CN111526553A

CN111526553A - UE execution method and UE, SMF entity execution method and SMF entity

Info

Publication number: CN111526553A
Application number: CN202010409871.4A
Authority: CN
Inventors: 熊春山
Original assignee: Tencent Technology Shenzhen Co Ltd
Current assignee: Tencent Technology Shenzhen Co Ltd
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2020-08-11

Abstract

The present disclosure provides a method performed by a user device and a corresponding user device, and a method performed by a session management functional entity and a corresponding session management functional entity. The method performed by the user device comprises: determining an activation mode for activating the multicast service; activating the multicast service according to the determined activation mode and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed in the activation process of the multicast service; and receiving service data corresponding to the multicast service.

Description

UE execution method and UE, SMF entity execution method and SMF entity

Technical Field

The present disclosure relates to the field of wireless communications, and more particularly, to a method performed by a User Equipment (UE) and a corresponding UE, and a method performed by a Session Management Function (SMF) entity and a corresponding SMF entity.

Background

Existing wireless communication systems may support Multimedia Broadcast and Multicast Services (MBMS). Specifically, the MBMS may be classified into a multicast service and a broadcast service. Multicasting, which may also be referred to as multicasting, is the transmission of the same content to multiple users. In the multicast manner, data for all target entities can be transmitted at once and data can be transmitted only for a specific user. Broadcasting also transmits the same content to a plurality of users, but it does not make a user's selection, and thus there may be a case where there is no user in the network but data transmission is performed.

In a conventional wireless communication system, a technical solution of how a User Equipment (UE) performs a multicast service has been proposed. For example, when multiple UEs all want to perform the same multicast service, first, each UE in the multiple UEs needs to activate the multicast service. The plurality of UEs that have activated the multicast service may be regarded as one multicast group. Then, a user plane corresponding to the multicast group needs to be established, so that the network transmits service data corresponding to the multicast service to the multicast group through the established user plane, and thus, the corresponding UE can acquire the service data corresponding to the multicast service.

The above described establishment of the user plane is for one multicast Group (i.e. Per Group) instead of for a single UE. The technical scheme is suitable for the situation that the multicast service is activated by a plurality of UE before the network transmits the service data corresponding to the multicast service to the plurality of UE. However, in a situation where the network has started to transmit service data corresponding to a multicast service to a plurality of UEs, there may be some other UEs that want to perform the multicast service (e.g., the UE has just been powered on). Then the solution described above is no longer applicable.

Disclosure of Invention

In order to overcome the drawbacks of the prior art, the present disclosure proposes a method performed by a user equipment and a corresponding user equipment, and a method performed by a session management function entity and a corresponding session management function entity.

According to an aspect of the present disclosure, there is provided a method performed by a user equipment, comprising: determining an activation mode for activating the multicast service; activating the multicast service according to the determined activation mode and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed in the activation process of the multicast service; and receiving service data corresponding to the multicast service.

According to an example of the present disclosure, before the determining the activation manner for activating the multicast service, the method further includes: and determining a first identifier and a second identifier corresponding to the multicast service, wherein the first identifier and the second identifier are used for accessing and selecting the session management function entity by the mobility management function entity.

According to an example of the present disclosure, the first identifier is used to identify a network segment corresponding to the multicast service, and the second identifier is used to identify a data network corresponding to the multicast service.

According to an example of the present disclosure, the determining the first identifier and the second identifier corresponding to the multicast service includes: obtaining a user device routing strategy rule corresponding to each multicast service in at least one multicast service from a strategy control function entity, wherein each user device routing strategy rule at least comprises a multicast address of the corresponding multicast service; determining a user device routing strategy rule corresponding to the multicast service according to the multicast address of the multicast service; and determining a first identifier and a second identifier corresponding to the multicast service according to the determined user device routing policy rule.

According to an example of the present disclosure, the activating the multicast service according to the determined activation manner and at least through a session management function entity includes: determining a third identification, wherein the third identification is used for identifying a user equipment multicast service context established for activating the multicast service; sending a request for activating the user equipment multicast service context to the session management function entity, the request for activating the user equipment multicast service context including the third identifier and a multicast address of the multicast service; receiving a response to the request for activating the user equipment multicast service context from the session management function entity, the response including a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated.

According to an example of the present disclosure, wherein sending the request for activating the user equipment multicast service context to the session management function entity comprises: sending, via the access and mobility management function entity, a request to the session management function entity for activation of the user equipment multicast service context.

According to an example of the present disclosure, wherein receiving a response to the request for activating the user equipment multicast service context from the session management function entity comprises: receiving a response to the request for activation of the user equipment multicast traffic context from the session management function entity via the serving base station of the user equipment and the access and mobility management function entity.

According to an example of the present disclosure, wherein prior to determining the third identity, the method further comprises: acquiring a first identifier, a second identifier and a multicast address from the session management function entity; and judging whether the acquired first identifier is the same as the determined first identifier, whether the acquired second identifier is the same as the determined second identifier and whether the acquired multicast address is the same as the multicast address of the multicast service.

According to an example of the present disclosure, before acquiring a first identifier, a second identifier, and a multicast address from the session management function entity, the method further includes: acquiring an internet protocol address from the session management functional entity according to the first identifier and the second identifier; and sending a data packet to a network according to the acquired internet protocol address so that a user plane function entity in the network acquires the data packet, wherein the data packet is used for indicating the multicast service which the user device wants to activate.

According to an example of the present disclosure, wherein obtaining an internet protocol address from the session management function entity according to the first identifier and the second identifier comprises: selecting the session management function entity and establishing a protocol data unit session according to the first identifier and the second identifier, and acquiring an internet protocol address from the session management function entity; and wherein the sending a data packet to a network according to the obtained internet protocol address so that a user plane functional entity in the network obtains the data packet comprises: according to the acquired internet protocol address, sending a data packet to a network so that a user plane functional entity participating in the establishment of the protocol data unit session in the network acquires the data packet; wherein the destination address of the packet is a multicast address of the multicast service or the protocol portion of the packet includes the multicast address of the multicast service.

According to an aspect of the disclosure, a method performed by a session management function entity, comprises: receiving a request from a user device for activating a user device multicast service context established by the user device for activating a multicast service, the request for activating the user device multicast service context including the third identification and a multicast address of the multicast service, the third identification identifying the user device multicast service context; determining a response to the request to activate the user device multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user device to determine whether the multicast service is activated; acquiring a fifth identifier corresponding to the multicast service, wherein the fifth identifier is used for identifying the start of a multicast service session corresponding to the multicast service; and conducting the multicast service session and sending the response to the user device.

According to an example of the present disclosure, the receiving, from the user equipment, a request for activating a multicast service context of the user equipment comprises: a request is received from the user device via an access and mobility management function entity for activating a user device multicast service context.

According to an example of the present disclosure, wherein the sending the response to the user equipment comprises: sending the response to the user equipment via a serving base station of the user equipment and an access and mobility management function entity.

According to an example of the present disclosure, prior to the receiving from the user device the request to activate the user device multicast service context, the method further comprises: establishing a protocol data unit session; assigning an internet protocol address to said user device; acquiring a multicast address of a multicast service to be activated by the user equipment from a user plane function entity participating in the establishment of the PDU session, wherein the multicast address is acquired after the user equipment transmits a packet to a network including the user plane function entity according to the IP address, wherein the packet indicates the multicast service which the user equipment wants to activate; when the session management function entity decides to instruct the user equipment to activate the multicast service, sending a request for instructing the user equipment to activate the multicast service to the user equipment, wherein the request for instructing the user equipment to activate the multicast service comprises a first identifier corresponding to the multicast service to be activated by the user equipment, a second identifier and a multicast address of the multicast service.

According to an example of the present disclosure, further comprising: receiving, from the access and mobility management function entity, a dedicated identity of the user equipment and an identity of a serving base station of the user equipment.

According to an example of the present disclosure, further comprising: recording the identities of the serving base stations of the user devices in the user device multicast service context in order to obtain identities of the serving base stations of all user devices that activate the multicast service through the session management function entity.

According to an example of the present disclosure, wherein determining a response to the request for activating the user device multicast service context comprises: determining whether the user device is capable of using the multicast service; when the user equipment can use the multicast service, sending a notice to the application function entity, wherein the notice is the notice of the multicast service authorization request; and receiving a response to the notification from the application function entity, wherein the response to the notification includes a fourth identification corresponding to the multicast traffic.

According to an example of the present disclosure, the notification comprises at least the first identity, the second identity, a multicast address of the multicast service, and an identity of the session management function entity, wherein the identity of the session management function entity facilitates the application function entity to obtain the session management function entity to which all user devices that are to activate the multicast service are involved in activating the multicast service.

According to an example of the present disclosure, wherein sending a notification to the application function entity comprises: a notification is sent to the application function entity via the network openness function entity.

According to an example of the present disclosure, the notification may further include an identifier of the application function entity, so that the network openness function entity determines the application function entity according to the identifier of the application function entity and sends the notification to the application function entity.

According to an example of the present disclosure, wherein receiving a response to the notification from the application function entity comprises: receiving a response to the notification from the application function entity via a network open function entity.

According to an example of the present disclosure, wherein conducting the multicast service session comprises: receiving a first request from a policy control function entity corresponding to the session management function entity, wherein the first request is for requesting a start of the multicast traffic session, the first request comprising at least a first identification of the user device, a fourth identification corresponding to multicast traffic, a quality of service rule of at least one data flow corresponding to the multicast traffic, and an identification of the multicast traffic session.

According to an example of the present disclosure, the first request is determined by the policy control function entity according to a second request received from a network openness function entity or an application function entity, the second request being for the network openness function entity or the application function entity to request a start of a multicast traffic session to the policy control function entity.

According to an example of the present disclosure, the second request comprises at least a first identification of the user equipment, the fourth identification, an identification of the session management function entity, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, and an identification of the multicast service session.

According to an example of the present disclosure, the policy control function entity is determined by the network open function entity or the application function entity according to an identity of the session management function entity.

According to an example of the present disclosure, the second request is determined by the network openness function entity according to a third request received from an application function entity, the third request being for the application function entity to request a start of a multicast service session to the network openness function entity.

According to an example of the present disclosure, the third request includes at least a second identification of the user equipment, the fourth identification, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, and an identification of the multicast service session.

According to an example of the present disclosure, any one of the first request, the second request, and the third request may further include an aggregated maximum rate corresponding to the multicast traffic.

According to an example of the present disclosure, wherein conducting the multicast service session further comprises: and generating a service quality flow identification, a service quality configuration file and a service quality execution rule corresponding to each data flow according to the service quality rule of each data flow.

According to an example of the present disclosure, wherein conducting the multicast service session further comprises: selecting a user plane functional entity according to the fourth identifier; sending a fourth request to the selected user plane functional entity, wherein the fourth request is used for establishing transmission resources of the multicast service session; and acquiring a response to the fourth request from the selected user plane functional entity, wherein the response to the fourth request comprises a tunnel multicast address allocated by the selected user plane functional entity for transmitting service data corresponding to the multicast service and a sixth identification corresponding to the tunnel multicast address, the tunnel multicast address is used for multicast tunnel transmission between network entities, and the sixth identification is used for identifying a transmission tunnel of the multicast service.

According to an example of the present disclosure, wherein conducting the multicast service session further comprises: selecting a user plane functional entity according to the fourth identifier; sending a fourth request to the selected user plane function entity, wherein the fourth request is used for establishing transmission resources of the multicast service session, the fourth request includes a tunnel multicast address allocated by the session management function entity for transmitting service data corresponding to the multicast service, and a sixth identifier corresponding to the tunnel multicast address, wherein the tunnel multicast address is used for multicast tunnel transmission between network entities, and the sixth identifier is used for identifying a transmission tunnel of the multicast service; obtaining a response to the fourth request from the selected user plane functional entity, wherein the response to the fourth request is an acknowledgement of the fourth request.

According to an example of the present disclosure, the fourth request includes at least a multicast address of the multicast traffic, a quality of service enforcement rule for the at least one data flow, and an aggregated maximum rate corresponding to the multicast traffic.

According to an example of the present disclosure, the performing the multicast service session and sending the response to the user equipment includes: sending first information to the access and mobility management function entity, wherein the first information includes the response and information related to the multicast service session, so that the access and mobility management function entity sends a fifth request to a corresponding serving base station according to the information related to the multicast service session, and sends the response to the user equipment via the corresponding serving base station, wherein the fifth request is used for requesting the start of the multicast service session.

According to an example of the present disclosure, the information related to the multicast service session includes at least the fourth identification, the aggregated maximum rate corresponding to the multicast service, quality of service flow identifications and quality of service profiles corresponding to respective data flows, the tunnel multicast address, and the sixth identification.

According to an aspect of the present disclosure, there is provided a user equipment including: a determining unit configured to determine an activation manner for activating the multicast service; an activation unit configured to activate the multicast service according to the determined activation manner and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed in an activation process of the multicast service; and a receiving unit configured to receive service data corresponding to the multicast service.

According to an aspect of the present disclosure, there is provided a session management function entity, including: a receiving unit configured to receive, from a user equipment, a request for activating a user equipment multicast service context established by the user equipment for activating a multicast service, the request for activating the user equipment multicast service context including the third identification and a multicast address of the multicast service, the third identification being used for identifying the user equipment multicast service context; a determining unit configured to determine a response to the request for activating the user equipment multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated; an obtaining unit, configured to obtain a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify a start of a multicast service session corresponding to the multicast service; a control unit configured to perform the multicast service session; and a transmitting unit configured to transmit the response to the user equipment.

According to an aspect of the present disclosure, there is provided a user equipment including: a processor; and a memory, wherein the memory has stored therein a computer-executable program that, when executed by the processor, performs the method performed by the user device described above.

According to an aspect of the present disclosure, there is provided a session management function entity, including: a processor; and a memory, wherein the memory has stored therein a computer-executable program that, when executed by the processor, performs the method performed by the session management function entity described above.

According to another aspect of the present disclosure, there is provided a computer-readable storage medium having stored thereon instructions, which, when executed by a processor, cause the processor to perform the above-described method.

According to the method performed by the user equipment and the corresponding user equipment in the above aspects of the present disclosure, the user equipment may determine an activation manner for activating the multicast service, and activate the multicast service according to the determined activation manner and at least through a session management function entity in the network, thereby optimizing or being compatible with a conventional process of activating the multicast service. In addition, in the process of activating the multicast service, a multicast service session corresponding to the multicast service is carried out, so that a user plane corresponding to the multicast service is established in the process of activating the multicast service.

Furthermore, according to the method performed by the session management function entity and the corresponding session management function entity in the above aspects of the present disclosure, in the process of activating the multicast service, the session management function entity may receive, from the user equipment, the third identifier corresponding to the multicast service to be activated by the user equipment and the multicast address of the multicast service, and determine, according to at least these pieces of information, the fourth identifier and the fifth identifier corresponding to the multicast service, so that the multicast service session corresponding to the multicast service can be performed according to the fifth identifier to establish the user plane corresponding to the multicast service, and the fourth identifier is fed back to the user equipment so that the user equipment activates the multicast service, thereby achieving establishment of the user plane corresponding to the multicast service in the process of activating the multicast service.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in more detail embodiments of the present disclosure with reference to the attached drawings. The accompanying drawings are included to provide a further understanding of the embodiments of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure and not to limit the disclosure. In the drawings, like reference numbers generally represent like parts or steps.

Fig. 1 is a schematic diagram of an architecture of a wireless communication system in which embodiments of the present disclosure may be applied.

Fig. 2 is a flow chart of a method performed by a user device in accordance with an embodiment of the present disclosure.

Fig. 3 is a flowchart of a method performed by a user device for determining a first identity and a second identity corresponding to a multicast service according to an embodiment of the present disclosure.

Fig. 4 is a flowchart of a method performed by a session management function entity when a user equipment activates a multicast service according to a first activation manner according to an embodiment of the present disclosure.

Fig. 5 is a flowchart of a method performed by a session management function entity when a user equipment activates a multicast service according to a second activation manner according to an embodiment of the present disclosure.

Fig. 6 is an exemplary flow for activating a multicast service based on a first activation manner and establishing a user plane corresponding to the multicast service in a wireless communication system according to an embodiment of the present disclosure.

Fig. 7 is an exemplary flow for activating a multicast service based on a second activation manner and establishing a user plane corresponding to the multicast service in a wireless communication system according to an embodiment of the present disclosure.

Fig. 8 is a schematic structural diagram of a user device according to an embodiment of the present disclosure.

Fig. 9 is a schematic structural diagram of a session management function entity according to an embodiment of the present disclosure.

Fig. 10 is another structural diagram of a session management function entity according to an embodiment of the present disclosure.

Fig. 11 shows a schematic diagram of an architecture of another wireless communication system in which the principles of the disclosed embodiments may be applied.

Fig. 12 is an exemplary flow for activating a multicast service and establishing a user plane corresponding to the multicast service based on the wireless communication system shown in fig. 11.

Fig. 13 illustrates an architecture of a device according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present disclosure more apparent, example embodiments according to the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. It should be understood that: the embodiments described herein are merely illustrative and should not be construed as limiting the scope of the disclosure. Further, a User Equipment (UE) as described herein may include various types of terminals, such as a mobile terminal or an IP terminal. For convenience, these terms are sometimes used interchangeably.

First, a wireless communication system in which an embodiment of the present disclosure can be applied is described with reference to fig. 1. Fig. 1 is a schematic diagram of an architecture of a wireless communication system in which embodiments of the present disclosure may be applied. The wireless communication system may be a fifth generation (5G) wireless communication system, or may be any other type of wireless communication system, such as a 6G wireless communication system. Hereinafter, embodiments of the present disclosure are described taking a 5G wireless communication system as an example, but it should be appreciated that the following description may also be applicable to other types of wireless communication systems.

Specifically, the wireless communication system 100 includes an Application Function (AF) entity 110, a Network open Function (NEF)/Policy Control Function (PCF) entity 120, a Session Management Function (SMF) entity 130, an Access and Mobility Management Function (AMF) entity 140, a User Plane Function (UPF) entity 150, and a Radio Access Network (RAN) 161 and 162 and

UEs

171 and 172 served thereby, wherein the NEF/AF entity 120, the SMF entity 130, and the AMF entity 140 belong to entities of a control Plane, and the UPF entity 150 belongs to an entity of a User Plane. In addition, the AF described herein may also be referred to as a Service Layer (Service Layer). Each of the entities described herein may be one or more servers. In this disclosure, an "entity" may also be referred to as a node. For convenience, entities and nodes are sometimes used interchangeably.

Further, the AF entity 110 may provide traffic data, support application impact on traffic paths, interact with a measurement framework for policy control, etc. The NEF entity in the NEF/PCF entity 120 may support QoS capability opening, event subscription capability opening, traffic steering of AF request, parameter issuing of AF request, and the like. The PCF entity of NEF/PCF entity 120 may support a unified policy framework to manage network behavior, provide policy rules to control the control plane, and the like. The SMF entity 130 may support session management, etc., wherein the session management may include session establishment, modification, release, etc. The AMF entity 140 may support access authentication, mobility management, registration management, connection management, lawful answering for the UE, session management information transmission between the UE and the SMF entity, and the like. The UPF entity 150 may have a packet routing function, for example, may obtain the packet from the AF entity 110 and send the packet to the

RAN

161 and 162, and so on. RAN 161 and/or 162 may be an access network formed by base stations. The base station here may be any type of base station, such as a 5G base station, or a base station in a conventional communication system or a WiFi AP, etc.

Further, the UEs 171 and/or 172 may be connected to the RANs 161 and/or 162 via the Uu interface. The RAN 161 and/or 162 may be connected to the AMF entity 140 via an N2 interface and to the UPF entity 150 via an N3 interface. The UPF entity 150 may be connected to the SMF entity 130 via an N4 interface and to the AF entity 110 via an N6 interface. The AMF entity 140 is connected to the SMF entity 130 via an N11 interface. The SMF entity 130 is connected to the NEF/PCF entity 120 via an N7 interface. NEF/PCF entity 120 is connected to AF entity 110 via N5 or the Nnef interface.

In addition, fig. 1 also shows the service area between the UPF entity 150 and the

RAN

161 and 162, as indicated by the ellipses in fig. 1. In the present disclosure, a plurality of routing switch devices (e.g., routers) may be deployed within the service area, where each routing switch device may be connected to the UPF entity 150 and to one or more RANs, such that the UPF entity 150 transmits the traffic data to the respective routing device and the respective routing device transmits the traffic data to the corresponding RAN.

Further, in the present disclosure, the AF entity may support a Multicast/broadcast service (MBS). Thus, the AF entity may also be referred to as MBS AF entity. For convenience, these terms may sometimes be used interchangeably.

It should be appreciated that although fig. 1 shows that the number of various entities is one, this is merely illustrative and the wireless communication system may include a greater number of entities. Furthermore, although two RANs and two UEs are shown in fig. 1, this is merely illustrative and the wireless communication system may include fewer or more RANs and/or fewer or more UEs and, accordingly, may include fewer or more cells.

In the present disclosure, when a UE wants to perform a multicast service, the UE needs to activate the multicast service first. During the activation of the multicast service, the network may establish a user plane for the UE and corresponding to the multicast service, so that the network transmits service data corresponding to the multicast service to the UE. Specifically, during the activation of the multicast service, the network may start conducting a multicast service session for the UE and corresponding to the multicast service. The above-described process involves communication between a plurality of entities (e.g., AF entity 110, NEF/PCF entity 120, SMF entity 130, AMF entity 140, UPF entity 150, etc. in fig. 1) in a wireless communication system.

The method performed by the UE in the above procedure will be described below with reference to fig. 2. Fig. 2 is a flow chart of a method 200 performed by a user device according to an embodiment of the present disclosure. As shown in fig. 2, in step S201, the UE determines an activation mode for activating the multicast service. In step S201, the determined activation manner may be a first activation manner or a second activation manner.

According to an example of the present disclosure, in the first activation mode, the UE does not need to establish a Protocol Data Unit (PDU) session and acquire an IP address (for example, an IP address is allocated by the SMF entity) before activating the multicast service. That is, in the first activation mode, the UE need not perform a step similar to step 1 shown in fig. 1. Therefore, the first activation method optimizes the traditional flow of activating the multicast service.

Further, according to an example of the present disclosure, in the second activation mode, the UE needs to establish one PDU session and acquire one IP address (e.g., one IP address is assigned by the SMF entity) before activating the multicast service. That is, in the second activation mode, the UE needs to perform a similar procedure to step 1 shown in fig. 1. Therefore, the second activation method is compatible with the traditional flow of activating the multicast service.

In the present disclosure, in step S201, the UE may determine an activation manner for activating the multicast service according to its own attribute. The attributes described herein may refer to the UE's support capabilities for various applications. For example, when the UE supports only a mobile application or the UE does not require an IP data transmission function, the UE may determine that an activation manner for activating the multicast service is the first activation manner. For example, when the UE needs to support an IP-based application, the UE may determine that the activation manner for activating the multicast service is the second activation manner.

It should be appreciated that, in step S201, the UE may also determine an activation manner for activating the multicast service according to other manners, which is not limited by the present disclosure.

Further, according to an example of the present disclosure, before step S201, the method 200 may further include: the UE may determine a first identifier and a second identifier corresponding to the multicast service, where the first identifier and the second identifier are used for an access and mobility management function entity to select the session management function entity. Specifically, the first identifier may be used to identify a network segment corresponding to the multicast service. For example, the first identifier may be single network Slice Selection Assistance Information (S-NSSAI). In addition, the second identifier may be used to identify a data network corresponding to the multicast service. For example, the second identification may be a Data Network Name (DNN).

In this example, the UE may determine the first identity and the second identity corresponding to the multicast service through the method 300 shown in fig. 3. Fig. 3 is a flow chart of a method 300 performed by a user device for determining a first identity and a second identity corresponding to a multicast service according to an embodiment of the present disclosure.

As shown in fig. 3, in step S301, the UE may obtain, from a Policy Control Function (PCF) entity, a user equipment routing policy (URSP) rule corresponding to each multicast service of the at least one multicast service, where each user equipment routing policy rule at least includes a multicast address of the corresponding multicast service. For example, first, the UE may initiate a registration procedure with the network; then, in the process of establishing UE Policy Association (UE Policy Association) between the AMF entity and the PCF entity, the PCF entity may provide the UE with the URSP rules corresponding to each of the at least one multicast service through the AMF entity, and accordingly, the UE may obtain the URSP rules corresponding to each of the at least one multicast service from the PCF entity through the AMF entity.

Then, in step S302, the UE may determine a user equipment routing policy rule corresponding to the multicast service according to the multicast address of the multicast service. For example, when the UE wants to activate a multicast service, the UE may determine the URSP rule corresponding to the multicast service according to the multicast address of the multicast service.

Then, in step S303, the UE may determine a first identifier and a second identifier corresponding to the multicast service according to the determined user equipment routing policy rule. For example, the UE may obtain a routing Descriptor (Route Selection Descriptor) according to the URSP rule corresponding to the multicast service, where the routing Descriptor includes a first identifier and a second identifier; then, the UE takes the first identity and the second identity included in the routing descriptor as the first identity and the second identity corresponding to the multicast service.

It should be appreciated that in the present disclosure, the multicast address of the multicast service may be an IPv4 multicast address, and may also be an IPv6 multicast address, which is not limited by the present disclosure.

Returning to fig. 2, after step S201, in step S202, the UE activates the multicast service according to the determined activation manner and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed during the activation of the multicast service. That is, the user plane corresponding to the multicast service is established in the activation process of the multicast service.

According to an example of the present disclosure, when the activation manner determined by the UE in step S201 is the first activation manner, the UE performs step S202'. In step S202', the UE activates the multicast service according to the first activation mode and at least through the session management function entity. In this example, step S202 'may include 3 sub-steps, step S2021', step S2022 ', and step S2023', respectively.

In particular, in step S2021', the UE may determine a third identifier, wherein the third identifier is used to identify a user equipment multicast service context established for activating the multicast service. For example, the UE may assign an Identification (ID) to the UE multicast service context. The "user device multicast service context established for activating the multicast service" described herein may also be referred to as a user device multicast service context (MBS UEContext) for multicast services. Accordingly, the third identifier may also be referred to as an identifier of a user equipment multicast service Context (MBS UE Context ID) for the multicast service.

It is to be appreciated that the UE can use the multicast address of different multicast services to activate multiple different multicast services. Accordingly, the UE may assign different third identities for different multicast services, thereby respectively identifying user device multicast service contexts established for activating the different multicast services.

Then, in step S2022', the UE sends a request for activating the user equipment multicast service context to the session management function entity, where the request for activating the user equipment multicast service context includes the third identifier and a multicast address of the multicast service. For example, the UE may send a request for activating the user equipment multicast service context to the session management function entity via the access and mobility management function entity.

Specifically, first, the UE may send an uplink-Access Stratum (NAS) Transport (UL NAS Transport) message to the AMF entity, where the UL NAS Transport message includes at least three cells, a first cell is a first identifier corresponding to the multicast service, a second cell is a second identifier corresponding to the multicast service, and a third cell is a request for activating MBS UE Context. The Request for activating the MBS UE Context may be denoted as an Active MBS UE Context Request, and may include a third identifier corresponding to the multicast service and a multicast address of the multicast service. In an example where the first identifier is an S-NSSAI, the second identifier is a DNN, and the third identifier is an MBS UE Context ID, the UL NAS Transport message sent by the UE to the AMF entity may include three cells, where the first cell is an S-NSSAI corresponding to the multicast service, the second cell is a DNN corresponding to the multicast service, and the third cell is a request for activating the MBS UE Context, where the request for activating the MBS UE Context includes the MBS UE Context ID corresponding to the multicast service and a multicast address of the multicast service.

In the present disclosure, the UE may encapsulate the "request to activate MBS UE Context" described herein using a specific format. For example, the specific format may be a session management Container (N1MBS SM Container) for multicast traffic associated with the N1 interface.

Then, the AMF entity may select a corresponding SMF entity according to the first identifier and the second identifier corresponding to the multicast service. In an example where the first identity is S-NSSAI and the second identity is DNN, the AMF entity may select a corresponding SMF entity according to S-NSSAI and DNN corresponding to the multicast service.

The AMF entity may then send a request to the corresponding SMF entity over the Nsmf interface, which may be used to request the creation of an MBS UE Context related to the MBS session. This Request may be denoted as Nsmf _ mbssessioncreatembuecontext Request. The request may include the first identity, the second identity corresponding to the multicast service, and the "request for activating MBS UE Context" described above. In an example where the first identity is an S-NSSAI, the second identity is a DNN, and the third identity is an MBS UE Context ID, the AMF entity may send a request to the SMF entity over the Nsmf interface, which may include the S-NSSAI corresponding to the multicast service, the DNN corresponding to the multicast service, and the "request to activate MBS UE Context" described above.

Further, according to an example of the present disclosure, the request sent by the AMF entity to the SMF entity may further include a dedicated identity of the UE. For example, the UE dedicated identity may be a Subscription permanent identifier (SUPI). Further, according to another example of the present disclosure, the request sent by the AMF entity to the SMF entity may further include an identification of a serving base station of the UE. For example, the identity of the serving base station of the UE may be a corresponding RAN ID, which may be reported to the AMF entity by the RAN to which the UE accesses. Furthermore, according to another example of the present disclosure, the request sent by the AMF entity to the SMF entity may also include both a dedicated identity of the UE and an identity of a serving base station of said UE, e.g. the SUPI of the UE and the corresponding RAN ID.

After step S2022', the SMF entity may record the received RAN ID in the MBS UE Context of the UE, so that the SMF entity acquires the identities of the serving base stations of all user devices activating the multicast service through the SMF entity. Furthermore, the SMF entity determines a fourth identity corresponding to the multicast service according to the received information, wherein the fourth identity is used for the user equipment to determine whether the multicast service is activated and is an identity allocated to the multicast service by an Application Function (AF) entity, and the SMF entity feeds back the fourth identity to the UE. These operations will be described in detail in the methods performed by the SMF entity described below in connection with fig. 4-5.

The fourth identifier described herein may be a Temporary Mobile Group Identity (TMGI) assigned by the AF entity to the multicast service activated based on the multicast address.

Then, in step S2023', the UE receives a response to the request for activating the user equipment multicast service context from the session management function entity, the response including a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated. In particular, the UE may receive a response to the request for activation of the user equipment multicast traffic context from the session management function entity via the serving base station of the user equipment and the access and mobility management function entity.

Specifically, first, the session management function entity may transmit first information to the access and mobility management function entity, wherein the first information includes a response to the request for activating the user equipment multicast service context and information related to the multicast service session. Further, the "information related to the multicast service session" described herein may include at least the fourth identifier, an Aggregate Maximum Rate (e.g., an Aggregate Maximum Bit Rate (AMBR)) corresponding to the multicast service, a quality of service flow identifier and a quality of service profile corresponding to each data flow of the multicast service, a tunnel multicast address corresponding to the multicast service, and a sixth identifier. The "tunnel multicast address" described herein may be a Transport layer IP multicast address (Transport IP MulticastAddress), and may be referred to as a CN N3 tunnel multicast address. The "sixth identification" described herein may be a Common-Tunnel End point identification (C-TEID) and may be referred to as CN N3C-TEID. The method performed by the SMF entity will be described in detail below in connection with fig. 4-5.

When the session management function entity sends the first information to the access and mobility management function entities, the session management function entity may encapsulate the "response to the request for activating the user equipment multicast service context" in the first information and the "information related to the multicast service session" in the first information, respectively, using different specific formats. For example, the session management function entity may encapsulate the "response to the request for activating the user device multicast service context" in the first information using a first format and encapsulate the "information related to the multicast service session" in the first information using a second format. The first format here may be a session management Container (N1MBS SM Container) for multicast traffic associated with the N1 interface. The second format here may be a session management Container (N2 MBS SM Container) for multicast traffic associated with the N2 interface.

Then, the access and mobility management functional entity sends a fifth request to the corresponding serving base station according to the information related to the multicast service session, wherein the fifth request is used for requesting the start of the multicast service session. The fifth request may include a response to the request to activate the user device multicast traffic context, the fourth identification, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast traffic, a quality of service flow identification and a quality of service profile corresponding to each data flow of the multicast traffic, a tunnel multicast address corresponding to the multicast traffic, and a sixth identification.

In case that the "response to the request for activating the user equipment multicast service context" acquired by the access and mobility management function entity from the session management function entity has been encapsulated by the session management function entity (e.g. using N1MBS SM Container encapsulation), when the access and mobility management function entity sends the fifth request to the corresponding serving base station, the access and mobility management function entity does not need to encapsulate the "response to the request for activating the user equipment multicast service context" in the fifth request using a specific format (e.g. N1MBS SM Container).

In addition, the "response to the request for activating the user equipment multicast service context" in the fifth request may be one information element of a downlink NAS Transport (DL NAS Transport) message.

The serving base station may then send a response to the user device for the request to activate the user device multicast traffic context. For example, the serving base station may send a response to the request for activating the user equipment multicast service context to the user equipment through Radio Resource Control (RRC) signaling. For example, the serving base station may transmit the downlink NAS transport message described above to the user equipment through RRC signaling, and one information element of the downlink NAS transport message may be "a response to the request for activating the multicast service context of the user equipment".

Accordingly, in step S2023', the UE can obtain a response to the request for activating the user equipment multicast service context from the session management function entity.

A specific example is given below in which the UE obtains a response from the session management function entity for the request for activating the user equipment multicast service context.

For example, first, the SMF entity may send the first information to the AMF entity through the Namf interface. The first information may be a message transmission related to the N1 interface and the N2 interface, which may be denoted as Namf _ Communication _ N1N2MessageTransfer, communicated through the Namf interface. The first information may include the "response to the request for activating the user equipment multicast service Context" described above in response to the request for activating the MBS UE Context transmitted by the AMF entity to the SMF entity described above in connection with step S3022'. The "Response to the request for activating the user equipment multicast service Context" may include a TMGI corresponding to the multicast service and may be represented as a Response (Activate MBS UE Context Response) activating MBS UE Context. The SMF entity may encapsulate the "response to activate MBS UE Context" using the N1MBS SM Context described above. In addition, the first information may further include a TMGI corresponding to the multicast service, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service stream identification and a quality of service profile corresponding to each data stream of the multicast service, a CN N3 tunnel multicast address corresponding to the multicast service, and a CN N3C-TEID. The SMF entity may encapsulate the "TMGI corresponding to the multicast traffic, the aggregated maximum rate (e.g., AMBR) corresponding to the multicast traffic, the quality of service flow identification and quality of service profile corresponding to each data flow of the multicast traffic, the CN N3 tunnel multicast address corresponding to the multicast traffic, and the CN N3C-TEID" using the N2MBS SMContainer described above.

The AMF entity may then send a fifth Request for requesting the Start of a multicast service Session, which may be denoted as N2MBS Session Start Request, to the RAN over the N2 interface. The fifth request may include a downlink NAS Transport (DL NAS Transport) message, one information element of which is the above-described response (active MBS UE Context) of activating MBS UE Context encapsulated using N1MBS SM Context. Through the downlink NAS Transport message, the AMF entity may instruct the RAN to directly send a DLNAS Transport message to the UE. In addition, the fifth request may further include a TMGI corresponding to the multicast service, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, a multicast address of the multicast service, a quality of service stream identifier and a quality of service profile corresponding to each data stream of the multicast service, a CN N3 tunnel multicast address corresponding to the multicast service, and a CN N3C-TEID.

The RAN may then send the DL NAS Transport message described above to the UE. Accordingly, the UE may acquire the fourth identifier corresponding to the multicast service through the DL NAS Transport message. In an example where the fourth identity is a TMGI, the UE may acquire the TMGI corresponding to the multicast service through a DL NAS Transport message.

In the present disclosure, the UE successfully acquires the fourth identifier corresponding to the multicast service, which indicates that the UE activates the multicast service.

So far, an exemplary procedure has been described in which the UE activates the multicast service according to the first activation manner and at least through the session management function entity. Next, an exemplary procedure for the UE to activate the multicast service according to the second activation manner and at least through the session management function entity will be described.

According to an example of the present disclosure, when the activation manner determined by the UE in step S201 is the second activation manner, the UE performs step S202 ". In step S202 ″, the UE activates the multicast service according to the second activation manner and at least through the session management function entity. In this example, step S202 "may comprise 7 sub-steps, respectively step S2021", step S2022 ", step S2023", S2024 ", step S2025", step S2026 "and step S2027".

Specifically, in step S2021 ″, the UE may obtain an internet protocol address (IP address) from the session management function entity according to the first identifier and the second identifier corresponding to the multicast service. For example, the UE may select the session management function entity and establish a pdu session according to the first identifier and the second identifier, and obtain an ip address from the session management function entity. In an example where the first identity is S-NSSAI and the second identity is DNN, the UE may send a PDU session setup request to the network according to S-NSSAI and DNN corresponding to the multicast service, where the PDU session setup request may include S-NSSAI and DNN corresponding to the multicast service. Then, the AMF entity may select one SMF entity from the plurality of SMF entities according to the S-NSSAI and the DNN corresponding to the multicast service. The selected SMF entity may then select a UPF entity from the plurality of UPF entities and assign an IP address to the UE.

Then, in step S2022 ″, the UE may send a data packet to the network according to the acquired internet protocol address so that a User Plane Function (UPF) entity in the network acquires the data packet. For example, the UE may send a data packet to the network according to the acquired internet protocol address so that a user plane functional entity participating in the establishment of the pdu session in the network acquires the data packet. Further, the data packet is used to indicate a multicast service that the user device wants to activate. The destination address of the data packet is a multicast address of the multicast service, or the protocol portion of the data packet includes the multicast address of the multicast service. For example, after step S3021 ″, the UE may transmit an IGMP Join packet to the network at the allocated IP address after the PDU session setup is completed. When IGMP version 1 or 2 is used, the destination IP address of the IGMP Join packet may be the multicast address of the multicast service. When IGMP version 3 is employed, the IGMP protocol portion of the IGMP Join packet may include the multicast address of the multicast traffic.

Then, in step S2023 ″, the UE may obtain a first identifier, a second identifier and a multicast address from the session management function entity.

Specifically, after step S2022 ″, the SMF entity may acquire the multicast address of the multicast service to be activated by the user equipment from the user plane functional entity. For example, the UPF entity may be configured according to a Packet Detection Rule (PDR) of the SMF entity, and report a multicast address corresponding to the IGMP Join Packet to the SMF entity after detecting the IGMP Join Packet (for example, report the multicast address corresponding to the IGMP Join Packet by using an N4 session report message).

The SMF entity may then decide to instruct the user device to activate the multicast service. When the SMF entity decides to instruct the user equipment to activate the multicast service, the SMF entity may transmit a request for instructing the user equipment to activate the multicast service to the user equipment, wherein the request for instructing the user equipment to activate the multicast service includes a first identifier corresponding to the multicast service to be activated by the user equipment, a second identifier, and a multicast address of the multicast service. For example, the SMF entity may send a request to the user equipment via an access and mobility management function entity for instructing the user equipment to activate the multicast service.

For example, the SMF entity may send a message to the AMF entity over the Namf interface, which may be denoted as Namf _ Communication _ N1MessageTransfer, via a message transfer related to the N1 interface that is communicated over the Namf interface. The message may include a request for instructing the user device to activate the multicast service. For example, the request for instructing the user equipment to activate the multicast service may be information for requesting MBS UE Context activation to instruct UEs to activate the multicast service. The information may include S-NSSAI, DNN corresponding to a multicast service to be activated by the user equipment and a multicast address of the multicast service, and may be represented as Request mbms Context Activation. Furthermore, the "Request MBS UE Context Activation" described herein may be encapsulated with the specific format described above (e.g., N1MBS SMContainer).

The AMF entity may then send a downlink NAS transport message associated with the N2 interface to the RAN over the N2 interface. This downlink NAS transport message related to the N2 interface may be denoted as N2 downlink NASTransport. The downlink NAS Transport message associated with the N2 interface may include a downlink NAS Transport (DLNAS Transport) message, which may include the "Request MBS UE Context Activation" encapsulated using N1MBS SMContainer described above. Through the downlink NAS Transport message related to the N2 interface, the AMF entity may instruct the RAN to directly send a DL NAS Transport message to the UE.

The RAN may then send the DL NAS Transport message described above to the UE. Accordingly, the UE can acquire one first identity, one second identity and one multicast address from the SMF entity through the DL NAS Transport message.

After step S2023 ", in step S2024", the UE may determine whether the acquired first identifier is the same as the determined first identifier, whether the acquired second identifier is the same as the determined second identifier, and whether the acquired multicast address is the same as the multicast address of the multicast service. For example, the UE may determine, according to the DL NAS Transport message received from the RAN, whether the multicast address in the "Request MBS UE Context Activation" encapsulated using N1MBS SM Container is the same as the multicast address of the multicast service that the UE wants to activate, and whether the S-NSSAI and DNN in the "Request MBS UE Context Activation" encapsulated using N1MBS SM Container are the same as the S-NSSAI and DNN when the PDU session is established.

When the UE determines in step S2024 "that the obtained first identifier is different from the determined first identifier, and/or the obtained second identifier is different from the determined second identifier, and/or the obtained multicast address is different from the multicast address of the multicast service, the UE cannot activate the multicast service. In contrast, when the UE determines in step S2024 "that the obtained first identifier is the same as the determined first identifier, the obtained second identifier is the same as the determined second identifier, and the obtained multicast address is the same as the multicast address of the multicast service, the UE may activate the multicast service.

The UE may perform step S2025 ", step S2026" and step S2027 "to activate the multicast service. In particular, in step S2025 ", the UE may determine a third identifier, wherein the third identifier is used to identify a user equipment multicast service context established for activating the multicast service. Then, in step S2026 ″, the UE may send, to the session management function entity, a request for activating the user equipment multicast service context, where the request for activating the user equipment multicast service context includes the third identifier and a multicast address of the multicast service. Then, in step S2027 ″, the UE may receive, from the session management function entity, a response to the request for activating the user equipment multicast service context, the response including a fourth identification corresponding to the multicast service, where the fourth identification is used for the user equipment to determine whether the multicast service is activated.

The above steps S2025 ", S2026" and S2027 "are similar to the above steps S2021 ', S2022 ' and S2023 ', respectively, and are not repeated herein.

Returning to fig. 2, in step S203, the user apparatus receives service data corresponding to the multicast service. For example, when the user equipment activates the multicast service and a multicast service session corresponding to the multicast service is successfully started, the AF entity may transmit multicast service data (e.g., a multicast service data packet) whose destination IP address is a multicast address of the multicast service to a downstream UPF entity. The UPF entity then sends the multicast traffic data to the RAN. The RAN may then transmit the multicast traffic data to the UE via the resources allocated to the UE.

According to the method performed by the user equipment of the embodiment of the present disclosure, the user equipment may determine an activation manner for activating the multicast service, and activate the multicast service according to the determined activation manner and at least through a session management function entity in the network, thereby optimizing or being compatible with a conventional process of activating the multicast service. In addition, in the process of activating the multicast service, a multicast service session corresponding to the multicast service is started, so that a user plane corresponding to the multicast service is established in the process of activating the multicast service.

The method performed by the SMF entity will be described in conjunction with fig. 4-5, where fig. 4 is a flowchart of a method performed by the session management function entity when the user equipment activates the multicast service according to the first activation mode according to an embodiment of the present disclosure, and fig. 5 is a flowchart of a method performed by the session management function entity when the user equipment activates the multicast service according to the second activation mode according to an embodiment of the present disclosure.

First, a method 400 performed by a session management function entity when a user equipment activates a multicast service according to a first activation manner is described in conjunction with fig. 4. As shown in fig. 4, in step S401, a request for activating a user equipment multicast service context established by the user equipment for activating the multicast service is received from the user equipment, the request for activating the user equipment multicast service context includes the third identifier and a multicast address of the multicast service, and the third identifier is used for identifying the user equipment multicast service context.

Specifically, first, the UE may send an uplink NAS Transport (UL NAS Transport) message to the AMF entity, where the UL NAS Transport message includes at least three information elements, a first information element is a first identifier corresponding to the multicast service, a second information element is a second identifier corresponding to the multicast service, and a third information element is a request for activating an MBS UE Context, where the request for activating the MBS UE Context includes a third identifier corresponding to the multicast service and a multicast address of the multicast service. In an example where the first identifier is S-NSSAI, the second identifier is DNN, and the third identifier is MBSUE Context ID, the UL NAS Transport message sent by the UE to the AMF entity may include three cells, where the first cell is S-NSSAI corresponding to the multicast service, the second cell is DNN corresponding to the multicast service, and the third cell is a request for activating MBS UE Context, where the request for activating MBS UE Context includes MBS UE Context ID corresponding to the multicast service and a multicast address of the multicast service.

Further, according to an example of the present disclosure, the SMF entity may record the identities of the serving base stations of the user devices in the user device multicast service context, so that the SMF entity acquires the identities of the serving base stations of all user devices that activate the multicast service through the SMF entity for use in establishing the user plane of the MBS session. For example, the SMF entity may record the received RAN ID in the MBS UE Context of the UE.

Returning to fig. 4, after step S401, in step S402, the SMF entity determines a response to the request for activating the user equipment multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated. For example, the SMF entity determines a fourth identifier corresponding to the multicast service according to at least the first identifier, the second identifier, and a multicast address of the multicast service, where the fourth identifier is an identifier assigned to the multicast service by an application function entity.

According to an example of the present disclosure, step S402 may include three substeps, step S4021, step S4022, and step S4023, respectively.

Specifically, in step S4021, the SMF entity may determine whether the user equipment is capable of using the multicast service. For example, the SMF entity may obtain subscription Data of the UE from a Unified Data Management (UDM) entity to determine whether the UE is subscribed to the multicast service. If the UE subscribes to the multicast service, the SMF entity may determine that the UE is capable of using the multicast service. If the UE does not subscribe to the multicast service, the SMF entity may determine that the UE cannot use the multicast service.

When the SMF entity determines in step S4021 that the UE can use the multicast service, the SMF entity may perform step S4022. In step S4022, the SMF entity sends a notification to the application function entity, where the notification is a notification of the multicast service authorization request. The notification comprises at least the first identity, the second identity, a multicast address of the multicast service, and an identity of the session management function entity. The "identifier of the session management function entity" is to facilitate the application function entity to obtain the session management function entity involved by all user devices that are to activate the multicast service when activating the multicast service, so as to be used when subsequently establishing a user plane corresponding to the multicast service.

In particular, the SMF entity may send the notification directly to the application function entity. For example, the SMF entity may determine the corresponding AF entity according to the first identifier, the second identifier, and the multicast address of the multicast service. The SMF entity may then send a notification to the determined AF entity. The notification may comprise the first identification, the second identification, a private identification and a public identification of the user device (e.g. a General Public Subscription Identifier (GPSI)), a multicast address of the multicast service, and an identification of the session management function entity (e.g. the SMF ID of the SMF entity and its IP address).

Alternatively, the SMF entity may send a notification to the application function entity via the network openness function entity.

In an example where the SMF entity sends the notification to the application function entity via the network openness function entity, first, the SMF entity may send a notification to the network openness function entity, where the notification may include the first identity, the second identity, the private identity and the public identity of the user equipment (e.g., General Public Subscription Identifier (GPSI)), the multicast address of the multicast service, the identity of the session management function entity, and the identity of the application function entity (e.g., the AF ID of the AF entity determined by the SMF entity), so that the network openness function entity sends another notification to the application function entity according to the identity of the application function entity. The further notification may comprise the first identity, said second identity, a private identity and a public identity of said user device, a multicast address of said multicast service, and an identity of said session management function node entity.

In an example where the first identity is S-NSSAI, the second identity is DNN, the dedicated identity of the UE is SUPI, the public identity of the UE is GPSI, the identity of the session management function entity is SMF ID, and the identity of the application function entity is AF ID, the SMF entity may send a notification of an MBS authorization request to the NEF entity over the Nsmf interface, which may be denoted as Nsmf _ MBS authorization request notification, and which may include S-NSSAI and DNN corresponding to the multicast service, the dedicated identity of the UE SUPI, the public identity of the UE GPSI, the multicast address of the multicast service, the SMF ID, and the AFID. In addition, the notification may also include other information, such as information related to the UE location, such as one or more of a Cell Global Identifier (CGI), a Tracking Area Identifier (TAI), a Globally Unique AMF Identifier (GUAMI), and so on.

Then, after receiving the notification, the network openness function entity may determine the application function entity according to the identifier of the application function entity and send another notification to the application function entity. The further notification may comprise the first identity, the second identity, a public identity of the user device, a multicast address of the multicast service, and an identity of the session management function entity.

In an example where the first identity is S-NSSAI, the second identity is DNN, the dedicated identity of the UE is SUPI, the public identity of the UE is GPSI, the identity of the session management function entity is SMF ID, and the identity of the application function entity is AF ID, the NEF entity may send a notification of an MBS authorization request to the corresponding AF entity according to the AF ID through the Nnef interface, which may be denoted as Nnef _ mbsauuthorizationrequest notification, and which may include S-NSSAI and DNN corresponding to the multicast service, the public identity of the UE GPSI, the multicast address of the multicast service, and SMFID. Further, the notification may also include other information, e.g. information related to the UE location, such as one or more of CGI, TAI, GUAMI, etc.

After step S4022, the AF entity may record the received SMF ID for use in establishing the user plane for the MBS session. In addition, the AF entity may further determine a fourth identifier corresponding to the multicast service. The fourth identifier described herein may be a Temporary Mobile Group Identity (TMGI) assigned by the AF entity to the multicast service activated based on the multicast address.

The fourth identity may be the TMGI when the AF entity receives the message from the NEF entity. Accordingly, the AF entity may feed back Response information for notification of the MBS authorization request to the NEF entity through the Nnef interface, where the Response information may be denoted as Nnef _ MBS authorization request notification Response, and the Response information may include the TMGI corresponding to the multicast service. Then, the NEF entity may feed back response information to the notification of the MBS authorization request to the SMF entity through the Nsmf interface, where the response information may be denoted as Nsmf _ MBS authorization request NotifyResponse, and the response information may include the TMGI corresponding to the multicast service.

Accordingly, in step S4023, the SMF entity may receive a response to the notification in step S4022 from the application function entity, wherein the response to the notification includes the fourth identity corresponding to the multicast service, thereby acquiring the fourth identity corresponding to the multicast service from the application function entity. In an example where the fourth identity is a TMGI, the SMF entity may directly acquire the TMGI corresponding to the multicast service from the AF entity, or the SMF entity may acquire the TMGI corresponding to the multicast service from the AF entity via the NEF entity.

It is to be appreciated that when the multicast service is not successfully authorized by the AF entity, the response information fed back by the AF entity does not include the TMGI and may include a reason for the failure.

Furthermore, it should be appreciated that, in the above-described communication between the NEF entity and the AF entity, the information sent from the NEF entity to the AF entity may include a NEF Transaction identifier (NEF Transaction ID), and the information fed back by the AF entity to the NEF entity for the information may also include the NEF Transaction identifier.

Returning to fig. 4, in step S403, the SMF entity acquires a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify the start of a multicast service session corresponding to the multicast service. The fifth identifier may be a multicast service Session Start identifier (Session Start Indicator) to Start a multicast service Session, so as to establish a user plane corresponding to the multicast service during the activation process of the multicast service. Step S403 may be performed simultaneously with step S402 described above, or step S403 may be performed after step S402.

In an example where step S403 is performed simultaneously with step S402 described above, step S403 may be performed simultaneously with sub-step S4023 of step S402 described above. That is, when the SMF entity receives a response to the request for activating the user equipment multicast service context from the application function entity in step S4023, the SMF entity may also receive a fifth identification corresponding to the multicast service from the application function entity. For example, the SMF entity may receive a response information from the application function entity, and the response information includes both a response to the request for activating the user equipment multicast service context and a fifth identification corresponding to the multicast service.

According to an example of the present disclosure, the SMF entity may receive a response to the request for activating the user equipment multicast service context and a fifth identification corresponding to the multicast service directly from the application function entity. For example, when the AF entity receives a message from the SMF entity, the response to the request for activating the user equipment multicast service context, i.e. the fourth identity, may be the TMGI. Accordingly, the AF entity may feed back response information to the notification of the MBS authorization request to the SMF entity through the Nsmf interface, where the response information may be denoted as Nsmf _ MBS authorization request NotifyResponse, and the response information may include the TMGI corresponding to the multicast service and the multicast service session start identifier.

According to another example of the present disclosure, the SMF entity may receive, from the application function entity via the network openness function entity, a response to the request for activating the user equipment multicast service context and a fifth identification corresponding to the multicast service. For example, when the AF entity receives a message from the NEF entity, the response to the request for activating the user equipment multicast service context, i.e., the fourth identity, may be the TMGI. Accordingly, the AF entity may feed back Response information to the notification of the MBS authorization request to the NEF entity through the Nnef interface, where the Response information may be denoted as Nnef _ mbsauuthorization request notification Response, and the Response information may include a TMGI corresponding to the multicast service and a multicast service session start identifier. Then, the NEF entity may feed back, to the SMF entity through the Nsmf interface, Response information for notification of the MBS authorization request, which may be denoted as Nsmf _ mbsauuthorization request notification Response, and which may include a TMGI corresponding to the multicast service and a multicast service session start identifier.

After step S403, the SMF entity may create MBS UE Context based on the multicast address for the UE, and then may feed back a response message to the AMF entity, where the response message may be a response to the Nsmf _ MBSSession _ creatembbsuecontext Request described above. The Response information may be an acknowledgement to the Nsmf _ MBSSession _ creatembuecontext Request described above, which may be denoted as Nsmf _ MBSSession _ creatembuecontext Response.

It should be appreciated that, in the conventional user plane establishment process, after the SMF entity feeds back the response information (Nsmf _ MBSSession _ creatembbsecontext responses) described above to the AMF entity, the SMF entity directly sends information related to the multicast service session to the AMF entity, for example, the TMGI corresponding to the multicast service, the qos flow identifier and qos profile corresponding to each data flow, the tunnel multicast address, the sixth identifier, and the like are sent through a naf _ Communication _ N1N2MessageTransfer message. However, in the present disclosure, since the SMF entity acquires the multicast service session start identifier corresponding to the multicast service from the application function entity in step S403, the SMF entity does not need to directly send the information related to the multicast service session to the AMF entity according to a conventional user plane establishment procedure, but sends the information related to the multicast service session to the AMF entity after receiving the message of the PCF entity.

Then, in step S404, the SMF entity conducts the multicast service session and sends a response to the request for activating the user equipment multicast service context to the user equipment. Step S404 may include 8 sub-steps, step S4041 to step S4048, respectively.

First, in step S4041, the SMF entity receives a first request from the policy control function entity, wherein the first request is for requesting the start of a multicast service Session (MBS Session). The first request may include at least a first identification of the user device, a fourth identification corresponding to multicast traffic, a quality of service rule for at least one data flow corresponding to the multicast traffic, and an identification of the multicast traffic session. In addition, the first request may further include other information, such as an expected Duration (expected Session Duration) of the multicast service Session and a data transmission time (time to MBS data transfer) of the multicast service. Through step S4041, Policy Control and Charging (PCC) technology is applied to the transmission of the multicast service data, so that the PCC and the transmission of the multicast service data are combined.

The first request includes a first identity (e.g., private identity, SUPI), of the user equipment to indicate that this is an operation performed for a particular one of the UEs. Further, the first identity of the user equipment may be determined by the network open function entity based on the second identity of the user equipment. For example, in an example where the first identity is a private identity (SUPI) and the second identity is a general identity (GPSI), the network open function entity may determine the private identity of the user equipment from the general identity of the user equipment.

According to an example of the present disclosure, the fourth identifier in the first request may be an identifier assigned by the application function entity to the multicast service, such as the TMGI described above. The identity of the multicast service session in the first request may be an ID of the multicast service session.

Further, according to an example of the present disclosure, a PCF entity corresponding to an SMF entity may send a first request to the SMF entity over an Nsmf interface to request a start of a multicast traffic session. This first Request may be denoted as Nsmf _ mbssessuonstartrequest.

Further, according to an example of the present disclosure, the first request in step S4041 is determined by the policy control function entity according to a second request received from a network openness function entity or an application function entity, the second request being for the network openness function entity or the application function entity to request the start of a multicast traffic session to the policy control function entity. The second request may include at least a first identification of the user device, the fourth identification, an identification of the session management function entity, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, and an identification of the multicast service session. The second request may also include other information, such as an expected duration of the multicast service session, and a data transmission time for the multicast service.

The second request includes a first identity (e.g., private identity, SUPI), of the user equipment to indicate that this is an operation performed for a particular one of the UEs.

In an example where the first request is determined by the policy control function entity from a second request received from the application function entity, the AF entity may send a second request to the PCF entity over the Npcf interface to request a start of a multicast traffic session. This second Request may be denoted as an Npcf _ MBS session start Request.

Further, in an example in which the first request is determined by the policy control function entity from a second request received from the network open function entity, the NEF entity may send a second request to the PCF entity over the Npcf interface to request a start of a multicast traffic session. This second Request may be denoted as an Npcf _ MBS session start Request.

In an example in which the first request is determined by the policy control function entity according to a second request received from a network openness function entity, the second request is determined by the network openness function entity according to a third request received from an application function entity, the third request being for the application function entity to request a start of a multicast traffic session to the network openness function entity. The third request may include at least a second identification of the user device, the fourth identification, information of at least one data flow corresponding to the multicast service, quality of service requirements of the at least one data flow, and an identification of the multicast service session. The third request may also include other information, such as an expected duration of the multicast service session, and a data transmission time for the multicast service.

The second identity of the user equipment (e.g. generic identity, GPSI) is included in the third request to indicate that this is an operation performed for a particular one of the UEs.

In this example, the AF entity may send a third request to the NEF entity over the Nnef interface to request the start of the multicast traffic session. This third Request may be denoted as a Nnef _ MBS session start Request.

Exemplary procedures for the AF entity to send the third request to the NEF entity, the NEF entity to send the second request to the PCF entity, and the PCF entity to send the first request to the SMF entity are given below.

Specifically, first, the AF entity transmits a third request (Nnef _ MBS SessionStartRequest) to the NEF entity, which may include a GPSI of a user equipment, a TMGI corresponding to the multicast service, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, an ID of a multicast service session, an expected duration of the multicast service session, and a data transmission time of the multicast service.

In an example where there are multiple PCF entities, each corresponding to one or more SMF entities, the PCF entity is determined by the NEF entity or the AF entity based on the identity of the SMF entity. For example, the NEF entity or the AF entity may determine an identification of the SMF entity (SMF ID) from the GPSI of the user equipment and the TMGI corresponding to the multicast service, and then may determine the PCF entity corresponding to the SMF ID based on the SMF ID.

Then, the NEF entity may transmit a second Request (Npcf _ mbssessuonstartrequest) to the corresponding PCF entity according to the SMF ID, where the second Request may include the SUPI of the user equipment, the TMGI corresponding to the multicast service, one SMF ID, information of at least one data flow corresponding to the multicast service, the quality of service requirement of the at least one data flow, the ID of the multicast service session, the expected duration of the multicast service session, and the data transmission time of the multicast service.

Finally, the PCF entity may send a first Request (Nsmf _ mbssessuonstartrequest) to the corresponding SMF entity based on the SMF ID, the first Request may include the SUPI of the user equipment, the TMGI corresponding to the multicast service, the quality of service rule of the at least one data flow, the ID of the multicast service session, the expected duration of the multicast service session, and the data transmission time of the multicast service.

In addition, the "information of at least one data stream corresponding to the multicast service" in the above-described third request may be information of all data streams to be used for transmitting the multicast service. The data flow here may be an IP flow. In this case, the information of each data flow may be determined by the IP triplet. The IP triplet may indicate that the destination IP address of the IP stream is a multicast address, a destination port, and the communication protocol (e.g., UDP protocol) employed. It is to be appreciated that in other examples of the present disclosure, the information for each data flow may be determined by an IP five-tuple, or may be determined by other triplets, which is not limited by the present disclosure.

Further, the "quality of service Requirement of the at least one data flow" in the third request described above may include a quality of service Requirement (QoS Requirement) corresponding to each data flow. The quality of service requirements for each data flow may include one or more of a QoS Class Identifier (QCI), an Allocation Retention Priority (ARP), a Priority Level (Priority Level), and the like. Further, the quality of service requirements of each data flow may be used to generate quality of service rules for each data flow in the first request. The specific generation method may adopt some existing generation methods, and the disclosure does not limit this.

Further, any of the first request, the second request, and the third request described above may further include an aggregated maximum rate corresponding to the multicast service. The aggregate maximum rate may only have a value in the downlink direction and not in the uplink direction. Alternatively, the aggregate maximum rate may have both a value for the downlink direction and a value for the uplink direction. The aggregate maximum Rate may be an Aggregate Maximum Bit Rate (AMBR).

After step S4041, in step S4042, the SMF entity may generate a quality of service flow identifier (QoSFlow Identity, QFI), a quality of service Profile (QoS Profile), and a quality of service enforcement Rule (QER) corresponding to each data flow according to a quality of service Rule of each data flow of the at least one data flow corresponding to the multicast service. In the present disclosure, the quality of service flow identification corresponding to each data flow may also be referred to as a quality of service flow identification (MBS QFI) for multicast traffic. Further, the quality of service enforcement rules described herein may be similar to conventional N4QER rules.

Then, in step S4043, the SMF entity may select a user plane functional entity according to the fourth identifier. In an example where the fourth identifier is a TMGI, the SMF entity may determine a corresponding MBS UE Context according to the TMGI, and obtain the S-NSSAI, DNN, and multicast address included in the MBS UE Context according to the determined MBS UE Context. The SMF entity may then select a UPF entity from the plurality of UPF entities based on the obtained S-NSSAI, DNN, and multicast address.

It is to be appreciated that if a UPF entity has been previously assigned, the SMF entity may not perform step S4043 described above.

Then, in step S4044, the SMF entity may send a fourth request to the selected user plane function entity, where the fourth request is used to establish transmission resources of the multicast service session. The fourth request includes at least a multicast address of the multicast traffic, a quality of service enforcement rule for at least one data flow corresponding to the multicast traffic, and an aggregated maximum rate (e.g., AMBR) corresponding to the multicast traffic. For example, the SMF entity may send a Request for requesting MBS session establishment, which may be denoted as N4 MBS session establishment Request, to the selected UPF entity through the N4 interface.

Then, in step S4045, the SMF entity may obtain a response to the fourth request from the selected user plane functional entity, where the response to the fourth request includes a tunneling multicast address allocated by the selected user plane functional entity for transmitting traffic data corresponding to the multicast traffic, and a sixth identity corresponding to the tunneling multicast address, where the tunneling multicast address is used for multicast tunneling between network entities (e.g., multicast tunneling between a UPF entity and a RAN), and the sixth identity is used for identifying a transport tunnel (e.g., a transport tunnel related to GTP) of the multicast traffic.

For example, the UPF entity may establish a GTP user plane tunneling tree from the UPF entity to the RAN according to the multicast routing protocol according to the received request, so as to transmit data (e.g., service data corresponding to the multicast/broadcast service) to be sent by the UPF entity to the RAN in a tree-like GTP user plane tunnel. The UPF entity may then assign a tunnel multicast address for transmitting service data corresponding to the multicast/broadcast service. Specifically, the UPF entity may allocate a multicast address of a GTP user plane tunnel through the N3 interface to the multicast/broadcast service, and use the multicast address of the allocated GTP user plane tunnel as a tunnel multicast address. The "tunnel Multicast Address" described herein may also be referred to as a Transport layer IP Multicast Address (Transport IP Multicast Address). The UPF entity may then assign a sixth identity, e.g., a Common-Tunnel End point ID (C-TEID), to the multicast/broadcast service.

After the UPF entity allocates the tunnel multicast address and the sixth identity to the multicast service, the UPF entity may send a response message to the SMF entity through the N4 interface in response to the above-described request for requesting MBS session establishment sent by the SMF entity to the UPF entity. The response information may include a tunnel multicast address corresponding to the multicast traffic and a sixth identification corresponding to the multicast traffic. This Response information may be denoted as N4 MBS session establishment Response.

Accordingly, the SMF entity may obtain a tunnel multicast address corresponding to the multicast service from the selected UPF entity and obtain a sixth identity corresponding to the multicast service from the selected user plane functional entity. Then, the SMF entity may record the tunnel multicast address and the sixth identity in a multicast service context of each user equipment that has activated the multicast service.

It should be understood that in the present disclosure, the tunnel multicast address and the sixth identification assigned by the UPF entity uniquely correspond to the multicast address of the multicast service.

It should also be understood that, in the present disclosure, the tunnel multicast address assigned by the UPF entity may be regarded as a tunnel multicast address assigned by a core network (core network, CN), and the sixth identity assigned by the UPF entity may be regarded as a sixth identity assigned by the CN.

It should be appreciated that in the present disclosure, the transmission channels of the data streams corresponding to different multicast services may be distinguished by different sixth identifiers, and the multiple data streams corresponding to each multicast service may be distinguished by the QFI described above.

Further, in the present disclosure, the SMF entity may record at least the tunnel multicast address assigned by the UPF entity and the sixth identification in the multicast service context of each user equipment that has activated the multicast service. For example, the SMF entity may record the identification of the PCF entity (PCF ID) involved in the above process, the identification of the UPF entity involved (UPF ID), and the tunnel multicast address and C-TEID allocated by the UPF entity to each user equipment multicast service Context (MBS UE Context) that has activated the multicast service. If a UPF entity has been previously assigned and the UPF entity has also assigned a tunneling multicast address and a C-TEID, only the tunneling multicast address and the C-TEID assigned by the UPF entity may be recorded into the user equipment multicast service Context (MBS UE Context) of the UE.

Further, it is to be appreciated that the UPF entity may also establish a transmission tree from the AF entity to the UPF entity. That is, the transmission from the AF entity to the UPF entity may also be in a transport layer multicast manner. Alternatively, the multicast transmission from the AF entity to the UPF entity may also be implemented by a routing means (e.g. a router) between the AF entity and the UPF entity.

Further, according to an example of the present disclosure, steps S4043 to S4045 may also be replaced with steps S4043 'to S4045' (not shown in the drawings). In step S4043', the SMF entity may select a user plane functional entity according to the fourth identity. Then, in step S4044', the SMF entity may send a fourth request to the selected user plane function entity, where the fourth request is used to establish transmission resources for the multicast service session, and the fourth request includes a tunnel multicast address allocated by the session management function entity for transmitting service data corresponding to the multicast service, and a sixth identifier corresponding to the tunnel multicast address, where the tunnel multicast address is used for multicast tunneling between network entities, and the sixth identifier is used to identify a transmission tunnel of the multicast service. Then, in step S4045', the SMF entity may obtain a response to the fourth request from the selected user plane functional entity, wherein the response to the fourth request is an acknowledgement of the fourth request. That is, the tunnel multicast address described herein may be assigned by the SMF entity and notified to the selected UPF entity by the SMF entity.

In addition, in this example, the fourth request may also include a multicast address of the multicast traffic, a quality of service enforcement rule for at least one data stream corresponding to the multicast traffic, and an aggregated maximum rate (e.g., AMBR) corresponding to the multicast traffic. In addition, similarly, the SMF entity may record its assigned tunnel multicast address and the sixth identification in the multicast service context of each user equipment that has activated the multicast service.

Then, in step S4046, the SMF entity may transmit first information to the access and mobility management function entity, wherein the first information includes the response and the information related to the multicast service session, so that the access and mobility management function entity transmits a fifth request to the corresponding serving base station according to the information related to the multicast service session, and transmits the response to the user equipment via the corresponding serving base station, wherein the fifth request is used for requesting the start of the multicast service session. The "information related to the multicast service session" described herein includes at least the fourth identification, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service flow identification and a quality of service profile corresponding to each data flow, the tunnel multicast address, and the sixth identification.

Accordingly, the UE can obtain a response to the request for activating the user equipment multicast service context from the session management function entity.

One specific implementation of step S4046 is given below.

First, the SMF entity may transmit first information to the AMF entity through the Namf interface. The first information may be a message transmission related to the N1 interface and the N2 interface, which may be denoted as Namf _ Communication _ N1N2MessageTransfer, communicated through the Namf interface. The first information may include the "response to the request for activating the user equipment multicast service Context" described above in response to the request for activating the MBS UE Context transmitted by the AMF entity to the SMF entity described above in connection with step S3022'. The "Response to the request for activating the user equipment multicast service Context" may include a TMGI corresponding to the multicast service and may be represented as a Response (Activate MBS UE Context Response) activating MBS UE Context. The SMF entity may encapsulate the "response to activate MBS UE Context" using the N1MBS SM Context described above. In addition, the first information may further include a TMGI corresponding to the multicast service, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service stream identification and a quality of service profile corresponding to each data stream of the multicast service, a CN N3 tunnel multicast address corresponding to the multicast service, and a CN N3C-TEID. The SMF entity may encapsulate the TMGI corresponding to the multicast traffic, the quality of service flow identification and quality of service profile corresponding to each data flow of the multicast traffic, the CN N3 tunnel multicast address corresponding to the multicast traffic, and the CN N3C-TEID using the N2MBS SMContainer described above.

The AMF entity may then send a fifth Request for requesting the Start of a multicast service Session, which may be denoted as N2MBS Session Start Request, to the RAN over the N2 interface. The fifth request may include a downlink NAS Transport (DL NAS Transport) message, one information element of which is the above-described response (active MBS UE Context) of activating MBS UE Context encapsulated using N1MBS SM Context. Through the downlink NAS Transport message, the AMF entity may instruct the RAN to directly send a DLNAS Transport message to the UE. In addition, the fifth request may further include a TMGI corresponding to the multicast service, a multicast address of the multicast service, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service stream identifier and a quality of service profile corresponding to each data stream of the multicast service, a CN N3 tunnel multicast address corresponding to the multicast service, and a CN N3C-TEID.

Then, the RAN can transmit the above-described DL NAS Transport message to the UE through RRC signaling. Accordingly, the UE may acquire the fourth identifier corresponding to the multicast service through the DL NAS Transport message. In an example where the fourth identity is a TMGI, the UE may acquire the TMGI corresponding to the multicast service through a DL NAS Transport message.

Through the above step S4046, not only the user plane corresponding to the multicast service is established, but also the UE activates the multicast service.

After step S4046, the serving base station of the UE may send a response to the fifth request to the access and mobility management function entity. For example, the RAN may send a response to the fifth request to the AMF entity through the N2 interface in response to the above-described fifth request sent by the AMF entity to the RAN for requesting the MBS session start. The Response may be an acknowledgement to the N2MBS Session Start Request sent by the AMF entity to the RAN described above and may be denoted as N2MBS Session Start Response.

The serving base station may then allocate resources for transmitting multicast traffic data to its served UEs to support data streams with different quality of service requirements. Accordingly, the UE can receive the multicast service data through the allocated resources.

The serving base station may then join the transport group corresponding to the tunneled multicast address described above (e.g., CN N3 tunneled multicast address) to receive the multicast traffic data from the UPF entity. That is, a transmission tree from the UPF entity to the serving base station may be established to transmit data (e.g., multicast traffic data) that the UPF entity intends to transmit to the serving base station in a tree-like manner.

It should be appreciated that if the serving base station has allocated resources corresponding to the multicast traffic for the UE it serves, the serving base station does not need to allocate resources for transmitting multicast traffic data for the UE again and does not need to join the transmission group corresponding to the tunnel multicast address.

Then, the AMF entity may send a notification message to the SMF entity to notify the first message sent by the SMF entity to the AMF entity described in the above step S4046. For example, the AMF entity may send the notification information to the SMF entity over the Namf interface. The notification information may be an acknowledgement of the first information transmitted by the SMF entity to the AMF entity described in step S4046 above. The notification information may be an MBS message transmission related to the N2 interface, which may be denoted as Namf _ Communication _ N2MBSMessageNotify, communicated over the Namf interface. Accordingly, in step S4047, the SMF entity receives notification information for the first information from the AMF entity.

Then, in step S4048, the SMF entity may send a response message to the PCF entity via the Nsmf interface in response to the first request sent by the PCF entity to the SMF entity as described in step S4041. For example, the Response information may be an acknowledgement of "Nsmf _ MBS SessionStartRequest" transmitted by the PCF entity to the SMF entity as described in step S4041, and may be denoted as Nsmf _ MBS SessionStart Response.

Further, after step S4048, the PCF entity may send a response message to the NEF entity over the Npcf interface in response to the second request sent by the NEF entity to the PCF entity as described in step S4041. For example, the response information may be an acknowledgement of "Npcf _ mbssessureq" transmitted by the NEF entity to the PCF entity as described in step S4041, and may be denoted as Npcf _ MBS SessionStartResponse.

Then, the NEF entity may send a response message to the AF entity through the Nnef interface in response to the third request sent by the AF entity to the NEF entity described in step S4041 above. For example, the NEF entity may send the Response information to the AF entity through the Nnef interface, and the Response information may be denoted as Nnef _ MBS session Response.

So far, the user plane corresponding to the multicast service has been successfully established. This means that the multicast service can start to proceed. For example, the AF entity may send multicast service data (e.g., multicast service data packets) with a destination IP address being a multicast address of the multicast service to a downstream UPF entity. The UPF entity may then send the multicast service data to the RAN by the transport layer multicast method described above. The RAN may then transmit the multicast traffic data to the UE via the resources allocated to the UE.

According to the method executed by the session management functional entity of the embodiment of the disclosure, in the process of activating the multicast service, the session management functional entity may receive, from the user device, the third identifier corresponding to the multicast service to be activated by the user device and the multicast address of the multicast service, and determine, according to at least these pieces of information, the fourth identifier and the fifth identifier corresponding to the multicast service, so that the multicast service session corresponding to the multicast service can be performed according to the fifth identifier to establish the user plane corresponding to the multicast service, and the fourth identifier is fed back to the user device so that the user device activates the multicast service, thereby achieving establishment of the user plane corresponding to the multicast service in the process of activating the multicast service.

A method 500 performed by the session management function entity when the user equipment activates the multicast service according to the second activation manner is described below in conjunction with fig. 5.

As shown in fig. 5, in step S501, the SMF entity may establish a protocol data unit session and assign an internet protocol address (IP address) to the user equipment. For example, in an example where the first identity is S-NSSAI and the second identity is DNN, the UE may send a PDU session setup request to the network according to S-NSSAI and DNN corresponding to the multicast service, which may include S-NSSAI and DNN corresponding to the multicast service. Then, the AMF entity may select one SMF entity from the plurality of SMF entities according to the S-NSSAI and the DNN corresponding to the multicast service. The selected SMF entity may then select a UPF entity from the plurality of UPF entities and assign an IP address to the UE.

Then, in step S502, a multicast address of a multicast service to be activated by the user equipment is obtained from a user plane function entity participating in the establishment of the pdu session, wherein the multicast address is obtained after the user equipment sends a packet to a network including the user plane function entity according to the internet protocol address, wherein the packet is used for indicating the multicast service which the user equipment wants to activate, a destination address of the packet is a multicast address of the multicast service, or a protocol portion of the packet includes the multicast address of the multicast service.

Specifically, the UE may send a data packet to the network according to the acquired IP address, so that a user plane functional entity in the network acquires the data packet. For example, the UE may send a data packet to the network according to the acquired internet protocol address so that a user plane functional entity participating in the establishment of the pdu session in the network acquires the data packet. Further, the data packet is used to indicate a multicast service that the user device wants to activate. The destination address of the data packet is a multicast address of the multicast service, or the protocol portion of the data packet includes the multicast address of the multicast service. For example, the UE may send an IGMP Join packet to the network at the assigned IP address after the PDU session setup is completed. When IGMP version 1 or 2 is used, the destination IP address of the IGMP Join packet may be the multicast address of the multicast service. When IGMP version 3 is employed, the IGMP protocol portion of the IGMP Join packet may include the multicast address of the multicast traffic.

Accordingly, the SMF entity may obtain a multicast address of a multicast service to be activated by the user equipment from the user plane functional entity. For example, the UPF entity may be configured according to a Packet Detection Rule (PDR) of the SMF entity, and report a multicast address corresponding to the IGMP Join packet to the SMF entity after detecting the IGMP Join packet (for example, report the multicast address corresponding to the IGMP Join packet through an N4 session report message).

When the SMF entity decides to instruct the user equipment to activate the multicast service, the SMF entity may perform step S503. In step S503, the SMF entity may transmit, to the user equipment, a request for instructing the user equipment to activate the multicast service, where the request for instructing the user equipment to activate the multicast service includes a first identifier corresponding to the multicast service to be activated by the user equipment, a second identifier, and a multicast address of the multicast service. For example, the SMF entity may send a request to the user equipment via an access and mobility management function entity for instructing the user equipment to activate the multicast service.

For example, the SMF entity may send a message to the AMF entity over the Namf interface, which may be denoted as Namf _ Communication _ N1MessageTransfer, via a message transfer related to the N1 interface that is communicated over the Namf interface. The message may include a request for instructing the user device to activate the multicast service. For example, the request for instructing the user equipment to activate the multicast service may be information for requesting MBS UE Context activation to instruct UEs to activate the multicast service. The information for requesting MBS UE Context activation may include S-NSSAI, DNN corresponding to a multicast service to be activated by the user equipment and a multicast address of the multicast service, and the information for requesting MBS UE Context activation may be represented as Request MBS UE Context. Furthermore, the "Request MBS UE Context Activation" described herein may be encapsulated with the specific format described above (e.g., N1MBS SM Container).

After step S503, the AMF entity may send a downlink NAS transport message associated with the N2 interface to the RAN through the N2 interface. This downlink NAS transport message related to the N2 interface may be denoted as N2 downlink NASTransport. The downlink NAS Transport message associated with the N2 interface may include a downlink NAS Transport (DL NAS Transport) message, which may include the "Request MBS UE Context Activation" encapsulated using N1MBS SMContainer described above. Through the downlink NAS Transport message related to the N2 interface, the AMF entity may instruct the RAN to directly send a DL NAS Transport message to the UE. The RAN may then send the DL NAS Transport message described above to the UE. Accordingly, the UE can acquire one first identity, one second identity and one multicast address from the SMF entity through a DL NASTransport message.

Then, after step S504, the SMF entity receives a request from a user equipment for activating a user equipment multicast service context established by the user equipment for activating the multicast service, the request for activating the user equipment multicast service context including the third identity and a multicast address of the multicast service, the third identity identifying the user equipment multicast service context. In step S505, the SMF entity determines a response to the request for activating the user equipment multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated. In step S506, the SMF entity obtains a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify the start of a multicast service session corresponding to the multicast service. In step S507, the SMF entity conducts the multicast service session and sends a response to the request for activating the user equipment multicast service context to the user equipment.

Step S504, step S505, step S506, and step S507 are similar to step S401, step S402, step S403, and step S404 of the method 400, respectively, and are not described again.

An exemplary flow of activating a multicast service and establishing a user plane corresponding to the multicast service in a wireless communication system according to an embodiment of the present disclosure will be described below with reference to fig. 6 to 7, where fig. 6 is an exemplary flow of activating a multicast service and establishing a user plane corresponding to the multicast service based on a first activation manner in a wireless communication system according to an embodiment of the present disclosure, and fig. 7 is an exemplary flow of activating a multicast service and establishing a user plane corresponding to the multicast service based on a second activation manner in a wireless communication system according to an embodiment of the present disclosure.

First, a specific procedure of activating a multicast service based on a first activation manner and establishing a user plane corresponding to the multicast service in a wireless communication system is described with reference to fig. 6.

As shown in fig. 6, in step 1, the UE may initiate a registration procedure with the network, and the AMF entity establishes a UE Policy Association (UE Policy Association) with the PCF entity.

Then, in step 2, in the process of establishing UE policy association between the AMF entity and the PCF entity, the PCF entity may provide a plurality of URSP rules to the UE through the AMF entity, where each URSP rule corresponds to one multicast service and each URSP rule at least includes a multicast address of the corresponding multicast service.

Then, in step 3, the UE wants to activate a multicast service, and may query the relevant URSP rule according to the multicast address of the multicast service to obtain a routing Descriptor (Route Selection Descriptor), where the routing Descriptor includes an S-NSSAI and a DNN.

Then, in step 4, the UE decides to activate the multicast service in the first activation mode (i.e. the mode that optimizes the conventional activation of the multicast service).

Then, in step 5, the UE initiates a multicast service activation procedure to the multicast address of the multicast service. The UE may allocate an MBS UE Context ID to the MBS UE Context established for activating the multicast service. In addition, the UE may send an uplink non-access Transport (UL NAS Transport) message to the AMF entity, the message including three cells, wherein the first cell is the S-NSSAI obtained in step 3, the second cell is the DNN obtained in step 3, and the third cell is a request for activating MBS UE Context, the request for activating MBS UE Context including an MBS UE Context ID corresponding to the multicast service and a multicast address of the multicast service. In addition, the UE may encapsulate the request for activating MBS UE Context using a session management Container (N1MBS SM Container) for multicast traffic associated with the N1 interface.

Then, in step 6, the AMF entity may select one SMF entity according to the received S-NSSAI and DNN, and send a Request (Nsmf _ mbssessessebsuecontext Request) for creating MBS UE Context related to the MBS session to the selected SMF entity through the Nsmf interface, the Request including S-NSSAI corresponding to the multicast service, DNN corresponding to the multicast service, the above-described "Request for activating MBS UE Context" encapsulated by N1MBS SM Context, and SUPI and GPSI of the UE and corresponding RAN ID. The SMF entity may record this RAN ID in the MBS UE Context of the UE.

Then, in step 7, the SMF entity may determine whether the UE can use the multicast service according to subscription data of the UE obtained from the UDM entity (the interaction of the SMF entity with the UDM entity is not shown in the figure). If the UE can use the multicast service, the SMF entity may determine the AF entity according to the received S-NSSAI, DNN, and multicast address. Then, the SMF entity may first send a notification (Nsmf _ mbsautionrequest notification) of the MBS authorization request to the NEF entity through the Nsmf interface, which may include S-NSSAI and DNN corresponding to the multicast service, UE private identity SUPI, UE public identity GPSI, multicast address of the multicast service, SMF ID, AF ID, and information (CGI, TAI, GUAMI, etc.) related to UE location. The SMF ID in this notification may be recorded by the AF entity for use when establishing the user plane for the MBS session. Furthermore, the AF ID in the notification may facilitate the NEF entity to determine the corresponding AF entity.

Then, in step 8, the NEF entity may send a notification (Nnef _ MBS authorization request notification) of the MBS authorization request to the corresponding AF entity according to the received AF ID through the Nnef interface, where the notification may include S-NSSAI and DNN corresponding to the multicast service, the common identity GPSI of the UE, the multicast address of the multicast service, the SMF ID, and information (CGI, TAI, GUAMI, etc.) related to the UE location.

Then, in step 9, the AF entity may feed back Response information (Nnef _ MBS authorization request notification Response) to the NEF entity through the Nnef interface, where the Response information includes a TMGI corresponding to the multicast service and a multicast service Session Start identifier (Session Start Indicator). The multicast service session start identifier is used for performing subsequent establishment of a user plane for the UE and corresponding to the multicast service.

Then, in step 10, the NEF entity may feed back Response information (Nsmf _ MBS authorization request notification Response) of the notification of the MBS authorization request to the SMF entity through the Nsmf interface, and the Response information may include the TMGI corresponding to the multicast service and the multicast service session start identifier.

Then, in step 11, the SMF entity may create MBS UE Context based on the above multicast address for the UE, and may then feed back a response message (Nsmf _ MBSSession _ creatembuecontextresponse) to the AMF entity as a response to the Nsmf _ MBSSession _ creatembuecontext Request in step 6 described above.

Then, in step 12, the AF entity may send a Request (Nnef _ MBS session start Request) for requesting to start a multicast service session to the NEF entity through the Nnef interface, where the Request may include a GPSI of the user equipment, a TMGI corresponding to the multicast service, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, an ID of the multicast service session, an expected duration of the multicast service session, and a data transmission time of the multicast service. The request includes the GPSI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE). In addition, the request includes a quality of service requirement of at least one data flow corresponding to the multicast service, so that the PCC technology is applied to the transmission of the multicast service data, and the transmission combination of the PCC and the multicast service data is realized.

Then, in step 13, the NEF entity may send a Request (Npcf _ MBS session start Request) for requesting start of a multicast service session to a corresponding PCF entity through an Npcf interface and according to an SMF ID, where the Request may include a SUPI of a user equipment, a TMGI corresponding to the multicast service, an SMF ID, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, an ID of a multicast service session, an expected duration of the multicast service session, and a data transfer time of the multicast service. The request includes the SUPI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE).

Then, in step 14, the PCF entity may send a Request (Nsmf _ MBS session start Request) for requesting start of a multicast service session to a corresponding SMF entity through the Nsmf interface and according to the SMF ID, where the Request may include the SUPI of the user equipment, the TMGI corresponding to the multicast service, the aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, the quality of service rule of the at least one data flow, the ID of the multicast service session, the expected duration of the multicast service session, and the data transmission time of the multicast service. The request includes the SUPI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE).

Then, in step 15, the SMF entity may determine a corresponding MBS UE Context according to the TMGI, and obtain the S-NSSAI, DNN, and multicast address included in the MBS UE Context according to the determined MBS UE Context. If not previously assigned to a UPF entity, the SMF entity may select a UPF entity from the plurality of UPF entities based on the acquired S-NSSAI, DNN, and multicast address. Then, the SMF entity may send a Request for requesting MBS Session Establishment (N4 MBS Session Establishment Request) to the selected UPF entity through the N4 interface. The request may include a multicast address for the multicast traffic, a quality of service enforcement rule for at least one data flow corresponding to the multicast traffic, and an aggregate maximum rate (e.g., AMBR) corresponding to the multicast traffic. The UPF entity may then establish a GTP user plane tunneling tree from the UPF entity to the RAN according to the multicast routing protocol based on the received request, so as to transmit data (e.g., service data corresponding to the multicast/broadcast service) that the UPF entity wants to send to the RAN in a tree-like GTP user plane tunnel. The UPF entity may then assign a tunnel multicast address for transmitting service data corresponding to the multicast/broadcast service. Specifically, the UPF entity may allocate a multicast address of a GTP user plane tunnel through the N3 interface to the multicast/broadcast service, and use the multicast address of the allocated GTP user plane tunnel as a tunnel multicast address (e.g., CN N3 tunnel multicast address). The UPF entity may then assign a sixth identity (e.g., CN N3C-TEID) to the multicast/broadcast service. The SMF entity may record the ID of the PCF entity, the ID of the UPF entity, the CN N3 tunnel multicast address corresponding to the multicast service, and the CN N3C-TEID in each MBS UE Context that has activated the multicast service. In addition, if the UPF entity and the CN N3 tunnel multicast address and the CNN 3C-TEID corresponding to the multicast service have been previously allocated, the CN N3 tunnel multicast address and the CN N3C-TEID corresponding to the multicast service may be recorded in the MBS UE Context of the UE, and this step need not be performed.

Then, in step 16, the SMF entity may send the first information (Namf _ Communication _ N1N2MessageTransfer) to the AMF entity through the Namf interface. The first information may include a Response (Activate MBS UE Context Response) activating the MBS UE Context, the Response activating the MBS UE Context may include a TMGI corresponding to the multicast service, and the SMF entity may encapsulate the "Response activating the MBS UE Context" using the N1MBS SM Context. In addition, the first information may further include a TMGI corresponding to the multicast service, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service stream identification and a quality of service profile corresponding to each data stream of the multicast service, a CN N3 tunnel multicast address corresponding to the multicast service, and a CN N3C-TEID. The SMF entity may encapsulate "TMGI corresponding to multicast service, quality of service flow identification and quality of service profile corresponding to each data flow of multicast service, CN N3 tunnel multicast address corresponding to multicast service, and CN N3C-TEID" using N2MBS SM Container.

Then, in step 17, the AMF entity may send a Request for requesting the Start of a multicast service Session (N2 MBS Session Start Request) to the RAN through an N2 interface. The request may include a downlink NAS transport (DL NASTransport) message, one element of which is the above described Response (active MBS UE Context Response) to Activate MBS UE Context encapsulated using N1MBS SMContainer. Through the downlink NAS Transport message, the AMF entity may instruct the RAN to directly send a DL NAS Transport message to the UE. The request may further include a TMGI corresponding to the multicast traffic, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast traffic, a multicast address for the multicast traffic, a quality of service flow identification and a quality of service profile corresponding to each data flow of the multicast traffic, a CN N3 tunnel multicast address corresponding to the multicast traffic, and a CN N3C-TEID.

Then, in step 18, the RAN can send the above-described DL NASTransport message to the UE through RRC signaling.

Then, in step 19, the RAN may send a Response to the request in step 17 to the AMF entity through the N2 interface (N2 MBS Session Start Response). The response may be an acknowledgement of the N2MBS Session Start Request sent by the AMF entity to the RAN as described in step 17.

The RAN may then allocate resources for transmitting multicast traffic data to its served UEs to support data streams with different quality of service requirements in step 20.

Then, in step 21, the RAN may join the transport group corresponding to the above-described CN N3 tunnel multicast address in order to receive multicast service data from the UPF entity.

Steps 20 and 21 may not be performed if the RAN has allocated resources for the multicast traffic.

Then, in step 22, the AMF entity may send notification information (Namf _ Communication _ N2MBSMessageNotify) to the SMF entity through the Namf interface. The notification information may be an acknowledgement of the information sent by the SMF entity to the AMF entity described in step 16 above.

Then, in step 23, the SMF entity may send a Response message (Nsmf _ MBS session start Response) to the PCF entity via the Nsmf interface in Response to the request sent by the PCF entity to the SMF entity described in step 14.

Then, in step 24, the PCF entity may send a Response message (Npcf _ MBS session start Response) to the NEF entity through the Npcf interface in Response to the request sent by the NEF entity to the PCF entity described in step 13.

Then, in step 25, the NEF entity may send a Response message (Nnef _ MBS session Response) to the AF entity through the Nnef interface in Response to the request sent by the AF entity to the NEF entity described in step 12 above.

Then, in step 26, the multicast service may be started. The AF entity may send a multicast packet with a destination IP address being a multicast address of the multicast service to a downstream UPF entity. The UPF entity may then send the multicast packet to the RAN by the transport layer multicast method described above. The RAN may then send the multicast packet to the UE via the resources allocated to the UE.

Next, a specific procedure of activating the multicast service based on the second activation manner and establishing the user plane corresponding to the multicast service in the wireless communication system is described with reference to fig. 7.

As shown in fig. 7, in step 1, the UE may perform steps 1 to 3 in fig. 6.

Then, in step 2, the UE decides to activate the multicast service in the second activation mode (i.e. compatible with the conventional mode of activating the multicast service).

Then, in step 3, the UE may send a PDU Session Establishment Request (PDU Session Establishment Request) to the network according to the S-NSSI and DNN obtained in step 1, where the PDU Session Establishment Request may include S-NSSAI and DNN corresponding to the multicast service. Then, the AMF entity may select one SMF entity from the plurality of SMF entities according to the S-NSSAI and the DNN corresponding to the multicast service. The selected SMF entity may then select a UPF entity from the plurality of UPF entities and assign an IP address to the UE.

Then, in step 4, the UE may send an IGMP Join packet to the network at the allocated IP address after the PDU session setup is completed. When IGMP version 1 or 2 is used, the destination IP address of the IGMP Join packet may be the multicast address of the multicast service. When IGMP version 3 is employed, the IGMP protocol portion of the IGMP Join packet may include the multicast address of the multicast traffic.

Then, in step 5, the UPF entity may report the multicast address corresponding to the IGMP Join packet to the SMF entity through an N4 session report message after detecting the IGMP Join packet according to the PDR configuration of the SMF entity.

Then, in step 6, the SMF entity decides to order the UE to activate the multicast service and sends a message (Namf _ Communication _ N1MessageTransfer) to the AMF entity through the Namf interface. The message may include information (Request MBS UE Context Activation) for requesting MBS UE Context Activation to instruct the UE to activate the multicast service. The information for requesting MBS UE Context activation may include S-NSSAI, DNN corresponding to a multicast service to be activated by the UE and a multicast address of the multicast service. The information for requesting MBS UE Context activation may be encapsulated using N1MBS SM Context. Furthermore, here, the S-NSSAI, DNN may be determined by step 3 described above, and the multicast address of the multicast service may be determined by step 5 described above. Since the user plane corresponding to the multicast service is not established in the process of activating the multicast service, the other response information does not include the N2MBS session container given to the RAN by the SMF entity.

Then, in step 7, the AMF entity may send a downlink NAS Transport message (N2 downlink NAS Transport) associated with the N2 interface to the RAN through the N2 interface, where the downlink NAS Transport message associated with the N2 interface may include a downlink NAS Transport (DL NAS Transport) message, and the DL NAS Transport message may include the above-described "Request MBS UE context information" encapsulated using the N1MBS SM Container. Through the downlink NAS Transport message related to the N2 interface, the AMF entity may instruct the RAN to directly send a DL NAS Transport message to the UE.

Then, in step 8, the RAN may send the DLNAS Transport message described above to the UE. Accordingly, the UE can acquire one S-NSSAI, one DNN, and one multicast address from the SMF entity through the DL NAS Transport message. The UE may determine whether the acquired multicast address coincides with the multicast address that the UE wants to join in step 4 and whether the acquired S-NSSAI and DNN coincide with the S-NSSAI and DNN when the UE establishes the PDU session in step 3. If the three are consistent, step 9 is executed.

Then, in step 9, steps 5 to 26 in fig. 6 may be performed.

Hereinafter, a UE corresponding to the method illustrated in fig. 2 according to an embodiment of the present disclosure is described with reference to fig. 8. Fig. 8 is a schematic structural diagram of a UE800 according to an embodiment of the present disclosure. Since the function of the UE800 is the same as the details of the method described above with reference to fig. 2, a detailed description of the same is omitted here for the sake of simplicity. As shown in fig. 8, the UE800 includes: a determining unit 810 configured to determine an activation manner for activating the multicast service; an activating unit 820 configured to activate the multicast service according to the determined activation manner and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed in an activation process of the multicast service; and a receiving unit 830 configured to receive service data corresponding to the multicast service. In addition to these three units, the UE800 may include other components, however, since these components are not relevant to the contents of the embodiments of the present disclosure, illustration and description thereof are omitted herein.

In this disclosure, the activation manner determined by the determining unit 810 may be a first activation manner or a second activation manner.

In the present disclosure, the determining unit 810 may determine an activation manner for activating the multicast service according to its own attribute. The attributes described herein may refer to the UE's support capabilities for various applications. For example, when the UE supports only a mobile application or the UE does not require an IP data transmission function, the UE may determine that an activation manner for activating the multicast service is the first activation manner. For example, when the UE needs to support an IP-based application, the UE may determine that the activation manner for activating the multicast service is the second activation manner.

It should be appreciated that the determining unit 810 may also determine the activation manner for activating the multicast service according to other manners, which is not limited by the present disclosure.

Further, according to an example of the present disclosure, the determining unit 810 may determine a first identifier and a second identifier corresponding to the multicast service, where the first identifier and the second identifier are used for an access and mobility management function entity to select the session management function entity. Specifically, the first identifier may be used to identify a network segment corresponding to the multicast service. For example, the first identifier may be Single Network Slice selection assistance Information (S-NSSAI). In addition, the second identifier may be used to identify a data network corresponding to the multicast service. For example, the second identification may be a Data Network Name (DNN).

In this example, the determining unit 810 may determine the first identity and the second identity corresponding to the multicast service in the following manner.

Specifically, the receiving unit 830 may obtain, from a Policy Control Function (PCF) entity, a user equipment routing Policy (UE Route Selection Policy Rule, URSP) Rule corresponding to each multicast service of the at least one multicast service, where each user equipment routing Policy Rule at least includes a multicast address of the corresponding multicast service. For example, first, the UE may initiate a registration procedure with the network; then, in the process of establishing UE policy association (UE policy association) between the AMF entity and the PCF entity, the PCF entity may provide the UE with the URSP rules corresponding to each of the at least one multicast service through the AMF entity, and accordingly, the UE may obtain the URSP rules corresponding to each of the at least one multicast service from the PCF entity through the AMF entity.

Then, the determining unit 810 may determine a user equipment routing policy rule corresponding to the multicast service according to the multicast address of the multicast service. For example, when the UE wants to activate a multicast service, the determining unit 810 may determine the URSP rule corresponding to the multicast service according to a multicast address of the multicast service.

Then, the determining unit 810 may determine the first identifier and the second identifier corresponding to the multicast service according to the determined user equipment routing policy rule. For example, the UE may obtain a routing Descriptor (Route Selection Descriptor) according to the URSP rule corresponding to the multicast service, where the routing Descriptor includes a first identifier and a second identifier; then, the UE takes the first identity and the second identity included in the routing descriptor as the first identity and the second identity corresponding to the multicast service.

In the present disclosure, the activation unit 820 activates the multicast service according to the determined activation manner and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed during the activation of the multicast service. That is, the user plane corresponding to the multicast service is established during the activation of the multicast service.

According to an example of the present disclosure, when the activation manner determined by the determining unit 810 is a first activation manner, the activating unit 820 activates the multicast service according to the first activation manner and through at least a session management function entity. In this example, the UE800 may further include a transmitting unit 840.

In particular, the activation unit 820 may determine a third identification identifying a user device multicast service context established for activating the multicast service. For example, the UE may assign an Identification (ID) to the UE multicast service context. The "user device multicast service context established for activating the multicast service" described herein may also be referred to as a user device multicast service context (MBS UEContext) for multicast services. Accordingly, the third identifier may also be referred to as an identifier of a user equipment multicast service Context (MBS UE Context ID) for the multicast service.

Then, the sending unit 840 sends, to the session management function entity, a request for activating the user equipment multicast service context, where the request for activating the user equipment multicast service context includes the third identifier and a multicast address of the multicast service. For example, the sending unit 840 may send a request for activating the user equipment multicast service context to the session management function entity via the access and mobility management function entity.

Specifically, first, the sending unit 840 may send an uplink Non-access stratum (NAS) Transport (UL NAS Transport) message to the AMF entity, where the UL NAS Transport message includes at least three cells, a first cell is a first identifier corresponding to the multicast service, a second cell is a second identifier corresponding to the multicast service, and a third cell is a request for activating MBS UE Context. The Request for activating MBS UE Context may be denoted as Active MBS UE Context Request and may include a third identity corresponding to the multicast service and a multicast address of the multicast service. In an example where the first identifier is an S-NSSAI, the second identifier is a DNN, and the third identifier is an MBS UE Context ID, the UL NAS Transport message sent by the UE to the AMF entity may include three cells, where the first cell is an S-NSSAI corresponding to the multicast service, the second cell is a DNN corresponding to the multicast service, and the third cell is a request for activating the MBS UE Context, where the request for activating the MBS UE Context includes the MBS UE Context ID corresponding to the multicast service and a multicast address of the multicast service.

In the present disclosure, the transmitting unit 840 may encapsulate the "request for activating MBS UEContext" described herein using a specific format. For example, the specific format may be a session management Container (N1MBS SM Container) for multicast traffic associated with the N1 interface.

The AMF entity may then send a request to the corresponding SMF entity over the Nsmf interface, which may be used to request the creation of an MBS UE Context related to the MBS session. This Request may be denoted as Nsmf _ mbssessioncreatembuecontext Request. The request may include a first identifier corresponding to the multicast service, a second identifier, and the "request to activate an MBSUE Context" described above. In an example where the first identity is an S-NSSAI, the second identity is a DNN, and the third identity is an MBS UE Context ID, the AMF entity may send a request to the SMF entity over the Nsmf interface, which may include the S-NSSAI corresponding to the multicast service, the DNN corresponding to the multicast service, and the "request to activate MBS UE Context" described above.

Thereafter, the SMF entity may record the received rand in the MBS UE Context of the UE, so that the SMF entity acquires the identities of the serving base stations of all user devices that activate the multicast service through the SMF entity. Furthermore, the SMF entity determines a fourth identity corresponding to the multicast service according to the received information, wherein the fourth identity is used for the user equipment to determine whether the multicast service is activated and is an identity allocated to the multicast service by an Application Function (AF) entity, and the SMF entity feeds back the fourth identity to the UE. These operations are described in detail in the methods performed by the SMF entity described below in connection with fig. 9-10.

Then, the receiving unit 830 receives a response to the request for activating the user equipment multicast service context from the session management function entity, the response including a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated. In particular, the UE may receive a response to the request for activation of the user equipment multicast traffic context from the session management function entity via the serving base station of the user equipment and the access and mobility management function entity.

Specifically, first, the session management function entity may transmit first information to the access and mobility management function entity, wherein the first information includes a response to the request for activating the user equipment multicast service context and information related to the multicast service session. Further, the "information related to the multicast service session" described herein may include at least the fourth identifier, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service flow identifier and a quality of service profile corresponding to each data flow of the multicast service, a tunnel multicast address corresponding to the multicast service, and a sixth identifier. The "tunnel Multicast Address" described herein may be a tunnel Multicast Address (Transport IP Multicast Address), and may be referred to as a CN N3 tunnel Multicast Address. The "sixth identification" described herein may be a Common-Tunnel End point identification (C-TEID) and may be referred to as CN N3C-TEID. The method performed by the SMF entity will be described in detail below in connection with fig. 4-5.

Accordingly, the receiving unit 830 is capable of obtaining a response to the request for activating the user equipment multicast service context from the session management function entity.

A specific example is given below in which the receiving unit 830 obtains a response to the request for activating the user equipment multicast service context from the session management function entity.

The RAN may then send the DL NAS Transport message described above to the UE. Accordingly, the receiving unit 830 may acquire the fourth identifier corresponding to the multicast service through the DL NAS Transport message. In an example where the fourth identity is a TMGI, the UE may acquire the TMGI corresponding to the multicast service through a DL NAS Transport message.

According to an example of the present disclosure, when the activation manner determined by the determining unit 810 is a second activation manner, the activating unit 820 activates the multicast service according to the second activation manner and through at least a session management function entity. In this example, the UE800 may further include a transmitting unit 840.

Specifically, the activating unit 820 may obtain an internet protocol address (IP address) from the session management function entity according to the first identifier and the second identifier corresponding to the multicast service. For example, the UE may select the session management function entity and establish a pdu session according to the first identifier and the second identifier, and obtain an ip address from the session management function entity. In an example where the first identity is S-NSSAI and the second identity is DNN, the UE may send a PDU session setup request to the network according to S-NSSAI and DNN corresponding to the multicast service, where the PDU session setup request may include S-NSSAI and DNN corresponding to the multicast service. Then, the AMF entity may select one SMF entity from the plurality of SMF entities according to the S-NSSAI and the DNN corresponding to the multicast service. The selected SMF entity may then select a UPF entity from the plurality of UPF entities and assign an IP address to the UE.

Then, the transmitting unit 840 may transmit a packet to a network according to the acquired internet protocol address so that a User Plane Function (UPF) entity in the network acquires the packet. For example, the UE may send a data packet to the network according to the acquired internet protocol address so that a user plane functional entity participating in the establishment of the pdu session in the network acquires the data packet. Further, the data packet is used to indicate a multicast service that the user device wants to activate. The destination address of the data packet is a multicast address of the multicast service, or the protocol portion of the data packet includes the multicast address of the multicast service. For example, after step S3021 ″, the UE may transmit an IGMP Join packet to the network at the allocated IP address after the PDU session setup is completed. When IGMP version 1 or 2 is used, the destination IP address of the IGMP Join packet may be the multicast address of the multicast service. When IGMP version 3 is employed, the IGMP protocol portion of the IGMP Join packet may include the multicast address of the multicast traffic.

The activation unit 820 may then obtain a first identity, a second identity and a multicast address from the session management function entity.

Specifically, the SMF entity may obtain a multicast address of a multicast service to be activated by the user equipment from the user plane functional entity. For example, the UPF entity may be configured according to a Packet Detection Rule (PDR) of the SMF entity, and report a multicast address corresponding to the IGMP Join packet to the SMF entity after detecting the IGMP Join packet (for example, report the multicast address corresponding to the IGMP Join packet through an N4 session report message).

The AMF entity may then send a downlink NAS transport message associated with the N2 interface to the RAN over the N2 interface. This downlink NAS transport message related to the N2 interface may be denoted as N2 downlink NASTransport. The downlink NAS Transport message associated with the N2 interface may include a downlink NAS Transport (DLNAS Transport) message, which may include the "Request MBS UE Context Activation" encapsulated using N1MBS SMContainer described above. Through this downlink NAS Transport message related to the N2 interface, the AMF entity can instruct the RAN to send the DL NAS Transport bearer to the UE directly.

Thereafter, the activation unit 820 may determine whether the obtained first identifier is the same as the determined first identifier, whether the obtained second identifier is the same as the determined second identifier, and whether the obtained multicast address is the same as a multicast address of the multicast service. For example, the Activation unit 820 may determine, according to the DL NAS Transport message received from the RAN, whether the multicast address in the "Request MBS UE Context Activation" encapsulated using N1MBS SM Container is the same as the multicast address of the multicast service that the UE wants to activate, and whether the S-NSSAI and DNN in the "Request MBS UE Context Activation" encapsulated using N1MBS SM Container are the same as the S-NSSAI and DNN when the PDU session is established.

When the activation unit 820 determines that the obtained first identifier is different from the determined first identifier, and/or that the obtained second identifier is different from the determined second identifier, and/or that the obtained multicast address is different from the multicast address of the multicast service, the UE cannot activate the multicast service. In contrast, when the activation unit 820 determines that the obtained first identifier is the same as the determined first identifier, the obtained second identifier is the same as the determined second identifier, and the obtained multicast address is the same as the multicast address of the multicast service, the activation unit 820 may activate the multicast service.

In particular, the determining unit 810 may determine a third identification identifying a user device multicast service context established for activating the multicast service. Then, the sending unit 840 may send, to the session management function entity, a request for activating the user equipment multicast service context, where the request for activating the user equipment multicast service context includes the third identifier and a multicast address of the multicast service. Then, the receiving unit 830 may receive a response to the request for activating the user equipment multicast service context from the session management function entity, the response including a fourth identification corresponding to the multicast service, where the fourth identification is used for the user equipment to determine whether the multicast service is activated.

Then, the receiving unit 830 receives service data corresponding to the multicast service. For example, when the user equipment activates the multicast service and a multicast service session corresponding to the multicast service is successfully started, the AF entity may transmit multicast service data (e.g., a multicast service data packet) whose destination IP address is a multicast address of the multicast service to a downstream UPF entity. The UPF entity then sends the multicast traffic data to the RAN. The RAN may then transmit the multicast traffic data to the UE via the resources allocated to the UE.

According to the user equipment of the embodiment of the disclosure, the user equipment can determine an activation mode for activating the multicast service, and activate the multicast service according to the determined activation mode and at least through a session management function entity in the network, so that the conventional process for activating the multicast service is optimized or compatible with the conventional process for activating the multicast service. In addition, in the process of activating the multicast service, a multicast service session corresponding to the multicast service is started, so that a user plane corresponding to the multicast service is established in the process of activating the multicast service.

Hereinafter, an SMF entity corresponding to the method illustrated in fig. 4 according to an embodiment of the present disclosure is described with reference to fig. 9. Fig. 9 is a schematic structural diagram of an SMF entity 900 according to an embodiment of the present disclosure. Since the function of the SMF entity 900 is the same as the details of the method described above with reference to fig. 4, a detailed description of the same is omitted here for the sake of simplicity. As shown in fig. 9, SMF entity 900 includes: a receiving unit 910 configured to receive, from a user equipment, a request for activating a user equipment multicast service context established by the user equipment for activating a multicast service, the request for activating the user equipment multicast service context including the third identifier and a multicast address of the multicast service, the third identifier being used for identifying the user equipment multicast service context; a determining unit 920 configured to determine a response to the request for activating the user equipment multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated; an obtaining unit 930 configured to obtain a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify a start of a multicast service session corresponding to the multicast service; a control unit 940 configured to conduct the multicast service session; and a transmitting unit 950 configured to transmit the response to the user equipment. In addition to these five units, SMF entity 900 may include other components, however, since these components are not relevant to the content of the embodiments of the present disclosure, illustration and description thereof are omitted herein.

As shown in fig. 9, the receiving unit 910 receives, from a user equipment, a request for activating a user equipment multicast service context established by the user equipment for activating the multicast service, where the request for activating the user equipment multicast service context includes the third identifier and a multicast address of the multicast service, and the third identifier is used for identifying the user equipment multicast service context.

Further, according to an example of the present disclosure, the receiving unit 910 may record the identities of the serving base stations of the user equipment in the user equipment multicast service context, so that the SMF entity obtains the identities of the serving base stations of all user equipment that activate the multicast service through the SMF entity for use in establishing the user plane of the MBS session. For example, the receiving unit 910 may record the received RAN ID in the MBS UE Context of the UE.

Returning to fig. 9, the determining unit 920 determines a response to the request for activating the multicast service context of the user equipment, wherein the response includes a fourth identifier corresponding to the multicast service, wherein the fourth identifier is used for the user equipment to determine whether the multicast service is activated. For example, the determining unit 920 determines a fourth identifier corresponding to the multicast service according to at least the first identifier, the second identifier, and a multicast address of the multicast service, where the fourth identifier is an identifier allocated to the multicast service by an application function entity.

Specifically, the determining unit 920 may determine whether the user equipment is capable of using the multicast service. For example, the SMF entity may obtain subscription Data of the UE from a Unified Data Management (UDM) entity to determine whether the UE is subscribed to the multicast service. If the UE subscribes to the multicast service, the SMF entity may determine that the UE is capable of using the multicast service. If the UE does not subscribe to the multicast service, the SMF entity may determine that the UE cannot use the multicast service.

When the determining unit 920 determines that the UE can use the multicast service, the transmitting unit 950 transmits a notification to the application function entity, wherein the notification is a notification of the multicast service authorization request. The notification comprises at least the first identity, the second identity, a multicast address of the multicast service, and an identity of the session management function entity. The "identifier of the session management function entity" is to facilitate the application function entity to obtain the session management function entity involved by all user devices that are to activate the multicast service when activating the multicast service, so as to be used when subsequently establishing a user plane corresponding to the multicast service.

In particular, the sending unit 950 may send the notification directly to the application function entity. For example, the SMF entity may determine the corresponding AF entity according to the first identifier, the second identifier, and the multicast address of the multicast service. The SMF entity may then send a notification to the determined AF entity. The notification may comprise the first identity, the second identity, the private identity and the public identity of the user device, a multicast address of the multicast service, and an identity of the session management function entity (e.g. the SMF ID of the SMF entity).

Alternatively, the sending unit 950 may send the notification to the application function entity via the network openness function entity.

In an example where the sending unit 950 sends the notification to the application function entity via the network openness function entity, first, the sending unit 950 may send a notification to the network openness function entity, where the notification may include the first Identifier, the second Identifier, the private Identifier and the Public Identifier (e.g., General Public Subscription Identifier (GPSI)), the multicast address of the multicast service, the Identifier of the session management function entity, and the Identifier of the application function entity (e.g., the AF ID of the AF entity determined by the SMF entity), so that the network openness function entity sends another notification to the application function entity according to the Identifier of the application function entity. The further notification may comprise the first identity, said second identity, a private identity and a public identity of said user device, a multicast address of said multicast service, and an identity of said session management function node entity.

Thereafter, the AF entity may record the received SMF ID for use in establishing the user plane for the MBS session. In addition, the AF entity may further determine a fourth identifier corresponding to the multicast service. The fourth identifier described herein may be a Temporary Mobile Group Identity (TMGI) assigned by the AF entity to the multicast service activated based on the multicast address.

Accordingly, the receiving unit 910 may receive a response to the notification from the application function entity, wherein the response to the notification includes a fourth identifier corresponding to the multicast service, so as to obtain the fourth identifier corresponding to the multicast service from the application function entity. In an example where the fourth identifier is a TMGI, receiving unit 910 may directly acquire the TMGI corresponding to the multicast service from an AF entity, or receiving unit 910 may acquire the TMGI corresponding to the multicast service from the AF entity via a NEF entity.

Returning to fig. 9, the obtaining unit 930 obtains a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify the start of a multicast service session corresponding to the multicast service. The fifth identifier may be a multicast service Session Start identifier (Session Start Indicator) to Start a multicast service Session, so as to establish a user plane corresponding to the multicast service. The obtaining unit 930 may operate simultaneously with the determining unit 920 described above, or may operate after the obtaining unit 930 operates.

In an example where the obtaining unit 930 operates simultaneously with the determining unit 920, when the receiving unit 910 receives a response to the request for activating the multicast service context of the user equipment from the application function entity, the receiving unit 910 may further receive a fifth identifier corresponding to the multicast service from the application function entity. For example, the receiving unit 910 may receive a response information from the application function entity, and the response information includes both a response to the request for activating the user equipment multicast service context and a fifth identification corresponding to the multicast service.

According to an example of the present disclosure, the receiving unit 910 may receive a response to the request for activating the user equipment multicast service context and a fifth identification corresponding to the multicast service directly from an application function entity. For example, when the AF entity receives a message from the SMF entity, the response to the request for activating the user equipment multicast service context, i.e. the fourth identity, may be the TMGI. Accordingly, the AF entity may feed back Response information to the notification of the MBS authorization request to the SMF entity through the Nsmf interface, where the Response information may be denoted as Nsmf _ MBS authorization request Response, and the Response information may include the TMGI corresponding to the multicast service and the multicast service session start identifier.

According to another example of the present disclosure, the receiving unit 910 may receive, from the application function entity via the network openness function entity, a response to the request for activating the user equipment multicast service context and a fifth identification corresponding to the multicast service. For example, when the AF entity receives a message from the NEF entity, the response to the request for activating the user equipment multicast service context, i.e., the fourth identity, may be the TMGI. Accordingly, the AF entity may feed back Response information to the notification of the MBS authorization request to the NEF entity through the Nnef interface, where the Response information may be denoted as Nnef mbsauuthorizationrequest notification Response, and the Response information may include a TMGI corresponding to the multicast service and a multicast service session start identifier. Then, the NEF entity may feed back, to the SMF entity through the Nsmf interface, Response information for notification of the MBS authorization request, which may be denoted as Nsmf _ mbsauuthorization request notification Response, and which may include a TMGI corresponding to the multicast service and a multicast service session start identifier.

Thereafter, the SMF entity may create MBS UE Context based on the multicast address for the UE, and then may feed back a response message to the AMF entity, where the response message may be a response to the Nsmf _ MBSSession _ creatembbsuecontext Request described above. The Response information may be an acknowledgement to the Nsmf _ MBSSession _ creatembuecontext Request described above, which may be denoted as Nsmf _ MBSSession _ creatembuecontext Response.

Then, the control unit 940 performs the multicast service session, and the transmitting unit 950 transmits a response to the request for activating the user equipment multicast service context to the user equipment.

First, the receiving unit 910 receives a first request from a policy control function entity, wherein the first request is for requesting a start of a multicast service Session (MBS Session). The first request may include at least a first identification of the user device, a fourth identification corresponding to multicast traffic, a quality of service rule for at least one data flow corresponding to the multicast traffic, and an identification of the multicast traffic session. In addition, the first request may further include other information, such as an expected Duration (expected Session Duration) of the multicast service Session and a data transmission time (time to MBS data transfer) of the multicast service.

Further, according to an example of the present disclosure, the first request is determined by the policy control function entity according to a second request received from a network openness function entity or an application function entity, the second request for the network openness function entity or the application function entity to request a start of a multicast traffic session to the policy control function entity. The second request may include at least a first identification of the user device, the fourth identification, an identification of the session management function entity, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, and an identification of the multicast service session. The second request may also include other information, such as an expected duration of the multicast service session, and a data transmission time for the multicast service.

Thereafter, the control unit 940 may generate a quality of service Flow identifier (QoS Flow Identity, QFI), a quality of service Profile (QoS Profile), and a quality of service enforcement Rule (QER) corresponding to each data Flow according to the quality of service Rule of each data Flow of the at least one data Flow corresponding to the multicast service. In the present disclosure, the quality of service stream identification corresponding to each data stream may also be referred to as a quality of service stream identification (MBSQFI) for multicast traffic. Further, the quality of service enforcement rules described herein may be similar to conventional N4QER rules.

Then, the control unit 940 may select one user plane functional entity according to the fourth identity. In an example where the fourth identifier is a TMGI, the SMF entity may determine a corresponding MBS UE Context according to the TMGI, and obtain the S-NSSAI, DNN, and multicast address included in the MBS UE Context according to the determined MBS UE Context. The SMF entity may then select a UPF entity from the plurality of UPF entities based on the obtained S-NSSAI, DNN, and multicast address.

Then, the sending unit 950 may send a fourth request to the selected user plane functional entity, wherein the fourth request is used for establishing transmission resources of the multicast service session. The fourth request includes at least a multicast address of the multicast traffic, a quality of service enforcement rule for at least one data flow corresponding to the multicast traffic, and an aggregated maximum rate (e.g., AMBR) corresponding to the multicast traffic. For example, the SMF entity may send a request for requesting MBS Session establishment, which may be denoted as N4 MBS Session establishment request, to the selected UPF entity through the N4 interface.

Then, the receiving unit 910 may obtain, from the selected user plane functional entity, a response to the fourth request, where the response to the fourth request includes a tunnel multicast address allocated by the selected user plane functional entity for transmitting traffic data corresponding to the multicast traffic, and a sixth identifier corresponding to the tunnel multicast address, where the tunnel multicast address is used for multicast tunneling between network entities (e.g., multicast tunneling between a UPF entity and a RAN), and the sixth identifier is used for identifying a transmission tunnel (e.g., a transmission tunnel related to GTP) of the multicast traffic.

Accordingly, the receiving unit 910 may obtain a tunnel multicast address corresponding to the multicast service from the selected UPF entity and obtain a sixth identity corresponding to the multicast service from the selected user plane functional entity. Then, the SMF entity may record the tunnel multicast address and the sixth identity in a multicast service context of each user equipment that has activated the multicast service.

Then, the sending unit 950 may send first information to the access and mobility management function entity, wherein the first information includes the response and the information related to the multicast service session, so that the access and mobility management function entity sends a fifth request to the corresponding serving base station according to the information related to the multicast service session, and sends the response to the user equipment via the corresponding serving base station, wherein the fifth request is used for requesting the start of the multicast service session. The "information related to the multicast service session" described herein includes at least the fourth identification, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service flow identification and a quality of service profile corresponding to each data flow, the tunnel multicast address, and the sixth identification.

Through the above operation, not only the user plane corresponding to the multicast service is established, but also the UE activates the multicast service.

Thereafter, the serving base station of the UE may send a response to the fifth request to the access and mobility management functional entity. For example, the RAN may send a response to the fifth request to the AMF entity through the N2 interface in response to the above-described fifth request sent by the AMF entity to the RAN for requesting the MBS session start. The Response may be an acknowledgement to the N2MBS Session Start Request sent by the AMF entity to the RAN described above and may be denoted as N2 mbssessing Start Response.

The AMF entity may then send a notification message to the SMF entity to notify the first message sent by the sending unit 950 to the AMF entity as described above. For example, the AMF entity may send the notification information to the SMF entity over the Namf interface. The notification information may be an acknowledgement of the first information transmitted by the transmitting unit 950 to the AMF entity. The notification information may be an MBS message transmission related to the N2 interface, which may be denoted as Namf _ Communication _ N2MBSMessageNotify, communicated over the Namf interface. Accordingly, the receiving unit 910 receives notification information for the first information from the AMF entity.

Then, the sending unit 950 may send a response message to the PCF entity via the Nsmf interface in response to the first request sent by the PCF entity to the SMF entity. For example, the Response information may be an acknowledgement of "Nsmf _ MBS session start Request" transmitted by the PCF entity to the SMF entity described in step S4041, and may be denoted as Nsmf _ mbssessuonstart Response.

Furthermore, the PCF entity may then send a response message to the NEF entity over the Npcf interface in response to the second request sent by the NEF entity to the PCF entity as described in step S4041. For example, the Response information may be an acknowledgement of "Npcf _ MBS session start Request" transmitted by the NEF entity to the PCF entity described in step S4041, and may be denoted as Npcf _ MBS session Response.

According to the session management functional entity of the embodiment of the disclosure, in the process of activating the multicast service, the session management functional entity may receive, from the user device, the third identifier corresponding to the multicast service to be activated by the user device and the multicast address of the multicast service, and determine, according to at least these pieces of information, the fourth identifier and the fifth identifier corresponding to the multicast service, so that the multicast service session corresponding to the multicast service can be performed according to the fifth identifier to establish the user plane corresponding to the multicast service, and the fourth identifier is fed back to the user device so that the user device activates the multicast service, thereby achieving establishment of the user plane corresponding to the multicast service in the process of activating the multicast service.

Hereinafter, an SMF entity corresponding to the method illustrated in fig. 5 according to an embodiment of the present disclosure is described with reference to fig. 10. Fig. 10 is a schematic structural diagram of an SMF entity 1000 according to an embodiment of the present disclosure. Since the function of the SMF entity 1000 is the same as the details of the method described above with reference to fig. 5, a detailed description of the same is omitted here for the sake of simplicity. As shown in fig. 10, the SMF entity 1000 includes: an assigning unit 1010 configured to establish a pdu session and assign an ip address to the user equipment; an obtaining unit 1020 configured to obtain, from a user plane function entity participating in the establishment of the protocol data unit session, a multicast address of a multicast service to be activated by the user equipment, wherein the multicast address is obtained after the user equipment sends a packet to a network including the user plane function entity according to the internet protocol address, wherein the packet indicates the multicast service that the user equipment wants to activate; a transmitting unit 1030 configured to transmit, to the user device, a request for instructing the user device to activate the multicast service, wherein the request for instructing the user device to activate the multicast service includes a first identifier corresponding to a multicast service to be activated by the user device, a second identifier, and a multicast address of the multicast service; a receiving unit 1040 configured to receive, from a user equipment, a request for activating a user equipment multicast service context established by the user equipment for activating a multicast service, the request for activating the user equipment multicast service context including the third identifier and a multicast address of the multicast service, the third identifier being used for identifying the user equipment multicast service context; a determining unit 1050 configured to determine a response to the request for activating the user equipment multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated; an obtaining unit 1020, further configured to obtain a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify a start of a multicast service session corresponding to the multicast service; a control unit 1060 configured to conduct the multicast service session; and a transmitting unit 1030 further configured to transmit the response to the user equipment. SMF entity 1000 may include other components in addition to these six units, however, since these components are not relevant to the contents of the embodiments of the present disclosure, illustration and description thereof are omitted herein.

As shown in fig. 10, the allocating unit 1010 may establish a protocol data unit session and allocate an internet protocol address (IP address) to the user device. For example, in an example where the first identity is S-NSSAI and the second identity is DNN, the UE may send a PDU session setup request to the network according to S-NSSAI and DNN corresponding to the multicast service, which may include S-NSSAI and DNN corresponding to the multicast service. Then, the AMF entity may select one SMF entity from the plurality of SMF entities according to the S-NSSAI and the DNN corresponding to the multicast service. The selected SMF entity may then select a UPF entity from the plurality of UPF entities and assign an IP address to the UE.

The obtaining unit 1020 may obtain, from a user plane functional entity participating in the establishment of the pdu session, a multicast address of a multicast service to be activated by the user equipment, where the multicast address is obtained after the user equipment sends a packet to a network including the user plane functional entity according to the internet protocol address, where the packet is used to indicate the multicast service that the user equipment wants to activate, a destination address of the packet is a multicast address of the multicast service, or a protocol portion of the packet includes the multicast address of the multicast service.

Accordingly, the obtaining unit 1020 may obtain the multicast address of the multicast service to be activated by the user equipment from the user plane functional entity. For example, the UPF entity may be configured according to a Packet Detection Rule (PDR) of the SMF entity, and report a multicast address corresponding to the IGMP Join packet to the SMF entity after detecting the IGMP Join packet (for example, report the multicast address corresponding to the IGMP Join packet through an N4 session report message).

When the SMF entity decides to instruct the user equipment to activate the multicast service, the transmitting unit 1030 may transmit, to the user equipment, a request for instructing the user equipment to activate the multicast service, where the request for instructing the user equipment to activate the multicast service includes a first identifier corresponding to the multicast service to be activated by the user equipment, a second identifier, and a multicast address of the multicast service. For example, the SMF entity may send a request to the user equipment via an access and mobility management function entity for instructing the user equipment to activate the multicast service.

For example, the sending unit 1030 may send a message to the AMF entity through the Namf interface, and the message may be transmitted through a message transfer related to the N1 interface, which may be denoted as Namf _ Communication _ N1MessageTransfer, communicated through the Namf interface. The message may include a request for instructing the user device to activate the multicast service. For example, the request for instructing the user equipment to activate the multicast service may be information for requesting MBS UE Context activation to instruct UEs to activate the multicast service. The information for requesting MBS UE Context activation may include S-NSSAI, DNN corresponding to a multicast service to be activated by the user equipment and a multicast address of the multicast service, and the information for requesting MBS UE Context activation may be represented as Request MBS UE Context. Furthermore, the "Request MBS UE Context Activation" described herein may be encapsulated with the specific format described above (e.g., N1MBS SM Container).

Thereafter, the AMF entity may send a downlink NAS transport message associated with the N2 interface to the RAN over the N2 interface. This downlink NAS transport message related to the N2 interface may be denoted as N2 downlink NASTransport. The downlink NAS Transport message associated with the N2 interface may include a downlink NAS Transport (DLNAS Transport) message, which may include the "Request MBS UE Context Activation" encapsulated using N1MBS SMContainer described above. Through the downlink NAS Transport message related to the N2 interface, the AMF entity may instruct the RAN to directly send a DL NAS Transport message to the UE. The RAN may then send the DL NAS Transport message described above to the UE. Accordingly, the UE can acquire one first identity, one second identity and one multicast address from the SMF entity through a DL NASTransport message.

Then, the receiving unit 1040 may receive, from the user device, a request for activating a user device multicast service context established by the user device for activating the multicast service, where the request for activating the user device multicast service context includes the third identifier and a multicast address of the multicast service, and the third identifier is used for identifying the user device multicast service context. The determining unit 1050 determines a response to the request for activating the user device multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user device to determine whether the multicast service is activated. The obtaining unit 1020 obtains a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify a start of a multicast service session corresponding to the multicast service. The control unit 1060 conducts the multicast service session and the sending unit 1030 sends a response to the user device for the request for activating the user device multicast service context.

The operations performed by the acquiring unit 1020, the transmitting unit 1030, the receiving unit 1040, the determining unit 1050, and the controlling unit 1060 are similar to the operations performed by the acquiring unit 930, the transmitting unit 950, the receiving unit 910, the determining unit 920, and the controlling unit 940 in fig. 9, respectively, and are not described again here.

The principles of the above-described embodiments are implemented based on the architecture of the wireless communication system shown in fig. 1. According to another implementation of the present disclosure, the principles of the above embodiments may also be implemented based on other architectures of wireless communication systems. Fig. 11 shows a schematic diagram of an architecture of another wireless communication system in which the principles of the disclosed embodiments may be applied.

Specifically, the wireless communication system 1100 includes a first type Application Function (AF) entity 1101, a Network open Function (NEF) entity 1102, a Multicast/Broadcast Service Function (MBSF) entity 1103, a Policy Control Function (PCF) entity 1104, a first type Session Management Function (SMF) entity 1105, a first type Access and mobility management Function (Access and mobility Function, AMF) entity 1106, a Multicast/Broadcast Service User Plane (Multicast/Broadcast Service, MBSU 1110) entity 1107, a first type User Plane Function (User Plane Function, UPF) entity, and a Radio Access Network (RAN) entity 1109, wherein the first type Application Function (AF) entity, the Network open Function (NEF) entity 1102, the first type Session management Function (smsf) entity 1103, the first type Access and mobility management Function (Access and mobility management Function, AMF) entity 1106, the first type Access Network (RAN) entity, the first type Access Network Function (apf) entity, the first type Access Network Function (PCF) entity, the first type Access Network Function (PCF) entity, the PCF entity, the first type management Function (AMF) entity 1104, whereas the MBSU entity 1107 and the first type UPF entity 1108 belong to entities of the user plane.

In the present disclosure, the first type AF entity 1101 may provide service data (e.g., MBS service data) and support the provision of the service data to downstream entities in the network in a multicast/broadcast manner, and thus may be referred to as an MBS AF, or MBS-AF, or MB-AF, or M-AF entity. The first type of SMF entity 1105 is an SMF entity that supports multicast/broadcast services and, therefore, may be referred to as an MBS SMF, or MBS-SMF, or MB-SMF, or M-SMF entity. The first type AMF entity 1106 is an AMF entity supporting a multicast/broadcast service, and thus, may be referred to as an mbamf, or an MBS-AMF, or an MB-AMF, or an M-AMF entity. The first type UPF entity 1108 is a UPF entity that supports multicast/broadcast services and, therefore, may be referred to as an MBS UPF, or MBS-UPF, or MB-UPF, or M-UPF entity. For convenience, these terms may sometimes be used interchangeably.

In addition, the UE1110 may be connected to the RAN 1109 through a Uu interface. The RAN 1109 may be connected to the first-type AMF entity 1106 through an N2 interface and to the first-type UPF entity 1108 through an MB-N3 interface. The first-type UPF entity 1108 may be connected to the first-type SMF entity 1105 via an Nx interface and to the MBSU entity 1107 via an N6 interface. The first-type AMF entity 1106 is connected to the first-type SMF entity 1105 via an MB-N11 interface. A first type SMF entity 1105 is connected to PCF entity 1104 via an interface, e.g. Np. PCF entity 1104 may be connected to MBSF entity 1103 via an interface (e.g., Nq). Furthermore, the first type SMF entity 1105 may also be directly connected to the MBSF entity 1103 through an interface N6mb _ C. MBSF entity 1103 is connected to NEF entity 1102 through an NxMB-C interface. The NEF entity 1102 is connected to the first type AF entity 1101 through an N33 interface. The MBSU entity 1107 is connected to the first type AF entity 1101 through an NxMB-U interface.

The wireless communication system 1100 may further include a second type AF entity, a second type SMF entity, a second type AMF entity, and a second type UPF entity (not shown). In the scenario of multicast/broadcast service, the second-type AF entity may have the functions of the first-type AF entity 1101, the MBSF entity 1103, and the MBSU entity 1107. In addition, the second type AF entity may also support Protocol Data Unit (PDU) session traffic (e.g., IP type PDU session traffic). The second type SMF entity may be an SMF entity supporting a PDU session service (e.g., an IP type PDU session service). The second type AMF entity may be an AMF entity supporting a PDU session service (e.g., an IP type PDU session service). The second type UPF entity may be a UPF entity that supports PDU session traffic (e.g., IP type PDU session traffic). The second-type AF entity described herein may be the AF entity 110 in fig. 1, the second-type SMF entity may be the SMF entity 130 in fig. 1, the second-type AMF entity may be the AMF entity 140 in fig. 1, and the second-type UPF entity may be the UPF entity 150 in fig. 1.

Further, in the present disclosure, the MBSF entity is an entity dedicated to the control plane of the MBS service, which may be used for the signaling part to satisfy the service layer capabilities in transport-only and full service modes, and may provide an interface to the first type AF entity or content provider in transport-only mode. The MBSU entity is an entity dedicated to the user plane of MBS traffic that can be used to process the payload portion to meet the traffic layer capabilities. The NEF entity may support QoS capability opening, event subscription capability opening, AF request traffic guidance, AF request parameter issuance, and the like. The PCF entity may support a unified policy framework to manage network behavior, provide policy rules to control the control plane, etc. The first type of SMF entity and the second type of SMF entity, similarly, may both support session management, etc., where the session management may include session establishment, modification, release, etc. The first type AMF entity and the second type AMF entity are similar and can support access authentication, mobility management, registration management, connection management and legal answering of the UE, session management information transmission between the UE and the SMF entity and the like. The first type of UPF entity and the second type of UPF entity, like each other, may have a packet routing function, for example, may obtain packets from a network and send packets to a RAN, etc. The RAN may be an access network formed by base stations. The base station here may be any type of base station, such as a 5G base station, a Next Generation (NG) RAN, or a base station in a conventional communication system or wifi ap, etc.

As shown in fig. 12, in step 1, the UE may initiate a process of activating a multicast service through a first activation mode. Alternatively, in step 1, the UE may initiate a process of activating the multicast service through the second activation mode.

Then, in step 2, the MBS AF entity may feed back Response information (Nnef _ MBS authorization request notification Response) to the NEF entity through the Nnef interface, where the Response information includes a TMGI corresponding to the multicast service and a multicast service Session Start identifier (Session Start Indicator). The multicast service session start identifier is used for subsequently establishing a user plane for the UE and corresponding to the multicast service.

Then, in step 3, the NEF entity may feed back Response information (Nmbsf _ MBS authorization request notification Response) of the notification of the MBS authorization request to the MBSF entity through the Nmbsf interface, and the Response information may include the TMGI corresponding to the multicast service and the multicast service session start identifier.

Then, in step 4, the MBSF entity may feed back Response information (Nsmf _ MBs authorization request notification Response) of the notification of the MBs authorization request to the MB-SMF entity through the Nmbsf interface, and the Response information may include the TMGI corresponding to the multicast service and the multicast service session start identifier.

Then, in step 5, the MB-SMF entity may create MBs UE Context for the UE based on the multicast address, and may then feed back a response message (Nsmf _ MBSSession _ creatembuecontextresponse) to the AMF entity in response to the request for creating MBs UE Context sent by the AMF entity to the MB-SMF entity in the process of activating the multicast service described in step 1.

Then, in step 6, the MBS AF entity may send a Request (Nnef _ MBS session start Request) for requesting to start a multicast service session to the NEF entity through the Nnef interface, which may include a GPSI of the user equipment, a TMGI corresponding to the multicast service, an aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, an ID of the multicast service session, an expected duration of the multicast service session, and a data transmission time of the multicast service. The request includes the GPSI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE). In addition, the request includes a quality of service requirement of at least one data flow corresponding to the multicast service, so that the PCC technology is applied to the transmission of the multicast service data, and the transmission combination of the PCC and the multicast service data is realized.

Then, in step 7, the NEF entity may send a Request (Nmbsf _ MBS session start Request) for requesting the start of a multicast service session to the MBSF entity through the Nmbsf interface, which may include the SUPI of the user equipment, the TMGI corresponding to the multicast service, the aggregated maximum rate (e.g., AMBR) corresponding to the multicast service, information of at least one data flow corresponding to the multicast service, the quality of service requirement of the at least one data flow, the ID of the multicast service session, the expected duration of the multicast service session, and the data transmission time of the multicast service. The request includes the SUPI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE).

Then, in step 8, the MBSF entity may select one MBSU entity from the plurality of MBSU entities according to the S-NSSAI and DNN corresponding to the multicast service and the multicast address of the multicast service. Furthermore, the MBSF entity may send a request for MBS Session establishment (N4 MBS Session establishment request) to the selected MBSU entity through the N4 interface, which may include the multicast address of the multicast service. The MBSU entity can establish a GTP user plane tunnel transmission tree from the MBSU entity to the MB UPF entity according to a multicast routing protocol, thereby realizing the transmission of data (e.g., service data corresponding to the multicast service) to be transmitted to the MB UPF entity by the MBSU entity in a tree-shaped GTP user plane tunnel manner. Then, the MBSU entity may assign a first tunnel multicast address for transmitting service data corresponding to the multicast service. Specifically, the MBSU entity may allocate a multicast address of a GTP user plane tunnel through the N6 interface to the multicast service, and use the multicast address of the allocated GTP user plane tunnel as the multicast address of the first tunnel. The MBSU entity may then assign an identity, e.g., a Common-Tunnel End point ID (C-TEID), to the multicast traffic. Then, the MBSU entity may feed back a Response message (N4 MBS Session Establishment Response) to the MBSF entity in Response to a Request for MBS Session Establishment (N4 MBS Session Establishment Request) sent by the MBSF entity to the MBSU entity. The response information may include a first tunnel multicast address assigned by the MBSU entity and an identification corresponding to the first tunnel multicast address. In addition, for the multicast service, the MBSF entity may record the PCF ID, the MBSU ID, the first tunnel multicast address corresponding to the multicast service, and the identifier corresponding to the first tunnel multicast address in the MBS UE Context of the UE. If the MBSU entity has been previously allocated and the MBSU entity has also allocated the first tunnel multicast address and the identity corresponding to the first tunnel multicast address, only the first tunnel multicast address and the identity corresponding to the first tunnel multicast address allocated by the MBSU entity may be recorded in the user equipment multicast service Context (MBS UE Context) of the UE, and this step need not be performed.

Alternatively, the MBSF entity may send a Request for MBS Session Establishment to the selected MBSU entity through the N4 interface, which may be denoted as N4 MBS Session Establishment Request and may include the multicast address of the multicast service, the first tunnel multicast address allocated by the MBSF entity, and an identification corresponding to the first tunnel multicast address, so that the MBSU entity establishes a GTP user plane tunneling tree from the MBSU entity to the MB UPF entity according to the multicast routing protocol, thereby enabling the transmission of data (e.g., traffic data corresponding to the multicast service) that the MBSU entity wants to send to the MBUPF entity in a tree-like GTP user plane tunnel. Then, the MBSU entity may feed back a Response message (N4 MBS Session Establishment Response) to the MBSF entity in Response to a Request for MBS Session Establishment (N4 MBS Session Establishment Request) sent by the MBSF entity to the MBSU entity. The response information may be an acknowledgement of a Request (N4 MBS session establishment Request) sent by the MBSF entity to the MBSU entity for MBS session establishment.

Then, in step 9, the MBSF entity may send a Request (Npcf _ MBs session start Request) to the corresponding PCF entity according to the recorded MB-SMF ID, where the Request may include the SUPI of the user equipment, the TMGI corresponding to the multicast service, the aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, an MB-SMF ID, information of at least one data flow corresponding to the multicast service, the quality of service requirement of the at least one data flow, the ID of the multicast service session, the expected duration of the multicast service session, and the data transfer time of the multicast service. The request includes the SUPI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE).

Then, in step 10, the PCF entity may send a Request (Nmb-SMF _ MBs session start Request) to the corresponding MB-SMF entity, which may include the SUPI of the user equipment, the TMGI corresponding to the multicast service, the aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, the quality of service rule of the at least one data flow, the ID of the multicast service session, the expected duration of the multicast service session, and the data transmission time of the multicast service, according to the MB-SMF ID obtained through step 9. The request includes the SUPI of the user equipment to indicate that this step is for the operation of the UE (i.e., a particular UE). Then, the MB-SMF entity may generate MBs QFI, QoS profile and N4 QER rules corresponding to each data flow according to the received quality of service rule of at least one data flow corresponding to the multicast service.

Then, in step 11, the MB-SMF entity may determine a corresponding MBs UE Context according to the TMGI, and obtain the S-NSSAI, DNN, and multicast address included in the MBs UE Context according to the determined MBs UE Context. The MB-SMF entity may then select one MB-UPF entity from the plurality of MB-UPF entities based on the acquired S-NSSAI, DNN, and multicast/broadcast address. Then, the MB-SMF entity may send a Request for requesting MBs Session Establishment to the selected MB-UPF entity through the N4 interface (N4 MBs Session Establishment Request). The request may include a multicast address for the multicast traffic, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast traffic, and a quality of service enforcement rule for at least one data flow corresponding to the multicast traffic. The MB-UPF entity may then establish a GTP user plane tunneling tree from the MB-UPF entity to the RAN according to the multicast routing protocol according to the received request, so as to transport data (e.g., service data corresponding to the multicast service) that the MB-UPF entity wants to send to the RAN in a tree-like GTP user plane tunnel. Then, the MB-UPF entity may assign a second tunneling multicast address for transmitting service data corresponding to the multicast service. Specifically, the MB-UPF entity may allocate a multicast address of a GTP user plane tunnel through the N3 interface to the multicast service, and use the multicast address of the allocated GTP user plane tunnel as the multicast address of the second tunnel. The second type UPF entity may then assign an identity (e.g., C-TEID) to the multicast service. In addition, for the multicast service, the MB-SMF entity may record the PCF ID, the MB-UPF ID, the second tunneling multicast address corresponding to the multicast service, and the identifier corresponding to the second tunneling multicast address in the MBs UE Context of the UE. If a MB-UPF entity has been previously assigned and the MB-UPF entity also has assigned a second tunnelling multicast address and an identity corresponding to the second tunnelling multicast address, it is possible to record only the second tunnelling multicast address assigned by the MB-UPF entity and the identity corresponding to the second tunnelling multicast address into the user equipment multicast service Context (MBs UE Context) of the UE, and this step need not be performed.

Alternatively, the MB-SMF entity may send a Request for MBs Session Establishment (N4 MBs Session Establishment Request) to the selected MB-UPF entity through the N4 interface, and the Request may include the multicast address of the multicast service, the second tunneling multicast address allocated by the MB-SMF entity, and the identification corresponding to the second tunneling multicast address, so that the MB-UPF entity establishes a GTP user plane tunneling tree from the MB-UPF entity to the RAN according to the multicast routing protocol, thereby enabling the transmission of data (e.g., traffic data corresponding to the multicast service) to be sent by the MB-UPF entity to the RAN in a tree-like GTP user plane tunnel. Then, the MB-UPF entity may feed back a Response message (N4 MBs Session Establishment Response) to the MB-SMF entity in Response to the Request for MBs Session Establishment sent by the MB-SMF entity to the MB-UPF entity (N4 MBs Session Establishment Request). The response information may be an acknowledgement of the Request for MBs session establishment (N4 MBs session establishment Request) sent by the MB-SMF entity to the MB-UPF entity.

Then, in step 12, the MB-SMF entity may send the first information (Namf _ Communication _ N1N2MessageTransfer) to the AMF entity through the Namf interface. The first information may include a Response (Activate MBS UE Context Response) activating MBS UE Context, the Response activating MBS UE Context may include TMGI corresponding to the multicast service, and the MB-SMF entity may encapsulate the "Response activating MBS UE Context" using N1 MBS SM Context. In addition, the first information may further include a TMGI corresponding to the multicast service, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, a quality of service flow identification and a quality of service profile corresponding to each data flow of the multicast service, a second tunnel multicast address corresponding to the multicast service, and an identification corresponding to the second tunnel multicast address. The MB-SMF entity may encapsulate the TMGI corresponding to the multicast service, the quality of service flow identification and quality of service profile corresponding to each data flow of the multicast service, the second tunneling multicast address corresponding to the multicast service, and the identification corresponding to the second tunneling multicast address using the N2MBs SM Container.

Then, in step 13, the AMF entity may send a Request for requesting the Start of a multicast service Session (N2 MBS Session Start Request) to the RAN through an N2 interface. The request may include a downlink NAS transport (DLNASTransport) message, one information element of which is the above-described Response (active MBS UE Context Response) to Activate MBS UE Context encapsulated using N1 MBS SMContainer. Through the downlink NAS Transport message, the AMF entity may instruct the RAN to directly send a DL NAS Transport message to the UE. The request may further include a TMGI corresponding to the multicast service, an aggregate maximum rate (e.g., AMBR) corresponding to the multicast service, a multicast address for the multicast service, a quality of service flow identification and a quality of service profile corresponding to each data flow of the multicast service, a second tunneling multicast address corresponding to the multicast service, and an identification corresponding to the second tunneling multicast address.

Then, in step 14, the RAN can transmit the above-described DL NASTransport message to the UE through RRC signaling.

Then, in step 15, the RAN may send a Response to the AMF entity over the N2 interface (N2 MBS session start Response). The response may be an acknowledgement of the N2 mbssessionstartrequest sent by the AMF entity to the RAN as described in step 13.

The RAN may then allocate resources for transmitting multicast traffic data to its served UEs to support data streams with different quality of service requirements in step 16.

Then, in step 17, the RAN may join the transport group corresponding to the second tunneling multicast address described above to receive the multicast service data from the MB-UPF entity.

Then, in step 18, the AMF entity may send a notification message (Namf _ Communication _ N2MBSMessageNotify) to the MB-SMF entity through the Namf interface. The notification information may be an acknowledgement of the information sent by the MB-SMF entity to the AMF entity described in step 12 above.

Then, in step 19, the MB-SMF entity may send a Response message (Nsmf _ MBs session start Response) to the PCF entity via the Nmb-SMF interface in Response to the request sent by the PCF entity to the MB-SMF entity described in step 10.

Then, in step 20, the PCF entity may send a response message (Npcf _ MBS SessionStartResponse) to the MBSF entity over the Npcf interface in response to the request sent by the MBSF entity to the PCF entity as described in step 9.

Then, in step 21, the MBSF entity may send a Response message (Nmbsf _ MBS session start Response) to the NEF entity through the Nmbsf interface in Response to the request sent by the NEF entity to the MBSF entity described in step 7.

Then, in step 22, the NEF entity may send a Response message (Nnef _ MBS session Response) to the MBS AF entity through the Nnef interface in Response to the request sent by the MBS AF entity to the NEF entity described in step 6 above.

Then, in step 23, the multicast service may be started. The MBS AF entity can send an MBS data packet with the destination IP address being the multicast address of the multicast service to the downstream MBSU entity. Then, the MBSU entity can transmit the multicast service data to the MB-UPF entity by the transport layer multicast method described above. The MB-UPF entity may then send MBs packets to the RAN by the transport layer multicast method described above. Then, the RAN may send MBS data packets to the UE through the resources allocated to the UE.

Further, devices (e.g., UE, RAN, AMF entity, SMF entity, UPF entity, PCF entity, NEF entity, AF entity, etc.) in accordance with embodiments of the present disclosure may also be implemented by way of the architecture of a computing device shown in fig. 13. Fig. 13 illustrates an architecture of the computing device. As shown in fig. 13, computing device 1300 may include a bus 1310, one or more CPUs 1320, a Read Only Memory (ROM)1330, a Random Access Memory (RAM)1340, a communication port 1350 to connect to a network, input/output components 1360, a hard disk 1370, and so forth. Storage devices in the computing device 1300, such as the ROM 1330 or the hard disk 1370, may store various data or files used for computer processing and/or communication and program instructions executed by the CPU. Computing device 1300 can also include a user interface 1380. Of course, the architecture shown in FIG. 13 is merely exemplary, and one or more components of the computing device shown in FIG. 13 may be omitted as needed in implementing different devices.

Embodiments of the present disclosure may also be implemented as a computer-readable storage medium. A computer readable storage medium according to an embodiment of the present disclosure has computer readable instructions stored thereon. The computer readable instructions, when executed by a processor, may perform a method according to embodiments of the present disclosure described with reference to the above figures. The computer-readable storage medium includes, but is not limited to, volatile memory and/or non-volatile memory, for example. The volatile memory may include, for example, Random Access Memory (RAM), cache memory (cache), and/or the like. The non-volatile memory may include, for example, Read Only Memory (ROM), hard disk, flash memory, etc.

Those skilled in the art will appreciate that the disclosure of the present disclosure is susceptible to numerous variations and modifications. For example, the various devices or components described above may be implemented in hardware, or may be implemented in software, firmware, or a combination of some or all of the three.

Furthermore, as used in this disclosure and in the claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are inclusive in the plural, unless the context clearly dictates otherwise. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Likewise, the word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

Furthermore, flow charts are used in this disclosure to illustrate operations performed by systems according to embodiments of the disclosure. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, various steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

While the present disclosure has been described in detail above, it will be apparent to those skilled in the art that the present disclosure is not limited to the embodiments described in the present specification. The present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure defined by the claims. Accordingly, the description of the present specification is for the purpose of illustration and is not intended to be in any way limiting of the present disclosure.

Claims

1. A method performed by a user device, comprising:

determining an activation mode for activating the multicast service;

activating the multicast service according to the determined activation mode and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed in the activation process of the multicast service; and

and receiving service data corresponding to the multicast service.

2. The method of claim 1, prior to the determining the activation means for activating the multicast service, the method further comprising:

and determining a first identifier and a second identifier corresponding to the multicast service, wherein the first identifier and the second identifier are used for accessing and selecting the session management function entity by the mobility management function entity.

3. The method of claim 2, wherein the first identifier identifies a network slice corresponding to the multicast service and the second identifier identifies a data network corresponding to the multicast service.

4. The method of claim 2 or 3, wherein the determining the first identity and the second identity corresponding to the multicast traffic comprises:

obtaining a user device routing strategy rule corresponding to each multicast service in at least one multicast service from a strategy control function entity, wherein each user device routing strategy rule at least comprises a multicast address of the corresponding multicast service;

determining a user device routing strategy rule corresponding to the multicast service according to the multicast address of the multicast service; and

and determining a first identifier and a second identifier corresponding to the multicast service according to the determined routing policy rule of the user device.

5. The method according to claim 2 or 3, wherein said activating the multicast service according to the determined activation manner and at least by a session management function entity comprises:

determining a third identification, wherein the third identification is used for identifying a user equipment multicast service context established for activating the multicast service;

sending a request for activating the user equipment multicast service context to the session management function entity, the request for activating the user equipment multicast service context including the third identifier and a multicast address of the multicast service;

receiving a response to the request for activating the user equipment multicast service context from the session management function entity, the response including a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated.

6. The method of claim 5, wherein sending a request to the session management function entity for activation of the user device multicast service context comprises:

sending, via the access and mobility management function entity, a request to the session management function entity for activation of the user equipment multicast service context.

7. The method of claim 5, wherein receiving a response to the request to activate the user device multicast service context from the session management function entity comprises:

receiving a response to the request for activation of the user equipment multicast traffic context from the session management function entity via the serving base station of the user equipment and the access and mobility management function entity.

8. The method of any of claims 5 to 7, prior to said determining a third identity, the method further comprising:

acquiring a first identifier, a second identifier and a multicast address from the session management function entity;

determining whether the obtained first identifier is the same as the determined first identifier, whether the obtained second identifier is the same as the determined second identifier, and whether the obtained multicast address is the same as a multicast address of the multicast service for a user device multicast service context.

9. The method of claim 8, prior to obtaining a first identity, a second identity and a multicast address from the session management function entity, the method further comprising:

acquiring an internet protocol address from the session management functional entity according to the first identifier and the second identifier; and

and sending a data packet to a network according to the acquired Internet protocol address so that a user plane functional entity in the network acquires the data packet, wherein the data packet is used for indicating the multicast service which the user device wants to activate.

10. The method of claim 9, wherein the first and second light sources are selected from the group consisting of a red light source, a green light source, and a blue light source,

wherein obtaining an internet protocol address from the session management function entity according to the first identifier and the second identifier comprises:

selecting the session management function entity and establishing a protocol data unit session according to the first identifier and the second identifier, and acquiring an internet protocol address from the session management function entity; and

wherein the sending a data packet to a network according to the obtained internet protocol address so that a user plane functional entity in the network obtains the data packet comprises:

according to the acquired internet protocol address, sending a data packet to a network so that a user plane functional entity participating in the establishment of the protocol data unit session in the network acquires the data packet;

wherein the destination address of the packet is a multicast address of the multicast service or the protocol portion of the packet includes the multicast address of the multicast service.

11. A method performed by a session management function entity, comprising:

receiving a request from a user device for activating a user device multicast service context established by the user device for activating a multicast service, the request for activating the user device multicast service context including the third identification and a multicast address of the multicast service, the third identification identifying the user device multicast service context;

determining a response to the request to activate the user device multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user device to determine whether the multicast service is activated;

acquiring a fifth identifier corresponding to the multicast service, wherein the fifth identifier is used for identifying the start of a multicast service session corresponding to the multicast service; and

and carrying out the multicast service session and sending the response to the user device.

12. The method of claim 11, wherein the receiving a request from a user device to activate a user device multicast service context comprises:

a request is received from the user device via an access and mobility management function entity for activating a user device multicast service context.

13. The method of claim 11 or 12, wherein sending the response to the user device comprises:

sending the response to the user equipment via a serving base station of the user equipment and an access and mobility management function entity.

14. The method of claim 11 or 12, prior to the receiving from a user device a request to activate the user device multicast service context, the method further comprising:

establishing a protocol data unit session;

assigning an internet protocol address to said user device;

acquiring a multicast address of a multicast service to be activated by the user equipment from a user plane function entity participating in the establishment of the PDU session, wherein the multicast address is acquired after the user equipment transmits a packet to a network including the user plane function entity according to the IP address, wherein the packet indicates the multicast service which the user equipment wants to activate;

when the session management function entity decides to instruct the user equipment to activate the multicast service, sending a request for instructing the user equipment to activate the multicast service to the user equipment, wherein the request for instructing the user equipment to activate the multicast service comprises a first identifier corresponding to the multicast service to be activated by the user equipment, a second identifier and a multicast address of the multicast service.

15. The method of claim 12, further comprising:

receiving, from the access and mobility management function entity, a dedicated identity of the user equipment and an identity of a serving base station of the user equipment.

16. The method of claim 15, further comprising:

recording the identities of the serving base stations of the user devices in the user device multicast service context in order to obtain identities of the serving base stations of all user devices that activate the multicast service through the session management function entity.

17. The method of claim 11, wherein determining a response to the request to activate a user device multicast service context comprises:

determining whether the user device is capable of using the multicast service;

when the user equipment can use the multicast service, sending a notice to the application function entity, wherein the notice is the notice of the multicast service authorization request; and

receiving a response to the notification from the application function entity, wherein the response to the notification includes a fourth identification corresponding to the multicast traffic.

18. The method of claim 17, wherein the notification comprises at least the first identification, the second identification, a multicast address for the multicast service, and an identification of the session management function entity, wherein the identification of the session management function entity facilitates the application function entity to obtain the session management function entity to which all user devices that are to activate the multicast service are involved in activating the multicast service.

19. The method of claim 17 or 18, wherein sending a notification to the application function entity comprises:

a notification is sent to the application function entity via the network openness function entity.

20. The method of claim 19, wherein the notification further comprises an identification of the application function entity, so that the network openness function entity determines the application function entity according to the identification of the application function entity and sends the notification to the application function entity.

21. The method of claim 17, wherein receiving a response to the notification from the application function entity comprises:

receiving a response to the notification from the application function entity via a network open function entity.

22. The method of claim 11, wherein conducting the multicast traffic session comprises:

receiving a first request from a policy control function entity, wherein the first request is for requesting a start of the multicast traffic session, the first request comprising at least a first identification of the user device, a fourth identification corresponding to multicast traffic, a quality of service rule of at least one data flow corresponding to the multicast traffic, and an identification of the multicast traffic session.

23. The method of claim 22, wherein the first request is determined by the policy control function entity according to a second request received from a network open function entity or an application function entity for the network open function entity or the application function entity to request a start of a multicast traffic session to the policy control function entity.

24. The method of claim 23, wherein the second request comprises at least a first identification of the user device, the fourth identification, an identification of the session management function entity, information of at least one data flow corresponding to the multicast service, a quality of service requirement of the at least one data flow, and an identification of the multicast service session.

25. The method of claim 24, wherein the policy control function entity is determined by the network open function entity or the application function entity according to an identity of the session management function entity.

26. The method of claim 23, wherein the second request is determined by the network openness function entity according to a third request received from an application function entity, the third request being for the application function entity to request a start of a multicast service session to the network openness function entity.

27. The method of claim 26, wherein the third request includes at least a second identification of the user device, the fourth identification, information of at least one data flow corresponding to the multicast service, quality of service requirements of the at least one data flow, and an identification of the multicast service session.

28. The method of claim 22, wherein conducting the multicast traffic session further comprises:

and generating a service quality flow identification, a service quality configuration file and a service quality execution rule corresponding to each data flow according to the service quality rule of each data flow.

29. The method of claim 28, wherein conducting the multicast traffic session further comprises:

selecting a user plane functional entity according to the fourth identifier;

sending a fourth request to the selected user plane functional entity, wherein the fourth request is used for establishing transmission resources of the multicast service session; and

and acquiring a response to the fourth request from the selected user plane functional entity, wherein the response to the fourth request comprises a tunnel multicast address allocated by the selected user plane functional entity for transmitting service data corresponding to the multicast service and a sixth identification corresponding to the tunnel multicast address, the tunnel multicast address is used for multicast tunnel transmission between network entities, and the sixth identification is used for identifying a transmission tunnel of the multicast service.

30. The method of claim 28, wherein conducting the multicast traffic session further comprises:

selecting a user plane functional entity according to the fourth identifier;

sending a fourth request to the selected user plane function entity, wherein the fourth request is used for establishing transmission resources of the multicast service session, the fourth request includes a tunnel multicast address allocated by the session management function entity for transmitting service data corresponding to the multicast service, and a sixth identifier corresponding to the tunnel multicast address, wherein the tunnel multicast address is used for multicast tunnel transmission between network entities, and the sixth identifier is used for identifying a transmission tunnel of the multicast service;

obtaining a response to the fourth request from the selected user plane functional entity.

31. The method of claim 29 or 30, wherein the fourth request comprises at least a multicast address for the multicast traffic, a quality of service enforcement rule for the at least one data flow, and an aggregated maximum rate corresponding to the multicast traffic.

32. The method of claim 29 or 30, further comprising:

recording at least the tunnel multicast address and the sixth identification in a multicast service context of each user device that has activated the multicast service.

33. The method of claim 29 or 30, wherein the conducting the multicast traffic session and sending the response to the user device comprises:

sending first information to the access and mobility management function entity, wherein the first information includes the response and information related to the multicast service session, so that the access and mobility management function entity sends a fifth request to a corresponding serving base station according to the information related to the multicast service session, and sends the response to the user equipment via the corresponding serving base station, wherein the fifth request is used for requesting the start of the multicast service session.

34. The method of claim 33, wherein the information related to the multicast traffic session includes at least the fourth identification, the aggregate maximum rate corresponding to the multicast traffic, quality of service flow identifications and quality of service profiles corresponding to respective data flows, the tunnel multicast address, and the sixth identification.

35. The method of any of claims 22 to 27, wherein any of the first request, the second request, and the third request may further include an aggregate maximum rate corresponding to the multicast traffic.

36. A user device, comprising:

a determining unit configured to determine an activation manner for activating the multicast service;

an activation unit configured to activate the multicast service according to the determined activation manner and at least through a session management function entity, wherein a multicast service session corresponding to the multicast service is performed in an activation process of the multicast service; and

a receiving unit configured to receive service data corresponding to the multicast service.

37. A session management function entity, comprising:

a receiving unit configured to receive, from a user equipment, a request for activating a user equipment multicast service context established by the user equipment for activating a multicast service, the request for activating the user equipment multicast service context including the third identification and a multicast address of the multicast service, the third identification being used for identifying the user equipment multicast service context;

a determining unit configured to determine a response to the request for activating the user equipment multicast service context, wherein the response includes a fourth identification corresponding to the multicast service, wherein the fourth identification is used for the user equipment to determine whether the multicast service is activated;

an obtaining unit, configured to obtain a fifth identifier corresponding to the multicast service, where the fifth identifier is used to identify a start of a multicast service session corresponding to the multicast service;

a control unit configured to perform the multicast service session; and

a transmitting unit configured to transmit the response to the user equipment.

38. A user device, comprising:

a processor; and

memory, wherein a computer-executable program is stored in the memory, which when executed by the processor performs the method of claims 1-10.

39. A session management function entity, comprising:

a processor; and

memory, wherein a computer-executable program is stored in the memory, which when executed by the processor performs the method of claims 11-35.