session Start Request (MBS Session Start Request) message to the M-AMF network element.

The message includes multicast group information, an identifier of the first multicast group, and an identifier of an associated multicast group of the first multicast group.

If the data stream corresponding to the first multicast group has not been delivered from the application server, the MB-SMF network element waits for the data stream corresponding to the first multicast group to be delivered from the application server.

For this step, refer to step S1001 that when the first network element is an M-AMF network element and the second network element is an M-AMF network element, the first network element obtains the multicast group information, the identifier of the first multicast group, and the first network element. The identifier of the associated multicast group of a multicast group.

This step also corresponds to step S1003 when the first network element is an M-AMF network element and the second network element is an M-AMF network element, the first network element sends the multicast group information to the second network element according to the first indication information .

S1409. The M-AMF network element stores the above-mentioned first IP multicast address and C-TEID, and sends an MBS Session Start Response (MBS Session Start Response) message to the MB-SMF network element.

S1410. The M-AMF network element sends an MBS session start request (MBS Session Start Request) message to the RAN network element.

The message includes multicast group information.

For this step, refer to step S1003 that when the first network element is an M-AMF network element and the second network element is a RAN network element, the first network element sends multicast group information to the second network element according to the first indication information.

S1411. The RAN network element sends an MBS session start response (MBS Session Start Response) message to the M-AMF network element.

The RAN network element establishes a user plane connection (or downlink data transmission path) with the MB-UPF network element according to the first IP multicast address corresponding to the first multicast group and the C-TEID, thereby receiving the first multicast The data stream corresponding to the group. In addition, the RAN network element allocates access network resources to the first multicast group and the associated multicast group, and sends a data stream corresponding to the first multicast group to the terminal device.

The RAN network element saves the first IP multicast address and C-TEID corresponding to the associated multicast group, but does not establish a user plane connection (or downlink data transmission path) with the MB-UPF network element, and does not receive the associated multicast group. The data stream corresponding to the multicast group is used to quickly join the multicast group, that is, the next time the terminal device requests to receive the data stream associated with the multicast group, the MB-UPF network element and the RAN network element can directly The IP multicast address and C-TEID are used to deliver the data stream associated with the multicast group, which reduces the delay for terminal equipment to join the multicast group.

It can be understood that, in the above embodiments, the methods and/or steps implemented by the SMF network element may also be implemented by a component (such as a chip or circuit) that can be used for the SMF network element, and the first UPF network element (unicast The methods and/or steps implemented by the UPF network element) may also be implemented by components available for the first UPF network element (unicast UPF network element); the methods and/or steps implemented by the second UPF network element (multicast UPF network element) /or steps can also be implemented by components available for the second UPF network element (multicast UPF network element); the methods and/or steps implemented by the RAN network element can also be implemented by components available for the RAN network element; by The methods and/or steps implemented by the first network element (MB-SMF network element or M-AMF network element) may also be implemented by components that can be used for the first network element (MB-SMF network element or M-AMF network element) ; The methods and/or steps implemented by the second network element (M-AMF network element or RAN network element) may also be implemented by components available for the second network element (M-AMF network element or RAN network element).

The foregoing mainly introduces the solutions provided by the embodiments of the present application from the perspective of interaction between various network elements. Correspondingly, an embodiment of the present application further provides a communication device, where the communication device is used to implement the above-mentioned various methods. The communication device may be the SMF network element, the first UPF network element (unicast UPF network element), the second UPF network element (multicast UPF network element), the RAN network element, the first network element ( MB-SMF network element or M-AMF network element), second network element (M-AMF network element or RAN network element), or including the above-mentioned SMF network element, first UPF network element (unicast UPF network element), first Two UPF network element (multicast UPF network element), RAN network element, first network element (MB-SMF network element or M-AMF network element), second network element (M-AMF network element or RAN network element) The device, or the SMF network element, the first UPF network element (unicast UPF network element), the second UPF network element (multicast UPF network element), the RAN network element, the first network element (MB-SMF network element or M -AMF network element), a chip or functional module in the second network element (M-AMF network element or RAN network element).

It can be understood that, in order to realize the above-mentioned functions, the communication apparatus includes corresponding hardware structures and/or software modules for executing each function. Those skilled in the art should easily realize that the present application can be implemented in hardware or a combination of hardware and computer software with the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein. Whether a function is performed by hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

In this embodiment of the present application, the communication device may be divided into functional modules according to the foregoing method embodiments. For example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. It should be noted that, the division of modules in the embodiments of the present application is schematic, and is only a logical function division, and there may be other division manners in actual implementation.

Take the communication device as the first UPF network element (unicast UPF network element) in the above method embodiments as an example. FIG. 15 shows a schematic structural diagram of a communication device 150 . The communication apparatus 150 may be the UPF network element in FIG. 1 . The communication device 150 includes a processing module 1501 and a transceiver module 1502 . The processing module 1501 may also be called a processing unit, and is used to implement the processing function of the first UPF network element (unicast UPF network element) in the above method embodiments, and is also used to control the transceiver module 1502 to perform corresponding functions. For example, step S802 in FIG. 8 , step S802 in FIG. 9 , and step S1107 in FIG. 11 are performed. The transceiver module 1502 may be called a transceiver circuit, a transceiver, a transceiver or a communication interface, and is used to implement the transceiver function of the first UPF network element (unicast UPF network element) in the above method embodiments. For example, perform steps S801, S802, S804, and S805 in FIG. 8, steps S801, S802, S804, and S805 in FIG. 9, steps S1106, S1107 in FIG. 11, steps S1202-S1205, S1212 in FIG. 12, and FIG. 13 in steps S1302 and S1303.

Exemplarily, the transceiver module 1502 is configured to receive a first message from the terminal device, where the first message includes an identifier of the first multicast group, and the first message is used to request that the terminal device be added to the first multicast group; The processing module 1501 is used to control the transceiver module 1502 to send first indication information to the session management function network element according to the first message, where the first indication information is used to instruct the terminal device to join the first multicast group; the transceiver module 1502 is used to Receive second activation information from the session management function network element, where the second activation information is used to indicate whether the data stream corresponding to the first multicast group has been sent on the access network element; If the data stream corresponding to the broadcast group has been sent on the access network element, the transceiver module 1502 is further configured to send the first indication information to the access network element.

In a possible implementation manner, the transceiver module 1502 is further configured to receive a second message from the terminal device, where the second message includes an identifier of a second multicast group, and the second multicast group is the first multicast One of the associated multicast groups of the group, the second message is used to request to withdraw the terminal device from the second multicast group; the processing module 1501 is also used to control the transceiver module 1502 to send the session management function network element according to the second message Send second indication information, where the second indication information is used to indicate that the terminal device has left the second multicast group.

In a possible implementation manner, the first indication information sent by the transceiver module 1502 to the network element of the access network is carried in the packet header of the data stream.

In this embodiment, the communication apparatus 150 is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to a specific ASIC, circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and/or other device that may provide the functions described above.

Specifically, the function/implementation process of the processing module 1501 in FIG. 15 may be implemented by the processor in the first UPF network element (unicast UPF network element) calling the computer execution instructions stored in the memory. The function/implementation process of the transceiver module 1502 in FIG. 15 may be implemented through a communication interface in the first UPF network element (unicast UPF network element).

Since the communication device 150 provided in this embodiment can perform the above method, the technical effect that can be obtained by the communication device 150 can refer to the above method embodiments, and details are not repeated here.

Take the communication device as the second UPF network element (multicast UPF network element) in the above method embodiment as an example. FIG. 16 shows a schematic structural diagram of a communication device 160 . The communication device 160 may be the UPF network element in FIG. 1 . The communication device 160 includes a processing module 1601 and a transceiver module 1602 . The processing module 1601 may also be referred to as a processing unit, and is used to implement the processing function of the second UPF network element (multicast UPF network element) in the above method embodiments, and is also used to control the transceiver module 1602 to perform corresponding functions. For example, step S1208 in FIG. 12 and step S1306 in FIG. 13 are performed. The transceiver module 1602 may be called a transceiver circuit, a transceiver, a transceiver or a communication interface, and is used to implement the transceiver function of the second UPF network element (multicast UPF network element) in the above method embodiments. For example, perform steps S806-S809 in FIG. 8, steps S806-S809, S903 in FIG. 9, step S1111 in FIG. 11, steps S1201, S1207, S1209-S1211 in FIG. 12, steps S1301, S1305 in FIG. 13 , S1207-S1209.

Exemplarily, the transceiver module 1602 is configured to receive a third message and the first indication information from the session management function network element, where the third message includes the identifier of the first multicast group, and the associated number of the first multicast group. The first indication information is used to instruct the terminal device to join the first multicast group; the transceiver module 1602 is further configured to receive the first multicast group and the data corresponding to the associated multicast group from the application server The transceiver module 1602 is further configured to send the first indication information and the data flow corresponding to the first multicast group to the network element of the access network.

In a possible implementation manner, the transceiver module 1602 is further configured to send third activation information to the session management function network element, where the third activation information is used to indicate the first multicast group and data corresponding to the associated multicast group Whether the stream has been sent on the access network element.

In a possible implementation manner, the transceiver module 1602 is further configured to receive port information corresponding to the first multicast group and the associated multicast group of the access network element from the session management function network element. It is used to establish a tunnel for transmitting data flow between the network element of the second user plane function and the network element of the access network.

In a possible implementation manner, the transceiver module 1602 is further configured to receive third indication information from the session management function network element, where the third indication information is used to instruct the terminal device to withdraw from the second multicast group, and the second multicast The group is one of the associated multicast groups; the transceiver module 1602 is further configured to send third indication information to the access network element.

In a possible implementation manner, the transceiver module 1602 stops sending the data stream corresponding to the second multicast group to the access network element.

In a possible implementation manner, the first indication information sent by the transceiver module 1602 to the network element of the access network is carried in the packet header of the data stream.

In this embodiment, the communication apparatus 160 is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to a specific ASIC, circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and/or other device that may provide the functions described above.

Specifically, the function/implementation process of the processing module 1601 in FIG. 16 can be implemented by the processor in the second UPF network element (multicast UPF network element) calling the computer execution instructions stored in the memory. The function/implementation process of the transceiver module 1602 in FIG. 16 may be implemented through a communication interface in the second UPF network element (multicast UPF network element).

Since the communication device 160 provided in this embodiment can execute the above method, the technical effect that can be obtained can be referred to the above method embodiment, and details are not repeated here.

Take the communication device as the SMF network element in the above method embodiment as an example. FIG. 17 shows a schematic structural diagram of a communication device 170 . The communication apparatus 170 may be the SMF network element in FIG. 1 . The communication device 170 includes a processing module 1701 and a transceiver module 1702 . The processing module 1701 may also be called a processing unit, and is used to implement the processing function of the SMF network element in the above method embodiments, and is also used to control the transceiver module 1702 to perform corresponding functions. For example, steps S1201 and S1206 in FIG. 12 and steps S1301 and S1304 in FIG. 13 are performed. The transceiver module 1702 may be called a transceiver circuit, a transceiver, a transceiver or a communication interface, and is used to implement the transceiver function of the SMF network element in the above method embodiments. For example, perform steps S802-S804, S806, S809 in FIG. 8, steps S802-S804, S806, S809, S901, S903 in FIG. 9, steps S1107, S1109a-S1112 in FIG. 11, steps S1201, S1202, S1205-S1207, S1211, S1212, steps S1301, S1303-S1205, S1309 in FIG. 13 .

Exemplarily, the transceiver module 1702 is used to receive the first indication information from the first user plane function network element, and the first indication information is used to add the terminal device to the first multicast group; the transceiver module 1702 is used to receive the first indication information from the unified data The storage library obtains the identifier of the first multicast group, and the identifier of the associated multicast group of the first multicast group; the transceiver module 1702 is configured to send the first activation information to the first user plane function network element, the first An activation message is used to indicate whether the data stream corresponding to the first multicast group and the associated multicast group has been sent on the access network element; the transceiver module 1702 is configured to send the first multicast group to the second user plane function network element Three messages and first indication information, where the third message includes the identifier of the first multicast group and the identifier of the associated multicast group; the transceiver module 1702 is further configured to receive third activation information from the second user plane function network element, The third activation information is used to indicate whether the first multicast group and the data stream corresponding to the associated multicast group have been sent on the access network element, and the third activation information is further used to update the first activation information.

In a possible implementation manner, the transceiver module 1702 is further configured to send the identifier of the first multicast group and the identifier of the associated multicast group to the access network element; The network element receives port information of the access network element that corresponds to the first multicast group and the associated multicast group, and the port information is used to establish the second user plane function network element and the access network element to transmit data between the network element The flow tunnel; the transceiver module 1702 is further configured to send port information to the second user plane function network element.

In a possible implementation manner, the transceiver module 1702 is further configured to receive second indication information from the first user plane function network element, where the second indication information is used to indicate that the terminal device has exited the second multicast group, and the second indication information The multicast group is one of the associated multicast groups; the transceiver module 1702 is further configured to send third indication information to the second user plane function network element, where the third indication information is used to instruct the terminal device to exit the second multicast group.

In this embodiment, the communication apparatus 170 is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to a specific ASIC, circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and/or other device that may provide the functions described above.

Specifically, the function/implementation process of the processing module 1701 in FIG. 17 can be implemented by the processor in the SMF network element calling the computer execution instructions stored in the memory. The function/implementation process of the transceiver module 1702 in FIG. 17 can be implemented through the communication interface in the SMF network element.

Since the communication device 170 provided in this embodiment can execute the above method, the technical effect that can be obtained by the communication device 170 can refer to the above method embodiment, and details are not repeated here.

It is assumed that the communication device is the (R)AN network element in the above method embodiment as an example. FIG. 18 shows a schematic structural diagram of a communication apparatus 180 . The communication apparatus 180 may be the RAN network element in FIG. 1 . The communication device 180 includes a processing module 1801 and a transceiver module 1802 . The processing module 1801 may also be referred to as a processing unit, and is used to implement the processing function of the RAN network element in the above method embodiments, and is also used to control the transceiver module 1802 to perform corresponding functions. For example, steps S1201 and S1213 in FIG. 12 and steps S1301 and S1310 in FIG. 13 are performed. The transceiver module 1802 may be referred to as a transceiver circuit, a transceiver, a transceiver or a communication interface, and is used to implement the transceiver function of the RAN network element in the foregoing method embodiments. For example, perform steps S805 and S808 in FIG. 8 , steps S805 , S808 , S902 and S903 in FIG. 9 , steps S1110 and S1111 in FIG. 11 , steps S1201 , S1204 and S1210 in FIG. 12 , and step S1308 in FIG. 13 . .

Exemplarily, the transceiver module 1802 is configured to receive first indication information from the first user plane function network element or the second user plane function network element, where the first indication information is used to add the terminal device to the first multicast group , the first user plane function network element is used to transmit unicast data streams, and the second user plane network element is used to transmit multicast data streams; the transceiver module 1802 is further configured to receive and first multicast data from the second user plane function network element. The data stream corresponding to the broadcast group; the transceiver module 1802 is further configured to send the data stream to the terminal device.

In a possible implementation manner, the transceiver module 1802 is further configured to receive the identifier of the first multicast group and the identifier of the associated multicast group of the first multicast group from the session management function network element; Module 1802 is further configured to send port information of the access network element corresponding to the first multicast group and the associated multicast group to the session management function network element, where the port information is used to establish the second user plane function network element and A tunnel for transferring data streams between network elements of an access network.

In a possible implementation manner, the transceiver module 1802 is further configured to receive third indication information from the first user plane function network element or the second user plane function network element, where the third indication information is used to instruct the terminal device to exit the first Two multicast groups, where the second multicast group is one of the associated multicast groups of the first multicast group; the transceiver module 1802 is further configured to stop sending data corresponding to the second multicast group to the terminal device flow.

In a possible implementation manner, the third indication information is carried in the packet header of the data stream.

In a possible implementation manner, the first indication information is carried in a packet header of the data stream.

In this embodiment, the communication apparatus 180 is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to a specific ASIC, circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and/or other device that may provide the functions described above.

Specifically, the function/implementation process of the processing module 1801 in FIG. 18 can be implemented by the processor in the RAN network element calling the computer-executed instructions stored in the memory. The function/implementation process of the transceiver module 1802 in FIG. 18 may be implemented through the communication interface in the RAN network element.

Since the communication device 180 provided in this embodiment can perform the above method, the technical effect that can be obtained can be referred to the above method embodiments, and details are not repeated here.

It is assumed that the communication device is the first network element (MB-SMF network element or M-AMF network element) in the foregoing method embodiment as an example. FIG. 19 shows a schematic structural diagram of a communication device 190 . The communication device 190 may be an SMF network element or an AMF network element in FIG. 1 . The communication device 190 includes a processing module 1901 and a transceiver module 1902 . The processing module 1901 may also be called a processing unit, and is used to implement the processing function of the first network element (MB-SMF network element or M-AMF network element) in the above method embodiments, and is also used to control the transceiver module 1902 to perform corresponding functions. For example, step S1003 in FIG. 10 and steps S1408 and S1410 in FIG. 14 are performed. The transceiver module 1902 may be called a transceiver circuit, a transceiver, a transceiver or a communication interface, and is used to implement the transceiver function of the first network element (MB-SMF network element or M-AMF network element) in the above method embodiments. For example, steps S1001-S1003 in FIG. 10 and steps S1402-S1411 in FIG. 14 are performed.

Exemplarily, the transceiver module 1902 is configured to acquire multicast group information, an identifier of the first multicast group, and an identifier of an associated multicast group of the first multicast group; the multicast group information includes the first multicast group. the first IP multicast address corresponding to the identifier of the multicast group, the first IP multicast address corresponding to the identifier of the associated multicast group, the common tunnel endpoint identifier C-TEID corresponding to the first multicast group, and, The C-TEID corresponding to the associated multicast group; the transceiver module 1902 is further configured to receive first indication information from the second network element, where the first indication information is used to add the terminal device to the first multicast group; the processing module 1901, It is used to control the transceiver module 1902 to send multicast group information to the second network element according to the first indication information; wherein, the first network element is the network element of multicast broadcast session management function, and the second network element is the multicast access and mobile network element. management function network element; or, the first network element is a multicast access and mobility management function network element, and the second network element is an access network element.

In a possible implementation manner, the communication device is a multicast broadcast session management function network element, and the transceiver module 1902 is specifically configured to receive multicast group information from the multicast broadcast user plane function network element.

In a possible implementation manner, the communication device is a multicast access and mobility management function network element, and the transceiver module 1902 is specifically configured to receive multicast group information from a multicast broadcast session management function network element.

In this embodiment, the communication apparatus 190 is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to a specific ASIC, circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and/or other device that may provide the functions described above.

Specifically, the function/implementation process of the processing module 1901 in FIG. 19 can be implemented by the processor in the first network element (MB-SMF network element or M-AMF network element) calling the computer execution instructions stored in the memory. The function/implementation process of the transceiver module 1902 in FIG. 19 may be implemented through a communication interface in the first network element (MB-SMF network element or M-AMF network element).

Since the communication apparatus 190 provided in this embodiment can execute the above method, the technical effects that can be obtained by the communication apparatus 190 can refer to the above method embodiments, which are not repeated here.

Take the communication device as the second network element (M-AMF network element or RAN network element) in the above method embodiment as an example. FIG. 20 shows a schematic structural diagram of a communication apparatus 200 . The communication apparatus 200 may be the AMF network element and the RAN network element in FIG. 1 . The communication device 200 includes a processing module 2001 and a transceiver module 2002 . The processing module 2001 may also be called a processing unit, and is used to implement the processing function of the second network element (M-AMF network element or RAN network element) in the above method embodiments, and is also used to control the transceiver module 2002 to perform corresponding functions. For example, steps S1002-S1003 in FIG. 10 and steps S1405-S1411 in FIG. 14 are performed. The transceiver module 2002 may be called a transceiver circuit, a transceiver, a transceiver or a communication interface, and is used to implement the transceiver function of the second network element (M-AMF network element or RAN network element) in the above method embodiments. For example, steps S1002-S1003 in FIG. 10 and steps S1405-S1411 in FIG. 14 are performed.

Exemplarily, the transceiver module 2002 is configured to send first indication information to the first network element, where the first indication information is used to add the terminal device to the first multicast group; The network element receives the multicast group information, where the multicast group information includes a first IP multicast address corresponding to the identifier of the first multicast group, a first IP multicast address corresponding to the identifier of the associated multicast group, The general tunnel endpoint identifier C-TEID corresponding to the first multicast group, and the C-TEID corresponding to the associated multicast group. The first network element is a multicast broadcast session management function network element, and the communication device 200 is a multicast access and mobility management function network element; or, the first network element is a multicast access and mobility management function network element, and the communication The apparatus 200 is an access network element.

In this embodiment, the communication apparatus 200 is presented in the form of dividing each functional module in an integrated manner. "Module" herein may refer to a specific ASIC, circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and/or other device that may provide the functions described above.

Specifically, the function/implementation process of the processing module 2001 in FIG. 20 can be implemented by the processor in the second network element (M-AMF network element or RAN network element) calling the computer execution instructions stored in the memory. The function/implementation process of the transceiver module 2002 in FIG. 20 may be implemented through a communication interface in the second network element (M-AMF network element or RAN network element).

Since the communication apparatus 200 provided in this embodiment can execute the above method, the technical effects that can be obtained by the communication apparatus 200 can refer to the above method embodiments, which are not repeated here.

As shown in FIG. 21 , an embodiment of the present application further provides a communication device. The communication device 210 includes a processor 2101, a memory 2102, and a communication interface 2103. The processor 2101 is coupled to the memory 2102. When the processor 2101 controls the communication interface 2103 When executing the computer program or instruction in the memory 2102, the SMF network element, the first UPF network element (unicast UPF network element), the second UPF network element (multicast UPF network element), and the RAN network element in FIG. 8-FIG. 14 . The methods corresponding to the first network element (MB-SMF network element or M-AMF network element) and the second network element (M-AMF network element or RAN network element) are executed.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when it runs on a computer or a processor, the computer or the processor causes the computer or the processor to execute the programs shown in FIGS. 8 to 14 . SMF network element, first UPF network element (unicast UPF network element), second UPF network element (multicast UPF network element), RAN network element, first network element (MB-SMF network element or M-AMF network element) ), a method corresponding to the second network element (M-AMF network element or RAN network element).

The embodiment of the present application also provides a computer program product containing instructions, when the instructions are run on a computer or a processor, the computer or processor is made to execute the SMF network element, the first UPF network element (unit: multicast UPF network element), second UPF network element (multicast UPF network element), RAN network element, first network element (MB-SMF network element or M-AMF network element), second network element (M-AMF network element) element or RAN element) corresponding method.

An embodiment of the present application provides a chip system, where the chip system includes a processor for a communication device to execute the SMF network element, the first UPF network element (unicast UPF network element), and the second UPF network element in FIG. 8 to FIG. 14 . Element (multicast UPF network element), RAN network element, first network element (MB-SMF network element or M-AMF network element), and second network element (M-AMF network element or RAN network element) Corresponding methods.

In a possible design, the chip system further includes a memory for storing necessary program instructions and data. The chip system may include chips, integrated circuits, or chips and other discrete devices, which are not specifically limited in this embodiment of the present application.

Wherein, the communication device, chip, computer storage medium, computer program product or chip system provided in this application are all used to execute the method described above, therefore, the beneficial effects that can be achieved can refer to the embodiments provided above The beneficial effects of , will not be repeated here.

The processor involved in the embodiments of the present application may be a chip. For example, it can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), or a central processing unit. It can be a central processor unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), or a microcontroller (MCU) , it can also be a programmable logic device (PLD) or other integrated chips.

The memory involved in the embodiments of the present application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory. Volatile memory may be random access memory (RAM), which acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (direct rambus RAM, DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but not be limited to, these and any other suitable types of memory.

It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can 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 the computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server, or data center Transmission to another website site, computer, server or data center via wired (eg coaxial cable, optical fiber, Digital Subscriber Line, DSL) or wireless (eg infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or data storage devices including one or more servers, data centers, etc. that can be integrated with the medium. The usable medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a Solid State Disk (SSD)), and the like.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A method for multicast group communication, comprising:

The first user plane function network element receives a first message from a terminal device, where the first message includes an identifier of a first multicast group, and the first message is used to request that the terminal device be added to the first multicast group;

The first user plane function network element sends first indication information to the session management function network element according to the first message, where the first indication information is used to instruct the terminal device to join the first multicast group ;

The first user plane function network element receives second activation information from the session management function network element, where the second activation information is used to indicate whether the data flow corresponding to the first multicast group is already in the access network sent on the network element;

If the second activation information indicates that the data stream corresponding to the first multicast group has been sent on the access network element, the first user plane function network element sends a message to the access network element. element sends the first indication information.
The method according to claim 1, wherein the method further comprises:

The first user plane function network element receives a second message from the terminal device, where the second message includes an identifier of a second multicast group, and the second multicast group is the first multicast group. one of the associated multicast groups of the multicast group, and the second message is used to request that the terminal device be withdrawn from the second multicast group;

The first user plane function network element sends second indication information to the session management function network element according to the second message, where the second indication information is used to indicate that the terminal device has exited the second multicast group.
The method according to claim 1 or 2, wherein the first indication information sent by the first user plane function network element to the access network element is carried in a packet header of the data stream.
A method for multicast group communication, comprising:

The second user plane function network element receives a third message and first indication information from the session management function network element, where the third message includes the identifier of the first multicast group, and the association of the first multicast group an identifier of a multicast group; the first indication information is used to instruct a terminal device to join the first multicast group;

receiving, by the second user plane function network element, a data stream corresponding to the first multicast group and the associated multicast group from an application server;

sending, by the second user plane function network element, the first indication information and a data stream corresponding to the first multicast group to an access network element;

The second user plane function network element sends third activation information to the session management function network element, where the third activation information is used to indicate the first multicast group and the associated multicast group. Whether the data stream has been sent on the access network element.
The method according to claim 4, wherein the method further comprises:

The second user plane function network element receives port information of the access network element corresponding to the first multicast group and the associated multicast group from the session management function network element, and the The port information is used to establish a tunnel for transmitting data flow between the second user plane function network element and the access network element.
The method according to claim 4 or 5, wherein the method further comprises:

The second user plane function network element receives third indication information from the session management function network element, where the third indication information is used to instruct the terminal device to withdraw from the second multicast group, and the second multiple The multicast group is one of the associated multicast groups;

The second user plane function network element sends the third indication information to the access network element.
The method according to claim 6, wherein the method further comprises:

The second user plane function network element stops sending the data stream corresponding to the second multicast group to the access network element.
The method according to any one of claims 4-7, wherein the first indication information sent by the second user plane function network element to the access network element is carried in the data stream in the header.
A method for multicast group communication, comprising:

The session management function network element receives first indication information from the first user plane function network element, where the first indication information is used to add the terminal device to the first multicast group;

obtaining, by the session management function network element, an identifier of the first multicast group from a unified data repository, and an identifier of an associated multicast group of the first multicast group;

The session management function network element sends first activation information to the first user plane function network element, where the first activation information is used to indicate the first multicast group and the associated multicast group. Whether the data stream has been sent on the access network element;

The session management function network element sends a third message and the first indication information to the second user plane function network element, where the third message includes the identifier of the first multicast group and the associated multicast group the identity of the group;

The session management function network element receives third activation information from the second user plane function network element, where the third activation information is used to indicate the first multicast group and the associated multicast group. Whether the data stream has been sent on the access network element, the third activation information is also used to update the first activation information.
The method according to claim 9, wherein the method further comprises:

sending, by the session management function network element, the identifier of the first multicast group and the identifier of the associated multicast group to the access network element;

The session management function network element receives, from the access network element, port information of the access network element corresponding to the first multicast group and the associated multicast group, the port information for establishing a tunnel for transmitting data flow between the second user plane function network element and the access network network element;

The session management function network element sends the port information to the second user plane function network element.
The method according to claim 9 or 10, wherein the method further comprises:

The session management function network element receives second indication information from the first user plane function network element, where the second indication information is used to indicate that the terminal device has exited the second multicast group, and the second multicast group the group is one of the associated multicast groups;

The session management function network element sends third indication information to the second user plane function network element, where the third indication information is used to instruct the terminal device to exit the second multicast group.
A method for multicast group communication, comprising:

The access network element receives first indication information from the first user plane function network element or the second user plane function network element, where the first indication information is used to add the terminal device to the first multicast group, and the The first user plane function network element is used for transmitting unicast data stream, and the second user plane network element is used for transmitting multicast data stream;

receiving, by the access network element, a data stream corresponding to the first multicast group from the second user plane function network element;

The access network element sends the data stream to the terminal device.
The method of claim 12, wherein the method further comprises:

The access network element receives, from the session management function network element, the identifier of the first multicast group, and the identifier of the associated multicast group of the first multicast group;

The access network element sends, to the session management function network element, port information of the access network element corresponding to the first multicast group and the associated multicast group, the port information A tunnel for establishing a data flow transmission tunnel between the second user plane function network element and the access network network element.
The method according to claim 12 or 13, wherein the method further comprises:

The access network element receives third indication information from the first user plane function network element or the second user plane function network element, where the third indication information is used to instruct the terminal device to exit the second multicast a group, wherein the second multicast group is one of the associated multicast groups of the first multicast group;

The access network element stops sending the data stream corresponding to the second multicast group to the terminal device.
The method according to claim 14, wherein the third indication information is carried in a packet header of the data stream.
The method according to any one of claims 12-15, wherein the first indication information is carried in a packet header of the data stream.
A method for multicast group communication, comprising:

The first network element obtains multicast group information, an identifier of the first multicast group, and an identifier of an associated multicast group of the first multicast group; the multicast group information includes the first multicast group. The first Internet Protocol IP multicast address corresponding to the identifier of the associated multicast group, the first IP multicast address corresponding to the identifier of the associated multicast group, and the generic tunnel endpoint identifier C- TEID, and the C-TEID corresponding to the associated multicast group;

receiving, by the first network element from the second network element, first indication information, where the first indication information is used to add a terminal device to the first multicast group;

sending, by the first network element, the multicast group information to the second network element according to the first indication information;

The first network element is a multicast broadcast session management function network element, and the second network element is a multicast access and mobility management function network element; or, the first network element is a multicast access and mobility management function network element. A mobility management function network element, wherein the second network element is an access network network element.
The method according to claim 17, wherein the first network element is the multicast broadcast session management function network element, and the first network element acquiring multicast group information comprises:

The first network element receives the multicast group information from a multicast broadcast user plane function network element.
The method according to claim 17, wherein the first network element is the multicast access and mobility management function network element, and the first network element obtains multicast group information, comprising:

The first network element receives the multicast group information from the multicast broadcast session management function network element.
A communication device, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to any one of claims 1-3.
A communication device, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to any one of claims 4-8.
A communication device, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to any one of claims 9-11.
A communication device, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to any one of claims 12-16.
A communication device, comprising: a processing module and a transceiver module; the processing module and the transceiver module are configured to execute the method according to any one of claims 17-19.
A communication device, characterized in that the communication device includes a processor, a memory and a transceiver, the processor is coupled with the memory, and when the processor controls the transceiver to execute computer programs or instructions in the memory , the method of any one of claims 1-3 is performed.
A communication device, characterized in that the communication device includes a processor, a memory and a transceiver, the processor is coupled with the memory, and when the processor controls the transceiver to execute computer programs or instructions in the memory , the method of any one of claims 4-8 is performed.
A communication device, characterized in that the communication device includes a processor, a memory and a transceiver, the processor is coupled with the memory, and when the processor controls the transceiver to execute computer programs or instructions in the memory , the method of any one of claims 9-11 is performed.
A communication device, characterized in that the communication device includes a processor, a memory and a transceiver, the processor is coupled with the memory, and when the processor controls the transceiver to execute computer programs or instructions in the memory , the method of any of claims 12-16 is performed.
A communication device, characterized in that the communication device includes a processor, a memory and a transceiver, the processor is coupled with the memory, and when the processor controls the transceiver to execute computer programs or instructions in the memory , the method of any of claims 17-19 is performed.
A communication system, characterized by comprising the communication device as claimed in claims 20-23, or the communication device as claimed in claim 24, or the communication device as claimed in claims 25-28, Alternatively, a communication device as claimed in claim 29 is included.