Method and apparatus for group communication

Abstract

The application provides a method and device for group communication. The method can include: a first session management network element receiving identification information of a second session management network element from a group management network element, and then the first session management network element sending a request message #1 to the second session management network element according to the identification information of the second session management network element. Further, the first session management network element receives a response message #1 from the second session management network element, wherein the response message #1 includes tunnel information of a second user plane network element and identification information of a second terminal device. The first session management network element configures a first forwarding rule at a first user plane network element, so as to send a data packet with a destination address pointing to the second terminal device to the second user plane network element. Through the above scheme, communication between group members served by different session management network elements in the same group can be established.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a method and apparatus for group communication. Background Technology

[0002] 5G Virtual Network (5G VN) service (also known as 5G Local Area Network, 5G LAN) is a service currently offered by 5G networks, primarily used in home communication, enterprise offices, factory manufacturing, vehicle-to-everything (V2X) communication, and power grid upgrades. This service enables private communication using either Internet Protocol (IP) or non-IP methods (such as Ethernet) for two or more terminal devices within a group. For example, multiple devices in a factory can form a 5G VN group, allowing different devices within the group to send Ethernet data packets to each other via the 5G VN service; or, employees' office devices (such as mobile phones, computers, or laptops) in a department of an enterprise can form a 5G VN group, allowing different office devices within the group to send IP data packets to each other via the 5G VN service, and so on.

[0003] When 5G VN spans a large area, or when members of different groups access 5G VN from different locations, multiple SMFs may be involved in the 5G VN group due to the limited service area of ​​the SMF. How to establish communication between 5G VN group members managed by different SMFs when a 5G VN group is served by different SMFs is a problem that needs to be considered. Summary of the Invention

[0004] This application provides a method and apparatus for group communication, which can establish communication between group members in the same group who are served by different session management network elements.

[0005] In a first aspect, a method for group communication is provided, the method comprising: a first session management network element receiving identification information from a second session management network element of a group management network element; wherein the first session management network element and the second session management network element provide services for sessions of different terminal devices belonging to the same group; the first session management network element sending a request message #1 to the second session management network element according to the identification information of the second session management network element, the request message #1 including the identification information of the group, tunnel information of a first user plane network element, and identification information of a first terminal device; wherein the first session management network element and the first user plane network element provide services for the sessions of the first terminal device. The first session management network element receives a response message #1 from the second session management network element. The response message #1 includes tunnel information of the second user plane network element and identification information of the second terminal device. The second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group. The first session management network element configures a first forwarding rule in the first user plane network element according to the tunnel information of the second user plane network element and the identification information of the second terminal device. The first forwarding rule is used to send data packets with destination addresses pointing to the second terminal device to the second user plane network element.

[0006] Based on the above scheme, communication can be established between terminal devices (i.e., the first terminal device and the second terminal device) served by different session management network elements within the same group. Specifically, the first session management network element can obtain the identification information of the second session management network element from the group management network element, and then send a request message to the second session management network element according to the identification information of the second session management network element to establish a tunnel between the first user plane network element and the user plane network element (i.e., the second user plane network element) managed by the second session management network element. Then, the first session management network element configures a first forwarding rule for the first user plane network element, thereby establishing a data forwarding path between the first terminal device and the second terminal device, realizing communication between the first terminal device and the second terminal device.

[0007] In conjunction with the first aspect, in some implementations of the first aspect, the first session management network element receiving the identification information of the second session management network element from the group management network element includes: the first session management network element receiving a notification message from the group management network element, the notification message including the identification information of the second session management network element and the identification information of the group.

[0008] Based on the above scheme, the first session management network element can receive the identification information of the second session management network element from the notification message of the group management network element.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the first session management network element sending a subscription message #1 to the group management network element, the subscription message #1 including the identification information of the group, and the subscription message #1 being used to subscribe to group information change notifications for the group.

[0010] Based on the above scheme, the first session management network element can subscribe to group information change notifications from the group management network element via subscription message #1. These group information change notifications can include change notifications from the session management network element corresponding to the group; they can also be used to notify the session management network elements of existing service groups to the session management network elements of newly joined service groups. Through subscription message #1, when group information changes, such as when a second session management network element registers in the group, the group management network element can send the identification information of the second session management network element to the first session management network element via a notification message.

[0011] In conjunction with the first aspect, in certain implementations of the first aspect, the first session management network element receiving the identification information of the second session management network element from the group management network element includes: the first session management network element sending a request message #2 to the group management network element for finding the session management network element serving the group, the request message #2 including the identification information of the group; and the first session management network element receiving a response message #2 from the group management network element, the response message #2 including the identification information of the second session management network element.

[0012] Based on the above scheme, the first session management network element can send a request message #2 to the group management network element to find the session management network element that serves the group, so as to establish a session between the first session management network element and the session management network elements of other service groups.

[0013] In conjunction with the first aspect, in certain implementations of the first aspect, the first session management network element receiving the identification information of the second session management network element from the group management network element includes: the first session management network element sending a request message #3 to the group management network element for finding a session management network element that serves the second terminal device in the group, the request message #3 including the identification information of the group and the identification information of the second terminal device; the first session management network element receiving a response message #3 from the group management network element, the response message #3 including the identification information of the second session management network element.

[0014] Based on the above scheme, the first session management network element can send a request message #3 to the group management network element to find the session management network element (i.e., the second session management network element) that serves the second terminal device in the group, so as to establish a session between the first session management network element and the second session management network element.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the response message #1 further includes a session identifier of the second session management network element; the session identifier of the second session management network element is used to identify the context of the second session management network element associated with the first session management network element for the group; the method further includes: the first session management network element receiving a session establishment request message for the group from a third terminal device; wherein the third terminal device belongs to the group; in response to the session establishment request message, the first session management network element allocates a third user plane network element for the session of the third terminal device; the first session management network element sends an update message #1 to the second session management network element according to the session identifier of the second session management network element, wherein the update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device.

[0016] Based on the above scheme, the second session management network element can also carry the session identifier of the second session management network element in the response message #1, so that when the terminal device or user plane network element managed by the first session management network element changes, the first session management network element can send an update message #1 to the second session management network element according to the session identifier of the second session management network element. The session identifier of the second session management network element is used to identify which session the second session management network element is processing.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes the first session management network element creating a session context associated with the second session management network element for the group.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the first session management network element storing the session identifier of the second session management network element and the identifier information of the group.

[0019] Based on the above scheme, when the topology information of the group members is updated, for example, when the group members or user plane network elements corresponding to the first session management network element change, the first session management network element can send an update message to the second session management network element according to the session identifier and group identifier information of the second session management network element that are saved.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the first session management network element receiving an update message #2 from the second session management network element, the update message #2 including tunnel information of the fourth user plane network element and identification information of the fourth terminal device; wherein the second session management network element and the fourth user plane network element are network elements providing services for the session of the fourth terminal device, and the fourth terminal device belongs to the group; the first session management network element configuring a second forwarding rule in the first user plane network element according to the tunnel information of the fourth user plane network element and the identification information of the fourth terminal device, the second forwarding rule being used to send data packets whose destination address points to the fourth terminal device to the fourth user plane network element.

[0021] Based on the above scheme, the first session management network element can configure the second forwarding rule to the first user plane network element according to the information carried in the update message #2 from the second session management network element, so that after the fourth terminal device in the group establishes a session through the fourth user plane network element and the second session management network element, a data forwarding path between the first terminal device and the fourth terminal device can be established in a timely manner.

[0022] In conjunction with the first aspect, in some implementations of the first aspect, before the first session management network element sends the request message #1 to the second session management network element, the method further includes: the first session management network element determining that there is no context on the first session management network element associated with the second session management network element for the group.

[0023] Based on the above scheme, the first session management network element can send a request message to the second session management network element if it is determined that there is no context (or session) for the group between the first session management network element and the second session management network element, so as to prevent session conflict.

[0024] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the first session management network element assigning a session identifier of the first session management network element to the group, the session identifier of the first session management network element being used to identify the context of the first session management network element associated with the second session management network element for the group; wherein, the request message #1 further includes the session identifier of the first session management network element.

[0025] Based on the above scheme, if there is a group-related session between the first session management network element and the second session management network element, the first session management network element can reject the request message #3 from the second session management network element to prevent session conflicts.

[0026] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the first session management network element sending a registration request message to the group management network element, the registration request message including the identification information of the group and the identification information of the first session management network element.

[0027] Secondly, a method for group communication is provided, the method comprising: a group management network element receiving a registration request message from a second session management network element, the registration request message including identification information of the group and identification information of the second session management network element; the group management network element sending the identification information of the second session management network element to a first session management network element, the first session management network element and the second session management network element providing services for sessions of different terminal devices belonging to the group respectively.

[0028] Based on the above scheme, after receiving the registration request message from the second session management network element, the group management network element can send the identification information of the second session management network element to the first session management network element so that a session can be established between the first session management network element and the second session management network element, enabling group members under the first session management network element and the second session management network element to communicate.

[0029] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: a group management network element receiving a subscription message #1 from a first session management network element, the subscription message #1 including the identifier of the group, the subscription message #1 being used to subscribe to group information change notifications for the group; the group management network element sending the identifier information of the second session management network element to the first session management network element, including: the group management network element sending a notification message to the first session management network element based on the subscription message #1, the notification message including the identifier information of the second session management network element.

[0030] Based on the above scheme, the group management network element can send the identification information of the second session management network element to the first session management network element based on the subscription message of the first session management network element.

[0031] In conjunction with the second aspect, in some implementations of the second aspect, the group management network element sends the identification information of the second session management network element to the first session management network element, including: the group management network element receiving a request message #2 from the first session management network element for finding a session management network element serving the group, the request message #2 including the identification information of the group; the group management network element determining the identification information of the second session management network element based on the identification information of the group; and the group management network element sending a response message #2 to the first session management network element, the response message #2 including the identification information of the second session management network element.

[0032] Based on the above scheme, the group management network element can send the identification information of the session management network element serving the group to the first session management network element according to the request message of the first session management network element, which may include the identification information of the second session management network element.

[0033] In conjunction with the second aspect, in certain implementations of the second aspect, the group management network element sends the identification information of the second session management network element to the first session management network element, including: the group management network element receiving a request message #3 from the first session management network element for finding a session management network element serving a second terminal device in the group, the request message #3 including the identification information of the group and the identification information of the second terminal device; the group management network element determining the identification information of the second session management network element based on the identification information of the group and the identification information of the second terminal device; and the group management network element sending a response message #3 to the first session management network element, the response message #3 including the identification information of the second session management network element.

[0034] Based on the above scheme, the group management network element can send the identification information of the session management network element serving the second terminal device in the group to the first session management network element according to the request message of the first session management network element.

[0035] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: the group management network element storing the association between the identification information of the second session management network element and the identification information of the group.

[0036] Thirdly, a method for group communication is provided, the method comprising: a second session management network element receiving a request message #1 from a first session management network element, the request message #1 including group identification information, tunnel information of a first user plane network element, and identification information of a first terminal device; wherein the first session management network element and the first user plane network element are network elements providing services for the session of the first terminal device, and the first terminal device belongs to the group; the second session management network element assigning a session identifier to itself according to the request message #1, the session identifier being used to identify the group associated with the first session management network element on the second session management network element. The context; the second session management network element sends a response message #1 to the first session management network element, the response message #1 including the tunnel information of the second user plane network element, the identification information of the second terminal device, and the session identifier of the second session management network element; wherein, the second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group; the second session management network element configures a third forwarding rule in the second user plane network element according to the tunnel information of the first user plane network element and the identification information of the first terminal device, the third forwarding rule is used to send data packets whose destination address points to the first user plane network element to the first user plane network element.

[0037] It should be understood that this application does not limit the order in which the second session management network element sends response message #1 and configures forwarding rule #3.

[0038] Based on the above scheme, communication can be established between terminal devices (i.e., the first terminal device and the second terminal device) served by different session management network elements within the same group. Specifically, the second session management network element can obtain the tunnel information of the first user plane network element and the identification information of the first terminal device from the first session management network element. Then, the second session management network element can send the tunnel information of the second user plane network element and the identification information of the second terminal device to the first user plane network element, and configure a third forwarding rule for the second user plane network element so as to establish a data forwarding path between the first terminal device and the second terminal device, thereby realizing communication between the first terminal device and the second terminal device.

[0039] In conjunction with the third aspect, in some implementations of the third aspect, the request message #1 further includes a session identifier of the first session management network element, wherein the session identifier of the first session management network element is used to identify the context of the first session management network element associated with the second session management network element for the group. The method further includes: the second session management network element storing the session identifier of the first session management network element, the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device in the context of the first session management network element associated with the group.

[0040] Based on the above scheme, the second user plane network element can save the identification information of the first user plane network element and the group identification information into the context of the first session management network element, and this context is indicated by the session identifier of the second session management network element. Therefore, when the group's topology information is updated, the second session management network element can update the data forwarding paths between group members based on this session identifier.

[0041] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes: the second session management network element receiving an update message #1 from the first session management network element, the update message #1 including the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device; wherein the first session management network element and the third user plane network element are network elements providing services for the session of the third terminal device, and the third terminal device belongs to the group; the second session management network element configures a fourth forwarding rule in the second user plane network element according to the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device, the fourth forwarding rule being used to send data packets whose destination address points to the third terminal device to the third user plane network element.

[0042] Based on the above scheme, after receiving update message #1 from the first session management network element, the second session management network element can determine that the third terminal device has accessed the group through the first session management network element. Therefore, the second session management network element can configure a fourth forwarding rule to the second user plane network element to establish a data forwarding path between the third terminal device and the second terminal device, thereby enabling communication between them. Thus, based on the above scheme, when the group topology information is updated, data forwarding paths between group members can be updated or established in a timely manner, enabling communication between group members.

[0043] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes: the second session management network element adding the tunnel information of the third user plane network element and the identification information of the third terminal device to the context associated with the first session management network element for the group, based on the session identifier of the second session management network element.

[0044] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes: a second session management network element receiving a session establishment request message from a fourth terminal device for the group; wherein the fourth terminal device belongs to the group; in response to the session establishment request message, the second session management network element assigns a fourth user plane network element to the session of the fourth terminal device; the second session management network element, in the context associated with the first session management network element and in the context associated with the group, obtains the session identifier of the first session management network element based on the identification information of the group; the second session management network element sends an update message #2 to the first session management network element based on the session identifier of the first session management network element, the update message #2 including the tunnel information of the fourth user plane network element, the identification information of the fourth terminal device, and the session identifier of the first session management network element.

[0045] Based on the above scheme, when the topology information of group members is updated, for example, when the group members or user plane network elements corresponding to the second session management network element change, the second session management network element can send an update message to the first session management network element according to the context information to update or establish a data forwarding path between group members. For example, the second session management network element allocates a fourth user plane network element for the session based on the received session establishment request from the fourth terminal device. Based on this, the second session management network element obtains the identification information of the first session management network element from the context associated with the first session management network element for the group, and sends an update message #2 to the first session management network element according to the identification information of the first session management network element, so as to establish a data forwarding path between the first terminal device and the fourth terminal device and realize communication between the first terminal device and the fourth terminal device.

[0046] Fourthly, a communication system is provided, comprising a first session management network element, a second session management network element, and a group management network element. The group management network element is used to send identification information of the second session management network element to the first session management network element. The first session management network element and the second session management network element provide services for sessions of different terminal devices belonging to the same group. The first session management network element is used to receive identification information of the second session management network element from the group management network element. Based on the identification information of the second session management network element, the first session management network element sends a request message #1 to the second session management network element. The request message #1 includes identification information of the group, tunnel information of a first user plane network element, and identification information of a first terminal device. The first session management network element and the first user plane network element are network elements providing services for the sessions of the first terminal device, and the first terminal device belongs to the group. The second session management network element is used to receive identification information of the second session management network element from the group management network element. The first session management network element sends a request message #1; sends a response message #1 to the first session management network element, the response message #1 including tunnel information of the second user plane network element and identification information of the second terminal device; wherein, the second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group; configures a third forwarding rule on the second user plane network element according to the tunnel information of the first user plane network element and the identification information of the first terminal device, the third forwarding rule is used to send data packets whose destination address points to the first user plane network element to the first user plane network element; the first session management network element is also used to receive the response message #1 from the second session management network element; configures a first forwarding rule on the first user plane network element according to the tunnel information of the second user plane network element and the identification information of the second terminal device, the first forwarding rule is used to send data packets whose destination address points to the second terminal device to the second user plane network element.

[0047] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the second session management network element is further used to allocate a session identifier for the second session management network element. The session identifier of the second session management network element is used to identify the context of the second session management network element associated with the first session management network element for the group. The response message #1 includes the session identifier of the second session management network element.

[0048] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first session management network element is further configured to receive a session establishment request message from a third terminal device for the group; wherein the third terminal device belongs to the group; in response to the session establishment request message, allocate a third user plane network element for the session of the third terminal device; send an update message #1 to the second session management network element according to the session identifier of the second session management network element, wherein the update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device; the second session management network element is further configured to receive the update message #1 from the first session management network element; configure a fourth forwarding rule in the second user plane network element according to the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device, wherein the fourth forwarding rule is used to send data packets whose destination address points to the third terminal device to the third user plane network element.

[0049] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first session management network element is further used to determine that there is no context for the group associated with the second session management network element on the first session management network element.

[0050] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the second session management network element is further configured to send a request message #3 to the first session management network element, the request message #3 including the identification information of the group; the first session management network element is further configured to receive the request message #3 from the second session management network element; and after determining that there is a session for the group between the first session management network element and the second session management network element, reject the request message #3.

[0051] Fifthly, a group communication apparatus is provided, comprising: a transceiver unit for receiving identification information from a second session management network element of a group management network element; wherein the apparatus and the second session management network element provide services for sessions of different terminal devices belonging to the same group; and a processing unit for sending a request message #1 to the second session management network element through the transceiver unit according to the identification information of the second session management network element, the request message #1 including the identification information of the group, tunnel information of a first user plane network element, and identification information of a first terminal device; wherein the first session management network element and the first user plane network element provide services for the sessions of the first terminal device. The transceiver unit is further configured to receive a response message #1 from the second session management network element, the response message #1 including tunnel information of the second user plane network element and identification information of the second terminal device; wherein, the second session management network element and the second user plane network element are network elements providing services for the session of the second terminal device, and the second terminal device also belongs to the group; the processing unit is further configured to configure a first forwarding rule in the first user plane network element according to the tunnel information of the second user plane network element and the identification information of the second terminal device, the first forwarding rule being used to send data packets with destination addresses pointing to the second terminal device to the second user plane network element.

[0052] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is specifically used to receive a notification message from the group management network element, the notification message including the identification information of the second session management network element and the identification information of the group.

[0053] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is also used to send a subscription message #1 to the group management network element. The subscription message #1 includes the identification information of the group and is used to subscribe to the group's information change notifications.

[0054] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is specifically configured to send a request message #2 to the group management network element for finding a session management network element serving the group, the request message #2 including the identification information of the group; and receive a response message #2 from the group management network element, the response message #2 including the identification information of the second session management network element.

[0055] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is specifically configured to send a request message #3 to the group management network element for finding a session management network element that serves the second terminal device in the group, the request message #3 including the identification information of the group and the identification information of the second terminal device; and receive a response message #3 from the group management network element, the response message #3 including the identification information of the second session management network element.

[0056] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the response message #1 further includes a session identifier of the second session management network element, which is used to identify the context of the second session management network element associated with the first session management network element for the group; the transceiver unit is further configured to receive a session establishment request message for the group from the third terminal device; wherein the third terminal device belongs to the group; in response to the session establishment request message, the first session management network element allocates a third user plane network element for the session of the third terminal device; the processing unit is further configured to send an update message #1 to the second session management network element according to the session identifier of the second session management network element, wherein the update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device.

[0057] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the apparatus further includes: the first session management network element receiving an update message #2 from the second session management network element, the update message #2 including tunnel information of the fourth user plane network element and identification information of the fourth terminal device; wherein the second session management network element and the fourth user plane network element are network elements providing services for the session of the fourth terminal device, and the fourth terminal device belongs to the group; the first session management network element configuring a second forwarding rule in the first user plane network element based on the tunnel information of the fourth user plane network element and the identification information of the fourth terminal device, the second forwarding rule being used to send data packets whose destination address points to the fourth terminal device to the fourth user plane network element.

[0058] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the processing unit is further configured to determine that there is no context for the group associated with the second session management network element on the first session management network element.

[0059] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is further configured to receive a request message #3 from the second session management network element, the request message #3 including the identification information of the group; the processing unit is further configured to reject the request message #3 after determining that there is a session for the group between the first session management network element and the second session management network element.

[0060] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the processing unit is further configured to send a registration request message to the group management network element, the registration request message including the identification information of the group and the identification information of the first session management network element.

[0061] A sixth aspect provides a group communication apparatus, the apparatus comprising: a transceiver unit, configured to receive a registration request message from a second session management network element, the registration request message including group identification information and identification information of the second session management network element; and to send the identification information of the second session management network element to a first session management network element, the first session management network element and the second session management network element respectively providing services for sessions of different terminal devices belonging to the group.

[0062] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is further configured to receive a subscription message #1 from the first session management network element, the subscription message #1 including the identifier of the group, the subscription message #1 being used to subscribe to group information change notifications; the transceiver unit is specifically configured to send a notification message to the first session management network element based on the subscription message #1, the notification message including the identifier information of the second session management network element.

[0063] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is specifically configured to receive a request message #2 from the first session management network element for finding a session management network element serving the group, the request message #2 including the identification information of the group; the processing unit is specifically configured to determine the identification information of the second session management network element based on the identification information of the group; the transceiver unit is further configured to send a response message #2 to the first session management network element, the response message #2 including the identification information of the second session management network element.

[0064] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is specifically configured to receive a request message #3 from the first session management network element for finding a session management network element that serves the second terminal device in the group, the request message #3 including the identification information of the group and the identification information of the second terminal device; the processing unit is specifically configured to determine the identification information of the second session management network element based on the identification information of the group and the identification information of the second terminal device; the transceiver unit is also specifically configured to send a response message #3 to the first session management network element, the response message #3 including the identification information of the second session management network element.

[0065] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the processing unit is also used to store the association between the identification information of the second session management network element and the identification information of the group.

[0066] A seventh aspect provides a group communication apparatus, comprising: a transceiver unit configured to receive a request message #1 from a first session management network element, the request message #1 including group identification information, tunnel information of a first user plane network element, and identification information of a first terminal device; wherein the first session management network element is a network element providing services for a session of the first terminal device, and the first terminal device belongs to the group; and a processing unit configured to allocate a session identifier for a second session management network element according to the request message #1, the session identifier of the second session management network element being used to identify the context of the second session management network element associated with the first session management network element for the group; The transceiver unit is further configured to send a response message #1 to the first session management network element. The response message #1 includes tunnel information of the second user plane network element, identification information of the second terminal device, and session identifier of the second session management network element. The second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group. The processing unit is further configured to configure a third forwarding rule in the second user plane network element according to the tunnel information of the first user plane network element and the identification information of the first terminal device. The third forwarding rule is used to send data packets whose destination address points to the first terminal device to the first user plane network element.

[0067] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the processing unit is further configured to store the identification information of the first session management network element and the identification information of the group in the context associated with the first session management network element and for the group.

[0068] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the transceiver unit is further configured to receive an update message #1 from the first session management network element, the update message #1 including the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device; wherein the first session management network element and the third user plane network element are network elements that provide services for the session of the third terminal device, and the third terminal device belongs to the group; the processing unit is further configured to configure a fourth forwarding rule in the second user plane network element according to the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device, the fourth forwarding rule being used to send data packets whose destination address points to the third terminal device to the third user plane network element.

[0069] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the transceiver unit is further configured to receive a session establishment request message from a fourth terminal device for the group; wherein the fourth terminal device belongs to the group; in response to the session establishment request message, the processing unit is further configured to allocate a fourth user plane network element for the session of the fourth terminal device; the second session management network element, in the context associated with the first session management network element and for the group, obtains the session identifier of the first session management network element based on the identification information of the group; and sends an update message #2 to the first session management network element based on the session identifier of the first session management network element, the update message #2 including the tunnel information of the fourth user plane network element and the session identifier of the fourth terminal device.

[0070] Eighthly, a group communication apparatus is provided. This apparatus may be a first session management network element or a chip within the first session management network element. The apparatus has the function of implementing any of the implementation methods of the first aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function.

[0071] Ninthly, a group communication apparatus is provided. This apparatus can be a group management network element or a chip within the group management network element. The apparatus has the function of implementing any of the implementation methods of the second aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function.

[0072] In a tenth aspect, a group communication apparatus is provided. This apparatus may be a second session management network element or a chip within the second session management network element. The apparatus has the function of implementing any of the implementation methods of the third aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned function.

[0073] Eleventhly, a group communication apparatus is provided, the group communication apparatus including a processor for implementing the functions of a first session management network element in the method described in the first aspect, or the functions of a second session management network element in the method described in the second aspect, or the functions of a group management network element described in the third aspect.

[0074] In one possible implementation, the group communication apparatus may further include a memory coupled to the processor, which is used to implement the functions of the first session management network element in the method described in the first aspect, the second session management network element in the method described in the second aspect, or the group management network element described in the third aspect.

[0075] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the processor, which can call and execute the program instructions stored in the memory to implement the functions of the first session management network element in the method described in the first aspect, the second session management network element in the method described in the second aspect, or the group management network element described in the third aspect.

[0076] In one possible implementation, the group communication apparatus may further include a communication interface for the data acquisition apparatus to communicate with other devices. This communication interface may be a transceiver, an input / output interface, or a circuit, etc.

[0077] In one possible design, the data acquisition device includes a processor and a communication interface. The processor runs a computer program to enable the group communication device to implement any of the methods described in the first to third aspects above. The processor uses the communication interface to communicate with an external entity. It is understood that the external entity can be an object other than the processor or an object other than the device.

[0078] In another possible design, the device for acquiring data is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pins, or related circuits on the chip or chip system. The processor can also be manifested as a processing circuit or logic circuit.

[0079] In a twelfth aspect, this application provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the methods described above.

[0080] In a thirteenth aspect, this application provides a computer program product containing instructions that, when run on a computer, cause the computer to perform the methods described above.

[0081] In a fourteenth aspect, a communication system is provided, including a first session management network element as shown in the first aspect, a second session management network element as shown in the second aspect, and a group management network element as shown in the third aspect.

[0082] In a fifteenth aspect, a chip or chip system is provided, comprising at least one processor and a communication interface, the communication interface and the at least one processor being interconnected via a circuit, the at least one processor being configured to execute computer programs or instructions to perform the methods of any of the possible implementations of the first to third aspects. The communication interface in the chip may be an input / output interface, a pin, or a circuit, etc.

[0083] In one possible implementation, the chip or chip system described above in this application further includes at least one memory storing instructions. The memory can be an internal storage unit of the chip, such as a register or cache, or it can be a storage unit of the chip itself (e.g., read-only memory, random access memory, etc.). Attached Figure Description

[0084] Figure 1 This is a schematic diagram of a communication system provided in this application;

[0085] Figure 2 Figures (a) and (b) show schematic diagrams of the architecture of a 5G system to which embodiments of this application are applicable;

[0086] Figure 3 A schematic diagram of the user plane architecture for a 5G VN service is shown.

[0087] Figure 4 This is a schematic flowchart illustrating a group communication method provided in an embodiment of this application;

[0088] Figure 5 This is a schematic flowchart illustrating another group communication method provided in an embodiment of this application;

[0089] Figure 6 This is a schematic diagram of a communication architecture provided in an embodiment of this application;

[0090] Figure 7 This is a schematic diagram of another communication architecture provided in an embodiment of this application;

[0091] Figure 8 This is a schematic diagram of another communication architecture provided in the embodiments of this application;

[0092] Figure 9 This is a schematic diagram of another communication architecture provided in the embodiments of this application;

[0093] Figure 10 This is a schematic block diagram of a communication device provided according to embodiments of this application;

[0094] Figure 11 This is another schematic block diagram of a communication device provided according to an embodiment of this application;

[0095] Figure 12 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0096] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The specific operating methods in the method embodiments can also be applied to the device embodiments or system embodiments. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0097] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0098] It is understood that the various numerical designations used in this application are merely for descriptive convenience and are not intended to limit the scope of this application. The order of the process numbers does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

[0099] The terms "first," "second," "third," "fourth," and other various terminology (e.g., #1, #2, #3, #4, etc.) used in the specification, claims, and accompanying drawings of this application are for distinguishing similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0100] The technical solutions provided in this application can be applied to various communication systems, such as 5th generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, and LTE time division duplex (TDD) systems. The technical solutions provided in this application can also be applied to future communication systems, such as 6th generation mobile communication systems. Furthermore, the technical solutions provided in this application can also be applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0101] To solve the problems mentioned in the background art, such as Figure 1 As shown, this application provides a communication system 100, which includes a first session management network element 110 and a second session management network element 120. Optionally, the communication system may further include a group management network element 130.

[0102] The first session management network element 110 is used to receive the identification information of the second session management network element 120 from the group management network element 130; and to send a request message #1 to the second session management network element 120 according to the identification information of the second session management network element 120. The request message #1 includes the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device; wherein, the first session management network element 110 and the first user plane network element are network elements that provide services for the session of the first terminal device, and the first terminal device belongs to the group;

[0103] The second session management network element 120 is used to receive the request message #1 from the first session management network element 110; send a response message #1 to the first session management network element 110, the response message #1 including tunnel information of the second user plane network element and identification information of the second terminal device; wherein, the second session management network element 120 and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group; configure a third forwarding rule in the second user plane network element according to the tunnel information of the first user plane network element and the identification information of the first terminal device, the third forwarding rule being used to send data packets whose destination address points to the first user plane network element to the first user plane network element;

[0104] The first session management network element 110 is also used to receive the response message #1 from the second session management network element 120; configure a first forwarding rule in the first user plane network element according to the tunnel information of the second user plane network element and the identification information of the second terminal device, the first forwarding rule being used to send data packets whose destination address points to the second terminal device to the second user plane network element.

[0105] The above scheme can establish communication between group members (i.e., the first terminal device) served by the first session management network element and group members (i.e., the second terminal device) served by the second session management network element.

[0106] It should be understood that Figure 1 The specific interaction process between various network elements can be referred to Figure 4 The method flow can be found in the above, or refer to the method flow in Figure 5. For specific implementation details, please refer to the detailed descriptions in Method 400 and Method 500.

[0107] Figure 1 The communication system 100 shown can be applied to Figure 2 (a) and / or Figure 2 The fifth-generation (5G) network architecture shown in (b) can of course also be used in future network architectures, such as the sixth-generation (6G) network architecture, etc. This application does not specifically limit this.

[0108] For example, suppose Figure 1 The communication system 100 shown is applied to Figure 2 (a) and / or Figure 2 In the 5G network shown in (b), the above session management network element can be the SMF in 5G.

[0109] The following will combine Figure 2 (a) and Figure 2Example (b) illustrates a 5G system to which embodiments of this application are applicable. It should be understood that the 5G systems described herein are merely examples and should not be construed as limiting the scope of this application.

[0110] It should also be understood that some network elements in a 5G system can communicate using service-oriented interfaces or point-to-point interfaces. The following section will discuss this further. Figure 2 (a) and Figure 2 Section (b) introduces the 5G system framework based on point-to-point interfaces and the 5G system framework based on service-oriented interfaces, respectively.

[0111] As an example, Figure 2 (a) shows a schematic diagram of the architecture of the 5G system 200a to which embodiments of this application apply. Figure 2 (a) in the diagram is a schematic of a 5G network architecture based on a point-to-point interface. Figure 2 As shown in (a), the network architecture may include, but is not limited to, the following network elements (or functional network elements, functional entities, nodes, devices, etc.):

[0112] The network includes radio access network (R)AN, access and mobility management function (AMF) network elements, session management function (SMF) network elements, user plane function (UPF) network elements, policy control function (PCF) network elements, unified data management (UDM) network elements, AF network elements, data network (DN), network slice selection function (NSSF), authentication server function (AUSF), unified data management (UDM), BSF network elements, unified data repository (UDR), etc.

[0113] The following is about Figure 2 A brief introduction to each network element shown in (a) is provided below:

[0114] 1. User Equipment (UE): This can also be called terminal equipment, terminal device, access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user device. Terminal equipment can be a device that provides voice / data connectivity to users, such as a handheld device with wireless connectivity, vehicle-mounted equipment, etc. Currently, examples of terminals include: mobile phones, tablets, computers with wireless transceiver capabilities (such as laptops and PDAs), mobile internet devices (MIDs), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving vehicles, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in 5G networks, or future public land mobile communication networks. Terminal devices in a network (PLMN), etc.

[0115] Furthermore, terminal devices can also be terminal devices in Internet of Things (IoT) systems. IoT is an important component of future information technology development. Its main technical characteristic is connecting objects to networks through communication technologies, thereby realizing an intelligent network that enables human-machine interconnection and machine-to-machine interconnection. IoT technology can achieve massive connectivity, deep coverage, and low power consumption at the terminal level through technologies such as narrowband (NB).

[0116] In addition, terminal devices may also include smart printers, train detectors, etc. Their main functions include collecting data (for some terminal devices), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0117] It should be understood that a user equipment can be any device capable of accessing a network. Terminal devices and access network devices can communicate with each other using some form of air interface technology.

[0118] Alternatively, the user equipment (UE) can be used to act as a base station. For example, the UE can act as a scheduling entity, providing sidelink signaling between UEs in V2X or D2D, etc. For instance, cellular phones and cars communicate with each other using sidelink signals. Cellular phones and smart home devices can communicate without relaying communication signals through a base station.

[0119] 2. Radio access network (RAN) equipment: used to provide network access functionality for authorized user equipment in a specific area, and can use transmission tunnels with different service quality according to the user equipment level, service requirements, etc.

[0120] (R)AN can manage radio resources, provide access services for user equipment, and then complete the forwarding of control signals and user equipment data between user equipment and the core network. (R)AN can also be understood as a base station in a traditional network.

[0121] For example, the access network device in this application embodiment can be any kind of communication device with wireless transceiver function for communicating with user equipment. The access network device includes, but is not limited to, an evolved NodeB (eNB) or 5G, such as NR, a gNB in ​​the system, or a transport point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or it can also be a network node constituting a gNB or transport point, such as a baseband unit (BBU) or a distributed unit (DU), etc.

[0122] In some deployments, a gNB may include a centralized unit (CU) and a dedicated unit (DU). The gNB may also include an active antenna unit (AAU). The CU implements some of the gNB's functions, and the DU implements others. For example, the CU handles non-real-time protocols and services, implementing radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions. The DU handles physical layer protocols and real-time services, implementing radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, radio frequency processing, and active antenna-related functions. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can be considered to be sent by the DU, or by the DU+AAU. It is understood that access network equipment can be one or more of the following: CU nodes, DU nodes, and AAU nodes. In addition, the CU can be classified as an access network device in the radioaccess network (RAN) or as an access network device in the core network (CN), and this application does not limit this.

[0123] 3. User plane function (UPF) network element: used for packet routing and forwarding, as well as quality of service (QoS) processing of user plane data.

[0124] In 5G communication systems, this user plane network element can be a user plane function (UPF) network element. In future communication systems, the user plane network element can still be a UPF network element, or it can have other names; this application does not limit this.

[0125] 4. Access and Mobility Management Function (AMF) Network Element: The access and mobility management function network element is mainly used for mobility management and access management. It can be used to implement other functions in the MME besides session management, such as access authorization / authentication.

[0126] In future communication systems, the access and mobility management equipment may still be an AMF, or may have other names; this application does not limit this.

[0127] 5. Session Management Function (SMF) network element: mainly used for session management, allocation and management of Internet Protocol (IP) addresses for user equipment, selection of manageable user plane functions, endpoints for policy control and charging function interfaces, and downlink data notification, etc.

[0128] In future communication systems, the session management network element can still be an SMF network element, or it can have other names; this application does not limit this.

[0129] 6. Policy control function (PCF) network element: A unified policy framework used to guide network behavior, providing policy rule information to control plane function network elements (such as AMF, SMF, etc.).

[0130] In future communication systems, the policy control network element can still be a PCF network element, or it can have other names; this application does not limit this.

[0131] 7. Application Function (AF): Used for data routing affected by applications, opening up functional network elements in wireless access networks, and interacting with the policy framework for policy control, etc.

[0132] In future communication systems, the application network element can still be an AF network element, or it can have other names; this application does not limit this.

[0133] 8. Unified Data Management (UDM) network element: used to handle UE identification, access authentication, registration, and mobility management, etc.

[0134] In future communication systems, unified data management can still be a UDM network element, or it can have other names; this application does not limit this.

[0135] 9. Authentication server function (AUSF) network element: used for authentication services, generating keys to achieve two-way authentication of user equipment, and supporting a unified authentication framework.

[0136] In future communication systems, the authentication server function network element can still be an AUSF network element, or it can have other names; this application does not limit this.

[0137] 10. Network Data Analytics Function (NWDAF): This network element is used to identify network slice instances and load their load level information. The NWDAF allows NF consumers to subscribe to or unsubscribe from periodic notifications and to notify consumers when thresholds are exceeded.

[0138] In future communication systems, the network data analysis function network element can still be an NWDAF network element, or it can have other names; this application does not limit this.

[0139] 11. Data Network (DN): A DN is a network located outside the carrier's network. Multiple DNs can be connected to the carrier's network, and various services can be deployed on a DN, providing data and / or voice services to terminal devices. For example, a DN might be the private network of a smart factory. Sensors installed in the workshop can act as terminal devices. A control server for these sensors is deployed within the DN, providing services to the sensors. Sensors can communicate with the control server, receive instructions, and transmit collected sensor data back to the control server accordingly. Another example is a DN serving as an internal office network for a company. Employees' mobile phones or computers can act as terminal devices, accessing information and data resources on the company's internal office network.

[0140] Figure 2 In (a), Nausf, Nnef, Npcf, Nudm, Naf, Namf, Nsmf, N1, N2, N3, N4, and N6 are interface sequence numbers. The meanings of these interface sequence numbers can be found in the definitions in the 3GPP standard protocols, and are not limited here.

[0141] exist Figure 2 In the network architecture shown in (a), network elements can communicate with each other through the interfaces shown in the figure. As shown, the UE and AMF can interact through the N1 interface, and the interaction message can be called an N1 message. The RAN and AMF can interact through the N2 interface, which can be used to send non-access stratum (NAS) messages. The RAN and UPF can interact through the N3 interface, which can be used to transmit user plane data. The SMF and UPF can interact through the N4 interface, which can be used to transmit information such as tunnel identification information for N3 connections, data buffer indication information, and downlink data notification messages. The UPF and DN can interact through the N6 interface, which can be used to transmit user plane data. The relationships between other interfaces and network elements are as follows: Figure 2As shown in (a), for the sake of brevity, not all details are provided here.

[0142] like Figure 2 As shown in (b), this is a schematic diagram of a 5G network architecture based on a point-to-point interface. For a description of the functions of the network elements, please refer to [reference needed]. Figure 2 The functions of the network elements corresponding to (a) will not be described in detail here. Figure 2 (b) and Figure 2 The main difference between (a) and (b) is: Figure 2 The interfaces between the network elements in (b) are point-to-point interfaces, not service-oriented interfaces.

[0143] exist Figure 2 In the architecture shown in (b), the interface names and functions between the various network elements are as follows:

[0144] 1) N7: The interface between PCF and SMF, used to issue protocol data unit (PDU) session granularity and business data stream granularity control strategies.

[0145] 2) N15: The interface between PCF and AMF, used to issue UE policies and access control related policies.

[0146] 3) N5: The interface between AF and PCF, used for issuing application service requests and reporting network events.

[0147] 4) N4: The interface between SMF and UPF, used to transmit information between the control plane and the user plane, including the distribution of forwarding rules, QoS control rules, traffic statistics rules, etc. from the control plane to the user plane, as well as the reporting of information from the user plane.

[0148] 5) N11: The interface between SMF and AMF, used to transmit PDU session tunnel information between RAN and UPF, transmit control messages sent to UE, transmit radio resource control information sent to RAN, etc.

[0149] 6) N2: The interface between AMF and RAN, used to transmit radio bearer control information from the core network side to the RAN.

[0150] 7) N1: The interface between AMF and UE, access-independent, used to transmit QoS control rules to UE, etc.

[0151] 8) N8: The interface between AMF and UDM, used by AMF to obtain access and mobility management related subscription data and authentication data from UDM, and by AMF to register UE's current mobility management related information with UDM.

[0152] 9) N10: The interface between SMF and UDM, used by SMF to obtain session management-related subscription data from UDM, and by SMF to register UE current session-related information with UDM.

[0153] 10) N35: The interface between UDM and UDR, used by UDM to obtain user subscription data information from UDR.

[0154] 11) N36: The interface between PCF and UDR, used by PCF to obtain policy-related contract data and application data related information from UDR.

[0155] 12) N12: The interface between AMF and AUSF, used by AMF to initiate the authentication process to AUSF, which can carry SUCI as the signing identifier;

[0156] 13) N13: The interface between UDM and AUSF, used by AUSF to obtain the user authentication vector from UDM in order to execute the authentication process.

[0157] Figure 3 The diagram illustrates a user plane architecture 300 for a 5G VN service. UPF1-UPF3 belong to a single 5G VN. UE1-UE3 are connected to a UPF within the 5G VN via a RAN. For example, UE1 connects to UPF1 via RAN1, UE2 connects to UPF2 via RAN2, and UE3 connects to UPF3 via RAN3, thus accessing the user plane (UP) of the corresponding 5G VN through the UPF. Alternatively, UE1-UE3 may access the 5GC UP via UPF1-UPF3, belonging to a single 5G VN group. A UE resides within a 5G VN (or, as can be understood, a UE belongs to a 5G VN or a 5G VN service, or the UE is subscribed to a 5G VN or a 5G VN service, or the UE is associated with or corresponds to a 5G VN or a 5G VN service). The 5G VN user plane can communicate with existing VNs within the DN via the N6 interface. Alternatively, the user plane of 5G VN can also associate protocol data unit (PDU) sessions of different UEs through N19 connections between various UPFs (e.g., UPF1 to UPF3) in the 5G VN, thereby enabling private communication between UEs.

[0158] To facilitate understanding of the embodiments of this application, the terms involved in this application will first be explained.

[0159] 1. Protocol Data Unit (PDU) Session

[0160] In a 5G communication system, a QoS flow is a combination of QoS flows established on the UE (User Equipment). These QoS flows share the same IP address and Data Network Name (DNN). A QoS flow refers to a data transmission channel within a 5G communication system.

[0161] The 5G core network (5GC) supports PDU connection services. PDU connection services refer to the exchange of PDU data packets between a terminal device and the data network (DN). PDU connection services are implemented by the terminal device initiating the establishment of a PDU session. Once a PDU session is established, a PDU session tunnel is created. This tunnel corresponds to the UE, and service data within the tunnel can be transmitted in the form of a unicast QoS stream. In other words, the PDU session is at the UE level. Each terminal device can establish one or more PDU sessions. The PDU session ID is used to distinguish different PDU sessions for the same UE.

[0162] 2. Tunnel Information

[0163] In the core network, tunnel information refers to the network address of N3 (between RAN and UPF) tunnels or N9 (between UPFs) tunnels within a PDU session. Tunnel information consists of the tunnel endpoint identifier and IP address. Based on operator configuration, the SMF or UPF is responsible for allocating and releasing core network tunnel information when a PDU session is established or released.

[0164] Depending on the operator configuration, if the allocation and release of tunnel information are performed by the SMF, the tunnel information space must be managed by the SMF. The SMF allocates tunnel information and provides the allocated tunnel information to the UPF when the PDU session is established, and releases the tunnel information and notifies the UPF of the released tunnel information when the PDU session is released.

[0165] Depending on the operator configuration, if the allocation and release of tunnel information are performed by the UPF, the UPF must manage the tunnel information space. When a PDU session is established, the SMF should request the UPF to allocate tunnel information, and the UPF will provide the allocated tunnel information to the SMF in a response message. The SMF will then provide the received tunnel information to the access network. When a PDU session is released, the SMF should request the UPF to release the core network tunnel information.

[0166] Figure 4An exemplary flowchart of the method 400 provided in an embodiment of this application is shown. The following is in conjunction with... Figure 4 The flowchart in the document provides an example illustration of method 400.

[0167] S401, the group management network element sends the identification information of the second session management network element to the first session management network element. Correspondingly, the first session management network element receives the identification information of the second session management network element from the group management network element.

[0168] For example, the first session management network element and the second session management network element provide services for sessions of different terminal devices belonging to the same group. For instance, the first session management network element provides services for the session of the first terminal device, and the second session management network element provides services for the session of the second terminal device, wherein the first terminal device and the second terminal device belong to the same group.

[0169] It should be understood that the identification information of the second session management network element can be information used to uniquely identify the second session management network element. For example, the identification information of the second session management network element can be the instance ID, fully qualified domain name (FQDN), address information, uniform resource identifier (URI), endpoint number, or context ID, etc. This application does not limit it.

[0170] It should also be understood that the group management network element is a logical function network element. It can be an independent network element, such as the group session management function (GSMF), or it can integrate its functions into other network elements, such as the unified data management (UDM), the session management function (SMF), or other core network elements. This application does not limit it.

[0171] In one implementation, the group management network element sends the identification information of the second session management network element to the first session management network element based on the subscription message #1 of the first session management network element.

[0172] For example, during the process of the first terminal device establishing a session through the first session management network element, or after the first terminal device has established a session through the first session management network element, in S402, the first session management network element sends a subscription message #1 to the group management network element. The subscription message #1 includes the identification information of the group and is used to subscribe to the group's information change notifications.

[0173] The identification information of the group can be information used to identify or determine the group. For example, the identification information of the group can be the group ID, the data network name (DNN), or a combination of the data network name and single network slice selection assistance information (S-NSSAI). This application does not limit this.

[0174] The notification of changes to the group information can include notifications of changes to the session management network element corresponding to the group. That is, the subscription message #1 is used to cause the group management network element to send a notification message to the first session management network element when a new session management network element registers to the group (or when another new session management network element starts providing services to the same group), or when a session management network element deregisters from the group (or when another session management network element stops providing services to the group). For example, after the second terminal device establishes a session through the second session management network element, the second session management network element can register its own identification information and the identification information of the group it serves with the group management network element. Specifically, for example, in S403, the second session management network element sends a registration request message to the group management network element. This registration request message includes the identification information of the second session management network element and the identification information of the group. Optionally, the second session management network element can also register information about the user plane network elements it manages and the identification information of the group members with the group management network element. The information about the user plane network elements can be the tunnel information of the user plane network elements, and the identification information of the group members can be the address information of the group members. It should be understood that in this application, the example of a group member as the terminal device is used for illustration.

[0175] Optionally, after receiving a registration request message from the second session management network element, the group management network element saves the association between the identification information of the second session management network element and the identification information of the group. If the second session management network element also registers the information of the user plane network elements it manages and the identification information of the group members with the group management network element, the group management network element saves the association between the identification information of the group, the identification information of the second session management network element, the information of the user plane network elements managed by the second session management network element, and the identification information of the group members. For example, if the second terminal establishes a session through the second session management network element, and the second session management network element selects the second user plane network element to serve the session and assigns an IP address to the second terminal device, then the group management network element saves the association between the identification information of the group, the identification information of the second session management network element, the information of the second user plane network element, and the IP address of the second terminal device.

[0176] In this implementation, after the group management network element receives a registration request message from the second session management network element, based on the subscription message #1, the group management network element sends a notification message to the first session management network element. This notification message includes the identification information of the second session management network element and the identification information of the group. This notification message can be used to indicate that the second session management network element serving the group has registered with the group management network element; alternatively, it can be used to indicate that the second session management network element is a network element providing services for the sessions of group members within the group; or it can be used to indicate that the second session management network element and the group are associated. The notification message may also indicate other meanings, which are not limited in this application.

[0177] The notification of changes to group information can also be used to notify the session management network elements of newly joined service groups from existing service group session management network elements. For example, assuming the first session management network element is an existing session management network element serving the group, when the second session management network element subsequently begins serving the group, the group management network element sends the identification information of the first session management network element to the second session management network element based on the subscription message #1. It should be understood that the session management network element of a service group refers to the session management network element that provides services for the sessions of one or more group members within the group.

[0178] In another implementation, after receiving the registration request message from the second session management network element, the group management network element determines the first session management network element and then sends the identification information of the second session management network element to the first session management network element. For example, after receiving the registration request message from the second session management network element, the group management network element queries or determines other session management network elements that provide services for the sessions of group members in the group. The group management network element can query other session management network elements in its local storage or through other network elements; this application does not impose any limitations. It should be understood that the group management network element pre-stores the association between the identification information of the first session management network element and the identification information of the group. For example, after the first terminal device in the group establishes a session through the first session management network element, the first session management network element registers its own identification information and the group's identification information with the group management network element. The group management network element receives and stores the association between the identification information of the first session management network element and the identification information of the group. For example, the first session management network element sends a registration request message to the group management network element. This registration request message includes the identification information of the group and the identification information of the first session management network element. After receiving the registration request message from the first session management network element, the group management network element saves the association between the identification information of the first session management network element and the identification information of the group. Therefore, when the group management network element receives a registration request message from the second session management network element, it can identify the first session management network element based on the identification information of the group, and then send a notification message to the first session management network element, carrying the identification information of the second session management network element in the notification message.

[0179] In another possible implementation, the group management network element can also send the identification information of the second session management network element to the first session management network element based on the request message from the first session management network element.

[0180] As an example, a first session management network element sends a request message #2 to a group management network element to locate a session management network element serving the group. This request message #2 includes the group's identification information. The group's identification information is used by the group management network element to determine which session management network element serves the group. Correspondingly, after receiving the request message #2 from the first session management network element, the group management network element queries for the session management network element serving the group, or in other words, queries for the session management network element corresponding to the group. Then, the group management network element sends a response message #2 to the first session management network element. This response message #2 includes the identification information of the session management network element serving the group, including the identification information of a second session management network element. Optionally, the second session management network element may be a subset of the session management network elements serving the group determined by the group management network element. It should be understood that the identification information of the session management network element carried in the response message #2 may also include the identification information of the first session management network element and / or other session management network elements serving the group. The first session management network element can query the group management network element for all session management network elements serving the group through request message #2, or it can query the group management network element for session management network elements other than itself (the first session management network element) through request message #2. This application does not limit this.

[0181] As another example, the first session management network element sends a request message #3 to the group management network element to query the session management network element that serves one or more group members. This request message #3 includes the group's identification information and the identification information of one or more group members or user plane network elements. If, in step S403, the group management network element stores the association between the group's identification information, the session management network element's identification information, the user plane network elements managed by the session management network element, and the group members' identification information, the group management network element can determine one or more session management network elements that serve one or more group members based on the identification information of those group members or the user plane network element information, and then send those one or more session management network elements to the first session management network element via response message #3. For example, the first session management network element sends a request message #3 to the group management network element. This request message #3 includes the group's identification information and the identification information of the second terminal device. This request message #3 can be used to find the session management network element that serves the second terminal device. Correspondingly, after receiving the request message #3, the group management network element determines, based on the identification information of the second terminal device, that the second session management network element is the network element that provides services for the session of the second terminal device. Therefore, the group management network element sends a response message #3 to the first session management network element, which includes the identification information of the second session management network element.

[0182] It should be understood that the second session management network element can also receive the identification information from the first session management network element from the group management network element through the above implementation method.

[0183] This application embodiment uses the example of a group management network element sending the identification information of a second session management network element to a first session management network element for illustration. However, it should be understood that if the group management network element determines that there are other session management network elements providing services for the sessions of one or more group members, the group management network element can also send the identification information of a second session management network element to that session management network element. The specific implementation method is similar and will not be described in detail here.

[0184] S404, the first session management network element sends request message #1 to the second session management network element. Correspondingly, the second session management network element receives request message #1 from the first session management network element.

[0185] In one implementation, after the first session management network element receives the identification information of the second session management network element from the group management network element, the first session management network element can determine that there are other session management network elements (i.e., the second session management network element) serving the current group. In order to enable group communication between group members managed by different session management network elements, the first session management network element determines to establish a session with the second session management network element, and / or establish a tunnel between the user plane network element managed by the first session management network element and the user plane network element managed by the second session management network element.

[0186] Based on this, the first session management network element sends a request message #1 to the second session management network element according to the identification information of the second session management network element. This request message #1 includes the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device. The first user plane network element is a user plane network element managed by the first session management network element that provides services to the first terminal device. The first terminal device may include one or more terminal devices, and the first user plane network element may also include one or more user plane network elements. One first user plane network element can correspond to one or more first terminal devices, meaning one first user plane network element can serve one or more first terminal devices. Optionally, the request message #1 may also include a session identifier of the first session management network element. This session identifier is used to identify the context associated with the second session management network element on the first session management network element for the group. The session identifier of the first session management network element is allocated or maintained by the first session management network element and can be an identifier such as a context ID or callback URI, used by the second session management network element to send response or update messages to the first session management network element. The session identifier of the first session management network element can be included in the request message #1 or in the message header of the request message #1, without limitation.

[0187] It should be understood that the session identifier of the first session management network element may be associated not only with the second session management network element, but also with other session management network elements (e.g., the third session management network element). In this case, the session identifier of the first session management network element is used to identify the context for the group, which can be regarded as a group-level context, rather than a session management network element-level context. Taking the first, second, and third session management network elements serving the group as an example, in one implementation, the first session management network element assigns two session identifiers to associate with the second and third session management network elements respectively. In another implementation, the first session management network element assigns only one session identifier to associate with both the second and third session management network elements simultaneously. The session identifier of the first session management network element can identify the context for the group associated with the second session management network element on the first session management network element, or the context for the group associated with the third session management network element on the first session management network element, and can also identify the context for the group on the first session management network element.

[0188] It should be understood that the tunnel information of the first user plane network element can be allocated by the first session management network element or by the first user plane network element, and this application does not limit it. The tunnel information of the first user plane network element can refer to the N19 tunnel information of the first user plane network element.

[0189] The identification information of the first terminal device may be the subscription permanent identifier (SUPI) of the first terminal device, or the generic public subscription identifier (GPSI), or address information (such as the Internet protocol address (IP address) or media access control address (MAC address) of the first terminal device).

[0190] The request message #1 can be a session establishment request (PDUSession_Create Request) message, for example, it can be used to request the establishment of a session between a first session management network element and a second session management network element; or, it can be a tunnel establishment request message, for example, it can be used to request the establishment of a tunnel between a first user plane network element and user plane network elements managed by the second session management network element; or, it can be a tunnel information request message, for example, it can be used to request tunnel information for user plane network elements managed by the second session management network element that provide services to group members. This application does not limit the specific name of this message.

[0191] It should be understood that if the second session management network element receives the identification information of the first session management network element from the group management network element, the second session management network element may also send a request message #1 to the first session management network element. This request message #1 includes the identification information of the group, the tunnel information of the second user plane network element, and the identification information of the second terminal device. The second user plane network element is a user plane network element managed by the second session management network element and providing services to the second terminal device. Optionally, the request message #1 may also include session information of the second session management network element. The session identifier of the second session management network element is used to identify the context associated with the first session management network element for the group on the second session management network element. The session identifier of the second session management network element is allocated or maintained by the second session management network element and may be a context ID or callback URI, etc., used by the first session management network element to send response or update messages to the second session management network element subsequently. The session identifier of the second session management network element may be included in the request message #1 or in the message header of the request message #1, without limitation. The following description uses the example of the first session management network element sending request message #1 to the second session management network element. The second session management network element sending request message #1 to the first session management network element and the corresponding response message #1 can refer to the corresponding steps and will not be repeated.

[0192] Optionally, before sending request message #1, the first session management network element may assign a session identifier to the group. This session identifier is used to identify the context of the first session management network element associated with the second session management network element for the group. In this case, the first session management network element may carry the session identifier in request message #1.

[0193] Optionally, in step S405, the first session management network element determines that there is no context associated with the second session management network element for the group on the first session management network element.

[0194] For example, before the first session management network element sends request message #1 to the second session management network element, the first session management network element checks whether there is a context associated with the second session management network element for that group on the first session management network element, or in other words, whether there is a session for that group between the first session management network element and the second session management network element. In one implementation, the first session management network element can determine this based on whether it has been allocated session information. If it already has session information, it can be determined that there is a context associated with the second session management network element for that group on the first session management network element. Otherwise, it does not exist. In another implementation, the first session management network element can determine this based on whether it has saved session information for the second session management network element. If it already has session information for the second session management network element, it can be determined that there is a context associated with the second session management network element for that group on the first session management network element. Otherwise, it does not exist.

[0195] It should be understood that the session identifier of the second session management network element may be associated not only with the first session management network element, but also with other session management network elements (e.g., the third session management network element). In this case, the session identifier of the second session management network element is used to identify the context for the group, that is, it can be regarded as the context at the group level, rather than the context at the session management network element level. In this case, the context for the group associated with the first session management network element on the second session management network element and the context for the group on the second session management network element can have the same meaning. Taking the first, second, and third session management network elements serving the group as an example, in one implementation, the second session management network element assigns two session identifiers to be associated with the first and third session management network elements respectively. In another implementation, the second session management network element is assigned only one session identifier and associated with both the first and third session management network elements. The session identifier of the second session management network element can identify the context of the group associated with the first session management network element on the second session management network element, or the context of the group associated with the third session management network element on the second session management network element.

[0196] Among them, the first session management network element and the second session management network element may establish different contexts (or sessions) for different groups. The session for the group refers to the session between the first session management network element and the second session management network element corresponding to the aforementioned group.

[0197] If the context does not exist, that is, when the first session management network element determines that there is no session for the group between the first session management network element and the second session management network element, the first session management network element executes step S404, that is, the first session management network element sends a request message #1 to the second session management network element.

[0198] If the context exists, in one implementation, the first session management network element no longer requests the second session management network element to establish a session, but instead requests to reuse a previously established session. In this case, the request message #1 can be a session update request message.

[0199] In another implementation, the first session management element does not make any judgment and always requests the second session management element to establish a session. After receiving the request message from the first session management element, the second session management element checks whether a session for that group has already been established between the first and second session management elements. If it has already been established, the second session management element rejects the first session management element's request. If the first session management element receives a rejection message from the second session management element, it can send a session update request message to the second session management element.

[0200] Optionally, in step S406, the first session management network element sends subscription message #2 to the second session management network element. Correspondingly, the second session management network element receives subscription message #2 from the first session management network element.

[0201] For example, the first session management network element can also send a subscription message #2 to the second session management network element. This subscription message #2 is used to subscribe to change notifications from user plane network elements corresponding to the second session management network element that serve group members in the group, and / or change notifications from group members corresponding to the second session management network element. Optionally, the subscription message #2 includes the group's identification information and the session identifier of the first session management network element. The session identifier of the first session management network element is allocated or maintained by the first session management network element and can be an identifier such as a notification URI, used by the second session management network element to send notification messages to the first session management network element subsequently. The session identifier of the first session management network element can be included in the subscription message #2 or in the message header of the subscription message #2, without limitation.

[0202] Correspondingly, the second session management network element receives subscription message #2 from the first session management network element. Based on this subscription message #2, when a new user plane network element serving group members connects to the second session management network element, or when a user plane network element serving group members deregisters from the second session management network element, the second session management network element needs to send a notification message to the first session management network element; and / or, when a new group member connects to the second session management network element, or when a group member deregisters / goes offline from the second session management network element, the second session management network element needs to send a notification message to the first session management network element. For example, if the second terminal device served by the second session management network element moves, and the second user plane network element serving the second terminal device changes, then the second session management network element sends a notification message to the first session management network element based on the subscription message #2. The notification message may include information about the new second user plane network element and / or the new address information of the second terminal device.

[0203] In one implementation, based on the subscription message #2, the second session management network element detects that there is a new IP allocation, IP address release, or IP address change in the group. These events can correspond to three types of events: a new group member joining the second session management network element, a group member deregistering / going offline from the second session management network element, and a change in the user plane network element serving the group member. In these cases, the second session management network element determines that it needs to send a notification message to the first session management network element.

[0204] It should be understood that S404 and S406 can be executed together or separately. That is, the request message #1 of S404 and the subscription message #2 of S406 can be two separate messages or they can be merged into one message. This application does not limit this.

[0205] Optionally, in S407, the second session management network element assigns a session identifier.

[0206] For example, after receiving request message #1 from the first session management network element, the second session management network element can save the association between the identification information of the first session management network element and the identification information of the group in the context, and assign a session identifier to the second session management network element. The session identifier of the second session management network element is used to identify the context in which the second session management network element is associated with the first session management network element. The session identifier of the second session management network element can be, for example, a context ID or a resource URI.

[0207] It should be understood that if the second session management network element sends request message #1 to the first session management network element, then the execution subject in this step is the first session management network element.

[0208] S408, the second session management network element sends response message #1 to the first session management network element. Correspondingly, the first session management network element receives response message #1 from the second session management network element.

[0209] For example, after receiving request message #1 from the first session management network element, the second session management network element sends response message #1 to the first session management network element. Response message #1 includes tunnel information of the second user plane network element and identification information of the second terminal device. The second terminal device may include one or more terminal devices, and the second user plane network element may also include one or more user plane network elements. One second user plane network element can correspond to one or more second terminal devices; that is, one second user plane network element can serve one or more second terminal devices.

[0210] It should be understood that the tunnel information of the second user plane network element can be allocated by the second session management network element or by the second user plane network element, and this application does not limit it.

[0211] Optionally, response message #1 also includes a session identifier of the second session management network element, which is used to identify the context of the second session management network element associated with the first session management network element for the group. The session identifier of the second session management network element may be, for example, a context ID or a resource URI.

[0212] Optionally, the first session management network element stores the session identifier of the second session management network element and the identification information of the group;

[0213] If the terminal device or user plane network element managed by the first session management network element changes subsequently, the first session management network element can send an update message #1 to the second session management network element based on the session identifier of the second session management network element. For example, the first session management network element receives a session establishment request message from a third terminal device for a group, wherein the third terminal device belongs to the group. In response to the session establishment request message, the first session management network element allocates a third user plane network element for the session of the third terminal device. Then, the first session management network element sends an update message #1 to the second session management network element based on the session identifier of the second session management network element, wherein the update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device. The session identifier in the update message #1 is used to identify which session the second session management network element is processing.

[0214] It should be understood that the update request message #1 may be a session update request message or a tunnel modification request message, and this application does not limit the name of the message.

[0215] Correspondingly, after receiving update message #1 from the first session management network element, the second session management network element configures (adds or updates) a third forwarding rule in the second user plane network element according to the tunnel information of the third user plane network element and the identification information of the third terminal device. The third forwarding rule is used to send data packets whose destination address points to the third terminal device to the third user plane network element. In other words, the third forwarding rule is used to encapsulate data packets whose destination address is the identification information of the third terminal device with the tunnel information of the third user plane network element and send them to the third user plane network element.

[0216] Optionally, after receiving update message #1, the second session management network element can add the tunnel information of the third user plane network element and the identification information of the third terminal device to the context associated with the first session management network element for that group, based on the session identifier of the second session management network element.

[0217] Update message #1 may also include indications for adding, updating, or releasing information. These indications are used to instruct the second session management network element to configure the third forwarding rule on the second user plane network element. The indication information can be a separate message or integrated into the message name; there are no restrictions on this.

[0218] For example, after the first terminal device releases its session, the first session management network element sends an update message #1 to the second session management network element. Update message #1 can be a session release request message or a tunnel release request message; the message name is not limited. This update message #1 may include the session identifier of the second session management network element. Based on this update message #1, the second session management network element deletes the third forwarding rule.

[0219] Optionally, after receiving the request message #1 from the first session management network element, the second session management network element configures forwarding rules for the second user plane network element, which are used to send data packets whose destination address is the first terminal device to the first user plane network element based on the tunnel information of the first user plane network element in step S404. In other words, for data packets whose destination address is the first terminal device, the tunnel information of the first user plane network element is encapsulated and sent to the first user plane network element.

[0220] Optionally, the first session management network element receives request message #3 from the second session management network element, where request message #3 includes group identification information. In this case, the first session management network element checks whether a session for the group exists between the first and second session management network elements (here, "session" can also be replaced with "context," and similar explanations will not be repeated). When the first session management network element determines that a session for the group exists between the first and second session management network elements, the first session management network element rejects request message #3.

[0221] Optionally, in step S409, the second session management network element sends subscription message #3 to the group management network element. Correspondingly, the group management network element receives subscription message #3 from the second session management network element. It should be understood that S409 is similar to S402, and the description in step S402 can be referred to.

[0222] For example, the subscription message #3 includes the identifier of the group. This subscription message #3 is used to subscribe to group information change notifications, which include notifications of changes to the session management network element corresponding to the group. In other words, the subscription message #3 is used by the group management network element to send a notification message to the second session management network element when a new session management network element registers with the group, or when a session management network element is deregistered from the group. The group information change notification can also be used to notify the new session management network element of the existing service group. For example, assuming the first session management network element serves the group first, and the second session management network element subsequently serves the group, after step S408, the group management network element sends the identifier of the first session management network element to the second session management network element.

[0223] It should be understood that S409 can be executed after S403 or after S408, and this application does not limit it.

[0224] It is worth noting that if the second session management network element receives the identification information of the first session management network element from the group management network element, similar to step S404, the second session management network element determines that there are other session management network elements serving the current group. In order to enable group communication between group members managed by different session management network elements, the second session management network element may also send a request message to the first session management network element. Optionally, the second session management network element checks whether a session has been established between the first and second session management network elements in the current group. If it has been established, in one implementation, the second session management network element may no longer request to establish a session with the first session management network element. In another implementation, the second session management network element does not make a judgment and always requests to establish a session with the first session management network element. The first session management network element checks whether a session has been established between the first and second session management network elements in the current group. If it has been established, the first session management network element rejects the request from the second session management network element.

[0225] Optionally, in S409, the second session management network element sends a subscription message #4 to the first session management network element. Correspondingly, the first session management network element receives the subscription message #4 from the second session management network element. It should be understood that S409 is similar to S405, so detailed steps can be found in the description of S405, and will not be repeated here.

[0226] For example, the subscription message #4 is used to subscribe to change notifications of user plane network elements corresponding to the first session management network element that serve the group members in the group, and / or change notifications of group members corresponding to the first session management network element.

[0227] Correspondingly, the first session management network element receives subscription message #4 from the second session management network element. Based on this subscription message #4, when a new user plane network element serving group members connects to the first session management network element, or when a user plane network element serving group members deregisters from the first session management network element, the first session management network element needs to send a notification message to the second session management network element; and / or, when a new group member connects to the first session management network element, or when a group member deregisters from the first session management network element, the first session management network element needs to send a notification message to the second session management network element.

[0228] S409, the first session management network element configures a first forwarding rule in the first user plane network element based on the tunnel information of the second user plane network element and the identification information of the second terminal device. The first forwarding rule is used to send data packets whose destination address points to the second terminal device to the second user plane network element.

[0229] It should be understood that a data packet whose destination address points to a second terminal device means that the destination address of the data packet points to the second terminal, or in other words, the destination address of the data packet is the identification information of the second terminal (e.g., IP address).

[0230] Based on the above scheme, communication can be achieved between terminal devices in the same group that correspond to different session management network elements. Specifically, when a second terminal device belonging to the group establishes a session through a second session management network element, the second session management network element registers its identification information and the group's identification information with the group management network element. Based on this, the group management network element notifies the session management network element currently providing services for the group members' sessions (taking the first session management network element providing services for the first terminal device in the group as an example), thereby triggering the first session management network element to establish a session with the second session management network element, as well as a tunnel between the first user plane network element and the second user plane network element. This establishes a data forwarding path between the first and second terminal devices, enabling communication between them, ensuring data transmission security, and effectively shortening the transmission path.

[0231] On the other hand, the solution in this application embodiment can also support the updating of group member topology information. For example, in subsequent processes, if the terminal device or user plane device managed by the second session management network element changes, the second session management network element sends update message #2 to the first session management network element.

[0232] For example, the second session management network element receives a session establishment request message from a fourth terminal device for the group, wherein the fourth terminal device belongs to the group. In response to the session establishment request message, the second session management network element allocates a fourth user plane network element for the session of the fourth terminal device.

[0233] In one implementation, the second session management network element maintains a context associated with the first session management network element for the group. In other words, the second session management network element maintains a session with the first session management network element for the group. Or, the second session management network element stores the association between the identification information of the first session management network element and the identification information of the group in the context associated with the first session management network element for the group. In this case, the second session management network element determines the identification information of the first session management network element based on the context associated with the second session management network element for the group, and then sends an update message #2 to the first session management network element based on the identification information of the first session management network element. The update message #2 includes the tunnel information of the fourth user plane network element, the identification information of the fourth terminal device, and the session identifier of the first session management network element.

[0234] In another implementation, the second session management network element sends a query request message to the group management network element to request information from other session management network elements in the corresponding group. After the group management network element determines the information of the other session management network elements (including the identification information of the first session management network element), it sends a response message to the second management network element, which includes the information of the other session management network elements (including the identification information of the first session management network element). Then, the second session management network element sends an update message #2 to the first session management network element based on the identification information of the first session management network element. Correspondingly, after receiving the update message #1 from the first session management network element, the first session management network element configures a second forwarding rule in the first user plane network element based on the tunnel information of the fourth user plane network element and the identification information of the fourth terminal device. This second forwarding rule is used to send data packets whose destination address points to the fourth terminal device to the fourth user plane network element.

[0235] It should be understood that if the first session management network element detects that it is no longer serving any terminal device, it sends a session release request message to the second session management network element. The session release request includes the session identifier of the second session management network element, and the second session management network element releases the forwarding rules configured on the second user plane network element related to the first user plane network element managed by the first session management network element. Correspondingly, if the second session management network element detects that it is no longer serving any terminal device, it can also send a session release request message to the first session management network element. The session release request includes the session identifier of the first session management network element, and the first session management network element releases the first forwarding rules configured on the first user plane network element related to the second user plane network element managed by the second session management network element.

[0236] Based on the above scheme, after the topology information of group members is updated, the data forwarding path between group members can be updated or established, thereby realizing communication between group members.

[0237] To facilitate understanding of the solutions provided in the embodiments of this application, the following is based on a 5G system, combined with... Figure 5 The method flowchart in this application describes method 500 provided in the embodiments. It should be understood that in some implementations, UE1 in method 500 may correspond to the first terminal device in method 400, UE2 may correspond to the second terminal device in method 400, UE3 may correspond to the fourth terminal device in method 400, SMF1 may correspond to the first session management network element in method 400, SMF2 may correspond to the second session management network element in method 400, UPF1 may correspond to the first user plane network element in method 400, and UPF2 may correspond to the second user plane network element in method 400. In this case, the relevant explanations or descriptions in method 400 and method 500 can be referenced mutually. Method 500 includes the following flow.

[0238] First, UE1 establishes a PDU session through the network device. UE1 belongs to a group, or in other words, UE1 is a group member within a group. The session establishment process of UE1 is briefly described below with reference to S501 to S506. For parts not explained in detail, please refer to the existing protocols.

[0239] S501, UE1 sends a Session Establishment Request (PDU) message to AMF1. Correspondingly, AMF1 receives the session establishment request message from UE1.

[0240] For example, the session establishment request message includes the identification information of UE1 and the identification information of the group. The identification information of UE1 can be UE1's SUPI, GPSI, or address information (such as IP address), indicating that UE1 belongs to the group, or that UE1 is a member of the group. In other words, the group identification information identifies the group to which UE1 belongs. In different scenarios, this group can have different names; for example, in a 5G VN communication scenario, the group can be called a 5G VN group or a 5G LAN group. The group identification information can be a specific group ID, a DNN, or a DNN+S-NSSAI; there are no limitations here.

[0241] It should be understood that the group consists of two or more group members. The group can be pre-configured or dynamically created, and this application does not impose any restrictions.

[0242] It should also be understood that the session establishment request message may also include information such as the PDU session identifier, S-NSSAI, and data network name, which are not limited in this application.

[0243] S502, AMF1 establishes a session context through SMF1.

[0244] For example, after receiving a session establishment request message from UE1, AMF1 selects a suitable SMF for the session. For instance, AMF1 queries the Network Service Discovery Function (NRF) based on information such as UE1's location information, the S-NSSAI provided by UE1, and the data network name to select SMF1 to provide services for the session.

[0245] Furthermore, AMF1 sends a PDU session context creation request (Nsmf_PDUSession_CreateSMContext Request) message to SMF1. SMF1 creates a session context based on this PDU session context creation request message, and then sends a PDU session context creation response (Nsmf_PDUSession_CreateSMContextResponse) message to AMF1.

[0246] S503, SMF1 selects UPF.

[0247] For example, SMF1 selects a suitable UPF to provide services for the session. For instance, SMF1 provides services for the session based on information such as UE1's location information, the UPF's service range, data network name, and PDU session type.

[0248] S504, SMF1 and UPF1 create an N4 session.

[0249] For example, after SMF1 selects UPF1 to serve the session, it creates an N4 session with UPF1. For instance, SMF1 sends an N4 Session Establishment Request message to UPF1. Correspondingly, UPF1 receives the N4 Session Establishment Request message from SMF1, then UPF1 allocates uplink tunnel information and sends an N4 Session Establishment Response message to SMF1, which includes UPF1's uplink tunnel information.

[0250] Optionally, SMF1 or UPF1 can also assign address information to UE1, such as UE1's IP address or MAC address.

[0251] Optionally, SMF1 or UPF1 can also pre-allocate N19 tunnel information for UE1. For example, if SMF1 determines that UE1 needs to perform 5G VN communication later based on the group identification information, SMF1 allocates N19 tunnel information to UPF1 for establishing tunnels with other UPFs; or, SMF1 instructs UPF1 to allocate N19 tunnel information, and then UPF1 sends the allocated tunnel information to SMF1. It should be understood that UPF1 can send the allocated tunnel information to SMF1 through an N4 session update request message.

[0252] S505, SMF1 sends uplink tunnel information of UPF1 to RAN1.

[0253] For example, SMF1 sends N2 SM information to RAN1, where the N2 SM information includes uplink tunnel information of UPF1. It should be understood that the uplink tunnel information here refers to the uplink N3 tunnel information.

[0254] S506, RAN1 sends downlink tunnel information of RAN1 to SMF1.

[0255] For example, RAN1 allocates downlink tunnel information and sends N2 SM information to SMF1, which includes RAN1's ​​downlink tunnel information. It should be understood that the downlink tunnel information here refers to the downlink N3 tunnel information.

[0256] Correspondingly, after receiving the downlink tunnel information from RAN1, SMF1 sends the downlink tunnel information of RAN1 to UPF1. At this point, the N3 tunnel between UPF1 and RAN1 is established.

[0257] SMF1 also establishes or configures the following forwarding rule on UPF1: data packets with address information destined for UE1 are sent to RAN1 through the corresponding N3 tunnel (i.e., the N3 tunnel between UPF1 and RAN1). It should be understood that data packets with address information destined for UE1 refer to data packets that need to be sent to UE1.

[0258] It should be understood that the forwarding rules in the embodiments of this application may also be referred to as N4 rules.

[0259] S507, SMF1 sends registration request message #1 to the group management network element. Correspondingly, the group management network element receives registration request message #1 from SMF1.

[0260] For example, SMF1 sends a registration request message #1 to the group management network element. This registration request message #1 includes the identification information of SMF1 and the identification information of the group. This registration request message #1 is used to register SMF1 to the group, or to register the association between the identification information of SMF1 and the identification information of the group, or to instruct SMF1 to provide services for the sessions of group members in the group. Optionally, SMF1 may also send the pre-allocated N19 tunnel information of UPF1 and the address information of UE1 to the group management network element in the registration request message #1.

[0261] Correspondingly, after receiving the registration request message #1 from SMF1, the group management network element records the correspondence between the SMF1 identifier and the group identifier information. Alternatively, it records the correspondence between the SMF1 identifier and the group identifier information, the UPF1 N19 tunnel information, and the UE1 address.

[0262] The group management network element can be UDM, GSMF or other 5GC network elements, or it can be a newly added network element, or it can be a module in a certain network element, or the function of the group management network element can be integrated into a certain 5GC network element. This application does not limit it.

[0263] The identifier of SMF1 can be a context ID, a fully qualified domain name (FQDN), an address or a uniform resource identifier (URI) (such as a notification URI or a callback URI), or an endpoint, etc., which are not limited in this application.

[0264] Optionally, prior to S507, SMF1 can determine the group management network element. That is, SMF1 can determine the group management network element before sending the registration request message #1 to the group management network element.

[0265] In one possible implementation, SMF1 determines the group management network element based on the identification information of UE1. For example, SMF1 determines the group management network element as UDM based on SUPI.

[0266] In another possible implementation, SMF1 determines the group management network element based on configuration information. For example, if SMF1 determines that the identification information of UE1 or the identification information of a group corresponds to a certain GSMF based on the configuration information, then SMF1 determines that the GSMF is the group management network element.

[0267] In another possible implementation, SMF1 determines the group management network element based on UE1's subscription information. For example, if UE1's subscription information includes the group management network element corresponding to UE1, and UDM stores UE1's subscription information, then SMF1 can query UDM for the group management network element corresponding to UE1, and then determine the group management network element based on UE1's subscription information.

[0268] Optionally, in step S508, SMF1 sends a subscription message #a to the group management network element. Correspondingly, the group management network element receives the subscription message #a from SMF1.

[0269] For example, the subscription message #a includes the group's identification information, and the subscription message #a is used to subscribe to group information change notifications. After receiving the subscription message a, the group management network element, based on the subscription message #a, sends a notification message to SMF1 when a new SMF registers to the group, or when an SMF deregisters from the group, or notifies the existing SMFs of the service group to the newly registered SMFs of the service group, and sends the identification information of SMF1 to SMF2 (the specific process can be found in step S511).

[0270] In one implementation, the subscription message #a may correspond to the subscription message #1 in method 400.

[0271] The subscription message #a may also include the URI (notification URI or callback URI) or endpoint of SMF1, which can be used by the group management network element to send notification messages to SMF1.

[0272] S509, UE2 performs the session establishment process through the network device.

[0273] It should be understood that the session establishment process for UE2 is similar to that of UE1 (i.e., steps S501 to S506), and will not be repeated here. However, it should be noted that, unlike UE1, UE2's session is served by SMF2 and UPF2, where SMF2 is different from SMF1, and UPF2 is different from UPF1. Furthermore, UE2 also belongs to this group. In other words, UE2 belongs to the same group as UE1, but is served by different SMFs and UPFs.

[0274] S510, SMF2 sends registration request message #2 to the group management network element. Correspondingly, the group management network element receives the registration request message #2 from SMF2.

[0275] It should be understood that S510 is similar to S507, the difference being that the registration request message #2 includes the identification information of SMF2 and the identification information of the group; the specific process will not be elaborated further. The registration request message #2 may also include the identification information of UPF2 and the address information of UE2.

[0276] Optionally, in step S511, SMF2 sends a subscription message #b to the group management network element. Correspondingly, the group management network element receives a subscription message #2 from SMF2.

[0277] It should be understood that S511 is similar to S508, the difference being that the subscription message #b is used by the group management network element to send a notification message to SMF2 when a new SMF registers to the group or when an SMF deregisters from the group. Furthermore, the subscription message #b includes the URI or endpoint number of SMF2. The specific process will not be elaborated further. It is worth noting that if immediate notification is supported, the identification information of SMF1 can be included in the subscription response message. Alternatively, after the subscription response message, SMF2 receives a notification message from the group management network element, which includes the identification information of SMF1.

[0278] In one implementation, the subscription message #b may correspond to the subscription message #3 in method 400.

[0279] S512, SMF1 receives the identification information of SMF2 from the group management network element.

[0280] In one implementation, the group management network element sends a notification message #1 to SMF1 based on the subscription message #a received from SMF1 in step S508. Correspondingly, SMF1 receives the notification message #1 from the group management network element. For example, after receiving the registration request message #2 from SMF2, the group management network element determines that the SMF corresponding to the group has changed, or in other words, it determines that a change event has occurred for the SMF corresponding to the group, or that a new SMF has registered to the group. Therefore, the group management network element sends the notification message #1 to SMF1 based on the subscription message #a. This notification message #1 includes the identifier of SMF2. In one implementation, the notification message may also include a new SMF joining indication, used to indicate that SMF2 has newly registered to the group.

[0281] In another implementation, the group management network element can be another session management network element (i.e., SMF1) that determines itself to provide services for the sessions of group members in the group after receiving the registration request message #2 from SMF2, and then sends the notification message #1 to SMF1.

[0282] In another implementation, SMF1 sends a request message to the group management network element to find the SMF serving the group. This request message includes the group's identification information, which the group management network element uses to determine the SMF serving the group, including SMF2. Alternatively, SMF1 sends a request message to the group management network element to find the SMF serving UE2 within the group. This request message includes both the group's identification information and UE2's identification information, which the group management network element uses to determine the SMF serving UE2. The group management network element determines the SMF2's identification information based on the recorded correspondence between the SMF2's identifier and the group's identification information, the UPF2's N19 tunnel information, and the UE2's identifier, and then sends the SMF2's identification information to SMF1.

[0283] S513, SMF1 sends request message #1 to SMF2.

[0284] For example, after SMF1 obtains the identification information of SMF2, SMF1 determines that SMF2 is still serving the current group, determines to establish a session between SMF1 and SMF2 corresponding to the current group, or in other words, determines to create a cross-SMF 5G VN session (i.e., a session between SMF1 and SMF2), and / or determines to create a tunnel between UPF1 and UPF2. Specifically, SMF1 sends a request message #1 to SMF2 based on the identification information of SMF2. This request message #1 includes the group identification information, the tunnel information of UPF1, and the address information of UE1. Optionally, the request message #1 may also include the identification information of SMF1. This application does not limit the name of the request message. For example, the request message may be a session establishment request message or a tunnel establishment request message, etc. This application does not limit it in this way. This request message is used to request the establishment of a session between SMF1 and SMF2 corresponding to this group. Alternatively, it requests the establishment of an N19 tunnel between UPF1 and the UPF managed by SMF2 (i.e., UPF2), or it requests to obtain tunnel information for the UPF managed by SMF2 (i.e., UPF2). It should be understood that the tunnel information here refers to N19 tunnel information. The session identifier for SMF1 can be either a context ID or the callback URI of SMF1. It is worth noting that before sending the session establishment request message to SMF2, SMF1 can check whether a session for this group has already been established between SMF1 and SMF2 in the current group; in other words, SMF1 checks whether a context associated with SMF2 for this group exists on SMF1.

[0285] It should be understood that the context associated with SMF2 for this group can be a group-level context or an SMF2-level context. For example, if SMF1, SMF2, and SMF3 serve this group, the context maintained by SMF1 for this group can be a context associated with both SMF2 and SMF3. Alternatively, the context maintained by SMF1 for this group can also be a context associated with SMF2, while SMF1 also maintains a context associated with SMF3 for this group.

[0286] For example, SMF1 determines whether a session for the current group has been established between SMF1 and SMF2 based on the existence of a session identifier for SMF1 and / or SMF2 corresponding to the current group. If a session exists, it indicates that a session for the current group between SMF1 and SMF2 has been established; otherwise, it indicates that a session has not been established. If a session has been established, in one implementation, SMF1 no longer sends a session establishment request message to SMF2, but instead reuses the previously established session and sends a session update request to SMF2. In another implementation, SMF1 does not make this determination and always sends a session establishment request message to SMF2. SMF2 then checks whether a session for the current group between SMF1 and SMF2 has been established. If a session has been established, SMF2 rejects SMF1's session establishment request.

[0287] Subsequently, SMF2 can send a session modification request to SMF1 based on the identification information of SMF1. For example, in step S520, SMF2 does not send a notification message to SMF1, but instead sends a session modification request. The information contained in the session modification request can be consistent with the information contained in the notification message in S520.

[0288] It should be understood that if there may be other UEs under UPF1 that are group members in the same group, or if UPF1 also provides services to other group members, then SMF1 carries the identification information of these group members in the request message.

[0289] It should also be understood that if there are other UPFs under SMF1 providing services to one or more group members, SMF1 can also include the tunnel information of that UPF and the identification information of the group members under that UPF in the aforementioned request message. Alternatively, SMF1 can send another request message, including the tunnel information of that UPF and the identification information of the group members under that UPF. The remaining process is similar to the operation process for UPF1 and will not be repeated hereafter.

[0290] Optionally, the tunnel information of UPF1 can be pre-allocated by SMF1 or UPF1 in S504, or it can be allocated by SMF1 or UPF1 after S512. For example, after SMF1 receives a notification message from the group management network element, it allocates the tunnel information of UPF1 and carries the tunnel information of UPF1 in the tunnel establishment request message in S513. Another example is that SMF1 sends a request message to UPF1 to request UPF1 to allocate tunnel information. UPF1 allocates the tunnel information according to the request of SMF1 and sends the allocated tunnel information to SMF1. After receiving the tunnel information sent by UPF1, SMF1 carries the tunnel information of UPF1 in the tunnel establishment request message in S513.

[0291] Optionally, in step S514, SMF1 sends a subscription message #c to SMF2. Correspondingly, SMF2 receives the subscription message #c from SMF1.

[0292] For example, the subscription message #c includes the identification information of SMF1, which can be the notification address of SMF1, such as a notification URI. This subscription message #c is used to subscribe to change notifications of the UPF corresponding to SMF2 that serves group members, and / or change notifications of group members corresponding to SMF2. That is, when a new UPF joins SMF2, or a UPF is deregistered from SMF2, or the UPF serving the UE is migrated, SMF2 needs to send an update message to SMF1, where the UPF here serves one or more group members; and / or, when a new group member joins SMF2, or a group member is deregistered from SMF2, SMF2 needs to send a notification message to SMF1.

[0293] It should be understood that S513 and S514 can be executed separately or as a single step. That is, the request message #1 of S513 and the subscription message #c of S514 can be two separate messages or can be combined into one message. This application does not impose any restrictions on this.

[0294] In one implementation, the subscription message #c may correspond to the subscription message #2 in method 400.

[0295] S515, SMF2 configures forwarding rule #1 for UPF2.

[0296] For example, after receiving a request message from SMF1, SMF2 configures forwarding rule #1 for UPF2. For instance, SMF2 sends an N4 session modification / update request message to UPF2, which includes UPF1's tunnel information and UE1's address information. UPF2 configures forwarding rule #1, which includes: encapsulating data packets with UE1's address information as the destination address with UPF1's N19 tunnel information and sending them to UPF1; or, sending data packets with UE1's address information as the destination address to UPF1 through the N19 tunnel between UPF1 and UPF2.

[0297] S516, SMF2 sends response message #1 to SMF1. Correspondingly, SMF1 receives response message #1 from SMF2. After receiving the request message from SMF1, SMF2 determines whether to accept the request. If so, SMF2 assigns a session identifier, which can be a context ID or a resource URI. The session identifier is then included in response message #1. Subsequently, SMF1 can send session modification request messages or update messages to SMF2 based on this session identifier.

[0298] For example, after SMF2 configures forwarding rule #1 to UPF2, it sends response message #1 to SMF1. The response message #1 includes UPF2's tunnel information and UE2's identification information (e.g., UE2's address information).

[0299] It should be understood that the tunnel information of UPF2 can be pre-allocated by SMF2 or UPF2 during the session establishment process, or it can be allocated by SMF2 or UPF2 after receiving request message #1 from SMF1 in S513. For example, after receiving request message #1, SMF2 allocates tunnel information of UPF2 and carries the tunnel information of UPF2 in response message #1 in S516. As another example, SMF2 sends a tunnel information request message to UPF2, which requests UPF2 to allocate tunnel information. UPF2 allocates tunnel information according to the request of SMF2 and sends the allocated tunnel information to SMF2. After receiving the tunnel information sent by UPF2, SMF2 carries the tunnel information of UPF2 in response message #1 in S516.

[0300] Optionally, in S517, SMF2 sends a subscription message #d to SMF1. Correspondingly, SMF1 receives the subscription message #d from SMF2. This step can be referred to the relevant description in S514.

[0301] For example, the subscription message #d includes the identifier of SMF2. This subscription message #d is used to subscribe to change notifications of the UPF corresponding to SMF1 that serves group members, and / or change notifications of the group members corresponding to SMF1. That is, when a new UPF joins SMF1, or a UPF is deregistered from SMF1, SMF1 needs to send a notification message to SMF2, where the UPF here is used to provide services to one or more group members; and / or, when a new group member joins SMF1, or a group member is deregistered from SMF1, SMF1 needs to send a notification message to SMF2.

[0302] It should be understood that S516 and S517 can be executed separately or as a single step. That is, the request message of S516 and the subscription message #3 of S517 can be two separate messages or can be combined into one message. This application does not impose any restrictions on this.

[0303] In one implementation, the subscription message #d may correspond to the subscription message #4 in method 400.

[0304] S518, SMF1 configures forwarding rule #2 to UPF1.

[0305] For example, after receiving the response message from SMF2, SMF1 configures forwarding rule #2 for UPF1. For instance, SMF1 sends an N4 session modification / update request message to UPF1, which includes UPF2's tunnel information and UE2's address information. UPF1 configures forwarding rule #2, which includes: encapsulating the data packet with UE2's address information as the destination address with UPF2's N19 tunnel information and sending it to UPF2.

[0306] In one implementation, forwarding rule #2 may correspond to the first forwarding rule in method 400.

[0307] It should be understood that steps S512 to S518 can be executed before data transmission between UE1, UE2, and UE3, i.e., the tunnel is established and the forwarding rules are configured in advance, allowing subsequent communication between the UEs based on the established tunnel and forwarding rules. In another implementation, steps S512 to S518 are executed only when data transmission is detected. For example, UE1 sends a data packet to UE2, and the packet is first transmitted to UPF2. At this time, UPF2 does not have forwarding rules configured. UPF2 sends a request to SMF2, and SMF2 then executes steps S512 to S518 or a portion thereof to establish a tunnel between UPF1 and UPF2 and configure the forwarding rules. This method of temporarily creating the tunnel and configuring the rules introduces significant latency.

[0308] Based on the above scheme, it is possible to enable communication between two UEs in a group that correspond to different SMFs, or in other words, it is possible for UEs in a group to communicate across SMFs. Specifically, SMF1 can trigger the creation of an N19 tunnel across SMFs, and SMF1 and SMF2 can configure forwarding policies to UPF1 and UPF2 respectively, so as to create 5G VN group communication between UE1 and UE2 across SMFs, thereby enabling UE1 to communicate across SMFs.

[0309] For example, Figure 6 A communication architecture diagram based on method 500 is shown. Figure 6 In the communication architecture shown, SMF1 is the network element providing services for UE1's session, and SMF2 is the network element providing services for UE2's session. SMF1 and SMF2 are different network elements. SMF1 is configured with the following forwarding rule to UPF1: data packets with UE2's address information as the destination address are encapsulated with UPF2's N19 tunnel information and sent to UPF2. SMF2 is configured with the following forwarding rule to UPF2: data packets with UE1's address information as the destination address are encapsulated with UPF1's N19 tunnel information and sent to UPF1. At this time, the data exchange path between UE1 and UE2 is: UE1-RAN1-UPF1-UPF2-RNA2-UE2.

[0310] The above scheme can establish a data exchange path between UE1 and UE2. This application embodiment can also support the updating of group member topology information. The following, with reference to Example 1, describes a scheme for establishing data exchange paths between UE1 and UE3, and between UE2 and UE3, after UE3 in the group establishes a session.

[0311] S519, UE3 performs the session establishment process through the network device.

[0312] It should be understood that the session establishment process of UE3 is similar to that of UE1 (i.e., steps S501 to S506), and will not be described in detail here.

[0313] In the first example, UE3's session is served by SMF2 and UPF2. In this case, SMF2 configures the following forwarding rules on UPF2: packets with UE2's address information as the destination address are sent to RAN2 through the N3 tunnel between UPF2 and RAN2; packets with UE3's address information as the destination address are sent to RAN3 through the N3 tunnel between UPF2 and RAN3. Here, RNA2 and RNA3 are the RANs corresponding to UE2 and UE3, respectively.

[0314] Furthermore, based on the subscription message #3 in S514, in S520, SMF2 sends a notification message #2 to SMF1. This notification message #2 includes the address information of UE3 and the tunnel information of UPF2. Correspondingly, after receiving the notification message #2 from SMF2, in S521, SMF1 configures a forwarding rule #3 for UPF1. This forwarding rule #3 includes: encapsulating data packets with the address information of UE3 as the destination address with the tunnel information of UPF2 and sending them to UPF2.

[0315] Alternatively, SMF2 sends a session modification request to SMF1 based on the saved session between SMF2 and SMF1. The request message includes the address information of UE3 and the tunnel information of UPF2. Correspondingly, after SMF1 receives the session modification request from SMF2, S521 is as described above.

[0316] It should be understood that in this example, if UE3's session is served by SMF1 and UPF3, SMF1 can send a session modification request to SMF2 based on the saved session with SMF2. The request message includes UE3's address information and UPF3's tunnel information. Alternatively, it can send a notification message to SMF2 according to the subscription message in step S410. Correspondingly, SMF2 receives the session modification request or notification message from SMF1 and configures forwarding rule #2 on UPF2. This forwarding rule #2 includes: encapsulating data packets with UE3's address information as the destination address with UPF3's tunnel information and sending them to UPF3. UPF3 can be the same as or different from UPF1.

[0317] For example, Figure 7 A communication architecture diagram based on the first example described above is shown. Figure 7 In the architecture diagram shown, SMF1 is the network element that provides services for UE1's session, and SMF2 is the network element that provides services for UE2 and UE3's sessions. SMF1 and SMF2 are different network elements. UPF2 serves UE2 and UE3.

[0318] The forwarding rules configured by SMF1 to UPF1 include: encapsulating data packets with address information destined for UE2 or UE3 with UPF2's N19 tunnel information before sending them to UPF2; the forwarding rules configured by SMF2 to UPF2 are: encapsulating data packets with address information destined for UE1 with UPF1's N19 tunnel information before sending them to UPF1; sending data packets with address information destined for UE2 to RAN2 via the N3 tunnel between UPF2 and RAN2; and sending data packets with address information destined for UE3 to RAN3 via the N3 tunnel between UPF2 and RAN3. At this time, the data exchange path between UE1 and UE2 is: UE1-RAN1-UPF1-UPF2-RNA2-UE2; the data exchange path between UE1 and UE3 is: UE1-RAN1-UPF1-UPF2-RNA3-UE3; and the data exchange path between UE2 and UE3 is: UE2-RAN2-UPF2-RAN3-UE3.

[0319] Therefore, through the above scheme, when a new group member establishes a session, the forwarding rules of the UPF for the UE with the established session can be updated, thereby establishing a data forwarding path between group members and realizing communication between group members. In other words, the scheme of this application embodiment supports the updating of group member topology information.

[0320] It should be understood that, for convenience, Figure 5 The flowchart for method 500 shows the case of the first example, but for the subsequent two examples, Figure 5 Method 500 is also supported. For network elements or steps not shown in the figure, please refer to the following text description.

[0321] In the second example, UE3's session is served by SMF2 and UPF3 (not shown in the figure), where UPF3 is a different network element from UPF2 and is managed by SMF2. In this case, SMF2 sends the tunnel information of UPF3 and the address information of UE3 to UPF2, and configures the following forwarding rule for UPF2: packets destined for UE3's address information are sent to UPF3 through the N19 tunnel between UPF2 and UPF3. SMF2 sends the tunnel information of UPF2 and the address information of UE2, as well as the tunnel information of UPF1 and the address information of UE1, to UPF3, and configures the following forwarding rule for UPF3: packets destined for UE2's address information are sent to UPF2 through the N19 tunnel between UPF2 and UPF3; packets destined for UE1's address information are encapsulated with UPF1's tunnel information and sent to UPF1.

[0322] Further, based on the subscription message #c in S514, in S520, SMF1 sends an update message #a to SMF2, or SMF2 sends a session update request to SMF1 based on SMF1's session identifier. This update message #a includes the tunnel information of UPF3 and the address information of UE3. In S521, SMF1 configures forwarding rule #3 for UPF1. This forwarding rule #3 is used to send data packets destined for UE3 to UPF3, or in other words, this forwarding rule #3 is used to encapsulate data packets destined for UE3 with UPF3's tunnel information and send them to UPF3.

[0323] In one implementation, the update message #a may correspond to the subscription message update message #2 in method 400.

[0324] For example, Figure 8 A communication architecture diagram based on the second example above is shown. Figure 8In the architecture shown, SMF1 is the network element that provides services for the session of UE1, and SMF2 is the network element that provides services for the sessions of UE2 and UE3.

[0325] The forwarding rules configured by SMF1 to UPF1 include: encapsulating data packets with UE2's address information into UPF2's N19 tunnel information and sending them to UPF2; encapsulating data packets with UE2's address information into UPF3's N19 tunnel information and sending them to UPF3. The forwarding rules configured by SMF2 to UPF2 include: encapsulating data packets with UE1's address information into UPF1 and sending them to UPF1; sending data packets with UE3's address information to UPF3 via the N19 tunnel between UPF2 and UPF3. The forwarding rules configured by SMF2 to UPF3 include: encapsulating data packets with UE1's address information into UPF1 and sending them to UPF1; sending data packets with UE2's address information to UPF2 via the N19 tunnel between UPF2 and UPF3.

[0326] In the third example, UE3's session is served by SMF3 (not shown in the figure) and UPF3 (not shown in the figure), where SMF3 is a different network element from SMF1 and SMF2, and UPF3 is managed by SMF3. In this case, after UE3 establishes a session, both SMF1 and SMF2 can receive identification information from SMF3, which is managed by the group management network element. In one implementation, based on subscription message #a in S508 and subscription message #b in S511, the group management network element sends notification messages to SMF1 and SMF2 respectively. These notification messages include tunnel information of UPF3 and address information of UE3. After receiving the identification information of SMF3 from the group management network element, SMF1 and SMF2 can initiate a session (or tunnel) establishment procedure with SMF3 respectively. The specific process is similar to that in S512 to S518, and will not be repeated here.

[0327] For example, Figure 9 A communication architecture diagram based on the third example above is shown. Figure 9 In the architecture shown, SMF1 is the network element that provides services for UE1's session, SMF2 is the network element that provides services for UE2's session, and SMF3 is the network element that provides services for UE3's session.

[0328] The forwarding rules configured by SMF1 to UPF1 include: encapsulating data packets with address information destined for UE2 with UPF2's N19 tunnel information before sending them to UPF2; and encapsulating data packets with address information destined for UE3 with UPF3's N19 tunnel information before sending them to UPF3. The forwarding rules configured by SMF2 to UPF2 include: encapsulating data packets with address information destined for UE1 with UPF1's N19 tunnel information before sending them to UPF1; and encapsulating data packets with address information destined for UE3 with UPF3's N19 tunnel information before sending them to UPF3. The forwarding rules configured by SMF3 to UPF3 include: encapsulating data packets with address information destined for UE1 with UPF1's N19 tunnel information before sending them to UPF1; and encapsulating data packets with address information destined for UE2 with UPF2's N19 tunnel information before sending them to UPF2.

[0329] The following example, using Example 2, describes a scheme for re-establishing the data exchange path between UE1 and UE2 when UE1 switches to another UPF.

[0330] S522, UE1 switches to UPF4.

[0331] For example, UE1 may switch from UPF1 to UPF4 due to reasons such as mobility. The specific process is not limited in this application. It should be understood that in this embodiment, it is assumed that UPF4 is also managed by SMF1.

[0332] S523, SMF1 sends an update message #b to SMF2. Correspondingly, SMF2 receives the update message #b from SMF1.

[0333] For example, based on subscription message #4 in S517, SMF1 sends update message #b to SMF2. This update message #b includes tunnel information of UPF4 and address information of UE1. This update message #b is used to notify UE3 that it has switched to UPF4.

[0334] This update message #b can also be called a session update request message, or a notification message, etc., and this application does not limit it.

[0335] In one implementation, the update message #b may correspond to the update message #1 in method 400.

[0336] SMF1 also configures forwarding rule #2 for UPF4. The specific process is similar to that of S518, so it will not be described in detail here.

[0337] S524, SMF2 configures forwarding rule #4 to SMF1.

[0338] For example, after receiving notification message #3 from SMF1, SMF2 configures forwarding rule #4 for UPF2 and deletes forwarding rule #1, or SMF2 updates forwarding rule #1 of UPF2 to forwarding rule #4. Forwarding rule #4 is used to send data packets destined for UE1 to UPF4, or in other words, forwarding rule #4 is used to encapsulate data packets containing address information destined for UE1 with UPF4's tunnel information and send them to UPF4.

[0339] In one implementation, forwarding rule #4 may correspond to the second forwarding rule in the method.

[0340] Therefore, through the above scheme, when a UE in the group undergoes a UPF handover, the forwarding rules can be updated on the UPFs of other group members, thereby enabling the re-establishment of data forwarding paths between group members.

[0341] It should be understood that in some of the above embodiments, some message names are involved, such as request message, subscription message, registration request message, etc. It should be understood that their naming does not limit the protection scope of the embodiments of this application. In different scenarios, these messages may also have other names.

[0342] It should also be understood that in some of the above embodiments, network elements in existing network architectures (such as SMF, UPF, etc.) are used as examples for illustrative purposes. It should be understood that the specific form of the network elements is not limited in the embodiments of this application. For example, any network element that can achieve the same function in the future is applicable to the embodiments of this application. Furthermore, any architecture in which service chains can be deployed in the future is applicable to the embodiments of this application.

[0343] It should also be understood that the specific examples of methods 400 and 500 shown in the embodiments of this application are only for helping those skilled in the art to better understand the embodiments of this application, and are not intended to limit the solutions of the embodiments of this application. For example, the process in the specific embodiments is mainly illustrated using communication between group members in a 5G VN group as an example, and it should be understood that this is not intended to limit the scope. For example, the solutions of the embodiments of this application can be used in any other scenario to establish communication between group members in a group.

[0344] It is understood that the methods and operations implemented by network devices (such as various network elements) in the above-described method embodiments can also be implemented by components (such as chips or circuits) that can be used in network devices.

[0345] It should also be understood that the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0346] It should also be understood that, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0347] It should be noted that the above description uses PDU session as an example of "session", UE as an example of "terminal equipment", SMF as an example of "session management network element" and UPF as an example of "user plane network element" to illustrate the methods. In practical applications, PDU session can be replaced by other sessions and UE can be replaced by other user equipment. This application does not limit this.

[0348] The above, combined with Figure 4 and Figure 5 The group communication method provided in the embodiments of this application is described in detail. The above-described group communication method is mainly introduced from the perspective of interaction between various network elements. It is understood that each network element includes hardware structures and / or software modules corresponding to perform the above functions in order to achieve the above functions.

[0349] Those skilled in the art will recognize that, based on the units and algorithm steps described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0350] The following, combined with Figures 10 to 12 The apparatus provided in the embodiments of this application is described in detail. It should be understood that the description of the apparatus embodiments corresponds to the description of the method embodiments. Therefore, for content not described in detail, please refer to the method embodiments above. For the sake of brevity, it will not be repeated here.

[0351] Figure 10 This is a schematic block diagram of the device 1000 provided in an embodiment of this application. The device 1000 includes a transceiver unit 1010 and a processing unit 1020. The transceiver unit 1010 can implement corresponding communication functions, and the processing unit 1020 is used for data processing. The transceiver unit 1010 can also be referred to as a communication interface or a communication unit.

[0352] Optionally, the device 1000 may further include a storage unit 1030, which can be used to store instructions and / or data, and the processing unit 1020 can read the instructions and / or data in the storage unit 1030 so that the device can implement the aforementioned method embodiments.

[0353] The device 1000 can be used to perform the actions performed by the network device (such as each network element) in the above method embodiment. In this case, the device 1000 can be a network device or a component that can be configured in the network device. The transceiver unit 1010 is used to perform the transceiver-related operations on the network device side in the above method embodiment, and the processing unit 11020 is used to perform the processing-related operations on the network device side in the above method embodiment.

[0354] As a design feature, the device 1000 is used to perform the actions performed by the first session management network element in the above method embodiment.

[0355] In one possible implementation, the transceiver unit 1010 is configured to receive identification information from a second session management network element from a group management network element; the processing unit 1020 is configured to send a request message #1 to the second session management network element through the transceiver unit 1010 based on the identification information of the second session management network element. The request message #1 includes the identification information of the group, tunnel information of a first user plane network element, and identification information of a first terminal device; wherein the first user plane network element is a network element providing services for the session of the first terminal device, and the first terminal device belongs to the group; the transceiver unit 1010 is also configured to receive... The response message #1 from the second session management network element includes tunnel information of the second user plane network element and identification information of the second terminal device; wherein, the second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group; the processing unit 1020 is further configured to configure a first forwarding rule in the first user plane network element according to the tunnel information of the second user plane network element and the identification information of the second terminal device, the first forwarding rule being used to send data packets whose destination address points to the second terminal device to the second user plane network element.

[0356] The apparatus 1000 can implement the steps or processes corresponding to the first session management network element / SMF1 executed in the method embodiment according to the present application. The apparatus 1000 may include units for executing the methods executed by the first session management network element / SMF1 in the method embodiment. Furthermore, each unit in the apparatus 1000 and the other operations and / or functions described above are respectively for implementing the corresponding processes in the method embodiment of the first session management network element / SMF1 in the method embodiment.

[0357] Among them, when the device 1000 is used to perform Figure 4 When method 400 is executed, the transceiver unit 1010 can be used to execute steps S401, S402, S404, S406, S408, and S410 in method 400. The processing unit 1010 can be used to execute steps S405 and S411 in method 400.

[0358] When the device 1000 is used to perform Figure 5 When performing method 500, the transceiver unit 1010 can be used to execute steps S505-S508, S512-S514, S516, S517, S520, and S523 in method 500; the processing unit 1020 can be used to execute processing steps in method 500, such as steps S503, S504, S518, and S521.

[0359] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0360] As an alternative design, the device 1000 is used to perform the actions performed by the second session management network element / SMF2 in the above method embodiment.

[0361] One possible implementation is that the transceiver unit 1010 is configured to receive a request message #1 from a first session management network element. The request message #1 includes group identification information, tunnel information of a first user plane network element, and identification information of a first terminal device. The first session management network element is a network element that provides services for the session of the first terminal device, and the first terminal device belongs to the group. The processing unit 1020 is configured to allocate a session identifier for the second session management network element according to the request message #1. The session identifier of the second session management network element is used to identify the context associated with the first session management network element and specific to the group on the second session management network element. 0, is also used to send a response message #1 to the first session management network element. The response message #1 includes tunnel information of the second user plane network element, identification information of the second terminal device, and session identifier of the second session management network element. The second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group. The processing unit 1020 is also used to configure a third forwarding rule in the second user plane network element according to the tunnel information of the first user plane network element and the identification information of the first terminal device. The third forwarding rule is used to send data packets whose destination address points to the first terminal device to the first user plane network element.

[0362] The apparatus 1000 can implement the steps or processes corresponding to the second session management network element / SMF2 executed in the method embodiment according to the present application. The apparatus 1000 may include units for executing the methods executed by the second session management network element / SMF2 in the method embodiment. Furthermore, each unit in the apparatus 1000 and the other operations and / or functions described above are respectively for implementing the corresponding processes in the method embodiment of the second session management network element / SMF2 in the method embodiment.

[0363] Among them, when the device 1000 is used to perform Figure 4 When the method 400 is executed, the transceiver unit 1010 can be used to execute steps S403, S404, S406, and S408-S410 in the method 400; the processing unit 1020 can be used to execute the processing steps in the method 400, such as step S407.

[0364] When the device 1000 is used to perform Figure 5 When performing method 500, the transceiver unit 1010 can be used to execute steps S510, S511, S513, S514, S516, S517, S520, and S523 in method 500; the processing unit 1020 can be used to execute processing steps in method 500, such as steps S515 and S524.

[0365] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0366] As another design, the device 1000 is used to perform the actions performed by the group management network element in the above method embodiments.

[0367] One possible implementation is that the transceiver unit 1010 is configured to receive a registration request message from a second session management network element, the registration request message including group identification information and the identification information of the second session management network element; and send the identification information of the second session management network element to the first session management network element, wherein the first session management network element and the second session management network element provide services for sessions of different terminal devices belonging to the group respectively.

[0368] Among them, when the device 1000 is used to perform Figure 4 When using method 400, the transceiver unit 1010 can be used to execute steps S401-S403 in method 400.

[0369] When the device 1000 is used to perform Figure 5 When performing method 500, the transceiver unit 1010 can be used to execute steps S507, S508, and S510-S512 in method 500.

[0370] The processing unit 1020 in the above embodiments can be implemented by at least one processor or processor-related circuitry. The transceiver unit 1010 can be implemented by a transceiver or transceiver-related circuitry. The storage unit can be implemented by at least one memory.

[0371] like Figure 11 As shown in the illustration, this application also provides an apparatus 1100. The apparatus 1100 includes a processor 1110.

[0372] Optionally, the device 1100 may include one or more processors 1110.

[0373] Optionally, such as Figure 11 As shown, the device 1100 may further include a memory 1120. A processor 1110 is coupled to the memory 1120, which stores computer programs or instructions and / or data. The processor 1110 executes the computer programs or instructions and / or data stored in the memory 1120, causing the methods in the above method embodiments to be performed.

[0374] Optionally, the device 1100 may include one or more memories 1120.

[0375] Alternatively, the memory 1120 may be integrated with the processor 1110 or set separately.

[0376] Optionally, such as Figure 11 As shown, the device 1100 may further include a transceiver 930 for receiving and / or transmitting signals. For example, the processor 1110 is used to control the transceiver 930 to receive and / or transmit signals.

[0377] As one option, the device 1100 is used to implement the operations performed by network devices (such as the network elements described above) in the above method embodiments.

[0378] This application also provides an apparatus 1200, which can be a network device or a chip. The apparatus 1200 can be used to perform the operations performed by the network device (such as the network elements described above) in the above method embodiments.

[0379] Figure 12A simplified structural diagram is shown. The device 1200 includes part 1210 and part 1220. Part 1210 is mainly used for transmitting and receiving radio frequency signals and converting radio frequency signals to baseband signals; part 1220 is mainly used for baseband processing, such as controlling the base station. Part 1210 is commonly referred to as a transceiver unit, transceiver, transceiver circuit, or transceiver. Part 1220 is typically the control center of the base station, often referred to as a processing unit, used to control the base station to perform the processing operations on the receiving end device side in the above method embodiments.

[0380] The transceiver unit of section 1210, also known as a transceiver or transceiver unit, includes an antenna and radio frequency (RF) circuitry, where the RF circuitry is primarily used for RF processing. Optionally, the devices in section 1210 that implement the receiving function can be considered as receiving units, and the devices that implement the transmitting function can be considered as transmitting units; that is, section 1210 includes both receiving and transmitting units. The receiving unit can also be called a receiver, receiver circuit, or receiving unit, while the transmitting unit can be called a transmitter, transmitter, or transmitting circuit.

[0381] Section 1220 may include one or more single boards, each single board may include one or more processors and one or more memories. The processor is used to read and execute programs in the memory to implement baseband processing functions and control the base station. If multiple single boards exist, they can be interconnected to enhance processing capabilities. As an optional implementation, multiple single boards may share one or more processors, or multiple single boards may share one or more memories, or multiple single boards may simultaneously share one or more processors.

[0382] It should be understood that Figure 12 This is merely an example and not a limitation; the network devices described above, including transceiver units and processing units, may not rely on... Figure 12 The structure shown.

[0383] When the device 1200 is a chip, the chip includes a transceiver unit and a processing unit. The transceiver unit can be an input / output circuit or a communication interface; the processing unit is a processor, microprocessor, or integrated circuit integrated on the chip. Alternatively, the device 1200 can be a chip system or a processing system, enabling devices equipped with the device 1200 to implement the methods and functions of the embodiments of this application. For example, the processing unit 1220 can be a processing circuit within the chip system or processing system, controlling devices equipped with the chip system or processing system. It can also be coupled to a storage unit to call instructions stored in the storage unit, enabling the device to implement the methods and functions of the embodiments of this application. The transceiver unit 1210 can be an input / output circuit within the chip system or processing system, outputting information processed by the chip system or inputting data or signaling information to be processed into the chip system for processing.

[0384] This application also provides a computer-readable storage medium storing computer instructions for implementing the methods executed by network devices (such as network elements) in the above method embodiments.

[0385] For example, when the computer program is executed by a computer, it enables the computer to implement the method executed by the network device in the above method embodiments.

[0386] This application also provides a computer program product containing instructions that, when executed by a computer, cause the computer to implement the method described above, which is executed by a network device (such as various network elements).

[0387] This application also provides a communication system, which includes network devices (such as various network elements) in the above embodiments, such as one or more of the SMF1, SMF2, UPF1, and UPF2 group management network elements.

[0388] The explanations and beneficial effects of the relevant contents in any of the devices provided above can be found in the corresponding method embodiments provided above, and will not be repeated here.

[0389] It should be understood that the processor mentioned in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0390] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory and / or non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM can include a variety of forms, such as: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DRRAM).

[0391] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0392] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0393] Those skilled in the art will recognize that the units and steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of protection of this application.

[0394] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of apparatus or units may be electrical, mechanical, or other forms.

[0395] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to implement the solution provided in this application, depending on actual needs.

[0396] In addition, the functional units in the various embodiments of this application can be integrated into one unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0397] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs). For example, the aforementioned available media may include, but are not limited to, USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, and other media capable of storing program code.

[0398] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for group communication, characterized in that, include: The first session management network element receives the identification information of the second session management network element from the group management network element; wherein the first session management network element and the second session management network element provide services for sessions of different terminal devices belonging to the same group; The first session management network element sends a request message #1 to the second session management network element based on the identification information of the second session management network element. The request message #1 includes the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device. The first session management network element and the first user plane network element are network elements that provide services for the session of the first terminal device, and the first terminal device belongs to the group. The first session management network element receives a response message #1 from the second session management network element. The response message #1 includes tunnel information of the second user plane network element and identification information of the second terminal device. The second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group. The first session management network element configures a first forwarding rule in the first user plane network element based on the tunnel information of the second user plane network element and the identification information of the second terminal device. The first forwarding rule is used to send data packets whose destination address points to the second terminal device to the second user plane network element.

2. The method according to claim 1, characterized in that, The first session management network element receives the identification information of the second session management network element from the group management network element, including: The first session management network element receives a notification message from the group management network element, the notification message including the identification information of the second session management network element and the identification information of the group.

3. The method according to claim 2, characterized in that, The method further includes: The first session management network element sends a subscription message #1 to the group management network element. The subscription message #1 includes the identification information of the group and is used to subscribe to the group information change notification.

4. The method according to claim 1, characterized in that, The first session management network element receives the identification information of the second session management network element from the group management network element, including: The first session management network element sends a request message #2 to the group management network element to locate the session management network element serving the group. The request message #2 includes the identification information of the group. The first session management network element receives a response message #2 from the group management network element, and the response message #2 includes the identification information of the second session management network element.

5. The method according to claim 1, characterized in that, The first session management network element receives the identification information of the second session management network element from the group management network element, including: The first session management network element sends a request message #3 to the group management network element to find the session management network element that serves the second terminal device in the group. The request message #3 includes the identification information of the group and the identification information of the second terminal device. The first session management network element receives a response message #3 from the group management network element, and the response message #3 includes the identification information of the second session management network element.

6. The method according to any one of claims 1 to 5, characterized in that, The response message #1 also includes a session identifier of the second session management network element; the session identifier of the second session management network element is used to identify the context of the group associated with the first session management network element on the second session management network element. The method further includes: The first session management network element receives a session establishment request message for the group from a third terminal device; wherein the third terminal device belongs to the group; In response to the session establishment request message, the first session management network element allocates a third user plane network element to the session of the third terminal device; The first session management network element sends an update message #1 to the second session management network element based on the session identifier of the second session management network element. The update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identification information of the third terminal device.

7. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The first session management network element receives update message #2 from the second session management network element. The update message #2 includes tunnel information of the fourth user plane network element and identification information of the fourth terminal device. The second session management network element and the fourth user plane network element are network elements that provide services for the session of the fourth terminal device, and the fourth terminal device belongs to the group. The first session management network element configures a second forwarding rule in the first user plane network element based on the tunnel information of the fourth user plane network element and the identification information of the fourth terminal device. The second forwarding rule is used to send data packets whose destination address points to the fourth terminal device to the fourth user plane network element.

8. The method according to claim 6, characterized in that, The method further includes: The first session management network element receives update message #2 from the second session management network element. The update message #2 includes tunnel information of the fourth user plane network element and identification information of the fourth terminal device. The second session management network element and the fourth user plane network element are network elements that provide services for the session of the fourth terminal device, and the fourth terminal device belongs to the group. The first session management network element configures a second forwarding rule in the first user plane network element based on the tunnel information of the fourth user plane network element and the identification information of the fourth terminal device. The second forwarding rule is used to send data packets whose destination address points to the fourth terminal device to the fourth user plane network element.

9. The method according to any one of claims 1 to 5, characterized in that, Before the first session management network element sends the request message #1 to the second session management network element, the method further includes: The first session management network element determines that there is no context associated with the second session management network element for the group on the first session management network element.

10. The method according to claim 9, characterized in that, The method further includes: The first session management network element assigns a session identifier to the group. The session identifier of the first session management network element is used to identify the context of the group associated with the second session management network element on the first session management network element. The request message #1 also includes the session identifier of the first session management network element.

11. The method according to claim 6, characterized in that, Before the first session management network element sends the request message #1 to the second session management network element, the method further includes: The first session management network element determines that there is no context associated with the second session management network element for the group on the first session management network element.

12. The method according to claim 11, characterized in that, The method further includes: The first session management network element assigns a session identifier to the group. The session identifier of the first session management network element is used to identify the context of the group associated with the second session management network element on the first session management network element. The request message #1 also includes the session identifier of the first session management network element.

13. The method according to claim 7, characterized in that, Before the first session management network element sends the request message #1 to the second session management network element, the method further includes: The first session management network element determines that there is no context associated with the second session management network element for the group on the first session management network element.

14. The method according to claim 13, characterized in that, The method further includes: The first session management network element assigns a session identifier to the group. The session identifier of the first session management network element is used to identify the context of the group associated with the second session management network element on the first session management network element. The request message #1 also includes the session identifier of the first session management network element.

15. The method according to claim 8, characterized in that, Before the first session management network element sends the request message #1 to the second session management network element, the method further includes: The first session management network element determines that there is no context associated with the second session management network element for the group on the first session management network element.

16. The method according to claim 15, characterized in that, The method further includes: The first session management network element assigns a session identifier to the group. The session identifier of the first session management network element is used to identify the context of the group associated with the second session management network element on the first session management network element. The request message #1 also includes the session identifier of the first session management network element.

17. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

18. The method according to claim 6, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

19. The method according to claim 7, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

20. The method according to claim 8, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

21. The method according to claim 9, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

22. The method according to claim 10, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

23. The method according to claim 11, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

24. The method according to claim 12, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

25. The method according to claim 13, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

26. The method according to claim 14, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

27. The method according to claim 15, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

28. The method according to claim 16, characterized in that, The method further includes: The first session management network element sends a registration request message to the group management network element. The registration request message includes the identification information of the group and the identification information of the first session management network element.

29. A method for group communication, characterized in that, include: The second session management network element receives a request message #1 from the first session management network element. The request message #1 includes the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device. The first session management network element and the first user plane network element are network elements that provide services for the session of the first terminal device, and the first terminal device belongs to the group. According to the request message #1, the second session management network element allocates a session identifier for the second session management network element. The session identifier of the second session management network element is used to identify the context of the second session management network element associated with the first session management network element for the group. The second session management network element sends a response message #1 to the first session management network element. The response message #1 includes the tunnel information of the second user plane network element, the identification information of the second terminal device, and the session identifier of the second session management network element. The second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group. The second session management network element configures a third forwarding rule in the second user plane network element based on the tunnel information of the first user plane network element and the identification information of the first terminal device. The third forwarding rule is used to send data packets whose destination address points to the first terminal device to the first user plane network element.

30. The method according to claim 29, characterized in that, The request message #1 further includes a session identifier of the first session management network element, wherein the session identifier of the first session management network element is used to identify the context of the first session management network element associated with the second session management network element for the group, and the method further includes: The second session management network element stores the session identifier of the first session management network element, the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device in the context associated with the first session management network element and for the group.

31. The method according to claim 30, characterized in that, The method further includes: The second session management network element receives update message #1 from the first session management network element. Update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identifier information of the third terminal device. The first session management network element and the third user plane network element are network elements that provide services for the session of the third terminal device, and the third terminal device belongs to the group. The second session management network element configures a fourth forwarding rule in the second user plane network element according to the tunnel information of the third user plane network element and the identifier information of the third terminal device. The fourth forwarding rule is used to send data packets whose destination address points to the third terminal device to the third user plane network element.

32. The method according to claim 31, characterized in that, The method further includes: The second session management network element adds the tunnel information of the third user plane network element and the identification information of the third terminal device to the context associated with the first session management network element for the group, based on the session identifier of the second session management network element.

33. The method according to any one of claims 30 to 32, characterized in that, The method further includes: The second session management network element receives a session establishment request message for the group from the fourth terminal device; wherein the fourth terminal device belongs to the group; In response to the session establishment request message, the second session management network element allocates a fourth user plane network element to the session of the fourth terminal device; The second session management network element obtains the session identifier of the first session management network element in the context of the group associated with the first session management network element; The second session management network element sends an update message #2 to the first session management network element based on the session identifier of the first session management network element. The update message #2 includes the tunnel information of the fourth user plane network element, the identification information of the fourth terminal device, and the session identifier of the first session management network element.

34. A method for group communication, characterized in that, include: The group management network element receives a registration request message from the second session management network element, the registration request message including the group's identification information and the identification information of the second session management network element; The group management network element sends the identification information of the second session management network element to the first session management network element. The first session management network element and the second session management network element provide services for sessions of different terminal devices belonging to the group, respectively. The identification information of the second session management network element is used to obtain the tunnel information of the second user plane network element. The tunnel information of the second user plane network element is used to configure the first forwarding rule in the first user plane network element. The first forwarding rule is used to send data packets with a destination address pointing to the second terminal device to the second user plane network element. The first session management network element and the first user plane network element are network elements that provide services for the session of the first terminal device. The second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device. The first terminal device and the second terminal device belong to the group.

35. The method according to claim 34, characterized in that, The method further includes: The group management network element receives a subscription message #1 from the first session management network element. The subscription message #1 includes the identifier of the group and is used to subscribe to group information change notifications. The group management network element sends the identification information of the second session management network element to the first session management network element, including: The group management network element sends a notification message to the first session management network element based on the subscription message #1. The notification message includes the identification information of the second session management network element.

36. The method according to claim 34, characterized in that, The group management network element sends the identification information of the second session management network element to the first session management network element, including: The group management network element receives a request message #2 from the first session management network element for finding a session management network element that serves the group, and the request message #2 includes the identification information of the group; The group management network element determines the identification information of the second session management network element based on the identification information of the group; The group management network element sends a response message #2 to the first session management network element, and the response message #2 includes the identification information of the second session management network element.

37. The method according to claim 34, characterized in that, The group management network element sends the identification information of the second session management network element to the first session management network element, including: The group management network element receives a request message #3 from the first session management network element for finding a session management network element that serves the second terminal device in the group. The request message #3 includes the identification information of the group and the identification information of the second terminal device. The group management network element determines the identification information of the second session management network element based on the identification information of the group and the identification information of the second terminal device; The group management network element sends a response message #3 to the first session management network element, and the response message #3 includes the identification information of the second session management network element.

38. The method according to any one of claims 34 to 37, characterized in that, The method further includes: The group management network element stores the association between the identification information of the second session management network element and the identification information of the group.

39. A communication system, characterized in that, Including the first session management network element and the second session management network element, The first session management network element is used to receive the identification information of the second session management network element from the group management network element; and to send a request message #1 to the second session management network element according to the identification information of the second session management network element. The request message #1 includes the identification information of the group, the tunnel information of the first user plane network element, and the identification information of the first terminal device; wherein, the first session management network element and the first user plane network element are network elements that provide services for the session of the first terminal device, and the first terminal device belongs to the group; The second session management network element is configured to receive the request message #1 from the first session management network element; send a response message #1 to the first session management network element, the response message #1 including tunnel information of the second user plane network element and identification information of the second terminal device; wherein, the second session management network element and the second user plane network element are network elements that provide services for the session of the second terminal device, and the second terminal device also belongs to the group; configure a third forwarding rule in the second user plane network element according to the tunnel information of the first user plane network element and the identification information of the first terminal device, the third forwarding rule being used to send data packets whose destination address points to the first user plane network element to the first user plane network element; The first session management network element is further configured to receive the response message #1 from the second session management network element; configure a first forwarding rule in the first user plane network element according to the tunnel information of the second user plane network element and the identification information of the second terminal device, wherein the first forwarding rule is configured to send data packets whose destination address points to the second terminal device to the second user plane network element.

40. The system according to claim 39, characterized in that, The second session management network element is also used to allocate a session identifier for the second session management network element, which is used to identify the context of the second session management network element associated with the first session management network element for the group. The response message #1 includes the session identifier of the second session management network element.

41. The system according to claim 40, characterized in that, The first session management network element is further configured to receive a session establishment request message from a third terminal device for the group; wherein the third terminal device belongs to the group; in response to the session establishment request message, allocate a third user plane network element for the session of the third terminal device; and send an update message #1 to the second session management network element according to the session identifier of the second session management network element, wherein the update message #1 includes the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identifier information of the third terminal device; The second session management network element is further configured to receive update message #1 from the first session management network element; and configure a fourth forwarding rule in the second user plane network element according to the session identifier of the second session management network element, the tunnel information of the third user plane network element, and the identifier information of the third terminal device. The fourth forwarding rule is used to send data packets whose destination address points to the third terminal device to the third user plane network element.

42. The system according to any one of claims 39 to 41, characterized in that, The first session management network element is further configured to determine that there is no context associated with the second session management network element for the group on the first session management network element.

43. A group communication apparatus, characterized in that, The apparatus includes: a module for performing the method as described in any one of claims 1 to 28, or a module for performing the method as described in any one of claims 29 to 33, or a module for performing the method as described in any one of claims 34 to 38.

44. A group communication apparatus, characterized in that, include: A processor for executing a computer program stored in a memory to cause the apparatus to perform the method as claimed in any one of claims 1 to 28, or to cause the apparatus to perform the method as claimed in any one of claims 29 to 33, or to cause the apparatus to perform the method as claimed in any one of claims 34 to 38.

45. A computer program product, characterized in that, The computer program product includes instructions for performing the method as described in any one of claims 1 to 28, or the computer program product includes instructions for performing the method as described in any one of claims 29 to 33, or the computer program product includes instructions for performing the method as described in any one of claims 34 to 38.

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