Communication method, communication device, and computer-readable storage medium

Abstract

A communication method, a communication device and a computer readable storage medium can be applied to the field of communication. The method comprises: a second network element receives a first service request message from a first network element through a first relay tunnel; wherein the first network element is an anchor user plane network element of a terminal; the first relay tunnel is a communication tunnel established between the second network element and the first network element for a first service; the first service request message is used to request first media data of the first service, and the message comprises a first tunnel identifier, which is an identifier of the first network element in a communication tunnel between the first network element and an access network device; the second network element has buffered the media data of the first service, and can then encapsulate a first service response message containing the first media data based on the first tunnel identifier to obtain a first service data packet and send the first service data packet to the terminal. Through the application, the transmission bandwidth is saved and the growth rate of the transmission bandwidth is reduced on the basis of ensuring the video quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and in particular to a communication method, a communication device and a computer readable storage medium. BACKGROUND

[0002] With the development of over-the-top application (OTT) of an Internet service provider, a terminal can access a video OTT application to obtain corresponding video data. With the increase in the number of users accessing the video OTT application, the transmission bandwidth required by the video OTT application may continuously increase. Due to the bandwidth cost, the OTT application may select a manner of reducing the code rate of a video source (for example, from 1080P to 540P) to control the continuous increase in the transmission bandwidth in a busy time. The low code rate of the video source in the busy time greatly reduces the user experience.

[0003] Therefore, how to balance the video quality and the transmission bandwidth is a research hotspot at present. SUMMARY

[0004] Embodiments of the present application provide a communication method, a communication device and a computer readable storage medium, which can reduce the growth rate of the transmission bandwidth on the basis of ensuring the video quality.

[0005] In a first aspect, the present application provides a communication method, which can be executed by a second network element. The second network element can be a core network element or a component (such as a module, a communication module, a circuit or a chip responsible for a communication function (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core), a logical node, a logical module or software capable of implementing all or part of the network element function. The following describes the second network element as an example. In the method, the second network element receives a first service request message from a first network element through a first relay tunnel. The first network element is an anchor user plane network element of a terminal. The first relay tunnel is a communication tunnel established between the second network element and the first network element for a first service. The first service request message is used to request first media data of the first service, and the request message includes a first tunnel identifier, which is an identifier of the first network element in a communication tunnel between the first network element and an access network device. The second network element has buffered media data of the first service. The second network element can encapsulate a first service response message containing the first media data based on the first tunnel identifier to obtain a first service data packet, and send the first service data packet to the terminal.

[0006] The first tunnel identifier is an identifier allocated by the first network element for a terminal session of the terminal accessing the first service, and is used to identify an endpoint of an N3 user plane tunnel serving the terminal session at the first network element. In other words, the first tunnel identifier can be used to instruct the wireless access network device to send user plane data or signaling of the first service of the terminal to the first network element, and can also be used to instruct the wireless access network device that the currently transmitted user plane data or signaling is from the first network element and needs to be sent to the terminal.

[0007] It can be seen that the first network element and the second network element can transmit the request message from the terminal through the first relay tunnel, and the second network element can return the media data requested by the terminal in the identity of the first network element through the first tunnel identifier of the first network element. In this way, bandwidth consumption caused by forwarding traffic between the first network element and the second network element can be avoided, bandwidth resources can be saved, and the cost of the first network element and the second network element can be reduced.

[0008] In a possible implementation, the method can further include: receiving a session establishment request message from the first network element, the session establishment request message including the first tunnel identifier; in response to the session establishment request message, establishing the first relay tunnel; and sending a session establishment response message to the first network element, the session establishment response message including indication information indicating that the first relay tunnel has been established.

[0009] The first network element and the second network element can establish the first relay tunnel, that is, a dedicated session context, which can be referred to as a media relay session context, is established locally. The first tunnel identifier can be recorded in the session context in the second network element. In this way, when the second network element receives a message or data through the first relay tunnel, the corresponding session context can be found based on the first tunnel identifier.

[0010] In a possible implementation, the session establishment response message further includes a second tunnel identifier, and the second tunnel identifier is an identifier of the second network element in the first relay tunnel. The specific implementation of establishing the first relay tunnel in response to the session establishment request message can include: establishing the first relay tunnel and determining the second tunnel identifier in response to the session establishment request message.

[0011] The second tunnel identifier is an identifier allocated by the second network element for a terminal session of the terminal accessing the first service, and is used to identify an endpoint of an N9 tunnel serving the terminal session at the second network element.

[0012] It can be seen that the second network element will also allocate a tunnel identifier when establishing the first relay tunnel to identify the relay tunnel.

[0013] In a possible implementation, the first service request message is obtained by encapsulating the request message based on the second tunnel identifier.

[0014] It can be seen that the first network element can encapsulate the request message from the terminal based on the received second tunnel identifier, so as to be forwarded through the first relay tunnel between the first network element and the second network element. Correspondingly, the first service request message received by the second network element is a packaged data packet, which needs to be decapsulated based on the second tunnel identifier.

[0015] Optionally, the first relay tunnel can be an N9 tunnel, and the second tunnel identifier can be an N9 tunnel identifier.

[0016] In a possible implementation, the session establishment request message further includes five-tuple information and chaining information between the terminal and the first service. The specific implementation of encapsulating the first service response message based on the first tunnel identifier to obtain the first service data packet can include: encapsulating the first service response message based on the five-tuple information, the chaining information and the first tunnel identifier to obtain the first service data packet.

[0017] For example, the five-tuple information can include source internet protocol (IP) and port (such as IP and port of the terminal), target IP and port (such as IP and port of the original content server of the first service), and a used transport layer protocol.

[0018] Through the five-tuple information and the chaining information, the second network element can maintain the service connection with the terminal, which is originally maintained by the first network element. By encapsulating the first service response based on the five-tuple information, the chaining information and the first tunnel identifier, the second network element can send the downlink message or data to the terminal in the identity of the first network element.

[0019] In a possible implementation, the session establishment request message further includes address information of the terminal. The method can further include: establishing a corresponding relationship between the address information of the terminal and the first tunnel identifier based on the address information of the terminal.

[0020] Based on this, the second network element can determine, based on the address information of the terminal, that the downlink data or message to the terminal needs to be encapsulated based on the first tunnel identifier.

[0021] Optionally, the corresponding relationship can also be a corresponding relationship between the address information of the terminal and the first tunnel identifier and the second tunnel identifier.

[0022] In this way, when the second network element receives the encapsulated data packet, the second network element can perform decapsulation processing on the data packet according to the second tunnel identifier, and determine, according to the address information of the terminal in the data packet, that the corresponding downlink data needs to be encapsulated by using the first tunnel identifier and then sent.

[0023] In a possible implementation, the session establishment response message further includes a link identifier corresponding to the user plane session context. The specific implementation of creating the user plane session context for the terminal based on the session establishment request message can include: creating the user plane session context for the terminal based on the session establishment request message, and determining the link identifier. The link identifier is used to instruct the first network element to forward, to the second network element, uplink data from the terminal and destined for the second network element through an N6 interface of the first network element.

[0024] In a possible implementation, the method can further include: receiving, by the second network element, a second service request message from the terminal through an N6 interface of the second network element, the second service request message being used to request second media data of the first service; the destination address of the second service request message being the second network element; determining, based on the correspondence, the first tunnel identifier corresponding to the address information of the terminal; encapsulating, based on the first tunnel identifier, the second service response message to obtain a second service data packet; the second service response message including the second media data; and sending the second service data packet to the terminal.

[0025] The second network element can establish a direct service connection with the terminal, so that the terminal can directly send uplink data or a request message, such as the second service request message, to the second network element. On one hand, the second network element can find the second media data from a cache of the second network element. On the other hand, the second network element can determine, based on the correspondence, how to process downlink data (the second media data and / or the second service response message) to be sent to the terminal. Therefore, the second network element can determine, based on the correspondence, that the second service response message needs to be encapsulated based on the first tunnel identifier and then returned to the terminal. In this way, the second network element can return the second service response message to the terminal in the identity of the first network element.

[0026] In a possible implementation, the session establishment request message further includes a service charging identifier of the first service, a traffic threshold, and a time threshold. The method can further include: counting downlink traffic and service time generated by the terminal for the first service; and sending, to the first network element, a session report message including the downlink traffic and the service time, in a case where the downlink traffic is greater than the traffic threshold and / or the service time is greater than the time threshold.

[0027] In this way, the first network element can accurately charge the terminal.

[0028] In a possible implementation, the method further includes: receiving a synchronization request message from the first network element, the synchronization request message being used to request synchronization of the resource indication information cached in the second network element and the address information of the second network element; and sending a synchronization response message to the first network element, the synchronization response message including the resource indication information cached in the second network element and the address information of the second network element.

[0029] It can be seen that resource sharing can be performed between the first network element and the second network element, so that it can be determined which media data is cached in each network element. This is beneficial to providing corresponding media data for the terminal.

[0030] In a second aspect, the present application provides another communication method, which can be performed by a first network element. The first network element can be a core network element, or a component (such as a module, a communication module, a circuit or a chip responsible for communication functions (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core), or a logical node, a logical module or software capable of implementing all or part of the functions of the network element. The following describes the first network element as an example, which is a user plane anchor network element of a terminal. In the method, the first network element receives a first access request message from the terminal, the message being used to request first media data of a first service. The first network element determines a second network element that caches the media data of the first service based on the shared resource information. The first network element sends a first service request message to the second network element through a first relay tunnel, the message being used to request the first media data. The first relay tunnel is a communication tunnel established between the first network element and the second network element for the first service. The first service request message includes a first tunnel identifier, which is an identifier of the first network element in a communication tunnel between the first network element and an access network device.

[0031] According to the embodiments of the present application, after receiving the service request message from the terminal, the first network element can determine which network element caches the first media data based on the shared resource information. When it is determined that the second network element caches the first media data, the first network element can send the first service request message to the second network element through the first relay tunnel, so as to request the first media data from the second network element. This is beneficial to the terminal successfully obtaining the required media data.

[0032] In a possible implementation, the method further includes: sending a session establishment request message to the second network element, the session establishment request message including the first tunnel identifier; and receiving a session establishment response message from the second network element, the session establishment response message including indication information, the indication information being used to indicate that the first relay tunnel has been established.

[0033] The first relay tunnel can be established between the first network element and the second network element, that is, a dedicated session context, which can be referred to as a media relay session context, is established locally. In the session context in the first network element, a correspondence between the terminal and the first session context can be recorded. For example, after the first relay tunnel is established, when the first network element receives a request message or uplink data from the terminal for the first service, the first relay tunnel corresponding to the terminal can be found based on the first relay tunnel, and it is determined that the request message or uplink data needs to be forwarded through the first relay tunnel.

[0034] In a possible implementation, the session establishment response message further includes a second tunnel identifier. The second tunnel identifier is an identifier of the second network element in the first relay tunnel.

[0035] Optionally, the correspondence between the service accessed by the terminal and the second tunnel identifier can also be recorded in the session context created by the first network element for the terminal. The service accessed by the terminal includes the first service.

[0036] In a possible implementation, the method can further include: encapsulating the first access request message based on the second tunnel identifier to obtain a first service request message.

[0037] It can be seen that the first network element can encapsulate the request message of the terminal, such as the first access request message, using the second tunnel identifier to obtain an encapsulation data packet, that is, the first service request message. In this way, the first service request message can be transmitted through the first relay tunnel.

[0038] In a possible implementation, the session establishment request message further includes five-tuple information between the terminal and the first service and chaining information. The five-tuple information, the chaining information, and the first tunnel identifier are used by the second network element to encapsulate the service response message.

[0039] Through the five-tuple information and the chaining information, the first network element can inform the second network element of the connection information between the terminal and the first service that has been established, thereby facilitating the second network element to process the request message or uplink data from the terminal.

[0040] In a possible implementation, the method can further include: the session establishment response message further includes a link identifier corresponding to the user plane session context. The link identifier is used to indicate that a request message from the terminal and having the second network element as a destination address is forwarded to the second network element through an N6 interface of the first network element.

[0041] The link identifier is allocated by the second network element.

[0042] In a possible implementation, the method further includes: receiving a second service request message from the terminal, the second service request message being used to request second media data of the first service, and a destination address of the second service request message being the second network element; and forwarding, based on the link identifier, the second service request message to the second network element through the N6 interface of the first network element.

[0043] It can be seen that when the first network element receives a service request message with a destination address of the second network element, the first network element can determine, based on the link identifier, that the service request message needs to be forwarded to the second network element through the N6 interface. Moreover, the service request message does not need to be encapsulated. In this way, the processing power consumption of the first network element can be reduced.

[0044] In a possible implementation, the method further includes: receiving a second access request message from the terminal, the second access request message being used to request third media data of the first service; determining redirection information based on the link identifier, the redirection information including address information of the second network element and storage location information of the third media data, and the redirection information being used to instruct the terminal to request the third media data from the second network element; and sending a second response message to the terminal, the second response message including the redirection information.

[0045] The storage location information of the third media data refers to corresponding path information of the third media data on the second network element.

[0046] It can be seen that when the first network element determines that the third media data requested by the terminal is cached in the second network element and the first network element records the link identifier, the first network element can generate a redirection information to inform the terminal to request the media data from the second network element again.

[0047] In a possible implementation, the method further includes: receiving a third service request message from the terminal, the message being used to request the third media data, and a destination address of the message being the second network element. Based on the link identifier, the third service request message is forwarded to the second network element through the N6 interface of the first network element.

[0048] It can be seen that after receiving the redirection information, the terminal can request media data from the second network element again based on the redirection information, and establish a connection with the second network element. Therefore, when the first network element receives a request message from the terminal and the destination address of the request message is the second network element, the first network element can forward the request message to the second network element through the N6 interface.

[0049] In a possible implementation, the session establishment request message further comprises a service charging identifier of the first service, the traffic threshold and the time threshold. The method can further comprise: receiving a session report message from the second network element, the session report message comprising downlink traffic generated by the terminal for the first service and service time length; determining the bypass traffic charging information corresponding to the terminal based on the session report message.

[0050] In this way, the first network element can accurately charge the terminal.

[0051] In a possible implementation, the method can further comprise: sending a synchronization request message to the second network element, the synchronization request message being used to request resource indication information of media data cached by the second network element and address information of the second network element; receiving a synchronization response message from the second network element, the synchronization response message comprising the resource indication information of the media data cached by the second network element and the address information of the second network element; the resource indication information comprising indication information used to indicate the media data of the first service; adding the resource indication information of the media data cached by the second network element and the address information of the second network element into shared resource information; the shared resource information comprising resource indication information of media resources cached by each network element in at least one network element and address information of each network element.

[0052] It can be seen that the first network element and the second network element can share resources, so that it can be determined which media data is cached by each other. In this way, it is beneficial to provide corresponding media data for the terminal. Based on this, the first network element can determine that the second network element caches the media data of the first service.

[0053] In a third aspect, an embodiment of the present application provides a communication apparatus, which comprises units or modules or means for implementing the method in any of the first aspect. The communication apparatus can be a core network element, such as the first network element. Alternatively, the apparatus can comprise units or modules or means for implementing the method in any of the second aspect. The communication apparatus can be a core network element, such as the second network element.

[0054] In a fourth aspect, a communication apparatus is provided, which comprises at least one processor. The at least one processor is configured to cause the communication apparatus to perform the method in any of the first aspect or perform the method in any of the second aspect. The communication apparatus can be a core network element, such as the first network element and the second network element. The at least one processor can execute a computer program or instructions in a memory to cause the above method to be performed. The memory can be included in the communication apparatus or located outside the communication apparatus. In addition, the communication apparatus can further comprise an interface.

[0055] In a fifth aspect, a computer-readable storage medium is provided, which stores computer instructions or programs, when executed, causing a computer to perform the method of any one of the first aspect, or the method of any one of the second aspect.

[0056] In a sixth aspect, a computer program product is provided, which comprises: a computer program or programs, when executed by a computer, causing the computer to perform the method of any one of the first aspect, or the method of any one of the second aspect.

[0057] In a seventh aspect, a chip is provided, which comprises at least one processor, the processor being configured to execute computer instructions or programs, when executed, causing the chip to perform the method of any one of the first aspect, or the method of any one of the second aspect. The processor can execute the computer program or instructions in the memory to cause the above-mentioned method to be performed. The memory can be included in the chip or located outside the chip. In addition, the chip can further comprise an interface.

[0058] In an eighth aspect, a communication system is provided, which comprises a first network element configured to perform the method of any one of the first aspect, and a second network element configured to perform the method of any one of the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 is a schematic diagram of a 5G network architecture provided by an embodiment of the present application;

[0060] Figure 2 are schematic diagrams of two application scenarios provided by an embodiment of the present application;

[0061] Figure 3 is a flowchart of a communication method provided by an embodiment of the present application;

[0062] Figure 4 is a flowchart of a method for establishing an N9 tunnel provided by an embodiment of the present application;

[0063] Figure 5 is a flowchart of another method for establishing an N9 tunnel provided by an embodiment of the present application;

[0064] Figure 6 is a flowchart of another communication method provided by an embodiment of the present application;

[0065] Figure 7 is a structural schematic diagram of a communication device provided by an embodiment of the present application;

[0066] Figure 8Fig. 2 is a structural schematic diagram of another communication device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0067] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0068] The terms "first", "second", "third", and "fourth" and the like in the description and in the claims of the present application and the accompanying drawings are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. The terms "include", "comprise", and "have" and variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a list of steps or units are not necessarily limited to the listed steps or units, but can optionally include additional steps or units not expressly listed or inherent to such process, method, system, product, or apparatus.

[0069] It should be understood that, in the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" is used to describe the relationship between associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that there are three cases: only A, only B, and A and B at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0070] Reference to "an embodiment" in this document means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor does it necessarily refer to a particular embodiment that is independent of or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0071] As used in this description, the terms "component," "module," "system" and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and / or thread of execution and a component can be localized, partially localized, and / or distributed across two or more computers. Also, these components can execute from various computer-readable media having various data structures stored thereon. The components can communicate by way of local and / or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and / or across a network such as the Internet with other systems via the signal).

[0072] The following detailed description is presented in order to better explain the nature and benefits of the application and it should be understood that no limitation with respect to the scope of the application is intended. It should be understood that only the application specifically set forth herein is intended as illustrative and that the application should be understood to encompass any changes and further modifications within the spirit and scope of the application as defined by the following claims. The specific embodiments of the application will now be described, with reference to the following drawings, in which:

[0073] In each of the various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be mutually referred to, if there is no special description and logical conflict. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0074] The method provided by the embodiments of the present application can be applied to various communication systems, for example, a wireless local area network (WLAN) system, an internet of things (IoT) system, a narrow band internet of things (NB-IoT) system, a long term evolution (LTE) system, a 5th-generation (5G) communication system, a new radio (NR) system, or a new communication system to be developed in future communication. The IoT network may, for example, include but is not limited to a vehicle-to-everything (V2X) network. The communication mode in the V2X network may, for example, include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, vehicle-to-network (V2N) communication, and the like. The method provided by the embodiments of the present application can also be applied to an NTN communication system or a scenario in which an NTN and a terrestrial network (TN) are fused. The NTN system may, for example, be a satellite communication system, or may include a drone, a high altitude platform station (HAPS), and other aerial access network devices, and the present application is not limited thereto.

[0075] To facilitate understanding of the embodiments of the present application, a 5G network architecture is taken as an example to introduce a communication system. Figure 1 As shown in FIG. 1, the communication system includes a terminal, an access network device, and a core network device. Optionally, the network architecture may Figure 1 also include a data network (DN) and / or an application network element. The terminal accesses the core network device in the core network through the access network device, and the core network device communicates with the DN or the application network element.

[0076] The various parts involved in the system architecture will be described in detail below.

[0077] I. Terminal device

[0078] A terminal is an entity that receives a signal, or transmits a signal, or receives and transmits a signal on the user side. The terminal is used to provide one or more of voice services and data connectivity services to users. The terminal can be a device that includes a wireless transceiver function and can cooperate with an access network device to provide communication services for users. Specifically, the terminal can refer to a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a terminal, a wireless communication device, a user agent, a user apparatus, or a road side unit (RSU). The terminal device can also be a communication module with satellite communication function, a satellite phone or its components, or a satellite communication terminal, such as a very small aperture terminal (VSAT) (usually referred to as a VSAT terminal), a portable station, a fixed station, a vehicle-mounted or airborne satellite communication terminal, etc. It should be understood that the satellite communication terminal can further provide a data interface to the accessed user equipment as a micro base station.The terminal can also be a drone, an internet of things (IoT) device, a station (ST) in a wireless local area network (WLAN), a cellular phone, a smart phone, a cordless phone, a wireless data card, a tablet computer, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a laptop computer, a machine type communication (MTC) terminal, a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device (which can also be referred to as a wearable smart device), a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in remote medical treatment, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. The terminal can also be a terminal in a 5G system, or a terminal in a next-generation communication system, and the embodiments of the present application do not limit this.

[0079] Embodiments of the present application do not limit the device form of the terminal, and the device for implementing the function of the terminal can be a complete machine; or it can be a device capable of supporting the terminal to implement the function, such as a chip system. The device can be installed in the terminal or used with the terminal. In embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0080] II. Access network device

[0081] The access network device is an entity for transmitting signals, or receiving signals, or transmitting and receiving signals on the side of the access network. The access network device can be a device deployed in a radio access network (RAN) to provide wireless communication functions for terminals.

[0082] In a possible scenario, the access network device can be a device with base station functions, such as an evolved NodeB (eNodeB), a transmitting and receiving point (TRP), a transmitting point (TP), a next generation NodeB (gNB), a base station in a future mobile communication system, an integrated access and backhaul (IAB) node. The access network device can be a transmission reception point (TRP), a base station, various forms of control nodes. For example, a network controller, a radio controller, and the like. Specifically, the access network device can be various forms of macro base stations, micro base stations (also known as small stations) in a heterogeneous network (HetNet) scenario, relay stations, access points (APs), radio network controllers (RNCs), node Bs (NBs), base station controllers (BSCs), base transceiver stations (BTSs), home base stations (for example, home evolved nodeBs, or home node Bs, HNBs), baseband units (BBUs) and remote radio units (RRUs) in a distributed base station scenario, transmission points (TRPs), transmitting points (TPs), mobile switching centers, and the like, and can also be an antenna panel of a base station. The control node can connect multiple base stations and configure resources for multiple terminals under the coverage of multiple base stations. The access network device can also be a satellite (or satellite base station) or a high altitude platform station (HAPS), or a base station device loaded on a satellite / HAPS. Among them, the satellite can include at least one of the following: a geostationary earth orbit (GEO) satellite (or a geosynchronous orbit satellite) or a non-geostationary earth orbit (NGEO).Non-geostationary orbit satellites may include at least one of the following: medium Earth orbit (MEO) satellites or low Earth orbit (LEO) satellites. No limitation is made here. Access network equipment may also be a gateway station (or ground station, earth station, signaling station, gateway, or gateway station), etc. In systems employing different wireless access technologies, the name of the equipment with base station functionality may differ. For example, it could be a gNB in ​​5G, or an access network device in networks after 5G, or an access network device in a future evolved public land mobile network (PLMN) network, or equipment that performs base station functions in device-to-device (D2D) communication, machine-to-machine (M2M) communication, or vehicle-to-everything (V2X) communication, etc. This application does not limit the specific name of the access network equipment. Access network equipment may also be an open RAN (O-RAN or ORAN), a baseband pool (BBU pool) under a cloud radio access network (CRAN), and an RRU, etc.

[0083] Optional, such as Figure 1 The (R)AN shown represents a radio access network device. In the 5G architecture, the (R)AN (usually referring to a gNB) connects to the 5G core network through standardized N2 (control plane) and N3 (user plane) interfaces.

[0084] In another possible scenario, a terminal is assisted by multiple access network devices to implement wireless access, and different access network devices respectively implement part of functions of a base station. For example, an access network device can include a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be separately arranged, or can be included in a same network element, for example, a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, for example, included in a remote radio unit (RRU), an active antenna processing module (AAU), or a remote radio head (RRH). It can be understood that the access network device can be a CU node, or a DU node, or a device including the CU node and the DU node. In addition, the CU can be divided into an access network device in a radio access network (RAN), or the CU can be divided into an access network device in a core network (CN), which is not limited here.

[0085] In different systems, the CU (or CU-CP and CU-UP), DU, or RU can also have different names, but those skilled in the art can understand their meanings. For example, in an ORAN system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. For the convenience of description, the CU, CU-CP, CU-UP, DU, and RU are taken as examples for description in this application. Any one of the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0086] In the embodiments of this application, the form of the access network device is not limited, and the device for implementing the function of the access network device can be a complete machine; or can be a device capable of supporting the access network device to implement the function, for example, a chip system. The device can be installed in the access network device or used in matching with the access network device.

[0087] III. Data network (DN)

[0088] The DN is a network outside the mobile communication system, and can provide services for users. For example, the DN can be a packet data network (PDN), such as the Internet, an Internet protocol multi-media service (IMS) network, a data network dedicated to some application, an Ethernet, an IP local network, and the like, and embodiments of the present application do not limit the DN. The DN can deploy various services, and can provide data, voice, short message, and the like for a terminal. The DN can have multiple application servers (ASs), and each AS can provide at least one service.

[0089] IV. Application network element

[0090] The application network element mainly supports interaction with a core network element to provide services, such as affecting a data routing decision, a policy control function, or providing some services of a third party to a network side. In a 5G communication system, the application network element can be an application function (AF) network element. In a future communication system, the application network element can still be an AF network element, or can have another name, and embodiments of the present application do not limit the application network element.

[0091] V. Core network

[0092] Devices in the core network can be divided into two categories: a user plane function network element (which can also be referred to simply as a user plane network element) and a control plane function network element (which can also be referred to simply as a control plane network element). The control plane network element includes an access management network element and a session management network element, and the like.

[0093] The user plane network element is responsible for forwarding and receiving user data in a terminal. For example, the user plane network element can receive user data from a data network, and transmit the user data to the terminal through an access network device. The user plane network element can also receive user data from the terminal through the access network device, and forward the user data to the data network. Transmission resources and scheduling functions provided by the user plane network element for a terminal are managed and controlled by a session management network element. In a 5G communication system, the user plane network element can be a user plane function (UPF) network element. In a future communication system, the user plane network element can still be a UPF network element, or can have another name, and embodiments of the present application do not limit the user plane network element.

[0094] The session management network element is mainly responsible for session management in a mobile network, such as session establishment, session modification, and session release. Specific functions include allocating an IP address for a user, selecting a user plane network element that provides message forwarding functions, and the like. In a 5G communication system, the session management network element can be a session management function (SMF) network element. In future communication systems, the session management network element can still be an SMF network element, or can also have other names, which are not limited by embodiments of the present application.

[0095] The mobility management function network element, for example, an access and mobility management function (AMF) in the 5G communication system. Figure 1 The AMF is used to manage the mobile context of a user, and is mainly responsible for wireless interface, non-access-stratum (NAS) encryption and integrity protection, registration management, connection management, reachability management, mobility management, delivery of session management (SM) messages between a terminal device and an SMF, or mobility event notification of the terminal device, and the like. The AMF and the SMF correspond to a mobility management entity (MME) in a 4G network, and it can be considered that the functions of the MME are separated into the AMF and the SMF after evolution from the 4G to the 5G.

[0096] The unified data management network element, for example, a unified data management (UDM) in the 5G communication system. Figure 1 The UDM is used to store user data, such as subscription information of a terminal device, attributes of the terminal device, authentication / authorization information, and the like. The UDM can provide services to an AMF, an SMF, a network exposure function (NEF), and an authentication server function (AUSF) through an interface based on Nudm services. For example, the AMF / SMF can obtain subscription information of a terminal device related to the AMF / SMF from the UDM through the interface of the Nudm service.

[0097] The UDM instance refers to a specific, independent running entity or a deployed copy of the UDM network element. In other words, a UDM instance is a software process that actually deploys and runs the logical functions of the UDM network element, and is a specific implementation of the logical functions of the UDM network element on a server (physical machine, virtual machine, or container).

[0098] A network repository function (NRF) network element is configured to store registration information of network function (NF) instances, such as instance status, service capability, service endpoint address, etc. The NRF can provide services to all service-based architecture (SBA) NFs through Nnrf service-based interfaces to achieve automatic registration and discovery of services. For example, the UDM can register its own service instance information through the Nnrf service-based interface to the NRF when starting; the AMF can discover and obtain the list of currently available SMF instances from the NRF through the Nnrf service-based interface.

[0099] As described above, the network elements involved in various embodiments of the present application are mainly introduced, in addition Figure 1 Other network elements are also involved, which are not described in detail here. For example, the network elements in the core network can also include a policy control function (PCF) network element, a network exposure function (NEF) network element, an AUSF network element, a network slice selection function (NSSF), etc.

[0100] In addition, Figure 1 The interfaces between multiple communication devices in a communication system are also shown in the above. For example, N1, N2, N3, N4, N5, N6, N7, N8, N9, N10, N11, N12, N13, N15, Nnssf, Nnef, Nnrf, Nausf, Namf, Npcf, Nudm, Naf, Nsmf, etc. are interface serial numbers, which can be referred to 3GPP TS 23.501, and are not limited here. Among them, Nnssf, Nnef, Nnrf, Nausf, Namf, Npcf, Nudm, Naf, Nsmf, etc. are service-based interfaces provided by the above NSSF, NEF, NRF, AUSF, AMF, PCF, UDM, AF and SMF, respectively, which are used to call corresponding service-based operations.

[0101] It can be understood that Figure 1The network elements or functions shown in the middle can be network elements in a hardware device, can be software functions running on a special hardware, or can be virtualized functions instantiated on a platform (e.g., a cloud platform), or can be a combination of the above. In a possible implementation, the network elements or functions described above can be implemented by one device, can be implemented by multiple devices together, or can be a functional module in one device, and the embodiments of the present application do not make specific limitations. In addition, in the following, in order to facilitate description, the "network element" can be omitted. For example, the AMF network element of the embodiments of the present application has the same meaning as AMF, and only the network element is omitted for the convenience of description, and the rest is similar. It should be noted that the embodiments of the present application also do not limit the names of the network elements in the communication system. For example, in different communication systems, the network elements can have other names; for example, when multiple network elements are integrated in the same physical device, the physical device can also have other names.

[0102] It should be noted that the above description of each core network element is only exemplary, and each core network element can have other names in the remaining network architecture, and the embodiments of the present application do not limit this.

[0103] The network architecture and service scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0104] The following will explain some of the terms involved in the embodiments of the present application to facilitate understanding by those skilled in the art. This part is only for the convenience of understanding and cannot be regarded as a specific limitation of the present application.

[0105] 1. Internet service provider over-the-top (OTT) application

[0106] The OTT application refers to a platform or software that does not depend on a specific operator network, does not pass through an operator's proprietary closed channel, and directly provides content, services and applications to users through a public Internet (Internet). The operator only acts as a "data transmission pipe" to send data packets from one end to the other, but does not control, manage or participate in the content and services of the OTT application itself.

[0107] When a terminal accesses an OTT application, it needs to obtain media resources provided by the OTT application through a content delivery network (CDN). In this process, the OTT application, especially the video OTT application, will consume a large amount of network bandwidth.

[0108] As the traffic of terminals accessing video OTT applications continues to increase, the transmission bandwidth required by the video OTT applications may continue to increase. Due to the bandwidth cost, the OTT application may choose to reduce the code rate of the video source (for example, from 1080P to 540P) to control the continuous increase of the transmission bandwidth during busy hours. The low code rate of the video source during busy hours greatly reduces the user experience.

[0109] 2. UPF media relay solution

[0110] The UPF media relay solution refers to taking the UPF network element as a relay node, requesting video data and other media resources from the OTT application by the UPF network element, and caching them locally in the UPF network element, and then returning the video data to the terminal. When the terminal accesses the same media resource subsequently, the UPF network element can return the locally cached media resource to the terminal.

[0111] The key of the UPF media relay solution is to reduce the service access to the central service by caching the hot media content of each OTT application. Caching hot media content will consume a large amount of cache resources and increase the cost of the UPF network element.

[0112] 3. Protocol data unit session anchor UPF (PSA-UPF)

[0113] The PSA-UPF is a UPF network element that acts as a PDU session anchor role, and is a location that provides a stable access point for users in a PDU session (complete data connection of the user). For example, when the user moves within the network (such as switching from one base station to another), the intermediate UPF serving it may change, but the PSA-UPF remains unchanged.

[0114] On the one hand, the PSA-UPF can be regarded as a gateway for the terminal to connect to external data networks. That is to say, the PSA-UPF is the official gateway for user plane traffic to enter or leave the operator network. All traffic to external data networks (such as the Internet, enterprise intranet, IoT platform) needs to pass through the PSA-UPF.

[0115] On the other hand, as the only point that all user plane traffic must pass through, the PSA-UPF is an ideal and unique location for performing deep packet inspection, traffic statistics, and policy enforcement, and is a reference point for charging and policy control. The operator can implement charging based on user traffic and service type (such as distinguishing between online traffic and voice traffic) and implement policies (such as speed limit, access control) through the PSA-UPF.

[0116] 4. General Packet Radio Service Tunneling Protocol for the User Plane (GTP-U) Tunnel

[0117] GTP-U Tunnel is a core data transport mechanism for the user plane of 5G (and 4G / LTE) mobile core network, referring to a logical point-to-point data channel between two network nodes (e.g. base station - RAN and UPF, or between two UPFs) established by GTP-U protocol.

[0118] GTP-U Tunnel essentially refers to creating a logically independent, addressable pipe for each user's data stream by encapsulating an additional GTP-U protocol header on top of the underlying IP network connection. All user plane packets (IP packets, Ethernet frames, etc.) belonging to a particular user session are packed into this pipe for transmission.

[0119] 5. Fully Qualified Tunnel Endpoint Identifier (F-TEID)

[0120] F-TEID is used to uniquely and explicitly define the endpoint of a GTP-U tunnel in the network.

[0121] A standard F-TEID contains the following key information:

[0122] (1) IP Address: Network layer address (IPv4 or IPv6) of the tunnel endpoint. This is the final destination that the packet needs to reach on the IP network.

[0123] (2) TEID: A 32-bit Tunnel Endpoint Identifier. This is a field in the GTP-U protocol header that is used to further distinguish different tunnels or different user sessions on the target IP device after reaching the target IP address.

[0124] Optionally, the F-TEID can also include the interface type, which identifies the network interface (such as N3, N9, N6, etc.) to which the tunnel endpoint belongs, providing more context information for the control plane.

[0125] 6. Five-Tuple Information

[0126] Five-Tuple Information is a composite identifier used to uniquely identify a specific network data flow (or data connection) at the network layer. It consists of five key fields, like a "complete communication address" of a data packet.

[0127] For example, a five-tuple includes the following five key fields:

[0128] (1) Source IP address: IP address of the device that initiates the communication.

[0129] (2) Source port number: Port used by the application program on the device that initiates the communication.

[0130] (3) Destination IP address: IP address of the device that receives the communication.

[0131] (4) Destination port number: Port of the application program on the target device that receives this communication.

[0132] (5) Transport layer protocol: Protocol used for the communication, such as Transmission Control Protocol (TCP) or User Datagram Protocol (UDP).

[0133] 7、N3 tunnel

[0134] N3 is a standardized interface referring to the interface between RAN and UPF. N3 tunnel refers to the GTP-U tunnel established on the N3 interface, which is a logical tunnel between RAN and UPF.

[0135] For example, N3 tunnel can refer to the tunnel between PSA-UPF and RAN. This N3 tunnel carries all user plane data: all uplink and downlink traffic data between the terminal (UE) and the external data network needs to be encapsulated in the N3 tunnel for transmission. When the terminal moves between base stations, the N3 tunnel can be dynamically reconstructed between different base stations and the same PSA-UPF, thereby maintaining the continuity of user IP address and session.

[0136] 8、N9 tunnel

[0137] N9 is a standardized interface. N9 tunnel refers to the GTP-U tunnel established on the N9 interface, which is usually a tunnel between two different UPFs. For example, it can refer to the tunnel between PSA-UPF and another UPF.

[0138] N9 tunnel supports flexible anchoring and forwarding of user plane paths: in complex network topologies (such as edge computing, traffic splitting), user data may need to be relayed and forwarded between different UPFs, which can be transmitted through N9 tunnel between these UPFs.

[0139] 9、N6 interface routing

[0140] N6 interface routing refers to the IP layer addressing and forwarding of user data packets by UPF on the N6 interface in the manner of a standard router.

[0141] The N6 interface, defined by the 5G standard, is the reference point interface located between the UPF and DN. The DN can be the public internet, a private enterprise network, an IMS network, or an IoT platform, etc. Routing refers to the standard IP network Layer 3 forwarding behavior where the UPF, based on the IP routing table, determines which physical port to forward a data packet from by looking up the destination IP address.

[0142] Please see Figure 2 In the diagram, 'a' represents an application scenario provided by an embodiment of this application. For example... Figure 2 As shown in section a, for terminals 210 and 220, UPF 230 can enable media relay capabilities. When terminal 210 requests hot video data, UPF 230 no longer directly transmits service packets, but instead acts as a relay node to request video data from the CDN. The CDN can send the video data to UPF 230 through the N6 interface. UPF 230 will cache the video data locally and send it to the base station (RAN) through the N3 interface, and the RAN will return the video data to terminal 210. If other terminals, such as terminal 220, request access to the same video data, UPF 230 can directly return the locally cached video data to terminal 220.

[0143] UPF can effectively reduce the pressure on CDN distribution by caching popular content in each OTT application. However, caching popular media content inevitably consumes a significant amount of UPF caching resources, increasing UPF costs. Therefore, this application provides a media relay UPF pool approach, establishing a global index of media resources within the intermediate media UPF pool to achieve transparent content sharing within the pool.

[0144] For example, please see Figure 2 In the diagram, 'b' represents another application scenario provided by an embodiment of this application. For example... Figure 2 As shown in b, the media relay UPF pool can include multiple UPFs, such as... Figure 2 The diagram shows UPF 1, UPF 2, and UPF 3. The various UPFs within the pool can share resource information corresponding to their cached media data, as well as their own node's IP address, through a publish / subscribe (Pub / Sub) mechanism. Any terminal can retrieve cached media data from the various UPFs in the media relay UPF pool through its PSA-UPF.

[0145] However, the selected PSA-UPF of each terminal is fixed and unchanged when activated, and the media resources accessed by the terminal can be cached in other UPFs in addition to the PSA-UPF, such as any node in the media relay UPF pool. For example, the PSA-UPF of the terminal is UPF1, and the media data accessed by the terminal is cached in UPF2 (which can be referred to as a resource-end UPF), then the PSA-UPF needs to obtain the media data from UPF2, and then return the media data to the terminal through the PSA-UPF. It can be seen that in this process, the UPFs share the media data through relay transfer, which can cause a large amount of downlink data forwarding data flow between the PSA-UPF and the resource-end UPF, and can significantly increase the switch bandwidth requirement between the UPFs and the relay processing consumption of the UPFs.

[0146] In view of this, the embodiments of the present application provide a communication method, a communication device and a computer readable storage medium, the PSA-UPF and the resource-end UPF in the same media relay UPF pool can share the resource information of the cached media data, after the PSA-UPF requests the media data from the resource-end UPF, the resource-end UPF can return the media data directly to the terminal without passing through the PSA-UPF, thereby realizing efficient delivery of cached media data, saving core network backhaul bandwidth, and reducing latency.

[0147] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. Here, it is uniformly stated that the messages or signaling interactions involved in the interaction process of the embodiments of the present application can adopt the messages or signaling in the standard or newly introduced messages or signaling, and the embodiments of the present application do not make specific limitations thereon.

[0148] Among them, the embodiments of the present application mainly take different network elements (such as different UPF network elements) as an example to illustrate the execution subject of the interaction in the schematic flowchart, but the present application does not limit the execution subject of the interaction. For example, the network element in the schematic flowchart can also be a whole machine or a component in the whole machine, and can also be a logical node, a logical module or software capable of realizing all or part of the functions of the network element. In order to facilitate description, the interaction between the terminal and two different UPF network elements will be described below as an example, which should not be regarded as a limitation of the present application.

[0149] Please refer to Figure 3 , a flowchart of a communication method provided by the embodiments of the present application. The method can be applied to the network architecture as shown in Figure 1 , the method includes but is not limited to the following steps: Figure 3

[0150] ​S301, the terminal sends a first access request message to the first network element, for requesting the first media data of the first service. Correspondingly, the first network element receives the first access request.

[0151] The first network element is an anchor user plane network element of the terminal, i.e., the first network element is a PSA-UPF of the terminal. The first network element can be regarded as a gateway for the terminal to connect to an external data network. That is to say, the first network element is an official gateway for user plane traffic to enter or leave an operator network. All traffic to an external data network (such as the Internet) needs to pass through the first network element. The first network element is responsible for establishing an initial session, charging anchoring, and uplink traffic processing.

[0152] The destination address of the first access request message can be an IP of an original content server. The original content server refers to a content server to which an OTT application used by the terminal belongs. For example, when a terminal user is using a certain video application, the user selects to download a certain video in the video application, and the terminal sends an access request message to the content server to which the video application belongs. That is to say, the first access request message is actually sent by the terminal to the original content server, but since the first network element is a PSA-UPF of the terminal, the request message passes through the first network element and is sent to the outside by the first network element.

[0153] When the terminal sends the first access request message to the network and the first network element through the RAN, the first network element can determine whether the first media data requested by the terminal is cached in the media relay UPF pool.

[0154] The media relay UPF pool refers to a resource sharing pool between the first network element and other multiple UPF network elements.

[0155] In a possible implementation, each UPF in the pool can broadcast resource indication information cached by itself and address information of the UPF to all UPFs in the pool through an N9 session establishment request message. The resource indication information can include a video ID of the cached media resource, a uniform resource locator (URL) or a hash value of the video, and the like.

[0156] Optionally, the first network element can send a synchronization request message to the second network element, for requesting to synchronize resource indication information cached in the second network element and address information of the second network element. Correspondingly, the second network element can send a synchronization response message to the first network element after receiving the synchronization request message, and the synchronization response message includes the resource indication information cached in the second network element and the address information of the second network element.

[0157] Each UPF can build a global resource index table based on the received information. This table is equivalent to a "map" that can quickly query "where a certain specific media file is stored in which UPF (or UPFs)".

[0158] Optionally, after receiving the synchronization response message, the first network element can add the resource indication information of the media data cached in the second network element and the address information of the second network element to the shared resource information. The shared resource information includes the resource indication information of the media data cached in each network element and the address information of each network element in at least one network element. Optionally, the shared resource information can refer to the global resource index table. Through the shared resource information, the first network element can quickly query the storage location of a certain media data in the media relay UPF pool.

[0159] In a possible implementation, in the media relay UPF pool, a master node can be selected to coordinate the resource information. This master node can be referred to as a master UPF, which is responsible for collecting the resource information (including the resource indication information and the UPF address) of all nodes, i.e., all UPFs, and performing aggregation and deduplication, thereby forming a unified global resource index information. Then, the master UPF broadcasts the global resource index information to all UPFs in the pool to synchronize the information to all UPFs. In this way, it can be ensured that the global resource index information held by all UPFs in the pool is consistent, accurate and efficient. Optionally, this global resource index information can be referred to as shared resource information.

[0160] S302, the first network element determines the second network element based on the shared resource information.

[0161] The first network element can query in the shared resource information which UPF the first media data is cached in, thereby determining the second network element. The second network element caches the media data of the first service, including the first media data. The second network element can be referred to as a resource-end UPF.

[0162] S303, the first network element sends a first service request message to the second network element through a first relay tunnel, and the message includes a first tunnel identifier. Correspondingly, the second network element receives the first service request message.

[0163] The first relay tunnel is a communication tunnel established between the first network element and the second network element for the first service. The first relay tunnel can be referred to as an N9 tunnel between the first network element and the second network element.

[0164] The first service request message is used to request the first media data.

[0165] The first tunnel identifier is an identifier allocated by the first network element for the terminal session (the terminal accesses the first service) in a communication tunnel between the first network element and the access network device. Using the first tunnel identifier, the N3 interface IP of the first network element and the transmitted user plane data or signaling can be identified in the communication tunnel, and the user plane data or signaling is related to the first service requested by the terminal to access. Moreover, through the first tunnel identifier, the first network element can determine the session context associated with the user plane data or signaling received from the terminal by the access network device. The communication tunnel between the first network element and the access network device is an N3 tunnel. Therefore, the first tunnel identifier can also be referred to as an N3 tunnel identifier or an N3 F-TEID.

[0166] In the first tunnel identifier, the IP address is the N3 interface user plane IP of the first network element; and the TEID is an identifier allocated by the first network element for distinguishing data of different terminals on the N3 interface.

[0167] In a possible implementation, the first network element can perform encapsulation processing on the first access request message based on the second tunnel identifier to obtain the first service request message. In other words, the first service request message is a GTP-U data packet after encapsulation. In this way, the first network element forwards the application layer protocol message (i.e., the first access request message) originally sent by the terminal to request or access the cached media data to the second network element through the first relay tunnel. In this case, the second tunnel identifier is an N9 F-TEID allocated by the second network element for the terminal session (the terminal accesses the first service) when establishing the first relay tunnel. Using the second tunnel identifier, the N9 interface IP of the second network element and the transmitted user plane data or signaling can be identified in the first relay tunnel, and the user plane data or signaling is associated with the terminal accessing the first service.

[0168] In the second tunnel identifier, the IP address is the N9 interface user plane IP of the second network element; and the TEID is an identifier allocated by the second network element for distinguishing data of different terminals on the N9 interface.

[0169] For example, the GTP-U data packet encapsulated by the first network element includes an outer IP header, a GTP-U header, and an original request message (i.e., a complete IP packet corresponding to the first access request message). In this case, the outer IP header can indicate that the destination address (destination IP) is the N9 interface IP address of the second network element (i.e., the IP in the second tunnel identifier); and the GTP-U header indicates that the TEID is the TEID allocated by the second network element (for example, an N9 TEID, i.e., the TEID in the second tunnel identifier). For example, the encapsulated first service request message can be as shown in Table 1.

[0170] Table 1: A structure of an uplink data packet

[0171]

[0172] The specific implementation process of establishing the first relay tunnel between the first network element and the second network element can be referred to Figure 4 and the description of Figure 4 hereinafter, which will not be repeated here.

[0173] S304, the second network element encapsulates the first service response message based on the first tunnel identifier to obtain the first service data packet.

[0174] After receiving the first service request message, the second network element can perform decapsulation processing thereon to extract the original request message, i.e., the first access request message. By analyzing the first access request message, it can be determined that the media data requested by the terminal is the first media data of the first service. Based on this, the second network element can read the corresponding media data from its local cache to generate the first service response message. The first service response message includes the first media data.

[0175] Optionally, the source IP of the first service response message is the IP address of the original content server (i.e., the destination IP in the first access request message of the terminal), or a virtual service IP to ensure correct transmission at the application layer. The destination IP address is the IP address of the terminal. The sequence number, acknowledgement number, and port number in the TCP header or UDP header of the first service response message need to be completely matched and continuous with the connection state established between the terminal and the first network element.

[0176] Further, the second network element can encapsulate the first service response message using the first tunnel identifier to encapsulate it into a GTP-U data packet. Specifically, the first service response message (i.e., the original IP data packet) is taken as the payload, and a GTP-U header is added thereto. In the TEID field in the GTP-U header, the TEID value in the first tunnel identifier (N3 F-TEID) is filled in. For example, the first service data packet can be represented as shown in Table 2 below.

[0177] Table 2: One structure of a downlink data packet

[0178]

[0179] S305, the second network element sends the first service data packet to the terminal.

[0180] Specifically, the second network element sends the first service data packet to the IP network path connected to the RAN (i.e., the N3 interface direction on the second network element logically), without sending it to the first network element.

[0181] The RAN receives a packet from the first network element that it knows. The RAN can decapsulate the first service packet, i.e., remove the GTP-U layer. The RAN can determine from the information in the decapsulated packet that it is downlink data from the first network element to the terminal. The RAN can then send the decapsulated original IP packet (i.e., the first request response message containing the first media data) to the terminal over the air interface.

[0182] In the above process, the RAN cannot perceive that the actual physical source of the first service packet is the second network element, but rather that it is sent by the first network element. Correspondingly, the terminal can receive the first request response message sent by the RAN, and thus obtain the first media data therefrom. The terminal is unaware of the change in the downlink routing, and to the terminal, the video is played or downloaded smoothly from the expected content server.

[0183] In the embodiments of the present application, the flow directions of the uplink data and the downlink data can be represented as follows:

[0184] (1) Uplink: terminal → RAN → first network element → (through the first relay tunnel) → second network element

[0185] (2) Downlink: terminal ← RAN ← second network element

[0186] In (1) and (2), the direction of the arrow represents the flow direction of the data. As can be seen, when the second network element sends downlink data to the terminal, the data can not pass through the first network element, and the data relay between the second network element and the first network element can be reduced, thereby effectively saving bandwidth.

[0187] Referring to Figure 4 , a method flowchart for establishing an N9 tunnel is provided in the embodiments of the present application. As shown in Figure 4 , the method can include but is not limited to the following steps:

[0188] S401, the first network element sends a session establishment request message to the second network element. Correspondingly, the second network element receives the session establishment request message.

[0189] When the terminal requests a media data, the first network element serving as the "gateway" of the terminal first determines whether the media data is cached in the media relay UPF pool. If so, the first network element triggers the establishment of a dedicated N9 tunnel with the UPF that caches the media data, which can also be referred to as establishing a relay session.

[0190] For example, when the terminal requests a first media data, the first network element determines that the second network element caches the first media data through the shared resource information. The first network element then initiates a session establishment request message to the second network element.

[0191] Optionally, the session establishment request message can be an N9 session establishment request message. This message carries the key information required for establishing direct services. For example, identity information, charging association information, flow identification information, and connection state information can be included.

[0192] The identity information refers to the endpoint identifier of the N3 tunnel established between the first network element and the base station (RAN), i.e., the first tunnel identifier. The charging association information can include service charging identification and trigger conditions (such as traffic threshold, time threshold) for reporting charges, etc., for traffic charging. The flow identification information can be the five-tuple information of the terminal service flow, such as the five-tuple information between the terminal and the first service, which can be used to identify the service flow of the terminal for the first service. The connection state information, also referred to as chain building information, refers to the established TCP sequence or transport layer security (TLS) key, which is used to ensure that the second network element can safely and reliably take over the existing connection between the terminal and the first service, and make the terminal unaware.

[0193] S402, the second network element establishes a first relay tunnel in response to the session establishment request message.

[0194] After receiving the session establishment request message, the second network element can create a special session, i.e., a forwarding context, to simulate and pretend to be the identity of the first network element to send downlink data to the terminal.

[0195] Specifically, S402 can include but is not limited to the following steps:

[0196] A, based on the session establishment request message, create a media relay session context of the second network element locally.

[0197] B, record the first tunnel identifier in the media relay session context.

[0198] In other words, when the second network element needs to send downlink data to the terminal, the first tunnel identifier is used to encapsulate the downlink data, so that the RAN and the terminal think that the downlink data comes from the first network element.

[0199] C, record the charging association information and other control information in the media relay session context.

[0200] In this way, the second network element can record the statistical information of the part of downlink traffic sent from the second network element to the terminal, and can send the statistical information to the first network element for charging.

[0201] In a possible implementation, the charging correlation information can include a service charging identifier, a traffic threshold and a duration threshold for the first service. Optionally, the second network element can count the downlink traffic and the service duration of the terminal for the first service in real time. When the counted downlink traffic is greater than the traffic threshold and / or the service duration is greater than the duration threshold, a session report message is sent to the first network element. The session report message includes the counted downlink traffic and the service duration. Optionally, the session report message also includes a session ID for identifying that the downlink traffic is generated for the first service.

[0202] Optionally, the session report message can be a packet forwarding control protocol (PFCP) session request message or a PFCP session response message. Alternatively, the session report message can also be carried in a PFCP session deletion response message sent by the second network element to the first network element.

[0203] Optionally, after receiving the session report message, the first network element can combine the traffic processed by the second network element with the traffic processed by itself, and generate a final charging bill of the terminal based on the complete data obtained by the combination, so as to ensure accurate charging.

[0204] Optionally, the first network element can report the traffic processed by itself and the second network element to a network data analytics function (NWDAF), or report the complete data obtained by the combination to the NWDAF, to request the NWDAF to analyze and optimize the usage of the terminal.

[0205] D, determining the second tunnel identifier.

[0206] S403, the second network element sends a session establishment response message to the first network element, and the session establishment response message includes the second tunnel identifier. Correspondingly, the first network element receives the session establishment response message.

[0207] In this way, the N9 tunnel, i.e., the first relay tunnel, between the first network element and the second network element is established.

[0208] Based on this, the first network element can encapsulate the signaling message (such as a video play control instruction or other uplink service request) and / or user plane data message from the terminal into a GTP-U data packet based on the second tunnel identifier, and forward the GTP-U data packet to the second network element through the first relay tunnel. Correspondingly, after receiving a GTP-U data packet through the first relay tunnel, the second network element can find the media relay session context corresponding to the GTP-U data packet by using the second tunnel identifier, and thus determine how to process the GTP-U data packet. For example, the first network element can encapsulate and process the first service response message based on the five-tuple information, the link establishment information and the first tunnel identifier, and thus obtain the first service data packet.

[0209] After receiving the session establishment response information, the first network element can record the correspondence between the second tunnel identifier and the first tunnel identifier and the five-tuple information in the session context of the first network element, and establish a forwarding flow table for the five-tuple information. For example, the forwarding flow table can be represented as "five-tuple information→first relay tunnel". That is to say, when the first network element receives a request message corresponding to the five-tuple information from the terminal, such as the first service request message in S301 shown in FIG. 3, or uplink data for the first service, the first network element can determine how to process the request message or the uplink data based on the correspondence and the forwarding flow table: encapsulate and process the request message / uplink data based on the second tunnel identifier to obtain a GTP-U data packet, and then forward the GTP-U data packet to the second network element through the first relay tunnel. Figure 3

[0210] In a possible implementation, when the terminal stops accessing the first service, the service session times out or a session release instruction is received, the first network element can clean up the session context of the first network element for the terminal accessing the first service. In addition, the first network element can send a session release notification, such as a PFCP session deletion request message, to the second network element to instruct the second network element to release the session context established by the second network element for the terminal accessing the first service, and release the related cache resources. Correspondingly, after completing the session release, the second network element can send a PFCP session deletion response message to the first network element. In this way, it can be effectively prevented that the useless session occupies resources.

[0211] ​Through the embodiments of the present application, the terminal can directly obtain the required media data from the edge resource end UPF, without detouring the central Internet, so as to effectively reduce the delay. The popular content of the OTT application can be saved in the edge resource end UPF, avoiding repeated transmission of the same content on the core backhaul link, thereby effectively saving the bandwidth. The terminal and the RAN are not aware of the change of the route, and the session continuity of the terminal can be guaranteed, which can greatly improve the user experience. The statistical charging synchronization mechanism between the PSA-UPF and the resource end UPF, that is, between the first network element and the second network element, can guarantee accurate charging in the case that the transmission path of the downlink traffic changes. In addition, through the N9 tunnel, the reasonable scheduling and sharing of each resource in the media relay UPF pool can also be realized.

[0212] Please refer to Figure 5 , Figure 5 Another method for establishing an N9 tunnel is provided in the embodiments of the present application. As shown in Figure 5 , the method can include but is not limited to the following steps:

[0213] S501, the first network element sends a session establishment request message to the second network element. Correspondingly, the second network element receives the session establishment request message.

[0214] Optionally, the session establishment request message can be an N9 session establishment request message. This message carries the key information required for establishing a direct service. For example, it can include identity information and charging association information.

[0215] Among them, the identity information can include a first tunnel identifier. The charging association information can include service charging identification and trigger conditions (such as traffic threshold, time threshold) for reporting charges, and other information, which are used for traffic charging.

[0216] Optionally, the session establishment request message can also include address information of the terminal. The address information can be an IP address of a N6 interface allocated by the first network element for the terminal.

[0217] As can be seen, the session establishment request message in S501 is different from the session establishment request message in S401. In the method as shown in Figure 5 , the five-tuple information and the chain establishment information can not be carried in the session establishment request message. Because the subsequent service connection will be established directly between the terminal and the second network element.

[0218] S502, the second network element establishes a media relay session context in response to the session establishment request message.

[0219] The specific implementation steps of S502 can be referred to Figure 4S402, the first network element determines the address information of the terminal.

[0220] S503, the second network element establishes a user plane session context based on the address information of the terminal, and determines the link identifier corresponding to the user plane session context.

[0221] When the first network element determines that the second media data requested by the terminal is buffered in the second network element, the first network element can construct a redirection information and return it to the terminal, which is used to instruct the terminal to request the second media data from a new address. The redirection information can be a hypertext transfer protocol (HTTP) 302 moved temporarily response message, and the location header in the message points to the IP address and URL opened by the second network element to the outside. The URL can represent the path information corresponding to the second media data on the second network element. Correspondingly, after receiving the redirection information, the terminal will initiate a new service request to the new target address (i.e. the IP of the second network element). For details, please refer to Figure 6 and the description of Figure 6 below, which will not be repeated here.

[0222] In this case, the user plane session context established by the second network element is a standard N6 interface user plane session context, which is used to process public network IP data packets from the Internet. The user plane session context records the correspondence between the address information of the terminal and the first tunnel identifier and the second tunnel identifier. This means that the second network element can encapsulate and send the downlink data returned to the terminal based on the first tunnel identifier for the uplink data packet with the source IP of the N6 interface IP of the terminal and the destination address of the IP of the second network element. And based on the second tunnel identifier and the first tunnel identifier, it can be determined that the uplink data packet comes from the first network element.

[0223] Here, the address information of the terminal refers to an N6 interface IP allocated by the first network element for the terminal. The link identifier corresponding to the user plane session context is used to indicate that the first network element forwards the uplink request with the source address of the terminal and the destination address of the second network element to the second network element through the N6 interface of the first network element.

[0224] S504, the second network element sends a session establishment response message to the first network element, which includes the second tunnel identifier and the link identifier.

[0225] In this way, the first relay tunnel between the first network element and the second network element is established, and the user plane session context in the second network element is also established.

[0226] After receiving the session establishment response message, the first network element can record the correspondence between the address information of the terminal and the first tunnel identifier, the second tunnel identifier and the link identifier in the local media relay session context, and establish a forwarding identifier for forwarding through the N6 interface continuously. The forwarding identifier can be represented as "IP of the second network element → N6 next hop". Based on the correspondence and the forwarding identifier, the first network element can determine that the next hop is the second network element when receiving uplink data or data request from the terminal and the destination address is the second network element. Therefore, the first network element can forward the uplink data or data request to the second network element through the N6 interface.

[0227] For example, the first network element can receive a second service request message from the terminal, which is used to request second media data of the first service. Moreover, the destination address of the second service request message is the second network element. The first network element can forward the second service request message to the second network element through the N6 interface based on the link identifier. Correspondingly, the second network element receives the second service request message. The second network element encapsulates the second service response message based on the first tunnel identifier to obtain a second service data packet. The second service response message includes the second media data. Further, the second network element can send the second service data packet to the terminal.

[0228] It can be seen that in the above process, the first network element can directly forward the second service request message to the second network element through the N6 interface without GTP-U encapsulation and other steps. Based on this, the processing pressure of the data plane of the first network element can be reduced. Such architecture is more simple and clear, and conforms to the standard IP network model. The second network element can be shared by multiple other PSA-UPFs, and is more flexible. For the terminal, the terminal can initiate a service request message facing the actual cache location of the media data. The same as the N9 tunnel establishment method shown in Figure 4 One point in common with the N9 tunnel establishment method shown in

[0229] Please refer to Figure 6 for another flowchart of a communication method provided by the embodiments of the present application. The method can be applicable to the N9 tunnel establishment method shown in Figure 5 The method can include but is not limited to the following steps:

[0230] S601, the terminal sends a second access request message to the first network element. Correspondingly, the first network element receives the second access request message.

[0231] The second access request message is used for requesting the third media data of the first service, and a destination address of the second access request message is an address of an original content server to which the third media data belongs.

[0232] S602, the first network element determines the second network element based on the shared resource information.

[0233] The first network element can query, in the shared resource information, a UPF on which the first media data is buffered, so as to determine the second network element. The second network element buffers the media data of the first service, including the third media data.

[0234] S603, the first network element determines redirection information based on the link identifier. The redirection information includes address information of the second network element.

[0235] The redirection information is used for instructing the terminal to request the third media data from the second network element. The redirection information can be an HTTP 302 moved temporarily response message, and a location header in the response message points to an IP address and a URL exposed by the second network element.

[0236] S604, the first network element sends a session establishment request message to the second network element. Correspondingly, the second network element receives the session establishment request message.

[0237] Optionally, the session establishment request message can include address information of the first network element, the first tunnel identifier, and address information of the terminal. Optionally, the address information of the terminal can be an IP of an N6 interface allocated by the first network element for the terminal.

[0238] S605, the second network element establishes a media relay session context and a user plane session context in response to the session establishment request message, and determines a second tunnel identifier and a link identifier.

[0239] The specific implementation steps of S605 can refer to S502 and S503 as shown in Figure 5 , and details are not described herein.

[0240] S606, the second network element sends a session establishment response message to the first network element, and the session establishment response message includes the second tunnel identifier and the link identifier. Correspondingly, the first network element receives the session establishment response message.

[0241] S607, the first network element sends a second access response message to the terminal, and the second access response message includes the redirection information. Correspondingly, the terminal receives the second access response message.

[0242] The terminal can determine, based on the redirection information in the second access response message, that the third media data needs to be acquired by reinitiating a service request message to the second network element.

[0243] S608, the terminal sends a third service request message to the first network element, and the destination address of the message is the second network element. Correspondingly, the first network element receives the third service request message.

[0244] The third service request message is used to request third media data.

[0245] In other words, the terminal sends the third service request message to the second network element, and the first network element, as the PSA-UPF of the terminal, receives the third service request message first and forwards it.

[0246] S609, the first network element forwards the third service request message to the second network element through the N6 interface of the first network element. Correspondingly, the second network element receives the third service request message.

[0247] The first network element can determine that the service request message needs to be sent from its N6 interface based on the link identifier.

[0248] The second network element receives the third service request message through its N6 interface.

[0249] The link identifier is the link identifier corresponding to the user plane session context established for the second network element. The link identifier can be used to instruct the first network element to forward the request message or uplink data with the source address of the terminal and the destination address of the second network element to the second network element based on the N6 interface of the first network element.

[0250] After the third service request message sent by the terminal reaches the first network element, the first network element can determine that the next hop of the third service request message is the second network element based on the destination address of the message and the forwarding identifier of the established forwarding based on the N6 interface. Therefore, the first network element will forward the third service request message to the second network element from its N6 interface.

[0251] Correspondingly, the second network element can receive the third service request message through its N6 interface. In response to the third service request message, the second network element will read the third media data required by the terminal from the media data cached locally.

[0252] S610, the second network element determines the first tunnel identifier corresponding to the address information of the terminal, and performs encapsulation processing on the third service response message based on the first tunnel identifier to obtain a third service data packet.

[0253] The second network element has established a user plane session context, and the first tunnel identifier and the second tunnel identifier corresponding to the address information of the terminal are recorded in the second network element. The source address of the third service request message is the address information of the terminal, that is, the IP of the N6 interface of the terminal. Therefore, the second network element can determine the processing mode of the downlink data corresponding to the third service request message based on the address information of the terminal and the user plane session context: performing encapsulation processing on the third service response message based on the first tunnel identifier and returning the third service response message.

[0254] S611, the second network element sends the third service data packet to the terminal.

[0255] Based on this, the second network element can "pretend" to be the identity of the first network element, and send the third service data packet to the terminal through the RAN. When the third service data packet reaches the RAN, the RAN considers that it has received a data packet from the first network element which is known to the RAN based on the first tunnel identifier. The RAN can perform decapsulation processing on the third service data packet, that is, remove the GTP-U layer. The RAN can determine from the information in that this is downlink data sent by the first network element to the terminal. Therefore, the RAN can send the original IP packet (that is, the third request response message containing the third media data) obtained by decapsulation to the terminal through the air interface.

[0256] S612, the second network element statistics the downlink traffic and service duration generated by the terminal for the first service.

[0257] In a possible implementation, the session establishment request message further includes a service charging identifier of the first service, a traffic threshold, and a duration threshold.

[0258] S613, the second network element sends a session report message to the first network element, the message including the downlink traffic and the service duration generated by the terminal for the first service. Correspondingly, the first network element receives the session report message.

[0259] The second network element can send the session report message to the first network element only when the downlink traffic is greater than the traffic threshold and / or the service duration is greater than the duration threshold.

[0260] Optionally, the session report message further includes a service ID of the first service, used to identify that the downlink traffic is generated for the first service.

[0261] S614, the first network element determines the bypass traffic charging information corresponding to the terminal based on the session report message.

[0262] The bypass traffic can refer to the traffic generated by the terminal on the path from the second network element to the RAN and then to the terminal.

[0263] Optionally, after receiving the session report message, the first network element can combine the bypass traffic with the traffic processed by itself, and generate a final billing account of the terminal based on the complete data obtained by the combination, to ensure that the billing can be accurately performed.

[0264] In the above process, the RAN cannot perceive that the actual physical source of the third service data packet is the second network element, but considers that the third service data packet is sent by the first network element. Correspondingly, the terminal can receive the third request response message sent by the RAN, and obtain the third media data from the third request response message. In this way, the downlink data can directly reach the terminal without passing through the first network element again, which can effectively avoid the increased bandwidth and resource consumption caused by the multiple switching of the downlink traffic between the UPFs in the media relay UPF pool, and will not affect the statistical reporting and billing of the traffic used by the terminal. It can be seen that the embodiments of the present application can achieve the three-win goal of saving bandwidth cost, improving the competitiveness of the UPF relay, and improving the experience of the terminal user.

[0265] The communication device related to the embodiments of the present application is introduced below.

[0266] Optionally, the communication device described above includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed in the present application, the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0267] The embodiments of the present application can divide the functional modules of the communication device according to the above method examples. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The integrated module can be realized in the form of hardware or software functional module. It should be noted that the division of modules in the embodiments of the present application is illustrative, and is only a logical functional division. Actual implementation can have another division manner.

[0268] Please refer to Figure 7 , Figure 7 The structure schematic diagram of a communication device provided by the embodiments of the present application is shown in the figure. The communication device can be applied to the method embodiments described above.

[0269] As Figure 7As shown, the communication apparatus includes a transceiver module 710 and a processing module 720. The transceiver module 710 can be a transceiver or a communication interface, and the processing module 720 can be one or more processors. The communication apparatus can be used to implement a network element involved in any of the above method embodiments, or to implement the functions of the network element involved in any of the above method embodiments. The network element or network function can be a network element in a hardware device, a software function running on a special hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the communication apparatus can further include a storage module for storing program codes and data of the communication apparatus. It should be understood that whether the functional modules are subdivided or combined, the communication apparatus performs substantially the same processes as those performed by any of the above method embodiments. For example, the transceiver module 710 in the above communication apparatus can include a receiving module and / or a sending module, and of course, the transceiver module can also be referred to as a communication module. In an implementation, each module can correspond to a respective program code (or program instructions), and the respective program code of each module, when executed on a processor, causes the unit to perform the corresponding processes to implement the corresponding functions.

[0270] When the communication apparatus is a component of the second network element and performs the steps performed by the second network element in the above method embodiments. The transceiver module 710 is configured to specifically perform the sending and / or receiving actions performed by the second network element in the embodiments shown, for example, other processes supporting the second network element to perform the technologies described herein. Figures 3 to 6 The processing module 720 can be configured to support the communication apparatus to perform the processing actions in the above method embodiments, for example, other processes supporting the second network element to perform the technologies described herein.

[0271] For example, the transceiver module 710 is configured to receive, through a first relay tunnel, a first service request message from a first network element. The first network element is an anchor user plane network element of a terminal; the first service request message is used to request first media data of a first service, and the first service request message includes a first tunnel identifier, which is an identifier of the first network element in a communication tunnel between the first network element and an access network device; the first relay tunnel is a communication tunnel established between the second network element and the first network element for the first service; and the second network element has buffered media data of the first service.

[0272] The processing module 720 is configured to perform encapsulation processing on a first service response message based on the first tunnel identifier to obtain a first service data packet; and the first service response message includes the first media data.

[0273] The transceiver module 710 is further configured to send the first service data packet to the terminal.

[0274] In a possible implementation, the transceiver 710 is further configured to receive a session establishment request message from the first network element, the session establishment request message comprising the first tunnel identifier. The processor 720 is further configured to establish the first relay tunnel in response to the session establishment request message. The transceiver 710 is further configured to send a session establishment response message to the first network element, the session establishment response message comprising indication information indicating that the first relay tunnel has been established.

[0275] In a possible implementation, the session establishment response message further comprises a second tunnel identifier, the second tunnel identifier being an identifier of the second network element in the first relay tunnel. The transceiver 710 is further configured to establish the first relay tunnel and determine the second tunnel identifier in response to the session establishment request message.

[0276] In a possible implementation, the first service request message is obtained by encapsulating the request message based on the second tunnel identifier.

[0277] In a possible implementation, the session establishment request message further comprises five-tuple information between the terminal and the first service and chaining information. The processor 720 is further configured to encapsulate the first service response message based on the five-tuple information, the chaining information, and the first tunnel identifier to obtain the first service data packet.

[0278] In a possible implementation, the session establishment request message further comprises address information of the terminal. The processor 720 is further configured to establish a correspondence between the address information of the terminal and the first tunnel identifier based on the address information of the terminal.

[0279] In a possible implementation, the session establishment response message further comprises a link identifier corresponding to a user plane session context. The processor 720 is further configured to create the user plane session context for the terminal based on the session establishment request message, and determine the link identifier.

[0280] The link identifier is used to instruct the first network element to forward, to the second network element, uplink data from the terminal and destined for the second network element through an N6 interface of the first network element.

[0281] In a possible implementation, the transceiver 710 is further configured to receive, from the terminal through an N6 interface of the second network element, a second service request message used to request second media data of the first service, the destination address of the second service request message being the second network element. The processor 720 is further configured to determine, based on the correspondence, the first tunnel identifier corresponding to the address information of the terminal, encapsulate a second service response message based on the first tunnel identifier to obtain a second service data packet, and the second service response message comprising the second media data. The transceiver 710 is further configured to send the second service data packet to the terminal.

[0282] In a possible implementation, the session establishment request message further includes a service charging identifier of the first service, a traffic threshold and a duration threshold. The processing module 720 is further configured to count downlink traffic and service duration generated by the terminal for the first service. The transceiver module 710 is further configured to send, to the first network element, a session report message including the downlink traffic and the service duration, in a case where the downlink traffic is greater than the traffic threshold and / or the service duration is greater than the duration threshold.

[0283] In a possible implementation, the transceiver module 710 is further configured to receive, from the first network element, a synchronization request message used to request synchronization of the address information of the second network element and the resource indication information cached in the second network element, and send, to the first network element, a synchronization response message including the address information of the second network element and the resource indication information cached in the second network element.

[0284] Or when the communication apparatus is used for the first network element, the communication apparatus includes:

[0285] The transceiver module 710 is configured to receive, from the terminal, a first access request message used to request first media data of the first service.

[0286] The processing module 720 is configured to determine, based on the shared resource information, the second network element that caches the media data of the first service.

[0287] The transceiver module 710 is further configured to send, to the second network element, a first service request message through a first relay tunnel. The first service request message is used to request the first media data. The first relay tunnel is a communication tunnel established between the first network element and the second network element for the first service. The first service request message includes a first tunnel identifier, which is an identifier of the first network element in a communication tunnel between the first network element and the access network device.

[0288] In a possible implementation, the transceiver module 710 is further configured to send, to the second network element, a session establishment request message including the first tunnel identifier, and receive, from the second network element, a session establishment response message including indication information used to indicate that the first relay tunnel has been established.

[0289] In a possible implementation, the session establishment response message further includes a second tunnel identifier. The second tunnel identifier is an identifier of the second network element in the first relay tunnel.

[0290] In a possible implementation, the processing module 720 is further configured to perform encapsulation processing on the first access request message based on the second tunnel identifier to obtain the first service request message.

[0291] In a possible implementation, the session establishment request message further includes five-tuple information between the terminal and the first service and chaining information. The five-tuple information, the chaining information and the first tunnel identifier are used by the second network element to encapsulate the service response message.

[0292] In a possible implementation, the session establishment response message further includes a link identifier corresponding to the user plane session context. The link identifier is used to instruct the first network element to forward a request message from the terminal and having a destination address of the second network element to the second network element through the N6 interface of the first network element.

[0293] In a possible implementation, the transceiver 710 is further configured to receive a second service request message from the terminal, the second service request message being used to request second media data of the first service, and the second service request message having a destination address of the second network element; and forward, based on the link identifier, the second service request message to the second network element through the N6 interface of the first network element.

[0294] In a possible implementation, the transceiver 710 is further configured to receive a second access request message from the terminal, the second access request message being used to request third media data of the first service. The processing module 720 is further configured to determine, based on the link identifier, redirection information, the redirection information including address information of the second network element, and the redirection information being used to instruct the terminal to request the third media data from the second network element. The transceiver 710 is further configured to send, to the terminal, a second response message including the redirection information.

[0295] In a possible implementation, the session establishment request message further includes a service charging identifier of the first service, a traffic threshold and a time threshold. The transceiver 710 is further configured to receive a session report message from the second network element, the session report message including downlink traffic and service time length generated by the terminal for the first service. The processing module 720 is further configured to determine, based on the session report message, bypass traffic charging information corresponding to the terminal.

[0296] In a possible implementation, the transceiver 710 is further configured to send, to the second network element, a synchronization request message, the synchronization request message being used to request resource indication information of media data cached by the second network element and address information of the second network element; and receive a synchronization response message from the second network element, the synchronization response message including the resource indication information of the media data cached by the second network element and the address information of the second network element, and the resource indication information including indication information used to indicate the media data of the first service. The processing module 720 is further configured to add, to shared resource information, the resource indication information of the media data cached by the second network element and the address information of the second network element, and the shared resource information including resource indication information of media resources cached by each network element in at least one network element and address information of each network element.

[0297] In one possible implementation, when the aforementioned device is a chip, such as a modem chip or a SoC chip or SIP chip containing a modem core, or when the aforementioned device is a communication module, the transceiver module 710 can be a communication interface, pins, or circuits. The communication interface can be used to input data to be processed to the processor and can output the processor's processing results. Specifically, the communication interface can be a general purpose input / output (GPIO) interface, which can connect to multiple peripheral devices (such as a liquid crystal display (LCD), camera, radio frequency (RF) module, antenna, etc.). The communication interface is connected to the processor via a bus.

[0298] The processing module 720 may be a processing circuit, which may be one or more processors, or all or part of the circuitry within one or more processors used for control and / or processing. The processing circuit or processor may execute computer-executable instructions stored in the storage module to cause the chip to perform... Figures 3 to 6 The method involved in any of the embodiments shown is described. Further, the processor may include a controller, an arithmetic logic unit (ALU), and registers. For example, the controller is primarily responsible for instruction decoding and issuing control signals for the operations corresponding to the instructions. The ALU is primarily responsible for performing fixed-point or floating-point arithmetic operations, shift operations, and logical operations, and can also perform address operations and translations. The registers are primarily responsible for storing register operands and intermediate operation results temporarily stored during instruction execution. In specific implementations, the processor's hardware architecture may be an application-specific integrated circuit (ASIC) architecture, a microprocessor without interlocked piped stages architecture (MIPS) architecture, an advanced reduced instruction set machine (RISC) machine (ARM) architecture, or a network processor (NP) architecture, etc. The processor may be single-core or multi-core. The storage module may be an in-chip storage module, such as a register or cache. Storage modules can also be external to the chip, such as read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM), etc.

[0299] Optionally, the functions of the processor, the interface, and the like, can be implemented by hardware, by software, or by a combination of hardware and software. The functions are not limited in the embodiments of the present application.

[0300] Figure 8 Another structure diagram of a communication apparatus is provided in the embodiments of the present application. It can be understood that the communication apparatus 810 includes necessary means such as modules, units, elements, circuits, or interfaces, and the like, which are properly configured together to execute the present solution. The communication apparatus 810 can be the first network element and the second network element described above, or can be a component (for example, a chip) of the devices to implement the methods described in the above method embodiments. The communication apparatus 810 includes one or more processors 811. The processor 811 can be a general purpose processor or a special purpose processor, and the like. For example, the processor 811 can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication apparatus (such as a terminal, an access network device, or a chip, and the like), execute software programs, and process data of the software programs.

[0301] Optionally, in one design, the processor 811 can include a program 813 (which can also be referred to as code or instructions), and the program 813 can be run on the processor 811, so that the communication apparatus 810 executes the methods described in the above embodiments. In another possible design, the communication apparatus 810 includes a circuit (not shown) for implementing the functions of the terminal, the access network device, the first core network proxy network element, or the user plane network element, and the like, in the above embodiments. Optionally, the communication apparatus 810 can include one or more memories 812, and the memories 812 have a program 814 (which can also be referred to as code or instructions) stored thereon, and the program 814 can be run on the memories 812, so that the communication apparatus 810 executes the methods described in the above method embodiments. Figure 8

[0302] Optionally, the processor 811 and / or the memory 812 can also store data. The processor and the memory can be separately arranged, or can be integrated together.

[0303] Optionally, the communication apparatus 810 can also include a transceiver 815 and / or an antenna 816. The processor 811 can also be referred to as a processing unit, and controls the communication apparatus (such as a terminal, an access network device, a first core network proxy network element, or a user plane network element). The transceiver 815 can also be referred to as a transceiving unit, a transceiver, or a transceiving circuit, and is used to realize the transceiving function of the communication apparatus through the antenna 816. Optionally, the transceiver 815 can include a receiver and / or a transmitter. The receiver can be referred to as a receiving unit, a receiver, or a receiving circuit. The transmitter can be referred to as a transmitting unit, a transmitter, or a transmitting circuit. ​

[0304] Optionally, the transceiver 815 can be a transceiver circuit, such as an input / output interface, or a transceiver interface.

[0305] The embodiments of the present application further provide a communication device, which comprises at least one processor; wherein the at least one processor is configured to execute any of the methods described in any of the embodiments of the present application. Figures 3 to 6 The embodiments of the present application further provide a computer readable storage medium, which stores computer instructions, when the computer instructions are executed, causing a computer to execute any of the methods described in any of the embodiments of the present application. The embodiments of the present application further provide a computer readable storage medium, which stores computer instructions, when the computer instructions are executed, causing a computer to execute any of the methods described in any of the embodiments of the present application.

[0306] The embodiments of the present application further provide a computer program product, which comprises: computer program code, when the computer program code is run by a computer, causing the computer to execute any of the methods described in any of the embodiments of the present application. Figures 3 to 6 The embodiments of the present application further provide a computer program product, which comprises: computer program code, when the computer program code is run by a computer, causing the computer to execute any of the methods described in any of the embodiments of the present application. The embodiments of the present application further provide a chip, which comprises at least one processor and an interface, the processor is used to read and execute instructions stored in a memory, when the instructions are executed, causing the chip to execute any of the methods described in any of the embodiments of the present application.

[0307] The embodiments of the present application further provide a chip, which comprises at least one processor and an interface, the processor is used to read and execute instructions stored in a memory, when the instructions are executed, causing the chip to execute any of the methods described in any of the embodiments of the present application. Figures 3 to 6 The embodiments of the present application further provide a chip, which comprises at least one processor and an interface, the processor is used to read and execute instructions stored in a memory, when the instructions are executed, causing the chip to execute any of the methods described in any of the embodiments of the present application. The embodiments of the present application further provide a chip, which comprises at least one processor and an interface, the processor is used to read and execute instructions stored in a memory, when the instructions are executed, causing the chip to execute any of the methods described in any of the embodiments of the present application.

[0308] Optionally, the processing performed by a single execution subject (terminal, access network device, first core network proxy network element, user plane network element, etc.) shown in any of the above embodiments can also be divided into processing performed by multiple execution subjects, which can be logically and / or physically separated. For example, the processing performed by the access network device can be divided into processing performed by at least one of the CU, the DU and the RU. Figures 3 to 6 In addition, each of the embodiments of the present application is only described by taking all the steps included therein as an example, and should not be regarded as a specific limitation of the present application. For example, the order between the steps in each of the embodiments can be simply changed according to the functions and inherent logic thereof; for another example, the steps in each of the embodiments can be executed in whole or in part, as long as the same functions as in the embodiments of the present application can be achieved.

[0309]

[0310] In addition, each of the embodiments of the present application is only described by taking all the steps included therein as an example, and should not be regarded as a specific limitation of the present application. For example, the order between the steps in each of the embodiments can be simply changed according to the functions and inherent logic thereof; for another example, the steps in each of the embodiments can be executed in whole or in part, as long as the same functions as in the embodiments of the present application can be achieved.

[0311] In this application, "sending" and "receiving" represent the direction of signal transmission. For example, "sending information to an access network device" can be understood as that the destination of the information is the access network device, which can include direct transmission through the air interface, and also includes indirect transmission through the air interface by other units or modules. "Receiving information from an access network device" can be understood as that the source of the information is the access network device, which can include direct reception from the access network device through the air interface, and also includes indirect reception from the access network device through the air interface from other units or modules. "Sending" can also be understood as "output" of a chip interface, and "receiving" can also be understood as "input" of a chip interface.

[0312] In other words, sending and receiving can be between devices, for example, between an access network device and a terminal; or can be within a device, for example, between components, modules, chips, software modules or hardware modules within a device through a bus, wire or interface.

[0313] In the embodiments of this application, "when", "if", "whether" and "in the case of" all refer to the objective situation that the device will make corresponding processing, not limited to time, and also does not require the device to have a judgment action when it is implemented, nor does it mean that there are other limitations.

[0314] In this application, "example", "exemplarily", "for example" or "such as" and the like are used to represent as an example, illustration or description. Any embodiment or design scheme described as "example", "exemplarily", "for example" or "such as" in this application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "example", "exemplarily", "for example" or "such as" and the like is intended to present the relevant concept in a specific manner.

[0315] The above is only a specific implementation of the application, but the protection scope of the application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A communication method, characterized in that, The method is applied to a second network element, and the method includes: A first service request message is received from a first network element through a first relay tunnel; wherein, the first network element is the anchor user plane network element of the terminal; the first service request message is used to request first media data of the first service, and the second network element caches the media data of the first service; the first service request message includes a first tunnel identifier, which is the identifier of the first network element in the communication tunnel between the first network element and the access network device; the first relay tunnel is a communication tunnel established between the second network element and the first network element for the first service; Based on the first tunnel identifier, the first service response message is encapsulated to obtain the first service data packet; the first service response message includes the first media data. The first service data packet is sent to the terminal.

2. The method according to claim 1, characterized in that, The method further includes: Receive a session establishment request message from the first network element, the session establishment request message including the first tunnel identifier; In response to the session establishment request message, the first relay tunnel is established; A session establishment response message is sent to the first network element. The session establishment response message includes indication information, which is used to indicate that the first relay tunnel has been established.

3. The method according to claim 2, characterized in that, The session establishment response message also includes a second tunnel identifier, which is the identifier of the second network element in the first relay tunnel; The step of establishing the first relay tunnel in response to the session establishment request message includes: In response to the session establishment request message, the first relay tunnel is established and the second tunnel identifier is determined.

4. The method according to claim 3, characterized in that, The first service request message is obtained by encapsulating the request message based on the second tunnel identifier.

5. The method according to claim 3, characterized in that, The session establishment request message also includes the five-tuple information and connection establishment information between the terminal and the first service; The first service response message is encapsulated based on the first tunnel identifier to obtain a first service data packet, including: Based on the five-tuple information, the link establishment information, and the first tunnel identifier, the first service response message is encapsulated to obtain the first service data packet.

6. The method according to claim 3, characterized in that, The session establishment request message also includes the terminal's address information; The method further includes: Based on the address information of the terminal, a correspondence is established between the address information of the terminal and the first tunnel identifier.

7. The method according to claim 6, characterized in that, The session establishment response message also includes the link identifier corresponding to the user plane session context; The step of creating a user plane session context for the terminal based on the session establishment request message includes: Based on the session establishment request message, a user plane session context for the terminal is created, and the link identifier is determined; The link identifier is used to instruct the first network element to forward uplink data from the terminal to the second network element through the N6 interface of the first network element.

8. The method according to claim 7, characterized in that, The method further includes: The second service request message is received from the terminal through the N6 interface of the second network element. The second service request message is used to request the second media data of the first service. The destination address of the second service request message is the second network element. Based on the correspondence, the first tunnel identifier corresponding to the address information of the terminal is determined; Based on the first tunnel identifier, the second service response message is encapsulated to obtain a second service data packet; the second service response message includes the second media data. The second service data packet is sent to the terminal.

9. The method according to any one of claims 2-8, characterized in that, The session establishment request message also includes the service billing identifier, traffic threshold, and duration threshold of the first service; The method further includes: The downlink traffic and service duration generated by the terminal for the first service are recorded. If the downlink traffic exceeds the traffic threshold and / or the service duration exceeds the duration threshold, a session report message is sent to the first network element. The session report message includes the service billing identifier, the downlink traffic, and the service duration.

10. The method according to claim 9, characterized in that, The method further includes: Receive a synchronization request message from the first network element, the synchronization request message being used to request the synchronization of the resource indication information cached in the second network element and the address information of the second network element; A synchronization response message is sent to the first network element, the synchronization response message including resource indication information cached in the second network element and address information of the second network element.

11. A communication method, characterized in that, The method is applied to a first network element, which is the anchor user plane network element of the terminal; the method includes: Receive a first access request message from the terminal, the first access request message being used to request first media data of a first service; Based on shared resource information, a second network element is identified, which caches the media data of the first service. A first service request message is sent to the second network element through a first relay tunnel. The first service request message is used to request the first media data. The first relay tunnel is a communication tunnel established between the first network element and the second network element for the first service. The first service request message includes a first tunnel identifier, which is the identifier of the first network element in the communication tunnel between the first network element and the access network device.

12. The method according to claim 11, characterized in that, The method further includes: Send a session establishment request message to the second network element, the session establishment request message including the first tunnel identifier; Receive a session establishment response message from the second network element, the session establishment response message including indication information, the indication information being used to indicate that the first relay tunnel has been established.

13. The method according to claim 12, characterized in that, The session establishment response message also includes a second tunnel identifier; The second tunnel identifier is the identifier of the second network element in the first relay tunnel.

14. The method according to claim 13, characterized in that, The method further includes: Based on the second tunnel identifier, the first access request message is encapsulated to obtain the first service request message.

15. The method according to claim 12, characterized in that, The session establishment request message also includes the five-tuple information and connection establishment information between the terminal and the first service; The five-tuple information, the chain establishment information, and the first tunnel identifier are used by the second network element to encapsulate the service response message.

16. The method according to claim 12, characterized in that, The session establishment response message also includes the link identifier corresponding to the user plane session context; The link identifier is used to indicate that a request message from the terminal with a destination address of the second network element is forwarded to the second network element through the N6 interface of the first network element.

17. The method according to claim 16, characterized in that, The method further includes: The system receives a second service request message from the terminal, the second service request message being used to request the second media data of the first service, and the destination address of the second service request message being the second network element; Based on the link identifier, the second service request message is forwarded to the second network element through the N6 interface of the second network element.

18. The method according to claim 16, characterized in that, The method further includes: Receive a second access request message from the terminal, the second access request message being used to request third media data of the first service; Based on the link identifier, redirection information is determined; the redirection information includes the address information of the second network element, and the redirection information is used to instruct the terminal to request the third media data from the second network element; A second response message is sent to the terminal, the second response message including the redirection information.

19. The method according to any one of claims 13-18, characterized in that, The session establishment request message also includes the service billing identifier, traffic threshold, and duration threshold of the first service; The method further includes: Receive a session report message from the second network element, the session report message including the service billing identifier, the downlink traffic generated by the terminal for the first service, and the service duration; Based on the session report message, the bypass traffic billing information corresponding to the terminal is determined.

20. The method according to claim 19, characterized in that, The method further includes: Send a synchronization request message to the second network element. The synchronization request message is used to request the synchronization of resource indication information of the media data cached by the second network element and the address information of the second network element. The system receives a synchronization response message from the second network element. The synchronization response message includes resource indication information of media data cached in the second network element and address information of the second network element. The resource indication information includes indication information for media data used to indicate the first service. The resource indication information of the media data cached in the second network element and the address information of the second network element are added to the shared resource information; the shared resource information includes the resource indication information of the media resources cached in at least one network element and the address information of each network element.

21. A communication system, characterized in that, Including the first network element and the second network element, The first network element is used to send a first service request message to the second network element through a first relay tunnel; wherein, the first service request message is used to request first media data of the first service, and the first service request message includes a first tunnel identifier, which is the identifier of the first network element in the communication tunnel between the first network element and the access network device; the first relay tunnel is a communication tunnel established between the second network element and the first network element for the first service; the first network element is the anchor user plane network element of the terminal, and the second network element caches the media data of the first service; The second network element is configured to receive the first service request message, encapsulate the first service response message based on the first tunnel identifier to obtain a first service data packet; the first service response message includes the first media data; and send the first service data packet to the terminal.

22. The system according to claim 21, characterized in that, The first network element is further configured to receive a first access request message from the terminal, the first access request message being used to request the first media data of the first service; and to determine the second network element based on shared resource information.

23. A communication device, characterized in that, It includes units or modules for implementing the method as described in any one of claims 1-10, or units or modules for implementing the method as described in any one of claims 11-20.

24. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions or programs that, when executed, cause the computer to perform the method as described in any one of claims 1-10, or the method as described in any one of claims 11-20.

25. A chip, characterized in that, The chip includes at least one processor, the processor being configured to execute computer instructions or programs, which, when run, cause the chip to perform the method as described in any one of claims 1-10, or the method as described in any one of claims 11-20.

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