Data transmission method, apparatus and system

Abstract

A data transmission method, apparatus and system. In the method, a first access network device sends first information, which indicates a first address of a first tunnel, wherein the first tunnel is used for performing data transmission between a terminal device and the first access network device by using a first transport layer network protocol, and the first address is associated with the first access network device; and the first tunnel is established with the terminal device on the basis of the first address. The method is used for designing a QUIC protocol suitable for a UE and an access network device.

Description

Data transmission method, device and system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on December 26, 2023, with application number 202311819277.2 and application name "A Data Transmission Method, Device and System", all contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a data transmission method, device and system. Background Art

[0004] In a wireless communication system, for example, in a new radio (NR) system, a user equipment (UE) can establish a protocol data unit (PDU) session with a data network (DN) network element through a user plane function (UPF) network element. The PDU session provides data transmission services between the UE and the DN network element. In order to support the UE to transmit data simultaneously between 3GPP and Non-3GPP access, a quick UDP internet connections (QUIC) protocol equivalent to TCP is used to establish a QUIC connection between the UE and the UPF network element, where each connection can have different paths carried on the 3GPP and Non-3GPP access paths respectively. The QUIC protocol also has a multi-stream multiplexing feature and can transmit data of multiple streams at the same time.

[0005] In some current designs, to fully utilize the multi-stream multiplexing and multi-path features of QUIC, the QUIC protocol is considered to be introduced between the UE and the access network equipment (such as the RAN). However, due to the mobility of the UE, the RAN that the UE accesses often changes, and the protocol stack between the UE and the RAN is complex. The QUIC protocol applicable to the connection between the UE and the UPF network element is not applicable between the UE and the RAN. Therefore, how to design a QUIC protocol suitable for the connection between the UE and the RAN remains an important issue that needs to be solved urgently.

[0006] Summary of the Invention

[0007] The present application provides a data transmission method, apparatus, and system for designing a QUIC protocol suitable for use between a UE and an access network device.

[0008] In the first aspect, the present application provides a data transmission method, which can be applied to a first access network device. The method may include: sending first information, the first information indicating a first address of a first tunnel, the first tunnel being used to transmit data between the terminal device and the first access network device using a first transport layer network protocol, and the first address being associated with the first access network device; and establishing the first tunnel with the terminal device according to the first address.

[0009] Through the above solution, a first tunnel using the first transport layer network protocol can be established between the terminal device and the first access network device, so that the air interface transmission quality can be improved based on the first tunnel.

[0010] In one possible implementation, the method may further include: receiving first indication information, wherein the first indication information indicates that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol; and configuring the first address of the first tunnel for the terminal device according to the first indication information.

[0011] In one possible implementation, the receiving of the first indication information includes: receiving a first access layer message from the terminal device, the first access layer message including the first indication information; or receiving the first indication information from a core network element.

[0012] In one possible implementation, the method may further include: receiving second indication information, the second indication information indicating establishment of the first tunnel between the terminal device and the first access network device; and configuring the first address of the first tunnel for the terminal device according to the second indication information.

[0013] In one possible implementation, the receiving of the second indication information includes: receiving a second access layer message from the terminal device, the second access layer message including the second indication information; or receiving the second indication information from the core network.

[0014] In one possible implementation, the first information also includes attribute information of the first tunnel, and establishing the first tunnel with the terminal device based on the first address includes: establishing the first tunnel with the terminal device based on the first address and the attribute information of the first tunnel.

[0015] In a possible implementation, the sending of the first information includes: sending the first information to the terminal device; or sending the first information to the core network.

[0016] In one possible implementation, the method further includes: determining the attribute information of the first tunnel based on fourth indication information from a core network network element, the fourth indication information being used to indicate the first address for configuring the first tunnel; or, receiving the attribute information of the first tunnel from the core network.

[0017] In one possible implementation, the first tunnel includes at least one communication path, a first communication path in the at least one communication path is used to transmit data between the terminal device and the first access network device, a first identifier of the first tunnel and the first address are associated with the first communication path, and a second communication path in the at least one communication path is used to transmit data between the terminal device and the second access network device. The method further includes: receiving second information from the second access network device, wherein the second information includes the second identifier of the first tunnel, or the second information includes the second identifier of the first tunnel and the second address of the first tunnel, and the second identifier and the second address are associated with the second communication path; sending the second identifier to the terminal device, or sending the second identifier and the second address to the terminal device.

[0018] In one possible implementation, sending the second identifier to the terminal device, or sending the second identifier and the second address to the terminal device, includes: sending a third access layer message to the terminal device, the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address; or, sending first control information to the terminal device through the first tunnel, the first control information includes the second identifier, or the first control message includes the second identifier and the second address.

[0019] In a possible implementation manner, the method further includes: sending a downlink data packet, where the downlink data packet includes the second identifier and the second address of the first tunnel.

[0020] In one possible implementation, the method further includes: sending sixth indication information to the second access network device, the sixth indication information indicating the fourth identifier of the first tunnel, or the sixth indication information indicating the fourth identifier and fourth address of the first tunnel, the fourth identifier and the fourth address being associated with the terminal device.

[0021] In a possible implementation manner, the method further includes: sending path information of the second communication path to the second access network device; or receiving path information of the second communication path from the second access network device.

[0022] In one possible implementation, the method further includes: receiving third information of the first tunnel from a third access network device, the third information including a third identifier of the first tunnel, or the third information including a third identifier of the first tunnel and a third address of the first tunnel, the third identifier and the third address being associated with a third access network device, and the third access network device being the target access network device of the terminal device; sending the third identifier to the terminal device, or sending the third identifier and the third address to the terminal device.

[0023] In a possible implementation, the method further includes: sending a downlink data packet to the terminal device, where the downlink data packet includes the third identifier and the third address.

[0024] In one possible implementation, sending the third identifier to the terminal device, or sending the third identifier and the third address to the terminal device, includes: sending a fourth access layer message to the terminal device, the fourth access layer message includes the third identifier, or the fourth access layer message includes the third identifier and the third address; or, sending second control information to the terminal device through the first tunnel, the second control information includes the third identifier, or the second control information includes the third identifier and the third address.

[0025] In one possible implementation, if the terminal device, the first access network device and the third access network device all support the DAPS function, the method further includes: adding a third communication path in the first tunnel, and the third communication path is associated with the third access network device; or, migrating the first tunnel from the first communication path to the third communication path, and the third communication path is associated with the third access network device.

[0026] In one possible implementation, the method further includes: sending a fifth indication message to a third access network device, wherein the fifth indication message indicates the fourth identifier of the first tunnel, or the fifth indication message indicates the fourth identifier and fourth address of the first tunnel, and the fourth identifier and fourth address are associated with the terminal device.

[0027] In a possible implementation manner, the method further includes: sending the context of the first tunnel to the third access network device.

[0028] In the second aspect, the present application provides a data transmission method, which can be applied to a terminal device, and the method includes: receiving first information, wherein the first information indicates a first address of a first tunnel, the first tunnel is used to transmit data between the terminal device and the first access network device using a first transport layer network protocol, and the first address is associated with the first access network device; according to the first address, establishing the first tunnel between the terminal device and the first access network device.

[0029] In one possible implementation, the method further includes: sending first indication information, wherein the first indication information indicates that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal supports multi-channel communication based on the first transport layer network protocol.

[0030] In one possible implementation, sending the first indication information includes: sending a first access layer message to the first access network device, wherein the first access layer message includes the first indication information; or sending a first non-access layer message to the core network, wherein the first non-access layer message includes the first indication information.

[0031] In a possible implementation, the method further includes: sending second indication information, where the second indication information indicates establishing the first tunnel between the terminal device and the first access network device.

[0032] In one possible implementation, the sending of the second indication information includes: sending a second access layer message to the first access network device, the second access layer message including the second indication information; or, sending a second non-access layer message to the core network, the second non-access layer message including the second indication information.

[0033] In one possible implementation, the first information also includes attribute information of the first tunnel; establishing the first tunnel with the first access network device based on the first address includes: establishing the first tunnel with the first access network device based on the first address and the attribute information of the first tunnel.

[0034] In one possible implementation, the method further includes: determining the attribute information of the first tunnel based on the first information; receiving the attribute information of the first tunnel from the first access network device, wherein the attribute information of the first tunnel is carried in a downlink access layer message; and receiving the attribute information of the first tunnel from the core network network element.

[0035] In a possible implementation, the receiving the first information includes: receiving the first information from a first access network device, wherein the first information is configured by the first access network device.

[0036] In one possible implementation, the first tunnel includes at least one communication path, a first communication path in the at least one communication path is used to transmit data between the terminal device and the first access network device, a first identifier of the first tunnel and the first address are associated with the first communication path, and a second communication path in the at least one communication path is used to transmit data between the terminal device and the second access network device. The method also includes: receiving second information of the first tunnel from the first access network device, the second information includes the second identifier of the first tunnel, or the second information includes the second identifier of the first tunnel and the second address of the first tunnel, and the second identifier and the second address are associated with the second communication path.

[0037] In one possible implementation, the receiving of the second information of the first tunnel from the first access network device includes: receiving a third access layer message from the first access network device, the third access layer message including the second information; or receiving first control information from the first access network device through the first tunnel, the first control information including the second information.

[0038] In a possible implementation, the method further includes: receiving a downlink data packet, where the downlink data packet includes a second identifier and a second address of the first tunnel.

[0039] In a possible implementation manner, the method further includes: sending an uplink data packet to the second access network device, where the uplink data packet includes a second identifier and a second address of the first tunnel.

[0040] In one possible implementation, the first access network device is the source access network device of the terminal device, and the method further includes: receiving a third identifier of the first tunnel, or receiving a third identifier and a third address of the first tunnel, the third identifier and the third address being associated with data transmitted between the terminal device and the third access network device in the first tunnel, and the third access network device is the target access network device of the terminal device.

[0041] In one possible implementation, the receiving of the third identifier of the first tunnel, or the receiving of the third identifier and the third address of the first tunnel, includes: receiving a fourth access layer message from the first access network device, the fourth access layer message including the third identifier, or the fourth access layer message including the third identifier and the third address; receiving second control information from the first access network device through the first tunnel, the second control information including the third identifier, or the first control information including the third identifier and the third address.

[0042] In a possible implementation, the method further includes: receiving a downlink data packet from the first access network device or receiving a downlink data packet from the third access network device, wherein the downlink data packet includes the third identifier and the third address.

[0043] In a possible implementation manner, the method further includes: sending an uplink data packet to the third access network device, where the uplink data packet includes the third identifier and the third address.

[0044] In the third aspect, the present application provides a data transmission method, which can be applied to SMF network elements, and the method includes: determining that a first tunnel needs to be established between a terminal device and a first access network device, the first tunnel adopts a first transport layer network protocol, and the first tunnel is used to transmit data between the terminal device and the first access network device; sending a fourth indication information to the first access network device, the fourth indication information indicating the first address for configuring the first tunnel.

[0045] In one possible implementation, the method further includes: receiving first information from the first access network device, the first information indicating a first address of a first tunnel; and sending the first information to the terminal device through the first access network device.

[0046] In a possible implementation manner, the method further includes: sending attribute information of the first tunnel to the first access network device; or sending attribute information of the first tunnel to the terminal device through the first access network device.

[0047] In one possible implementation, the method further includes: receiving first indication information, the first indication information indicating that the terminal device supports the first transport layer network protocol, or the first indication information indicating that the terminal device supports multi-channel communication based on the first transport layer network protocol; determining the need to establish a first tunnel between the terminal device and the first access network device includes: determining the need to establish the first tunnel between the terminal device and the first access network device based on the first indication information.

[0048] In one possible implementation, the determination of the need to establish a first tunnel between the terminal device and the first access network device includes: determining the need to establish a first tunnel between the terminal device and the first access network device based on policy information from the PCF network element or subscription information from the UDM network element.

[0049] In a fourth aspect, the present application provides a data transmission method, which can be applied to a second access network device, the method comprising: sending a second identifier of a first tunnel, or sending a second identifier and a second address of the first tunnel, the first tunnel being used to transmit data between the terminal device and the second access network device using a first transport layer network protocol, the second identifier and the second address being associated with a second communication path of the first tunnel, the first tunnel comprising at least one communication path, the first communication path in the at least one communication path being used to transmit data between the terminal device and the first access network device, the first identifier and the first address of the first tunnel being associated with the first communication path, the second communication path in the at least one communication path being used to transmit data between the terminal device and the second access network device; receiving an uplink data packet from the terminal device, the uplink data packet comprising the second identifier and the second address.

[0050] In one possible implementation, sending the second identifier of the first tunnel, or sending the second identifier and the second address of the first tunnel, includes: sending the second information to the first access network device; or sending the second identifier and the second address to the first access network device.

[0051] In one possible implementation, the method further includes: receiving sixth indication information from the first access network device, the sixth indication information indicating the fourth identifier of the first tunnel, or the sixth indication information indicating the fourth identifier and fourth address of the first tunnel, the fourth identifier and fourth address being associated with the terminal device; based on the fourth identifier and the fourth address, sending a downlink data packet to the terminal device, the downlink data packet including the second identifier and the second address.

[0052] In a possible implementation manner, the method further includes: receiving path information of the second communication path from the first access network device; or sending path information of the second communication path to the first access network device.

[0053] In the fifth aspect, the present application provides a data transmission method, which can be applied to a third access network device, the method including: sending a third identifier of a first tunnel, or sending a third identifier and a third address of the first tunnel, the first tunnel being used to transmit data between the terminal device and the third access network device using a first transport layer network protocol, the third address being associated with the third access network device, and the third access network device being the target access network device of the terminal device; receiving an uplink data packet from the terminal device, the uplink data packet including the third identifier and the third address.

[0054] In one possible implementation, the third identifier of the first tunnel, or sending the third identifier and third address of the first tunnel, includes: sending the third identifier of the first tunnel to the first access network device, or sending the third identifier and third address of the first tunnel to the first access network device.

[0055] In one possible implementation, the method further includes: receiving fifth indication information from the first access network device, the fifth indication information indicating the fourth identifier of the first tunnel, or the fifth indication information indicating the fourth identifier and fourth address of the first tunnel, and the fourth identifier and fourth address are associated with the terminal device.

[0056] In one possible implementation, the method further includes: configuring the third address for the terminal device based on indication information from the first access network device, or configuring the third identifier and the third address for the terminal device based on indication information from the first access network device.

[0057] In a possible implementation, the method further includes: sending a downlink data packet to the terminal device based on the fourth identifier and the fourth address, wherein the downlink data packet includes the third identifier, the third address, and the fourth identifier and the fourth address.

[0058] In a possible implementation manner, the method further includes: receiving the context of the first tunnel from the first access network device.

[0059] In a possible implementation manner, the method further includes: instructing the first access network device to delete the context of the first tunnel.

[0060] In a sixth aspect, the present application provides a communication device comprising at least one processor and an interface circuit, wherein the interface circuit is used to provide data or code instructions to the at least one processor, and the at least one processor is used to implement the method described in the first aspect and any possible design of the first aspect through a logic circuit or executing code instructions, or implement the method described in the second aspect and any possible design of the second aspect, or implement the method described in the third aspect and any possible design of the third aspect, or implement the method described in the fourth aspect and any possible design of the fourth aspect, or implement the method described in the fifth aspect and any possible design of the fifth aspect through a logic circuit or executing code instructions.

[0061] In the seventh aspect, an embodiment of the present application provides a communication system, comprising a communication device for implementing the method described in the first aspect and any possible design of the first aspect, or comprising a communication device for implementing the method described in the second aspect and any possible design of the second aspect, or comprising a communication device for implementing the method described in the third aspect and any possible design of the third aspect, or implementing the method described in the fourth aspect and any possible design of the fourth aspect, or implementing the method described in the fifth aspect and any possible design of the fifth aspect.

[0062] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable medium stores a program code, and when the program code is run on a computer, the computer executes the method described in the first aspect and any possible design of the first aspect, or, when the program code is run on a computer, the computer executes the method described in the second aspect and any possible design of the second aspect, or, when the program code is run on a computer, the computer executes the method described in the third aspect and any possible design of the third aspect, or, when the program code is run on a computer, the computer executes the method described in the fourth aspect and any possible design of the fourth aspect, or, when the program code is run on a computer, the computer executes the method described in the fifth aspect and any possible design of the fifth aspect.

[0063] In the ninth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on a computer, the computer executes the method described in the first aspect and any possible design of the first aspect, or executes the method described in the second aspect and any possible design of the second aspect, or executes the method described in the third aspect and any possible design of the third aspect, or executes the method described in the fourth aspect and any possible design of the fourth aspect, or executes the method described in the fifth aspect and any possible design of the fifth aspect.

[0064] Based on the implementations provided in the above aspects, the embodiments of the present application can be further combined to provide more implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figures 1(a) and 1(b) illustrate schematic diagrams of a communication system to which embodiments of the present application are applicable;

[0066] FIG2 shows a schematic diagram of the architecture of a protocol stack;

[0067] FIG3 is a schematic diagram showing the encapsulation mode of a QUIC data packet;

[0068] FIG4 shows a schematic diagram of a QUIC data packet frame;

[0069] FIG5A shows a schematic diagram of an address change;

[0070] FIG5B shows a schematic diagram of a terminal connecting to a server based on multiple access technologies;

[0071] FIG5C shows a schematic diagram of a DC scenario;

[0072] FIG6 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0073] FIG7 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0074] FIG8 shows a schematic diagram of multipath characteristics;

[0075] FIG9 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0076] FIG10 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0077] FIG11 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0078] FIG12 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0079] FIG13 is a schematic diagram showing the buffer state;

[0080] FIG14 is a schematic diagram showing a flow chart of a data transmission method according to an embodiment of the present application;

[0081] FIG15 shows a schematic structural diagram of a communication device;

[0082] FIG16 shows a schematic structural diagram of another communication device. DETAILED DESCRIPTION

[0083] To meet the challenges of wireless broadband technology and maintain the leading edge of the Third Generation Partnership Project (3GPP) network, the 3GPP standards group has developed the Next Generation System (NGS) architecture, known as the 5G network architecture. This architecture not only supports access to the 5G core network (CN) using 3GPP-defined radio access technologies (such as Long Term Evolution (LTE) and 5G Radio Access Network (RAN)), but also supports access to the 5G core network using non-3GPP access technologies via the non-3GPP interworking function (N3IWF) or the next generation packet data gateway (ngPDG).

[0084] Figure 1(a) is a schematic diagram of a 5G network architecture based on a service-oriented architecture. The 5G network architecture shown in Figure 1(a) may include access network equipment and core network equipment. The terminal device accesses the data network (DN) through the access network equipment and the core network equipment. Among them, the core network equipment includes but is not limited to some or all of the following network elements: authentication server function (AUSF) network element (not shown in the figure), unified data management (UDM) network element, unified data repository (UDR) network element, network storage function (NRF) network element (not shown in the figure), network expos network element (not shown in the figure), application function (AF) network element, policy control function (PCF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, user plane function (UPF) network element, binding support function (BSF) network element (not shown in the figure).

[0085] Terminal devices can be user equipment (UE), mobile stations, mobile terminal devices, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver functions, wearable devices, vehicles, urban air vehicles (such as drones and helicopters), ships, robots, robotic arms, smart home devices, etc.

[0086] Access network equipment can be a radio access network (RAN) device or a wireline access network (FAN) device. Among them, radio access network equipment includes 3GPP access network equipment, untrusted non-3GPP access network equipment and trusted non-3GPP access network equipment. 3GPP access network equipment includes but is not limited to: evolved NodeB (eNodeB) in LTE, next generation NodeB (gNB) in 5G mobile communication system, base station in future mobile communication system or module or unit that completes part of the functions of base station, such as centralized unit (CU), distributed unit (DU), etc. Untrusted non-3GPP access network equipment includes but is not limited to: untrusted non-3GPP access gateway or N3IWF device, untrusted wireless local area network (WLAN) access point (AP), switch, router. Trusted non-3GPP access network equipment includes but is not limited to: trusted non-3GPP access gateway, trusted WLAN AP, switch, router. Wired access network equipment includes but is not limited to: wireline access gateway, fixed telephone network equipment, switches, and routers.

[0087] Access network equipment and terminal devices can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of access network equipment and terminal devices.

[0088] The AMF network element is responsible for UE mobility management, including mobile state management, allocating temporary identities to UEs, and authenticating and authorizing UEs.

[0089] The SMF network element is responsible for the selection and reselection of UPF network elements, IP address allocation, bearer establishment, modification and release, and quality of service (QoS) control.

[0090] The UPF network element supports all or part of the following functions: interconnecting protocol data unit (PDU) sessions with the data network; packet routing and forwarding (for example, supporting uplink classification (Uplink classifier) ​​of traffic before forwarding to the data network); and data packet inspection.

[0091] The UDM network element is responsible for managing contract data and notifying the corresponding network element when the contract data is modified.

[0092] The UDR network element stores and retrieves contract data, policy data, and public architecture data; it provides access to relevant data for UDM, PCF, and NEF network elements. The UDR network element must implement different data access authentication mechanisms for different types of data, such as contract data and policy data, to ensure data access security. The UDR network element must be able to return a failure response with an appropriate cause value for illegal service-based operations or data access requests.

[0093] NEF network element is used to support the opening of capabilities and events.

[0094] The AF network element communicates application-side requirements to the network, such as QoS requirements or user status event subscriptions. The AF can be a third-party functional entity or an application service deployed by a carrier, such as the IP Multimedia Subsystem (IMS) voice call service. AF network elements include those within the core network (i.e., the carrier's AF network element) and third-party AF network elements (such as an enterprise's application server).

[0095] The PCF network element includes policy control functions such as billing for sessions and service flows, QoS bandwidth assurance, mobility management, and terminal device policy decisions. PCF network elements include the access and mobility management policy control function (AM PCF) network element and the session management policy control function (SM PCF) network element. The AM PCF network element is used to formulate AM policies for terminal devices. The AM PCF network element can also be called a policy control network element that provides services for terminal devices (PCF for a UE). The SM PCF network element is used to formulate session management policies (SM policies) for sessions. The SM PCF network element can also be called a policy control network element that provides services for sessions (PCF for a PDU session).

[0096] NRF network elements can be used to provide network element discovery capabilities, providing network element information corresponding to the network element type based on requests from other network elements. NRF also provides network element management services such as network element registration, update, and deregistration, as well as network element status subscription and push.

[0097] The BSF network element can provide BSF service registration / deregistration / update, NRF connection detection, session binding information creation, UE information acquisition, and session binding information query for duplicate IP addresses.

[0098] The AUSF network element is responsible for authenticating the UE to determine whether the UE is allowed to access the network.

[0099] A DN is a network located outside of a carrier network. A carrier network can connect to multiple DNs, and a variety of services can be deployed on the DN, providing data and / or voice services to terminal devices. For example, a DN is the private network of a smart factory. Sensors installed in the workshop can be terminal devices. The DN houses a sensor control server, which provides services to the sensors. Sensors can communicate with the control server, receive instructions from the control server, and transmit collected sensor data to the control server based on the instructions. Another example is a DN that is a company's internal office network. An employee's mobile phone or computer can be a terminal device, allowing them to access information and data resources on the company's internal office network.

[0100] In Figure 1(a), Npcf, Nufr, Nudm, Naf, Namf, and Nsmf are the service-oriented interfaces provided by the PCF, UDR, UDM, AF, AMF, and SMF, respectively, for invoking corresponding service-oriented operations. N1, N2, N3, N4, and N6 are interface serial numbers, and their meanings are as follows:

[0101] 1) N1: The interface between AMF and terminal devices, which can be used to deliver non-access stratum (NAS) signaling (such as QoS rules from AMF) to terminal devices.

[0102] 2) N2: The interface between AMF and access network equipment, which can be used to transmit radio bearer control information from the core network side to the access network equipment.

[0103] 3) N3: The interface between the access network equipment and UPF, mainly used to transmit uplink and downlink user plane data between the access network equipment and UPF.

[0104] 4) N4: The interface between SMF and UPF can be used to transmit information between the control plane and the user plane, including controlling the issuance of forwarding rules, QoS rules, traffic statistics rules, etc. for the user plane and reporting information on the user plane.

[0105] 5) N6: Interface between UPF and DN, used to transmit uplink and downlink user data flows between UPF and DN.

[0106] Figure 1(b) is a schematic diagram of a 5G network architecture based on point-to-point interfaces. The functions of the network elements in Figure 1(a) can be referred to for the functions of the corresponding network elements, and will not be repeated here. The main difference between Figure 1(b) and Figure 1(a) is that the interfaces between the control plane network elements in Figure 1(a) are service-oriented interfaces, while the interfaces between the control plane network elements in Figure 1(b) are point-to-point interfaces.

[0107] In the architecture shown in Figure 1(b), the interface names and functions between the various network elements are as follows:

[0108] 1) For the meanings of the N1, N2, N3, N4 and N6 interfaces, please refer to the above description.

[0109] 2) N5: The interface between the AF network element and the PCF network element, which can be used to issue application service requests and report network events.

[0110] 3) N7: The interface between PCF network element and SMF network element, which can be used to issue PDU session granularity and service data flow granularity control strategy.

[0111] 4) N8: The interface between the AMF network element and the UDM network element, which can be used by the AMF network element to obtain access and mobility management related contract data and authentication data from the UDM network element, and the AMF network element to register terminal device mobility management related information with the UDM network element.

[0112] 5) N9: User plane interface between UPF network elements, used to transmit uplink and downlink user data flows between UPF network elements.

[0113] 6) N10: The interface between the SMF network element and the UDM network element, which can be used by the SMF network element to obtain session management related contract data from the UDM network element, and the SMF network element to register terminal device session related information with the UDM network element.

[0114] 7) N11: The interface between the SMF network element and the AMF network element, which can be used to transmit PDU session tunnel information between the access network device and the UPF, transmit control messages sent to the terminal device, transmit wireless resource control information sent to the access network device, etc.

[0115] 8) N15: The interface between the PCF network element and the AMF network element, which can be used to issue terminal device policies and access control related policies.

[0116] 9) N35: The interface between the UDM network element and the UDR network element, which can be used by the UDM network element to obtain user contract data information from the UDR network element.

[0117] 10) N36: Interface between PCF network element and UDR network element, which can be used by PCF network element to obtain policy-related contract data and application data-related information from UDR network element.

[0118] It is understood that the above-mentioned network element or function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the above-mentioned network element or function can be implemented by a single device, or by multiple devices, or can be a functional module within a single device, and this is not specifically limited in the embodiments of the present application.

[0119] The mobility management network element, session management network element, data management network element, and network storage function network element in this application can be the AMF network element, SMF network element, UDM network element, and NRF network element in the 5G system, respectively, or can be a network element with the functions of the above-mentioned AMF network element, SMF network element, UDM network element, and NRF network element in future communications such as 6G networks. This application is not limited to this. In the embodiments of this application, an example is described in which the AMF network element, SMF network element, UDM network element, and NRF network element are the mobility management network element, session management network element, data management network element, and network storage function network element, respectively. In addition, the AMF network element, SMF network element, UDM network element, and NRF network element are referred to as AMF, SMF, UDM, and NRF, respectively.

[0120] For ease of explanation, the embodiments of the present application are described using a base station and a UE as specific examples of an access network device and a terminal device, respectively. Any base station and UE appearing in any subsequent location can be replaced by an access network device and a terminal device, respectively.

[0121] To facilitate understanding of the content of this application, the relevant background involved in the embodiments of this application is first introduced below.

[0122] 1. Quick UDP internet connections (QUIC) protocol:

[0123] The QUIC protocol is a transport protocol equivalent to the Transmission Control Protocol (TCP). As shown in the protocol stack structure in Figure 2, the QUIC protocol is carried on the UDP protocol and incorporates the advantages of the HTTP / 2 API, TLS, and TCP during its design. Its goal is to optimize overall latency and throughput, and improve performance during network handoffs.

[0124] The encapsulation mode of QUIC data packets is shown in Figure 3, including the header and payload (or payload) parts. It follows the principle of encrypting the payload and encrypting the header as much as possible to avoid problems such as network middleware parsing and intercepting network traffic, thereby enhancing the security of data transmission.

[0125] The header includes a UDP header and a common header, for example, including at least one public flag, a connection ID (CID), a QUIC version, a sequence number, etc. The CID can be used to associate data with the same link.

[0126] The payload part is an encrypted ciphertext that can encapsulate frame data of multiple streams. The frame may include type, stream identifier, offset value, data length, stream data, etc. For example, as shown in Figure 4, taking the terminal device and the server as the sender and receiver of the QUIC data packet respectively, for the QUIC connection between the terminal device and the server, QUIC data packet 1, QUIC data packet 2, and QUIC data packet 3 can be associated based on CID1. A certain frame of QUIC data packet 1 (for example, represented as 2QUIC frame) can encapsulate the data of streams 1 and 2, a certain frame of QUIC data packet 2 (for example, represented as 3QUIC frame) can encapsulate the data of streams 1, 2, and 3, and a certain frame of QUIC data packet 3 (for example, represented as 1QUIC frame) can encapsulate the data of stream 2.

[0127] It should be understood that Figures 3 and 4 are merely examples of the QUIC data packet format and are not intended to be limiting. The width of the rectangular box is merely an example and does not represent the length of the contents within the packet. For example, in a specific implementation, a QUIC data packet can be either a long header packet or a short header packet. The long header packet contains source CID and destination CID fields. The destination CID is specified by the receiver and is used to provide stable routing for the packet. The source CID is set by the peer end as the destination CID. These fields can be used to set the CID for a new connection. The short header packet contains only the destination CID and omits the explicit length. The length of the destination CID field is assumed to be known to the peer end.

[0128] 2. QUIC Tunnel and CID:

[0129] Each connection between the terminal device and the server is called a QUIC connection, which can also be a QUIC tunnel (hereinafter "tunnel" and "connection" can be used interchangeably), and can usually have a set of CIDs, expressed as CIDs, each of which can identify the QUIC tunnel.

[0130] Among them, CID can be independently selected by the terminal device, and each terminal device selects a CID for use by the other end. The main function of CID is to ensure that when the address of the underlying protocol (such as UDP protocol, IP protocol or lower-level protocol stack) changes, it will not cause a QUIC connection data packet to be transmitted to the wrong QUIC terminal device, and can support application (APP) unaware connection migration. The terminal device can use a special implementation (and possibly special deployment) method to select the CID, which will enable the data packet with the CID to be routed back to the terminal device and correctly identified when received.

[0131] End devices can maintain a set of CIDs received from peers, each of which can be used to send QUIC packets. End devices can restrict the use of CIDs, for example, allowing a CID to only be used to send packets from the same local address to the same destination address. When the address changes, the CID needs to be updated.

[0132] At any time during a QUIC connection with a server, a terminal device can change the CID it uses to interact with the peer to another available CID. When the peer migrates the connection, the CID published by the terminal device is consumed, meaning that the CID is no longer used. When a terminal device wants to stop using a CID, it can send a Revoke CID frame to the peer. Sending a Revoke CID frame means that the CID will not be used again and requests the peer to replace it with a new CID using a New CID frame.

[0133] For example, during the handshake, a QUIC packet with a long header sets the CID used by both peers. The source CID of each peer becomes the destination CID for packets sent to that peer. After processing the initial packet, each peer sets the destination CID field of subsequent packets to the value of the source CID field it received.

[0134] In the embodiments of the present application, only the negotiation and use of the CID of the QUIC connection between the UE and the RAN are focused on, and the data packet format is not focused on.

[0135] 3. QUIC Path Migration and QUIC Multipath Features:

[0136] The target CID sent by the terminal device can change during the life cycle of a QUIC connection, especially when responding to connection migration. For mobile communication networks, QUIC has the following two features: QUIC path migration and QUIC multipath. Among them, the QUIC multipath feature is more important for mobile communication networks.

[0137] (1) QUIC path migration: Applicable to the case where the UE moves or the UE's access changes, resulting in a change in the UE's IP address. For a TCP connection, changes in the communication quadruple (including source IP, source port, destination IP, destination port) will cause the TCP connection to be interrupted, resulting in an interruption of the application layer service, thus affecting the user experience. However, in the QUIC protocol, the concept of "connection" and CID are used. As long as the CID remains unchanged, the connection can be guaranteed to be uninterrupted even if the network is switched, that is, the connection between the communication endpoints will not be interrupted due to changes in the quadruple. The application layer can no longer perceive the interruption of the protocol state of the underlying transport protocol, so the application layer service will not be interrupted and the user experience will not be affected. As shown in Figure 5A, different quadruple groups can correspond to one connection, and changes in any element in the quadruple group (such as source IP changes) will not affect the application layer service.

[0138] ① Initiate connection migration: The terminal can migrate the connection by sending a data packet containing a non-probe frame from a new local address.

[0139] ② Response to connection migration: Receiving a data packet containing a non-probe frame from the new peer address indicates that the peer has migrated to that address. If the receiver recognizes the migration, it must send subsequent data packets to the new peer address and, if not already initiated, must initiate path verification (see explanation below) to verify the peer's ownership of that address. If the receiver does not have an unused CID from the peer, it will not be able to send any data on the new path until the peer provides one.

[0140] Each endpoint verifies the peer's address during connection establishment. Therefore, a migrating endpoint can send data to a peer knowing that the peer is willing to receive data at its current address. Thus, a endpoint can migrate to a new local address without first verifying the peer's address.

[0141] (2) QUIC multipath: Applicable when the UE supports multiple access technologies for simultaneous access, or when the UE supports dual active protocol stack switching (DAPS, also known as zero-interruption seamless switching) during mobility, such as handover (HO), or when there can be multiple sessions, such as in 5G session SSC mode 3, the UE can maintain two session connections at the same time during switching. At this time, there can be multiple paths from the UE to the application server (AS) at the same time. As shown in Figure 5B, the smart terminal is connected to the server through two access technologies at the same time, and there are two communication paths.

[0142] IV. Access traffic steering, switching and splitting (ATSSS) rules:

[0143] The ATSSS rules specify the overall technical requirements for the offloading, migration and separation of access services in the core network of the 5G mobile communication network, including the new technical functional requirements of network elements such as PCF, AMF, SMF, UPF and NRF relative to 5G network functions and interfaces.

[0144] Access service offloading is a process of directing a flow. A new data flow selects an access network and transmits its traffic over the specified access network. Access service offloading is applicable between a 3rd Generation Partnership Project (3GPP) access and a non-3GPP access.

[0145] Access service migration is a flow migration process that migrates all traffic of an ongoing service flow from one access network to another, maintaining service flow continuity. Access service migration is applicable between a 3GPP access network and a non-3GPP access network.

[0146] Access service splitting involves splitting and dividing service data flows between multiple access networks. When traffic splitting (splitting) is applied to a data flow, some traffic within that flow is transmitted over one access, while other traffic within the same flow is transmitted over another access. Access service splitting is applicable between a 3GPP access and a non-3GPP access.

[0147] In an embodiment of the present application, the terminal device can control the diversion of services according to ATSSS rules. For example, the terminal device determines according to the ATSSS rules that the data flow of the service is transmitted only through 3GPP access technology, or is transmitted only through non-3GPP access technology, or is transmitted through both 3GPP access technology and non-3GPP access technology, that is, diverting the service through the two access technologies.

[0148] 5. Protocol Data Unit (PDU) Session:

[0149] One of the key tasks of 5GS session management is to provide data connection to DN for terminal devices. In order to establish a connection between terminal devices and DN, a PDU session needs to be established. A PDU session is a logical connection between a terminal device and a specific DN, which provides the terminal device with a user plane connection to the DN. Among them, "PDU" is the basic user protocol type carried by the PDU session, which can be an IP data packet or an Ethernet frame, depending on the PDU session type. 5GS currently supports three PDU session types, including IP-based PDU session type, Ethernet PDU session type, and unstructured PDU session type. The "PDU" carried by the IP-based PDU session is an IP data packet, and the "PDU" carried by the Ethernet PDU session is an Ethernet frame. For unstructured PDU sessions, 5GS does not interpret the "PDU" it carries.

[0150] During the PDU session establishment process, the corresponding user plane connection between the terminal device and the DN will be activated. The user plane connection provides the transmission of PDUs between the terminal device and the DN, carrying actual data, such as voice and video. A terminal device can request to establish multiple PDU sessions simultaneously. These multiple PDU sessions can be connected to different DNs respectively. For example, if the UE requires both Internet connectivity and IMS services, a PDU session from the terminal device to the Internet and a PDU session from the terminal device to the IMS can be established simultaneously. In addition, a terminal device can also request to establish multiple PDU sessions to a single DN at the same time.

[0151] The specific process of session establishment or modification can refer to the relevant process in 4.3 of 3GPP standard protocol 23.502, which will not be repeated here. In the following embodiments, only the PDU session scenario is used as an example of the application scenario of the improved QUIC protocol to introduce the implementation details of the QUIC protocol applicable to the UE and the access network device, which does not constitute any limitation.

[0152] 6. Dual connection (DC):

[0153] Dual connectivity means that the UE maintains connections with two access network devices simultaneously. DC technology was originally developed to address coverage issues for users at the cell edge.

[0154] As shown in Figure 5C, a UE is at the edge of base station A's signal coverage (denoted as cell 1). If only base station A is used to provide network access to the UE, the signal strength may be insufficient, impacting UE-side service delivery. In this case, the network service operator can deploy base station B at the cell edge and configure base stations A and B as a DC to enhance coverage. The UE maintains connections to both base stations A and B.

[0155] In the embodiments of the present application, the DC scenario is only used as an example of the application scenario of the improved QUIC protocol to introduce the implementation details of the QUIC protocol applicable to the UE and the access network device, and does not constitute any limitation.

[0156] 7. Xn switching and NG switching:

[0157] Next-generation (NG) handover refers to handover within a 4G LTE network, where NG stands for next generation. NG handover is based on LTE technology and is commonly used within LTE networks. It enables seamless handover from one base station to another, providing a better user experience and quality of service.

[0158] Xn handover refers to handover within a 5G network, where Xn stands for Extended Network. Xn handover is a handover method based on 5G technology and is used within 5G networks. Xn handover can enable handover from one 5G base station to another or from 4G to 5G, supporting a variety of different scenarios and application requirements.

[0159] In the embodiments of the present application, the switching scenario is only used as an example of the application scenario of the improved QUIC protocol to introduce the implementation details of the QUIC protocol applicable to the UE and the access network device, and does not constitute any limitation.

[0160] Due to the complexity of the protocol stack between the UE and the access network equipment (such as RAN), especially when transmitting traffic data similar to QUIC packets, the application layer multiplexes multiple streams on a QUIC packet, making it impossible for the air interface to distinguish the data in multiple streams or datagrams in the transmitted QUIC packet.

[0161] The embodiments of the present application provide a data transmission method, device and system for designing a QUIC protocol suitable for use between a UE and an access network device to better transmit QUIC-like traffic. The method and the device are based on the same technical concept. Since the principles of the method and the device for solving problems are similar, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated. Moreover, in the various embodiments of the present application, unless otherwise specified and there is a logical conflict, the terms and / or descriptions between the various embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form a new embodiment according to their inherent logical relationships.

[0162] It should be noted that, in the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0163] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish between multiple objects, and are not used to limit the priority or importance of multiple objects. For example, the first access network device and the second access network device are only used to distinguish different access network devices, rather than to indicate the difference in priority or importance of the two devices. For example, in some embodiments, the method steps performed by the first access network device and the second access network device can be interchangeable. For example, in a handover scenario, the first access network device can serve as the source access network device of the UE, and the second access network device can serve as the target access network device of the UE. Conversely, the first access network device can serve as the target access network device of the UE, and the second access network device can serve as the source access network device of the UE.

[0164] Figure 6 shows a flow chart of the data transmission method of an embodiment of the present application. The method can be implemented in collaboration between a terminal device and a network-side device. In different embodiments, the specific implementation of the network-side device may be different. For example, in a PDU session scenario, the network-side device may include an SMF network element, etc. In a dual-connectivity (DC) scenario, the network-side device may include at least one access network device. In a mobile switching scenario, the network-side device may include a source access network device and a target access network device, etc.

[0165] Referring to FIG6 , the data transmission method may include the following steps:

[0166] S610 (optional step): The first access network device configures the first address of the first tunnel for the terminal device.

[0167] In the embodiment of the present application, the first tunnel may adopt a first transport layer network protocol and may be used to transmit data between the terminal device and the first access network device. This may be understood as the presence of a protocol function layer based on the first transport layer network protocol between the terminal device and the first access network device, or as the reference point protocol stack between the terminal device and the first access network device including the first transport layer network protocol layer.

[0168] Exemplarily, the first transport layer network protocol may be the QUIC protocol introduced above, and the first tunnel is the QUIC tunnel, or referred to as a QUIC connection. The first address includes the address of the first access network device used for QUIC communication with the terminal device, such as the IP address and port number of the first access network device. In other embodiments, the first transport layer network protocol may be other transport protocols having the functions described in the present invention, or other transport layer network protocols similar to the QUIC protocol. The first address includes the address information configured by the first access network device under the corresponding protocol, and may also be the address identifier of the communication endpoint of the first transport layer network protocol or the address identifier of the communication endpoint of the low-layer protocol carrying the first transport layer network protocol, such as a tunnel identifier, a protocol layer identifier, a channel identifier, a logical channel identifier, etc. This embodiment of the present application does not limit this.

[0169] It is worth noting that in the embodiment of the present application, "configuration (provision or configure or allocate)" can be replaced by "generate and send" or "allocate", for example, the first access network device configures the first address for the terminal device, specifically the first access network device generates the first address for the terminal device and sends the first address to the terminal device.

[0170] In specific implementation, the first access network device may be triggered to implement S610 based on various methods to configure the first address of the first tunnel for the terminal device. Examples of triggering methods are described below:

[0171] (1) Method 1: A first access network device receives first indication information, where the first indication information indicates that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol. When implementing S610, the first access network device may configure a first address of the first tunnel for the terminal device based on the first indication information.

[0172] During specific implementation, according to different interaction processes in different implementation modes, the source of the first indication information may be a terminal device or a core network element.

[0173] For example, in Example 1 of Method 1, the terminal device may send a first access layer message to the first access network device, where the first access layer message includes first indication information. Accordingly, the first access network device receives the first access layer message from the terminal device and obtains the first indication information from the first access layer message. After accessing the first access network device, the terminal device may send the first access layer message to the first access network device during or after establishing a PDU session.

[0174] Among them, the first access layer message can be any uplink radio resource control (RRC) message from the terminal device, for example, a newly added uplink RRC message sent by the terminal device to the first access network device after accessing the first access network device, and the uplink RRC message includes the first indication information.

[0175] Or for example, the first access layer message can be a multiplexing of an existing uplink RRC message between the terminal device and the first access network device, for example, the first indication information is carried in a reserved field of the existing uplink RRC message between the terminal device and the first access network device, or the first indication information is a replacement for other information elements in the original uplink RRC message between the terminal device and the first access network device.

[0176] Alternatively, for example, in Example 2 of Method 1, the core network element may send first indication information to the first access network device. The first indication information may be included in a control message sent by the core network element to the first access network device. Accordingly, the first access network device receives the control message from the core network element and obtains the first indication information from the control message. The core network element may send the control message to the first access network device during or after the PDU session is established.

[0177] In Example 2 of the first specific implementation, the second control message may be a newly added control message between the core network element and the first access network device, or the control message may be a reuse of an existing control message between the core network element and the first access network device.

[0178] For example, the core network element may be an SMF element, and the control message may be implemented as a newly added control message from the SMF element. The newly added control message includes first indication information for directly or indirectly instructing the first access network device to configure the first address of the first tunnel for the terminal device. Alternatively, the control message may be implemented as an Nx session message from the SMF element, for instructing the establishment of a PDU session for the terminal device. The first indication information may be carried in a reserved field of the Nx session message, or in a newly added information element or container, or may replace other information elements originally carried in the Nx session message.

[0179] The core network element may learn about the tunnel capability of the terminal device when interacting with the terminal device, the first access network device, or other core network elements.

[0180] For example, the terminal device carries the first indication information in the first non-access layer message sent to the core network network element. For example, the terminal device carries the first indication information in the (PDU) session message sent to the AMF network element through the N1 interface. The AMF network element can forward the (PDU) session message to the SMF network element through the N11 interface, and the SMF network element obtains the first indication information from the (PDU) session message from the AMF network element. The SMF network element can send the first indication information to the first access network device.

[0181] Or for example, the terminal device carries the first indication information in the (PDU) session message sent to the first access network device, the first access network device forwards the (PDU) session message to the AMF network element through the N2 interface, the AMF network element forwards the (PDU) session message to the SMF network element through the N11 interface, and the SMF network element obtains the first indication information from the (PDU) session message from the AMF network element. The SMF network element can send the first indication information to the first access network device. It should be understood that in the interaction process here, the first access network device is only a transparent transmission node for the (PDU) session message and does not parse the session message.

[0182] (2) Method 2: The first access network device receives second indication information, which indicates that a first tunnel is to be established between the terminal device and the first access network device. For example, the second indication information may be a request indicator, indicating a request or need to establish a tunnel between the terminal device and the first access network device. For example, it may be a requirement description information, indicating that there is a requirement for stable latency, thereby implicitly indicating that the first tunnel is to be established between the terminal device and the first access network device. When implementing S610, the first access network device may configure the first address of the first tunnel for the terminal device based on the second indication information.

[0183] During specific implementation, according to different interaction processes in different implementation modes, the source of the second indication information may be a terminal device or a core network element.

[0184] For example, in Example 1 of Method 2, the terminal device may send a second access layer message to the first access network device, where the second access layer message includes the second indication information. Accordingly, the first access network device may receive the second access layer message from the terminal device and obtain the second indication information from the second access layer message. After accessing the first access network device, the terminal device may send the second access layer message to the first access network device during or after establishing a PDU session.

[0185] Among them, the second access layer message can be any uplink RRC message from the terminal device, for example, a newly added uplink RRC message sent by the terminal device to the first access network device after accessing the first access network device, and the uplink RRC message includes the second indication information.

[0186] Or for example, the second access layer message can be a multiplexing of an existing uplink RRC message between the terminal device and the first access network device, for example, the second indication information is carried in a reserved field of the existing uplink RRC message between the terminal device and the first access network device, or a newly added information element or container, or the second indication information is a replacement for other information elements in the existing uplink RRC message between the terminal device and the first access network device.

[0187] Or, for example, in Example 2 of Mode 2, the core network element may send a control message to the first access network device, where the control message may include the second indication information. Accordingly, the first access network device receives the control message from the core network element and obtains the second indication information from the control message.

[0188] In Example 2 of the second specific implementation method, the control message may be a newly added control message between the core network element and the first access network device, or the control message may be a reused control message between the core network element and the first access network device.

[0189] For example, the core network element may be an SMF element. The control message may be implemented as a newly added control message from the SMF element, including second indication information for directly or indirectly instructing the first access network device to configure the first address of the first tunnel for the terminal device. Alternatively, the control message may be implemented as an Nx session message from the SMF element, for instructing the establishment of a PDU session for the terminal device. The second indication information may be carried in a reserved field of the Nx session message, or in a newly added information element or container, or may replace other information elements originally carried in the Nx session message.

[0190] The core network element may learn about the tunnel capability of the terminal device when interacting with the terminal device, the first access network device, or other core network elements.

[0191] For example, the terminal device carries the second indication information in the second non-access layer message sent to the core network network element. For example, the terminal device carries the second indication information in the (PDU) session message sent to the AMF network element through the N1 interface. The AMF network element can forward the (PDU) session message to the SMF network element through the N11 interface, and the SMF network element obtains the second indication information from the (PDU) session message from the AMF network element. The SMF network element can send the second indication information to the first access network device. The SMF network element sends the second indication information to the first access network device, which can also be understood as the SMF network element determining whether it is necessary to establish a first tunnel between the terminal device and the first access network device, and then sending the second indication information to the first access network device.

[0192] For example, the SMF network element may determine whether it is necessary to establish a first tunnel between the terminal device and the first access network device. For example, the SMF network element may determine whether it is necessary to establish a first tunnel between the terminal device and the first access network device during the process of establishing a PDU session or after establishing a PDU session, during the process of interacting with the terminal device, or the first access network device, or other core network network elements. If the SMF network element determines that it is necessary to establish a first tunnel between the terminal device and the first access network device, the SMF network element may instruct the first access network device to configure a first address of the first tunnel for the terminal device.

[0193] Exemplarily, the SMF network element may receive first indication information from a terminal device, where the first indication information indicates that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol. The SMF network element may determine, based on the first indication information, that a first tunnel needs to be established between the terminal device and the first access network device.

[0194] Alternatively, the SMF network element may further determine that a first tunnel needs to be established between the terminal device and the first access network device according to at least one of the following information:

[0195] (1) The contract information of the terminal device. The SMF network element may obtain the contract information of the terminal device from the UDM network element. If the contract information indicates that the terminal device requires a stable latency, then the contract information indicates that a first tunnel is allowed to be established between the terminal device and the first access network device. The SMF network element may determine that the first tunnel needs to be established between the terminal device and the first access network device.

[0196] (2) DNN / Slice information. The SMF network element can obtain DNN / Slice information from a session request (e.g., a PDU session) from a terminal device. If the service corresponding to the DNN / Slice requires a stable latency or requires a first tunnel, the SMF network element can determine that a first tunnel needs to be established between the terminal device and the first access network device.

[0197] (3) Policy information of the PCF network element. The SMF network element can obtain the policy information from the PCF network element. If the policy information indicates that a session of the terminal device (e.g., a PDU session) requires a stable delay or requires a first tunnel, the SMF network element can determine that a first tunnel needs to be established between the terminal device and the first access network device.

[0198] (4) Second indication information from the terminal device, where the second indication information indicates to establish the first tunnel between the terminal device and the first access network device.

[0199] It should be understood that the above is merely an example of the information that the SMF network element relies on to decide whether it is necessary to establish a first tunnel between the terminal device and the first access network device, and it is not a limitation. In other embodiments, the SMF network element can also determine whether it is necessary to establish a first tunnel between the terminal device and the first access network device through other information, which will not be repeated here.

[0200] In an embodiment of the present application, the SMF network element instructs the first access network device to configure the first address of the first tunnel for the terminal device. For example, the SMF network element may send a fourth indication message to the first access network device, and the fourth indication message may indicate the configuration of the first address of the first tunnel.

[0201] In one example, the fourth indication information can be carried in a control message sent by the SMF network element to the first access network device, and the control message includes the fourth indication information. Similarly, the control message can be a newly added control message between the SMF network element and the first access network device, or it can be a multiplexing of an existing message between the SMF network element and the first access network device. The fourth indication information can be carried in the multiplexing of the existing control message. The fourth indication information can be carried in a reserved field of the existing control message, or the fourth indication information can be a replacement for other information elements in the existing control message. The first access network device can configure a first address for the terminal device according to the fourth indication information, and feed back the first address to the SMF network element as a response example to the fourth indication information. For example, the first access network device can send first information to the SMF network element, and the first information indicates the address of the first tunnel.

[0202] In another example, the fourth indication information can be carried in the Nx session message sent by the SMF network element to the first access network device. The first access network device can configure the first address for the terminal device according to the fourth indication information and send the first information to the terminal device.

[0203] In an optional implementation, the SMF network element may also send attribute information of the first tunnel to the first access network device. In a specific implementation, the fourth indication information may also indicate the attribute information of the first tunnel. Alternatively, the attribute information of the first tunnel may be carried in the same message from the SMF network element as the attribute information of the first tunnel, but may be different indication information. Alternatively, the attribute information of the first tunnel and the fourth indication information may be carried in different control messages or Nx session messages. The embodiment of the present application does not limit the carrying method of the fourth indication information and the attribute information of the first tunnel.

[0204] In another optional implementation, the first transport layer network protocol may also agree on the default attributes of the first tunnel, and the SMF network element and / or the first access network device may determine the default attributes as the attributes of the first tunnel in accordance with the protocol agreement. Wherein, if the attributes of the first tunnel are determined by the SMF network element, the SMF network element may send the attribute information of the first tunnel to the first access network device, for example, in a manner similar to the fourth indication information in the foregoing text. If the attributes of the first tunnel are determined by the first access network device, the first access network device may send the attribute information of the first tunnel to the SMF network element, for example, in a manner similar to the response example for the fourth indication information described above. Alternatively, the first access network device may send the attribute information of the first tunnel to the terminal device. For example, when sending the first information to the terminal device, the first information may include the attribute information of the first tunnel, which will be described in detail below and will not be repeated here.

[0205] Or for example, the terminal device carries the second indication information in the (PDU) session message sent to the first access network device, the first access network device forwards the (PDU) session message to the AMF network element through the N2 interface, the AMF network element forwards the (PDU) session message to the SMF network element through the N11 interface, and the SMF network element obtains the second indication information from the (PDU) session message from the AMF network element. The SMF network element can send the second indication information to the first access network device. For example, during the interaction process with the terminal device, or the first access network device, or other core network network elements, the SMF network element determines that it is necessary to establish a first tunnel between the terminal device and the first access network device based on information from the terminal device, or the first access network device, or other core network network elements, and sends the second indication information to the first access network device. The detailed implementation details can be found in the above introduction and will not be repeated here. It should be understood that during the interaction process here, the first access network device is only a transparent transmission node for the (PDU) session message and does not parse the session message. Therefore, the first access network device will not parse the second indication information from the (PDU) session message from the terminal device, but needs to be sent down through the SMF network element.

[0206] It should be understood that the above-mentioned first indication information and the second indication information can be sent by the terminal device to the access network device in the same AS signaling, or can be sent by the core network network element to the access network device in the same control message. In this case, the first access layer message and the second access layer message can be the same message. Alternatively, the above-mentioned first indication information and the second indication information can be sent by the terminal device to the access network device in different AS signaling at different times, or can be sent by the core network network element to the access network device in different control messages at different times. The embodiments of the present application do not limit this.

[0207] The dotted arrows and dotted boxes in Figure 6 represent optional steps / nodes. The details of the process under the above-mentioned different triggering methods will be introduced in combination with different embodiments and drawings below, which will not be repeated here. When the source of the above-mentioned first indication information or second indication information is a core network network element, the first access network device can decide whether it is necessary to send the first address of the first tunnel configured for the terminal device to the core network element based on the first transport layer network protocol and the relevant indication information received. For details, please refer to the detailed introduction of different embodiments below, which will not be repeated here.

[0208] S620: The first access network device sends first information to the terminal device, where the first information indicates the first address of the first tunnel. Accordingly, the terminal device may receive the first information.

[0209] Exemplarily, the first information may be carried in a downlink control message from the first access network device, such as a downlink RRC message. The following description will be made using an RRC message as an example.

[0210] Among them, according to the different methods of triggering the configuration of the first address introduced when implementing S610, the downlink RRC message carrying the first information can be a response of the first access network device to the first access layer message from the terminal device, or the downlink RRC message carrying the first information can be a corresponding control message sent by the first access network device to the terminal device based on relevant messages or relevant indication information from the core network network element.

[0211] Exemplarily, the SMF network element may request the first information from the first access network device. After the first access network device feeds back the first information to the SMF network element, the SMF network element may carry the first information in the control message sent to the terminal device. For example, as described above, the SMF network element may send a second indication message to the first access network device, indicating a request or need to establish a tunnel between the terminal device and the first access network device. The first access network device may configure a first address for the terminal device based on the second indication information, and feed back the first information as response information to the second indication information to the SMF network element. Furthermore, the SMF network element may carry the first information in the control message sent to the terminal device.

[0212] In other words, in the embodiment of the present application, the first access network device may send the first information to the terminal device directly or indirectly, and the embodiment of the present application does not limit this. The arrow corresponding to S620 in Figure 6 only indicates that the first access network device can send the first information to the terminal device, and does not limit the method of sending the first information. In other embodiments, the first access network device may also send the first information to the terminal device through other core network network elements, for example, which will not be repeated here.

[0213] S630: The terminal device establishes a first tunnel with the first access network device according to the first address.

[0214] In the embodiment of the present application, S630 may be initiated by the terminal device or by the first access network device, and the embodiment of the present application does not limit this.

[0215] Taking the terminal device initiating S630 as an example, S630 may include the following steps:

[0216] S631a: The terminal device sends an uplink initial data packet using the first transport layer network protocol to the first access network device based on the first address. The destination address of the initial data packet can be set to the received first address, and the source protocol address of the first transport layer network protocol of the initial data packet, which can also be called the source connection identifier (SCID), is set to C1, and C1 is generated by the terminal device. Since no initial data packet or retry data packet has been received from the first access network device before the initial packet, the terminal device generates an unpredictable value S1 to fill in the destination protocol address of the first transport layer network protocol of the initial packet to be sent, which can also be called the destination connection identifier (DCID), and the terminal device sends the initial data packet to the first access network device.

[0217] S632b: After receiving the initial data packet from the terminal device, the first access network device parses C1 from the initial data packet and uses C1 as the destination protocol address of the downlink data packet sent to the terminal device. The first access network device generates its source protocol address S3. The first access network device sends a downlink initial data packet to the terminal device. The destination protocol address (DCID) of the downlink initial data packet is the source protocol address C1 of the terminal device, and the source protocol address is the source protocol address S3 generated by the first access network device.

[0218] S633c: The terminal device receives the initial downlink data packet from the first access network device and obtains its destination protocol address S3 from the initial downlink data packet. Subsequently, the terminal device sends a first transport layer network protocol data packet carrying upper layer protocol data to the first access network device, using S3 as the destination protocol address. For the QUIC protocol, this is the 1-RTT data portion.

[0219] S634d: If 1-RTT data is received from the terminal device, the first access network device uses C1 as the destination protocol address and sends a first transport layer network protocol data packet carrying upper layer protocol data to the terminal device.

[0220] At this point, the terminal device and the first access network device have completed the negotiation of the communication identifier and address implemented based on the first tunnel, and the establishment process of the first tunnel is completed.

[0221] In an optional implementation, the terminal device and the first access network device may also use a retry packet to negotiate a CID. This process may include the following steps:

[0222] S631b: The terminal device sends an uplink initial data packet of the first transport layer network protocol to the first access network device based on the first address. The destination address of the initial data packet is set to the received first address, and the source protocol address of the first transport layer network protocol of the initial data packet is set to C1, which is generated by the terminal. Since no initial data packet or retry data packet has been received from the first access network device before this initial packet, the terminal device generates an unpredictable value S1 to fill in the destination protocol address of the initial packet to be sent, and the terminal device sends the initial data packet to the first access network device.

[0223] S632b: The first access network device receives an initial data packet from the terminal device, parses C1 from the initial data packet, and uses C1 as the destination protocol address of a downlink data packet sent to the terminal device. The first access network device generates its source protocol address S2. The first access network device sends a downlink retry data packet to the terminal device. The destination protocol address (DCID) of the downlink retry data packet is the source protocol address C1 of the terminal device, and its source protocol address is the source protocol address S2 generated by the first access network device.

[0224] S633b: The terminal device receives the retry data packet and sends the initial data packet again. The destination protocol address (DCID) of the initial data packet is the source protocol address C1 of the terminal device, and its source protocol address is the source protocol address S2 generated by the first access network device.

[0225] S634b: The first access network device receives the initial data packet from the terminal device, parses C1 from the initial data packet, and uses C1 as the destination protocol address of the downlink data packet sent to the terminal device. The first access network device generates its source protocol address S3. The first access network device sends a downlink initial data packet to the terminal device. The destination protocol address (DCID) of the downlink initial data packet is the source protocol address C1 of the terminal device, and the source protocol address is the source protocol address S3 generated by the first access network device.

[0226] S635b: The terminal device receives the initial downlink data packet from the first access network device and obtains its destination protocol address S3 from the initial downlink data packet. Subsequently, the terminal device sends a first transport layer network protocol data packet carrying upper layer protocol data to the first access network device, using S3 as the destination protocol address. For the QUIC protocol, this is the 1-RTT data portion.

[0227] S636b: If 1-RTT data is received from the terminal device, the first access network device uses C1 as the destination protocol address and sends a first transport layer network protocol data packet carrying upper layer protocol data to the terminal device.

[0228] At this point, the terminal device and the first access network device have completed the negotiation of the communication identifier and address implemented based on the first tunnel, and the establishment process of the first tunnel is completed.

[0229] In an optional implementation, the terminal device may also obtain attribute information of the first tunnel. When implementing S630, the terminal device may establish the first tunnel with the first access network device according to the first address and the attribute information of the first tunnel.

[0230] In one example, the first transport layer network protocol may agree on the default attributes of the first tunnel, and the terminal device may determine that the default attributes are the attribute information of the first tunnel. Alternatively, the attribute information of the first tunnel may also be configured by the first access network device, for example, the first information sent by the first access network device to the terminal device may also include the attribute information of the first tunnel. Or, for example, the first access network device may carry the attribute information of the first tunnel in the AS signaling that carries the first information. The first access network device may send the attribute information of the first tunnel to the terminal device in an independent AS signaling, which is different from the AS signaling that carries the first information. The embodiment of the present application does not limit the implementation method of the terminal device obtaining the attribute information of the first tunnel.

[0231] Similarly, if S630 is initiated by the first access network device, the first access network device can also obtain the attribute information of the first tunnel. The first transport layer network protocol can stipulate the default attributes of the first tunnel, and the first access network device can determine that the default attributes are the attribute information of the first tunnel based on the received first indication information, or the first access network device can determine that the default attributes are the attribute information of the first tunnel based on the fourth indication information from the core network network element, and the fourth indication information is used to indicate the first address for configuring the first tunnel. Alternatively, the attribute information of the first tunnel can also be configured by the core network network element. The "configuration" here can be understood as being generated and sent by the core network, for example, the core network network element determines the attributes of the first tunnel and sends the attribute information of the first tunnel to the first access network device. The attribute information of the first tunnel can be carried in the corresponding control message sent by the core network to the first access network device, and the first access network device can obtain the attribute information of the first tunnel from the control message. It should be understood that the core network elements here may include SMF network elements and other core network elements. When interacting with different core network elements, the control message carrying the attribute information of the first tunnel received by the first access network device may be different. The embodiments of the present application do not limit this.

[0232] In an optional embodiment, the data transmission scheme of the embodiment of the present application can also be applied to the DC scenario. In the DC scenario, the first access network device can serve as a master node (MN) and the second access network device can serve as a secondary node (SN). The first transport layer network protocol can support multipath characteristics, and the first tunnel can include at least one communication path, such as a first communication path between the terminal device and the first access network device, and a second communication path between the terminal device and the second access network device. In order to enable the terminal device to simultaneously transmit data with the first access network device and the second access network device based on different communication paths, the first access network device also needs to interact with the terminal device or the second access network device to exchange information so that the three parties are aware of part or all of the information of the second communication path of the first tunnel, so that the terminal device can communicate with the second access network device based on the information of the second communication path of the first tunnel.

[0233] For example, the information of the second communication path may include the second identifier and second address of the first tunnel, the second identifier and second address are associated with the second access network device. The information of the second communication path may also include the fourth identifier and fourth address of the first tunnel, the fourth identifier and fourth address are associated with the terminal device.

[0234] The first access network device may send Xn signaling to the second access network device, instructing the second access network device to configure (or be understood as allocating or generating) the second identifier and / or second address of the first tunnel. The first access network device may send Xn signaling to the second access network device at any of the following times: when receiving the first indication information from the terminal device, or when receiving the second indication information from the terminal device, or when receiving the first indication information from the core network element, or when receiving the second indication information from the core network element, or when receiving the fourth indication information from the core network element. The embodiment of the present application does not limit the triggering timing of the Xn signaling.

[0235] In one example, the first access network device can assign a second identifier to the first tunnel, and the first access network device can carry the second identifier in the Xn signaling sent to the second access network device, instructing the second access network device to configure the second address of the first tunnel for the first tunnel, or it can be understood that the Xn signaling carrying the second identifier instructs the second access network device to configure the second address of the first tunnel for the terminal device, and the second identifier and the second address are associated with the second access network device, or it can be understood that the second address is used to transmit data between the terminal device and the second access network device based on the first tunnel. In an optional embodiment, the Xn instruction from the first access network device also includes the tunnel identifier and address information of the terminal device, represented as a fourth identifier and a fourth address. Alternatively, the first access network device can also send the fourth identifier and the fourth address of the terminal device to the second access network device in a separate Xn instruction. The embodiment of the present application does not limit the timing of the first access network device announcing the fourth identifier and the fourth address to the second access device.

[0236] Optionally, the second access network device may send the second address to the first access network device. Optionally, the second access network device may also send the second identifier along with the second address. Specifically, the second access network device may, for example, send the second address in a response message to the Xn signaling sent by the first access network device, or send the second address and the identifier in a response message to the Xn signaling sent by the first access network device. It is worth noting that in the embodiments of the present application, whether the second access network device sends the second address or the second identifier to the first access network device is related to the initiator of the process of adding the second communication path in the first tunnel. This may be a communication system-level design, such as whether the MN initiates the path addition process, the SN initiates the path addition process, or the terminal device initiates the path addition process. For example, if the MN initiates the addition of the second communication path, the SN needs to send the second address, or the second address and the identifier, to the MN. If the SN initiates the addition of the second communication path, the SN does not need to send the second address or the second identifier to the MN. Instead, the SN may synchronize information about the second communication path with the MN when initiating the addition of the second communication path. This information about the second communication path may include the second identifier and / or the second address. In an optional implementation, it is also possible to dynamically specify which node initiates the path addition in the communication system. In this case, for example, the MN can decide which node initiates the path addition. If the MN chooses to initiate the path addition by itself, the message sent to the SN can indicate by default that the SN needs to return the second identifier and / or the second address; if the MN chooses to have the SN initiate the path addition, the MN can indicate the SN to initiate subsequent path additions in the message sent to the SN. For example, the indication can be indicated by the fourth identifier and the fourth address of the terminal device, or there is an independent indication information for requesting the SN to initiate the path addition. At this time, the SN does not return the second identifier and / or the second address to the MN, but initiates the addition of the second communication path on its own based on the received information. The implementation details of the second communication path addition process (i.e., updating the identifier and address of the data packet) can be found in the following description and will not be elaborated here.

[0237] In another example, the first access network device may send Xn signaling to the second access network device, instructing the second access network device to configure the second identifier and second address of the first tunnel, or it can be understood that the Xn signaling instructs the second access network device to configure the second identifier and second address of the first tunnel for the terminal device, and the second identifier and second address are associated with the second access network device. Optionally, the Xn instruction from the first access network device may also include the tunnel identifier and address information of the terminal device, expressed as a fourth address and a fourth identifier. Alternatively, the first access network device may also send the fourth identifier and fourth address of the terminal device to the second access network device in a separate Xn instruction. The embodiment of the present application does not limit the timing when the first access network device announces the fourth identifier and the fourth address to the second access device.

[0238] Optionally, the second access network device may send the second identifier and second address to the first access network device. For example, the second access network device may send the second address and second identifier in a response message to the Xn signaling sent by the first access network device. Similarly, whether the second access network device sends the second address and second identifier to the first access network device is described in the relevant description of the aforementioned embodiments. The implementation details of the second communication path addition process are described below and are not further elaborated here.

[0239] In another example, the first access network device may send Xn signaling to the second access network device, instructing the second access network device to configure the second identifier of the first tunnel, or it can be understood that the Xn signaling instructs the second access network device to configure the second identifier of the first tunnel for the terminal device. Optionally, the Xn instruction from the first access network device may also include the tunnel identifier and address information of the terminal device, expressed as a fourth identifier and a fourth address. Alternatively, the first access network device may also send the fourth identifier and the fourth address of the terminal device to the second access network device in a separate Xn instruction. The embodiment of the present application does not limit the timing of the first access network device announcing the fourth identifier and the fourth address to the second access device. It should be understood that in this example, the process of adding the second communication path may be initiated by the SN by default. The implementation details of the path addition process can be found in the following description and will not be elaborated here.

[0240] In another example, a first access network device may send Xn signaling to a second access network device, where the Xn signaling includes the fourth identifier and fourth address of the terminal device. For example, the terminal device may include the fourth identifier and fourth address of the terminal device in uplink AS signaling sent to the first access network device, and the first access network device may obtain the fourth identifier and fourth address of the terminal device from the uplink AS signaling. Alternatively, the terminal device may include the fourth identifier and fourth address in control information sent to the second access network device via the first tunnel, and the first access network device may obtain the fourth identifier and fourth address of the terminal device from the control information of the first tunnel. Alternatively, the terminal device may send an uplink data packet to the first access network device, where the uplink data packet includes the fourth identifier and fourth address of the first tunnel, and the first access network device may obtain the fourth identifier and fourth address from the uplink data packet. The fourth identifier and fourth address are associated with the second communication path. It is worth noting that the fourth address may also be associated with the first communication path, meaning that the first identifier and fourth address are associated with the first communication path. Optionally, the Xn signaling may trigger the second access network device to add a second communication path. The implementation details of the second communication path adding process can be found in the following introduction and will not be described here in detail.

[0241] It should be understood that in the above description, "indication" can also be equivalently understood as "request", and the embodiment of the present application does not specifically limit the meaning of Xn signaling.

[0242] To enable communication between the second access network device and the terminal device based on the second communication path of the first tunnel, it is necessary to add the second communication path to the first tunnel before data is transmitted between the terminal device and the second access network device. In this embodiment of the present application, the process of adding the second communication path to the first tunnel can be initiated by the first access network device, the second access network device, or the terminal device.

[0243] The following is an example of the interaction process involved when different initiators add a second communication path.

[0244] Taking the process of the first access network device initiating the addition of a second communication path to the first tunnel as an example, the first access network device can obtain information about the second communication path during the previous interaction with the terminal device and the second access network device, and initiate the process of adding the second communication path to the first tunnel.

[0245] A first access network device may receive second information about a first tunnel from a second access network device. The second information may include the second identifier of the first tunnel, or the second address of the first tunnel, or the second identifier and address of the first tunnel. According to the aforementioned solution, if the first access network device configures the second identifier for the second access network device, the second information from the second access network device may include the second address. If the second access network device configures the second identifier and the second address, the second information from the second access network device may include the second identifier and the second address.

[0246] When the first access network device initiates the process of adding a second communication path in the first tunnel, it may send a second identifier to the terminal device before adding the second communication path, or send a second identifier and a second address to the terminal device. Specifically, in one example, the first access network device may send a third access layer message to the terminal device, and the third access network message may include the second identifier, or the third access network message may include the second identifier and the second address. In another example, the first access network device may send first control information to the terminal device through the first tunnel, and specifically, the first access network device may send the first control information to the terminal device through the first communication path of the first tunnel. The first control information may include the second identifier, or the first control information may include the second identifier and the second address. In another example, the first access network device may also send a downlink data packet to the terminal device, and the downlink data packet includes the second identifier and the second address of the first tunnel.

[0247] The first access network device then sends a downlink data packet to the terminal device. The downlink data packet includes the terminal device's fourth identifier and fourth address, the second identifier, and the second address. This downlink data packet is used to add the second communication path. After receiving the downlink data packet, the terminal device may send an uplink data packet to the second access network device. The uplink data packet includes the terminal device's fourth identifier and fourth address, the second identifier, and the second address. The terminal device's sending of the uplink data packet indicates that the terminal device accepts the second communication path. The second access network device may then send subsequent downlink data packets to the terminal device to implement data transmission between the terminal device and the terminal device. In this case, the first access network device and the second access network device need to share packet space, path identifier, packet sequence number, congestion window, and other information on the second communication path. For example, the first access network device may also send information about the second communication path to the second access network device. This information may include, for example, the packet number space, path identifier, packet sequence number, and congestion window associated with data packets transmitted between the terminal device and the second access network device. The first access network device may send Xn signaling to the second access network device, and this Xn signaling may include information about the second communication path.

[0248] In an optional implementation, the first access network device and the second access network device also need to share the context of the first tunnel, where the context of the first tunnel may include at least one of the following information: QUIC configuration / attributes, and security context;

[0249] The last packet number sent or received in the upstream and downstream of the QUIC protocol;

[0250] Stream / Connection flow control status: offset of data consumed per stream;

[0251] The buffer state is shown in Figure 13;

[0252] Multipath status: PID, PN, and the packet number of the last packet sent and received on each communication path.

[0253] Taking the process of the second access network device initiating the addition of a second communication path to the first tunnel as an example, the second access network device may obtain information associated with the terminal device of the second communication path during the interaction with the terminal device and the first access network device, and initiate the process of adding the second communication path to the first tunnel.

[0254] For example, the first access network device may send sixth indication information to the second access network device. This sixth indication information may indicate the fourth identifier of the first tunnel, or the fourth identifier and fourth address of the first tunnel. This sixth indication information may be carried in Xn signaling from the first access network device. In other words, according to the aforementioned solution, the first access network device may trigger the process of adding a second communication path to the first tunnel when sending terminal device information to the second access network device.

[0255] Optionally, before the second access network device initiates adding the second communication path to the first tunnel, in one implementation, it may be to directly send the second identifier to the terminal device, or to directly send the second identifier and second address to the terminal device. In another implementation, the second access network device may send the second identifier to the terminal device through the first access network device, or to send the second identifier and second address to the terminal device through the first access network device. Specifically, the second access network device may send the second identifier to the first access network device, or send the second identifier and second address to the first access network device. For example, the second access network device may carry the second identifier, or carry the second identifier and second address, in the Xn signaling sent to the first access network device or the response message of the Xn signaling. The first access network device sends the second identifier to the terminal device, or sends it to the second identifier and second address based on the received information.

[0256] The second access network device can then send a downlink data packet to the terminal device. The downlink data packet includes the terminal device's fourth identifier and fourth address, the second identifier, and the second address. The downlink data packet is used to add the second communication path. After receiving the downlink data packet, the terminal device sends an uplink data packet to the second access network device. The uplink data packet includes the terminal device's fourth identifier and fourth address, the second identifier, and the second address. The terminal device's sending of the uplink data packet indicates that the terminal device accepts the second communication path. The second access network device can then send subsequent downlink data packets to the terminal device, enabling data transmission between the terminal device and the terminal device. In this case, the first access network device and the second access network device need to share packet space, path identifier, packet sequence number, congestion window, and other information on the second communication path. For example, the second access network device can also send information about the second communication path to the first access network device. This information can include, for example, the packet number space, path identifier, packet sequence number, and congestion window associated with data packets transmitted between the terminal device and the second access network device. The second access network device can send Xn signaling to the first access network device, where the Xn signaling can include information about the second communication path.

[0257] In an optional implementation, the first access network device and the second access network device also need to share the context of the first tunnel. The content of the context of the first tunnel can be found in the relevant introduction above and will not be repeated here.

[0258] Taking the process of a terminal device initiating the addition of a second communication path in the first tunnel as an example, the terminal device may receive the second identifier and / or the second address from the first access network device or the second access network device. The terminal device may receive the second identifier in the AS signaling from the first access network device, or receive the second identifier and the second address. Alternatively, the terminal device may receive the second identifier in the control information on the first communication path through the first tunnel, or receive the second identifier and the second address. Alternatively, the terminal device may receive the second identifier and the second address in the AS signaling from the second access network device. The embodiment of the present application does not limit the manner in which the terminal device obtains the second identifier and / or the second address.

[0259] Furthermore, the terminal device may initiate a process of adding a second communication path by sending an uplink data packet to the second access network device. The uplink data packet may include a second identifier and a second address. Alternatively, the uplink data packet may further include a fourth identifier and a fourth address, wherein the fourth identifier and the fourth address are associated with the terminal device.

[0260] After the second communication path is successfully added, data can be transmitted between the terminal device and the second access network device based on the second communication path. For example, the terminal device can send an uplink data packet to the second access network device, and the uplink data packet can include a destination identifier and a destination address, such as the second identifier and the second address. Alternatively, the uplink data packet can also include a source identifier and a source address, such as the fourth identifier and the fourth address. Alternatively, the second access network device can send a downlink data packet to the terminal device, and the downlink data packet can include a source identifier and a source address, such as the second identifier and the second address. Alternatively, the downlink data packet can also include a destination identifier and a destination address, such as the fourth identifier and the fourth address.

[0261] At this time, the terminal device needs to share the packet space, path identifier, packet sequence number, congestion window and other information on the second communication path with the first access network node device or the second access network node device. For example, the terminal device can send information about the second communication path to the first access network device. The information about the second communication path can include, for example, the packet number space, path identifier, packet sequence number, congestion window and other information associated with the data packets transmitted between the terminal device and the second access network device. Or, for example, the terminal device can send information about the second communication path to the second access network device. The information about the second communication path can include, for example, the packet number space, path identifier, packet sequence number, congestion window and other information associated with the data packets transmitted between the terminal device and the second access network device. Among them, the terminal device can send AS signaling to the first access network device or the second access network device. The AS signaling can include information about the second communication path. In an optional implementation, the first access network device and the second access network device also need to share the context of the first tunnel. The content of the context of the first tunnel can be found in the relevant introduction above and will not be repeated here.

[0262] It should be understood that due to the multipath characteristics, in the above-mentioned DC scenario, the first communication path between the terminal device and the first access network device, or the second communication path between the terminal device and the second access network device, can be used to transmit data between the terminal device and different access network devices.

[0263] In another optional implementation, the data transmission scheme of the embodiment of the present application can also be applied to a switching scenario. In the switching scenario, the first access network device can serve as a source access network device, and the third access network device can serve as a target access network device. When the terminal device needs to switch from the first access network device to the third access network device, if the third access network device also supports the first transport layer network protocol, or supports multi-channel communication based on the first transport layer network protocol, the first access network device also needs to interact with the terminal device or the third access network device to mutually understand how to migrate the first tunnel based on the first transport layer network protocol.

[0264] Among them, the communication path based on the first transport layer network protocol between the terminal device and the third access network device can be understood as the third communication path of the first tunnel, that is, when the tunnel is migrated in the switching scenario, it includes migrating the first communication path to the third communication path. If the terminal device, the first access network device, and the third access network device all support DAPS, then in one implementation, the first access network device can choose to first add the third communication path to the first tunnel, and simultaneously transmit the same data in the first communication path and the third communication path for a period of time, and then abolish the first communication path to achieve tunnel migration. Specifically, for example, after achieving data synchronization between the first communication path and the third communication path, the terminal device or the first access network device can delete the context of the first communication path, that is, the terminal device and the first access network device stop transmitting data on the first communication path. The specific implementation details of adding the third communication path can refer to the relevant description of adding the second communication path described in the previous embodiment, and the implementation details of deleting the first communication path can refer to the description below that tunnel migration is deleting the first communication path, which will not be repeated here.

[0265] In another implementation method based on DAPS, the first access network device may decide to adopt a tunnel migration method, that is, the tunnel migration solution described in the following embodiment. If the first access network device and the third access network device both support the DC scenario described above, when migrating tunnels in the switching scenario and the DC scenario, it includes migrating the first communication path to the third communication path, migrating the second communication path to the fourth communication path, and the fifth identifier and the fifth address of the first tunnel are associated with the fourth access network device, and the fourth access network device is the secondary node corresponding to the third access network device. Among them, the interaction process between the third access network device and the fourth access network device is similar to the interaction process between the first access network device and the second access network device in the above text. Please refer to the relevant introduction in the above text and will not be repeated here. It can be understood that in the embodiment of the present application, if the terminal device, the first access network device and the third access network device all support the DAPS function, the first access network device adds a third communication path in the first tunnel, and the third communication path is associated with the third access network device; or, the first tunnel is migrated from the first communication path to the third communication path, and the third communication path is associated with the third access network device.

[0266] The first access network device may send Xn signaling to the third access network device, instructing the third access network device to configure (or allocate or generate) a third identifier and / or a third address for the first tunnel. The first access network device may send the Xn signaling to the third access network device when determining that a handover to the third access network device is required. This embodiment of the present application does not limit the triggering timing of the Xn signaling.

[0267] In one example, the first access network device can allocate a third identifier, and the first access network device can carry the third identifier in the Xn signaling sent to the third access network device, instructing the third access network device to configure the third address of the first tunnel for the first tunnel, or it can be understood that the Xn signaling carrying the third identifier instructs the third access network device to configure the third address of the first tunnel for the terminal device, and the third identifier and the third address are associated with the third access network device. In an optional embodiment, the Xn instruction from the first access network device also includes the fourth identifier and the fourth address of the terminal device. Alternatively, the first access network device can also send the fourth identifier and the fourth address of the terminal device to the third access network device in a separate Xn instruction. The embodiment of the present application does not limit the timing when the first access network device announces the fourth identifier and the fourth address to the third access device. Exemplarily, the above-mentioned Xn signaling can be implemented as a switching request from the first access network device.

[0268] Optionally, the third access network device may send the third address to the first access network device. Optionally, the third access network device may also carry a third identifier when sending the third address. Specifically, the third access network device may, for example, send the third address in a response message of the Xn signaling sent by the first access network device, or send the third address and the third identifier in a response message of the Xn signaling sent by the first access network device. It is worth noting that in the embodiment of the present application, whether the third access network device sends the third address or the third identifier to the first access network device is related to the initiator of the path migration process. Among them, it may be a communication system-level design, such as the first access network device initiating tunnel migration, or the third access network device initiating tunnel migration, or the terminal device initiating tunnel migration. If the source access network device initiates the tunnel migration process, the target access network device needs to send the third address, or the third address and the third identifier to the source access network device. If the target access network device initiates the tunnel migration, the target access network device does not need to send the third address to the source access network device, or does not need to send the third address and the third identifier to the source access network device. Instead, when the target access network device initiates the process, the target access network device can synchronize the information of the third communication path to the source access network device. The information of the third communication path may include the third identifier and / or the third address, etc. In an optional implementation, it is also possible to dynamically specify which node initiates the tunnel migration in the communication system. In this case, for example, the source access network device can decide which node initiates the tunnel migration. If the source access network device chooses to initiate the tunnel migration by itself, the message sent to the target access network device can indicate by default that the target access network device needs to return the third identifier and / or the third address; if the source access network device chooses to have the destination access network device initiate the tunnel migration, the source access network device can instruct the target access network device to initiate subsequent tunnel migration in the message sent to the target access network device. For example, the indication can be indicated by the fourth identifier and the fourth address of the terminal device, or there is an independent indication information for requesting the SN to initiate the path addition. At this time, the target access network device does not return the third identifier and / or third address to the source access network device, but initiates tunnel migration based on the received information. The implementation details of the tunnel migration process (i.e., updating the packet identifier and address) can be found in the following description and will not be repeated here.

[0269] In another example, the first access network device may send Xn signaling to the third access network device, instructing the third access network device to configure the third identifier and third address of the first tunnel, or it can be understood that the Xn signaling instructs the third access network device to configure the third identifier and third address of the first tunnel for the terminal device, and the third identifier and third address are associated with the third access network device. Optionally, the Xn instruction from the first access network device may also include the fourth address and fourth identifier of the terminal device. Alternatively, the first access network device may also send the fourth identifier and fourth address of the terminal device to the third access network device in a separate Xn instruction. The embodiment of the present application does not limit the timing when the first access network device announces the fourth identifier and fourth address to the third access device.

[0270] Optionally, the third access network device can send the third identifier and the third address to the first access network device. For example, the third access network device can send the third address and the third identifier in the response message of the Xn signaling sent by the first access network device. Similarly, whether the third access network device sends the third address and the third identifier to the first access network device is related to the initiator of the path migration process. If the source access network device initiates the process, the target access network device needs to send the third address and the third identifier to the source access network device. If the target access network device initiates the process, the target access network device does not need to send the third address and the third identifier to the source access network device in addition. Instead, it can send information about the third communication path to the source access network device when the target access network device initiates the process. The information about the third communication path may include the third identifier and the third address, etc. The implementation details of the path migration process can be found in the following description and will not be elaborated here.

[0271] In another example, the first access network device may send Xn signaling to the third access network device, instructing the third access network device to configure the third identifier of the first tunnel, or it can be understood that the Xn signaling instructs the third access network device to configure the third identifier of the first tunnel for the terminal device. Optionally, the Xn instruction from the first access network device may also include the fourth identifier and fourth address of the terminal device. Alternatively, the first access network device may also send the fourth identifier and fourth address of the terminal device to the third access network device in a separate Xn instruction. The embodiment of the present application does not limit the timing of the first access network device announcing the fourth identifier and fourth address to the third access device. It should be understood that in this example, the process of initiating the path by the target access network device may be understood as a default. The implementation details of the path migration process can be found in the following description and will not be elaborated here.

[0272] In another example, the first access network device may send an Xn signaling to the third access network device, and the Xn signaling includes the fourth identifier and fourth address of the terminal device. For example, the terminal device may carry the fourth identifier and fourth address of the terminal device in the uplink AS signaling sent to the first access network device, and the first access network device may obtain the fourth identifier and fourth address of the terminal device from the uplink AS signaling. Alternatively, the terminal device may carry the fourth identifier and fourth address in the control information sent to the second access network device through the first tunnel, and the first access network device obtains the fourth identifier and fourth address of the terminal device in the control information of the first tunnel. Alternatively, the terminal device may send an uplink data packet to the first access network device, and the uplink data packet may include the fourth identifier and fourth address of the first tunnel, and the first access network device may obtain the fourth identifier and fourth address from the uplink data packet. The fourth identifier and fourth address are associated with the second communication path. It is worth noting that the fourth address may also be associated with the first communication path, that is, it is understood that the first identifier and fourth address are associated with the first communication path.

[0273] It should be understood that in the above description, "indication" can also be equivalently understood as "request", and the embodiment of the present application does not specifically limit the meaning of Xn signaling.

[0274] In the embodiment of the present application, any one of the terminal device, the first access network device or the third access network device may serve as the initiator to trigger the path migration process of the first tunnel.

[0275] The following examples illustrate the interaction process involved with different initiators.

[0276] Taking the process of initiating path migration of the first tunnel by the first access network device as an example, when the first access network device determines that the terminal device needs to switch (HO) to the third access network device, it can receive third information of the first tunnel from the third access network device. The third information can include the third identifier of the first tunnel, or the first tunnel can include the third address of the first tunnel, or the first tunnel can include the third identifier and the third address of the first tunnel. According to the solution described above, if the first access network device configures the third identifier for the third access network device, the third information from the third access network device can include the third address. If the third access network device configures the second identifier and the second address, the third information from the third access network device can include the third identifier and the third address.

[0277] When the first access network device initiates the process of path migration, it may send a third identifier to the terminal device, or send a third identifier and a third address. Specifically, in one example, the first access network device may send a fourth access layer message to the terminal device, and the fourth access network message may include the third identifier, or the fourth access network message may include the third identifier and the third address. Specifically, the fourth access network message may be, for example, a switching command. In another example, the first access network device may send second control information to the terminal device through the first tunnel, and specifically, the first access network device may send the second control information to the terminal device through the first communication path of the first tunnel. The second control information may include the third identifier, or the second control information may include the third identifier and the third address. In another example, the first access network device may also send a downlink data packet to the terminal device, and the downlink data packet includes the third identifier and the third address of the first tunnel.

[0278] The first access network device may also send the context of the first tunnel to the third access network device. For example, taking the QUIC protocol as an example, the context of the first tunnel may include the following:

[0279] QUIC configuration / properties, security context;

[0280] The last packet number sent or received in the upstream and downstream of the QUIC protocol;

[0281] Stream / Connection flow control status: offset of data consumed per stream;

[0282] The buffer state is shown in Figure 13;

[0283] Multipath status: PID, PN, and the packet number of the last packet sent and received on each communication path.

[0284] It should be understood that the above-described path migration process can be applied to a handover process in which there is a connection between access network devices, or can be applied to a handover process in which there is no connection between access network devices and the handover needs to be performed via the core network. The first access network device can send the context of the first tunnel to the third access network device via a direct forwarding tunnel or an indirect forwarding tunnel between the first access network device and the third access network device.

[0285] Before switching to the third access network device (for example, before the first access network device sends a switching command to the terminal device), the terminal device sends a downlink data packet to the terminal device, which includes the fourth identifier and fourth address, and the third identifier and third address of the terminal device.

[0286] After the terminal device switches to the third access network device (for example, after the terminal device accesses the third access network device), it can send an uplink data packet to the third access network device. The uplink data packet may include the fourth identifier and fourth address of the terminal device, the third identifier and third address, indicating that the terminal device accepts path migration.

[0287] It should be understood that the above example is merely an illustrative description of the interaction process that may be involved in the process of the first access network device initiating the path migration of the first tunnel, and is not intended to be limiting in any way.

[0288] Taking the process of the third access network device initiating the path migration of the first tunnel as an example, the third access network device may obtain information associated with the terminal device, such as the fourth identifier and fourth address of the terminal device, during the interaction with the terminal device and the first access network device, and initiate the path migration process of the first tunnel.

[0289] For example, the first access network device may send fifth indication information to the third access network device. The fifth indication information may indicate the fourth identifier of the first tunnel, or the fifth indication information may indicate the fourth identifier and fourth address of the first tunnel. The fifth indication information may be carried in Xn signaling from the first access network device. Exemplarily, the fifth indication information may be carried in a handover request sent by the first access network device.

[0290] Optionally, before the third access network device initiates path migration, it may send a third identifier to the terminal device through the first access network device, or send a third identifier and a third address to the terminal device through the first access network device. The first access network device may send a third identifier to the terminal device, or the first access network device may send a third identifier and a third address to the terminal device. In one optional implementation, the first access network device may send a fourth access layer message to the terminal device, the fourth access layer message includes the third identifier, or the fourth access layer message includes the third identifier and the third address. Specifically, the fourth access layer message may be a switching command. In another optional implementation, the first access network device may send a second control information to the terminal device through the first tunnel, the second control information includes the third identifier, or the second control information includes the third identifier and the third address. In another optional implementation, the first access network device may send a downlink data packet to the terminal device, and the downlink data packet may include the third identifier and the third address. Exemplarily, the third access network device may carry a third identifier in a handover request response message sent to the first access network device, or carry a third identifier and a third address in a handover request response message sent to the first access network device. The first access network device may carry a third identifier in a handover command sent to the terminal device, or carry a third identifier and a third address.

[0291] The first access network device may also send the context of the first tunnel to the third access network device. The context of the first tunnel can be found in the above description and will not be repeated here.

[0292] After the terminal device switches to the third access network device, the third access network device may send a downlink data packet to the terminal device, where the downlink data packet includes the fourth identifier and fourth address of the terminal device, and the third identifier and third address. The terminal device may also send an uplink data packet to the third access network device, where the uplink data packet includes the fourth identifier and fourth address of the terminal device, and the third identifier and third address, indicating that the terminal device accepts the path migration.

[0293] Taking the path migration of the first tunnel initiated by the terminal device as an example, the terminal device can receive the third identifier and / or third address of the third access network device through the first access network device. The terminal device may obtain the third identifier and the third address in the switching command from the first access network device. Alternatively, the terminal device may obtain the third identifier in the AS signaling from the first access network device, or obtain the third identifier and the third address in the AS signaling. Specifically, the AS signaling may be a switching command or a newly added AS signaling. Alternatively, the terminal device may receive control information from the first access network device through the first tunnel, and the control information may include the third identifier, or the control information may include the third identifier and the third address. The embodiment of the present application does not limit the manner in which the terminal device obtains the third identifier and / or the third address.

[0294] The first access network device may also send the context of the first tunnel to the third access network device. The context of the first tunnel can be found in the above description and will not be repeated here.

[0295] After switching to the third access network device, the terminal device can send an uplink data packet to the third access network device. The uplink data packet may include the fourth identifier and fourth address of the terminal device, the third identifier and third address, indicating that the terminal device accepts path migration.

[0296] It should be understood that the above process is only an example of information interaction involved in the process of different initiators initiating path migration and is not intended to be limiting. In other embodiments, other interaction processes may also exist between the first access network device, the third access network device, and the terminal device, which will not be described in detail here.

[0297] In an optional implementation, if the terminal device only supports single-path communication with the access network device, the terminal device may freeze uplink and downlink transmissions based on the first tunnel after receiving the handover command. After handover to the third access network device, the terminal device may restore the context of the first tunnel and restart uplink and downlink transmissions based on the first tunnel, so as to perform data transmission with the third access network device based on the first tunnel, the third identifier, and the third address.

[0298] In another optional implementation, if the terminal device, the first access network device, and the third access network device all support DAPS, zero-interruption tunnel migration can also be supported. The first access network device can also indicate to the terminal device the data transmission rules on the first communication path (or source path, old path, etc.) and the third communication path (or target path, new path, etc.) of the first tunnel. The data transmission rules may include, for example, any of the following transmission modes:

[0299] (1) Replication mode, that is, the same data is transmitted on the first communication path and the third communication path at the same time.

[0300] (2) New path priority transmission mode, the new path is the third communication path between the terminal device and the third access network device, and the first communication path between the terminal device and the first access network device is the old path. In the new path priority transmission mode, uplink data is sent on the new path first. When the new path cannot perform uplink transmission, uplink data is sent on the old path.

[0301] (3) Proportional transmission mode, that is, the ratio of data transmission on the first communication path and the third communication path can be set, and the terminal device can perform data transmission on the first communication path and the third communication path respectively according to the set ratio.

[0302] (4) Transmission mode according to transmission quality, that is, the transmission quality for data transmission on the first communication path and the third communication path can be set, and the terminal device can perform data transmission on the first communication path and the third communication path respectively according to the set transmission quality.

[0303] Accordingly, the terminal device can implement data transmission with the first access network device and / or the third access network device according to the received data transmission rule and the corresponding transmission mode.

[0304] The terminal device, the first access network device, or any one of the third access network devices can decide whether to delete the source path, and can instruct other devices to delete the context related to the source path, or notify other devices after it has deleted the context related to the source path.

[0305] For example, the third access network device can decide whether the source path needs to be deleted. For example, if the replication mode is adopted, the third access network device can determine that the source path needs to be deleted when it determines that the uplink data sent through the source path and the target path have arrived synchronously. Or, for example, if the third access network device does not receive the context information from the first access network device within a set time, it determines that the source path needs to be deleted. Or, for example, if the third access network device receives an end marker from the first access network device, it determines that the source path needs to be deleted. In the case of determining that the source path needs to be deleted, in one implementation, the third access network device can send an indication message to the terminal device, and the indication message instructs the terminal device to delete the first communication path between it and the first access network device. Specifically, the third access network device can instruct the terminal device to delete the context of the first communication path. In another implementation, the third access network device can send an indication message to the first access network device, and the indication message instructs the first access network device to delete the first communication path between it and the terminal device. Specifically, the third access network device can instruct the first access network device to delete the context of the first tunnel.

[0306] Alternatively, for example, the first access network device may determine whether to delete the source path. For example, the first access network device may determine that the source path needs to be deleted when there is no data to be transmitted on the source path. If the source path needs to be deleted, the first access network device sends an indication to the terminal device, instructing the terminal device to delete the first communication path between the terminal device and the first access network device. Simultaneously, the first access network device deletes the first communication path context and sends an indication to the third access network device, indicating that the context associated with the source path has been deleted.

[0307] Or, for example, the terminal device can decide whether to delete the source path. For example, when the terminal device determines that the first communication path is no longer needed, it sends an indication message to the third access network device, and the indication message instructs the third access network device to delete the context of the first communication path. The third access network device can also send a notification message to the first access network device to notify that the first communication path has been deleted. Alternatively, when the terminal device determines that the first communication path is no longer needed, it sends an indication message to the first access network device, and the indication message instructs the first access network device to delete the context of the first communication path. The first access network device can also send a notification message to the third access network device to notify that the first communication path has been deleted.

[0308] For ease of understanding, the implementation details of the data transmission method of the embodiment of the present application are introduced below in combination with different embodiments.

[0309] Example 1:

[0310] In this embodiment one, during the session establishment process between the terminal device and the core network, the SMF network element requests the first access network device to configure the first address of the first tunnel for the terminal device, and the SMF network element sends the first information to the terminal device through the first access network device to inform the terminal device of the first address of the first tunnel, so as to introduce the first tunnel using the first transport layer network protocol between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device.

[0311] As shown in FIG7 , the data transmission method may include the following steps:

[0312] S701: The terminal device sends a session message to the SMF network element through the AMF network element. The session message may be a session establishment message, indicating that a session is established for the terminal device, such as a PDU session. Alternatively, the session message may be a session modification message, such as a PDU session modification message. This embodiment of the present application does not limit this.

[0313] Accordingly, the AMF network element can receive the session message and forward it to the SMF network element. The "forwarding" here can also be understood as "transmitting", that is, the AMF network element only converts the format of the session message and does not parse it. For relevant explanations, please refer to the relevant introduction in the previous article and will not be repeated here.

[0314] In an embodiment of the present application, the session message can be represented as a first non-access layer message, and the session message can include first indication information, and the first indication information can indicate that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol. The terminal device can send a session message to the AMF network element through the N1 interface. The AMF network element sends the session message to the SMF network element through the N11 interface. Accordingly, the SMF network element can receive the session message from the AMF network element and obtain the first indication information from the session message. The SMF network element can decide whether the terminal device and the first access network device support establishing a first tunnel using the first transport layer network protocol based on the first indication information, or decide whether the terminal device and the first access network device support multi-channel communication based on the first transport layer network protocol based on the first indication information.

[0315] In an optional implementation, the session message may be represented as a second non-access layer message, and the session message may include second indication information, where the second indication information indicates that a first tunnel is to be established between the terminal device and the first access network device. The second indication information may be an explicit indication or an implicit indication. For example, the second indication information is service requirement description information. If the service requirement description information describes that the service on the terminal device side requires a stable latency, it may be regarded as an indication that a first tunnel needs to be established between the terminal device and the first access network device.

[0316] It should be understood that in the embodiment of the present application, the first indication information and the second indication information can be carried in the same message or in different messages, and the embodiment of the present application does not limit this.

[0317] S702: The terminal device, the first access network device, and multiple network elements of the core network (for example, including AMF network elements, SMF network elements, PCF network elements, and UDM network elements) implement contract processing, policy processing, authentication / authorization processing, user plane function processing, etc. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be repeated here.

[0318] S703: The SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device.

[0319] In an embodiment of the present application, the SMF network element may determine that a first tunnel needs to be established between the terminal device and the first access network device based on the content of the session message received from the terminal device in S701. For example, when the session message carries second indication information, the SMF network element may determine that a first tunnel needs to be established between the terminal device and the first access network device based on the second indication information. Or for example, when the session message carries first indication information, the SMF network element may also obtain the tunnel capability information of the first access network device. If both the terminal device and the first access network device can support the first transport layer network protocol, or both can support multi-channel communication based on the first transport layer network protocol, the SMF network element may determine that a first tunnel needs to be established between the terminal device and the first access network device.

[0320] Alternatively, the SMF network element may be the one that determines the need to establish a first tunnel between the terminal device and the first access network device through interaction with the terminal device, or the first access network device, or other core network network elements during the implementation of S702. For example, during the implementation of S702, the SMF network element may also receive other request information from the terminal device, such as DNN or Slice information, etc. The SMF network element may determine the need to establish a first tunnel between the terminal device and the first access network device based on the DNN or Slice information. Or, for example, during the implementation of S702, the SMF network element may also receive policy information from the PCF network element or contract information from the UDM network element, and determine the need to establish a first tunnel between the terminal device and the first access network device based on the received policy information or contract information.

[0321] S704: The SMF network element sends tunnel address configuration indication information to the first access network device. The tunnel address configuration indication information is used to request the first access network device to configure the first address of the first tunnel, or it can be understood that the tunnel address configuration indication information is used to instruct the first access network device to configure the first address of the first tunnel for the terminal device.

[0322] In an optional implementation, the tunnel address configuration indication information from the SMF network element can be expressed as the second indication information, and the second indication information indicates that the first tunnel is established between the terminal device and the first access network device. The second indication information can be carried in a control message from the SMF network element. The control message can be a newly added control plane message. The SMF network element can send the control message to the AMF network element through the N11 interface, and the AMF network element can send the control message to the first access network device through the N2 interface. It can be understood that the message carrying the second indication information can be a control message of the SMF network element.

[0323] In an optional implementation, the tunnel address configuration indication information from the SMF network element can be represented as fourth indication information, and the fourth indication information is used to indicate the configuration of the first address of the first tunnel. The first access network device can determine the attribute information of the first tunnel as the default mode based on the fourth indication information and the agreement of the first transport layer network protocol. The attribute information may include, for example, any one of the following transmission modes: data packet mode, flow mode, or security mode. In another optional implementation, the tunnel address configuration indication information from the SMF network element may also indicate the attribute information of the first tunnel. The first access network device can obtain the attribute information of the first tunnel from the tunnel address configuration indication information. The attribute information may include, for example, any one of the following transmission modes: data packet mode, flow mode, or security mode.

[0324] In an optional implementation, the tunnel address configuration indication information may further include the IP address of the terminal device. The IP address of the terminal device may be used by the first access network device to proactively initiate a process of establishing the first tunnel to the terminal device.

[0325] In another optional embodiment, in a DC scenario, the communication system may further include a second access network device (SN), the first access network device being a primary node of the terminal device, and the second access network device being a secondary node of the terminal device. The first access network device and the second access network device may further collaboratively execute the following S705a and / or S705b to configure the second identifier and the second address of the first tunnel for the terminal device, thereby extending the multipath characteristics of the first tunnel in the DC scenario:

[0326] S705a (optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface. The Xn signaling is used to request to add or modify the SN, and at the same time request the SN to configure the second address of the first tunnel for the terminal device, or request the SN to configure the second identifier and second address of the first tunnel for the terminal device. Accordingly, the second access network device can configure the second address of the first tunnel for the terminal device based on the received Xn signaling, or configure the second identifier and second address of the first tunnel for the terminal device. The number of the second identifiers can be one or more. The second address can include the IP address and port number provided by the second access network device for the first tunnel.

[0327] S705b (optional step): The second access network device sends an Xn signaling response to the first access network device via the Xn interface. The Xn signaling response may include the second address. Alternatively, the Xn signaling response may include the second identifier and the second address. Accordingly, the first access network device receives and stores the second identifier and the second address of the first tunnel. It should be understood that S705a-S705b are optional steps. In one embodiment, only S705a may be implemented, while in another embodiment, both S705a and S705b may be implemented simultaneously. The implementation details can be found in the previous description and will not be repeated here.

[0328] S706: The first access network device sends a response message to the SMF network element via the AMF network element regarding the tunnel address configuration indication information. Correspondingly, the SMF network element receives the response message from the first access network device.

[0329] The response message may include the first identifier and the first address of the first tunnel. In an optional DC scenario, the response message may include the first identifier, the first address, the second identifier, and the second address of the first tunnel.

[0330] The first access network device sends the response message to the AMF network element through the N2 interface, and the AMF network element sends the response message to the SMF network element through the N11 interface. The SMF network element can receive the response message from the AMF network element and obtain the first identifier and first address of the first tunnel from the response message. In the optional DC scenario, the first identifier, first address, second identifier, and second address of the first tunnel are obtained.

[0331] S707: The SMF network element sends an Nx session message to the first access network device via the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0332] In an embodiment of the present application, the SMF network element may send a session message to the AMF network element through the N11 interface, and the session message carries an information element sent to the terminal device, and the information element sent to the terminal device includes the first address of the first tunnel reported by the first access network device. In an optional embodiment, the information element sent to the terminal device includes attribute information of the first tunnel reported by the first access network device. In an optional DC scenario, the information element sent to the terminal device may include the first address and the second address of the first tunnel reported by the first access network device.

[0333] The AMF network element sends a session message to the first access network device via the N2 interface. The session message carries an information element sent to the terminal device, and the information element sent to the terminal device includes the first address of the first tunnel reported by the first access network device. In an optional embodiment, the information element sent to the terminal device includes attribute information of the first tunnel reported by the first access network device. In an optional DC scenario, the information element sent to the terminal device may include the first address and the second address of the first tunnel reported by the first access network device.

[0334] S708: The first access network device sends the first information to the terminal device. Correspondingly, the terminal device feeds back response information for the first information to the first access network device.

[0335] In an embodiment of the present application, the first information is carried in a downlink RRC message from the first access network device, and the first information may indicate the first address of the first tunnel. Response information for the first information may be carried in an uplink RRC message from the terminal device, and the response information for the first information may indicate receipt of the first address of the first tunnel.

[0336] In an optional implementation, when implementing S708, the first access network device may further send attribute information of the first tunnel to the terminal device. The first information may include the attribute information of the first tunnel. Alternatively, the first information and the attribute information of the first tunnel may be carried in the same downlink RRC message or in a different downlink RRC message.

[0337] In an optional DC scenario, the first information may indicate the first address and the second address of the first tunnel, and the second information may indicate the attribute information and the second attribute of the first tunnel, where the second attribute is associated with the second communication path between the terminal device and the second access network device.

[0338] The above-mentioned RRC message transmitted between the first access network device and the terminal device may be a newly added access layer message, or may be a multiplexing of the existing access layer message between the first access network device and the terminal device. The first information or the second information may be carried in the reserved field of the existing access layer message, or may be a replacement for other information elements in the existing access layer message. The embodiments of the present application do not limit this.

[0339] S709: The first access network device feeds back an Nx session response message to the SMF network element via the AMF network element. Correspondingly, the SMF network element receives the Nx session response message from the first access network device.

[0340] S710: The SMF network element and other core network elements execute the remaining steps of establishing the PDU session. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be repeated here.

[0341] S711: A first tunnel using a first transport layer network protocol is established between the terminal device and the first access network device.

[0342] In one implementation, the terminal device may initiate S711 based on the received information. In an optional DC scenario, the first access network device may also send the second identifier of the first tunnel to the terminal device, or send the second identifier and the second address of the first tunnel to the terminal device.

[0343] In another implementation, the first access network device may initiate S711 according to the received information.

[0344] The specific implementation details of S711 can be found in the connection establishment process of the first transport layer network protocol, such as the connection establishment process of the QUIC protocol, which will not be repeated here.

[0345] Afterwards, the terminal device can transmit data with the first access network device based on the first tunnel.

[0346] In the optional DC scenario, a second communication path needs to be added to the first tunnel so that the terminal device can transmit data to the second access network device based on the second communication path. In this case, the first access network device can also perform the following optional steps:

[0347] S712 (optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface to notify the CID of the terminal device. For example, the first access network device sends the sixth indication information to the second access network device through the Xn interface. The sixth indication information may indicate the fourth identifier of the first tunnel, or the sixth indication information may indicate the fourth identifier and the fourth address of the first tunnel. The fourth identifier and the fourth address are associated with the terminal device, which may be obtained by the first access network device in S711, or may be obtained in other previous interaction processes. This embodiment of the present application does not limit this. That is, the execution timing of S712 is not limited.

[0348] The terminal device, the first access network device, and the second access network device need to interact with each other to add a second communication path to the first tunnel. The process of adding the second communication path can be initiated by the first access network device, the second access network device, or the terminal device.

[0349] For example, if the first access network device initiates a process of adding a second communication path to the terminal device, the following optional steps may be included after S711:

[0350] S713 (optional step): The first access network device initiates a path adding operation to the terminal device based on the address and CID of the SN. For example, the first access network device initiates a path adding operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0351] In one example, S713 may be implemented through AS signaling. For example, the first access network device may send a third access layer message to the terminal device, where the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address.

[0352] In another example, S713 may be implemented through the first tunnel. For example, the first access network device may send first control information to the terminal device through the first tunnel. The first control information may include the second identifier, or the first control information may include the second identifier and the second address. Specifically, the first access network may send the first control information to the terminal device through the first communication path of the first tunnel.

[0353] Here, unlike the multipath characteristics of the general QUIC protocol, the two endpoints of the multipath characteristics of the general QUIC protocol are the same entity (or node), and are caused by the address change of the terminal device (for example, in the technologies of 3GPP and WIFI, the IP address of the UE changes due to switching), the situation here is caused by the data transmission between the terminal device and different access network devices. As shown in Figure 8, the terminal device can transmit data to different access network devices through different paths in the same QUIC tunnel, for example, through the first communication path (for example, represented by path 1), the first identifier, and the first address in the same QUIC tunnel to transmit data to the first access network device, and through the second communication path (for example, represented by path 2), the second identifier, and the second address to transmit data to the second access network device.

[0354] S714 (optional): The first access network device sends an Xn signaling to the second access network device via the Xn interface to notify the second access network device of information about the second communication path. For example, the Xn signaling includes information about the second communication path, such as the second identifier, packet number space, and packet sequence number.

[0355] For example, if the second access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be included after S711:

[0356] S715 (optional step): The second access network device initiates a path adding operation to the terminal device.

[0357] S715 may be implemented through the first tunnel. For example, the second access network device may send third control information to the terminal device through the first tunnel. The third control information may include the second identifier, or the third control information may include the second identifier and the second address. Optionally, the third control information may also include the fourth identifier and the fourth address of the first tunnel. The source path identifier of the third control information may be the first identifier or the second identifier, and the target path identifier of the third control information may be the fourth identifier.

[0358] S716 (optional): The second access network device synchronizes information about the second communication path with the first access network device. For example, the second access network device sends Xn signaling to the first access network device via an Xn interface to notify the first access network device of the information about the second communication path. For example, the Xn signaling includes information about the second communication path, such as the second identifier, the packet number space, and the packet sequence number.

[0359] Based on the above-mentioned embodiment 1, by designing the interaction between the terminal device and the first access network device and some core network elements, a tunnel using the QUIC protocol can be introduced between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device. At the same time, in the optional DC scenario, by designing the interaction between the second access network device and the first access network device or the terminal device, different QUIC communication paths can be introduced between the terminal device and the second access network device to ensure the communication quality between the terminal device and the second access network device.

[0360] Example 2:

[0361] In this second embodiment, during the session establishment process between the terminal device and the core network, the SMF network element can instruct the first access network device to configure the first address of the first tunnel for the terminal device, and inform the terminal device to introduce the first tunnel using the first transport layer network protocol between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device.

[0362] As shown in FIG9 , the data transmission method may include the following steps:

[0363] S901: The terminal device sends a session message to the SMF network element through the AMF network element. The session message is used to indicate the establishment of a session for the terminal device, such as the establishment of a PDU session. Accordingly, the AMF network element can receive the session message and forward it to the SMF network element. Detailed implementation details can be found in the above description of S701 and will not be repeated here.

[0364] S902: The terminal device, the first access network device, and multiple network elements of the core network (for example, including AMF network elements, SMF network elements, PCF network elements, and UDM network elements) implement contract processing, policy processing, authentication / authorization processing, user plane function processing, etc. Detailed implementation details can be found in the introduction of S702 above and will not be repeated here.

[0365] S903: The SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device. Detailed implementation details can be found in the above description in conjunction with S703 and will not be repeated here.

[0366] S904: The SMF network element sends an Nx session message to the first access network device via the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0367] In an embodiment of the present application, the SMF network element may send an N11 session message to the AMF network element through the N11 interface, and the N11 session message may carry tunnel address configuration indication information. The AMF network element sends an N2 session message to the first access network device through the N2 interface, and the N2 session message may carry tunnel address configuration indication information. The tunnel address configuration indication information is used to request the first access network device to configure the first address of the first tunnel, or it can be understood that the tunnel address configuration indication information is used to instruct the first access network device to configure the first address of the first tunnel for the terminal device.

[0368] In an optional implementation, the tunnel address configuration indication information from the SMF network element can be expressed as second indication information, and the second indication information indicates that the first tunnel is established between the terminal device and the first access network device. The second indication information can be carried in a fourth non-access layer message from the SMF network element. The fourth non-access layer message can be a newly added control plane message. The SMF network element can send the fourth non-access layer message to the AMF network element through the N11 interface, and the AMF network element can send the fourth non-access layer message to the first access network device through the N2 interface.

[0369] S905: The first access network device configures the first address of the first tunnel for the terminal device according to the relevant indication information from the SMF network element.

[0370] In an optional implementation, the tunnel address configuration indication information from the SMF network element may be represented as fourth indication information, where the fourth indication information is used to indicate the configuration of the first address of the first tunnel. The first access network device may also determine, based on the fourth indication information and the agreement of the first transport layer network protocol, that the default mode is attribute information of the first tunnel, where the attribute information may include, for example, any one of the following transmission modes: data packet mode, stream mode, or security mode.

[0371] In another optional implementation, the tunnel address configuration indication information from the SMF network element may include attribute information of the first tunnel. When implementing S905, the first access network device may also obtain attribute information of the first tunnel from the tunnel address configuration indication information. The attribute information may, for example, include any one of the following transmission modes: data packet mode, stream mode, or security mode.

[0372] In the DC scenario, the communication system may further include a second access network device (SN), wherein the first access network device is a primary node of the terminal device, and the second access network device is a secondary node of the terminal device. The first access network device and the second access network device may further collaboratively execute the following S906a and S906b to configure the second identifier and the second address of the first tunnel for the terminal device, thereby extending the multipath characteristics of the first tunnel in the DC scenario. The detailed implementation details of S906a can be found in the above description in conjunction with S705a, and the detailed implementation details of S906b can be found in the above description in conjunction with S705b, which will not be repeated here.

[0373] S906a (optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface. The Xn signaling is used to request to add or modify the SN, and at the same time request the SN to configure the second address of the first tunnel for the terminal device, or request the SN to configure the second identifier and second address of the first tunnel for the terminal device. Accordingly, the second access network device can configure the second address of the first tunnel for the terminal device based on the received Xn signaling, or configure the second identifier and second address of the first tunnel for the terminal device. The number of the second identifiers can be one or more. The second address can include the IP address and port number provided by the second access network device for the first tunnel.

[0374] S906b: (Optional step): The second access network device sends an Xn signaling response to the first access network device via the Xn interface. The Xn signaling response may include the second address. Alternatively, the Xn signaling response may include the second identifier and the second address. Accordingly, the first access network device receives and stores the second identifier and the second address of the first tunnel. It should be understood that S906a-S906b are optional steps. In one embodiment, only S906a may be implemented, while in another embodiment, both S906a and S906b may be implemented simultaneously. The implementation details can be found in the previous description and will not be repeated here.

[0375] S907: The first access network device sends the first information to the terminal device. Correspondingly, the terminal device feeds back response information for the first information to the first access network device. Detailed implementation details can be found in the above description in conjunction with S708 and will not be repeated here.

[0376] S908: The first access network device feeds back an Nx session response message to the SMF network element via the AMF network element. Correspondingly, the SMF network element receives the Nx session response message from the first access network device.

[0377] S909: The SMF network element and other core network elements execute the remaining steps of establishing the PDU session. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be repeated here.

[0378] S910: A first tunnel using a first transport layer network protocol is established between the terminal device and the first access network device.

[0379] In one implementation, the terminal device may initiate S910 based on the received information. In an optional DC scenario, the first access network device may further send the second identifier of the first tunnel to the terminal device.

[0380] In another implementation, the first access network device may initiate S910 according to the received information.

[0381] The specific implementation details of S910 can be found in the connection establishment process of the first transport layer network protocol, such as the connection establishment process of the QUIC protocol, which will not be repeated here.

[0382] After that, the terminal device can transmit data with the first access network device based on the first tunnel. In the optional DC scenario, the terminal device can transmit data with the first access network device or the second access network device based on multiple communication paths of the first tunnel. For example, the first identifier and the first address of the first tunnel are associated with the first communication path of the first tunnel, and the terminal device transmits data with the first access network device through the first communication path. The second identifier and the second address of the first tunnel are associated with the second communication path of the first tunnel, and the terminal device transmits data with the second access network device through the second communication path.

[0383] In the optional DC scenario, the first access network device may further perform the following optional steps:

[0384] S911 (optional step): The first access network device sends Xn signaling to the second access network device via the Xn interface to notify the terminal device of the CID. For example, the first access network device sends sixth indication information to the second access network device via the Xn interface. The sixth indication information may indicate the fourth identifier of the first tunnel, or the fourth identifier and fourth address of the first tunnel. The fourth identifier and fourth address are associated with the terminal device and may be obtained by the first access network device in S910.

[0385] The terminal device, the first access network device, and the second access network device need to interact to add a second communication path in the first tunnel. The process of adding the second communication path can be initiated by the first access network device, the second access network device, or the terminal device.

[0386] If the first access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be included after S711:

[0387] S912 (optional step): The first access network device initiates a path adding operation to the terminal device based on the address and CID of the SN. For example, the first access network device initiates a path adding operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0388] In one example, S912 may be implemented through AS signaling. For example, the first access network device may send a third access layer message to the terminal device, where the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address.

[0389] In another example, S912 may be implemented through the first tunnel. For example, the first access network device may send first control information to the terminal device through the first tunnel, and the first control information may include the second identifier, or the first control information may include the second identifier and the second address.

[0390] Here, unlike the multipath characteristics of the general QUIC protocol, the two endpoints of the multipath characteristics of the general QUIC protocol are the same entity (or node), and are caused by the change of the UE's address (for example, in the technologies of 3GPP and WIFI, the UE's IP address changes due to switching), while the situation here is caused by data transmission between the terminal device and different access network devices. As shown in Figure 8, the UE transmits data to different access network devices through different paths in the same QUIC tunnel, for example, through the first communication path (for example, represented by path 1), the first identifier, and the first address in the same QUIC tunnel to transmit data to the first access network device, and through the second communication path (for example, represented by path 2), the second identifier, and the second address to transmit data to the second access network device.

[0391] S913 (optional): The first access network device sends an Xn signaling to the second access network device via the Xn interface to notify the second access network device of information about the second communication path. For example, the Xn signaling includes information about the second communication path, such as the second identifier, packet number space, and packet sequence number.

[0392] If the second access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be further included after S910:

[0393] S914 (optional step): The second access network device (SN) initiates a path adding operation to the terminal device.

[0394] S914 may be implemented through the first tunnel. For example, the second access network device may send third control information to the terminal device through the first tunnel. The third control information may include the second identifier, or the third control information may include the second identifier and the second address. Optionally, the third control information may also include the fourth identifier and the fourth address of the first tunnel. The source path identifier of the third control information may be the first identifier or the second identifier, and the target path identifier of the third control information may be the fourth identifier.

[0395] S915 (optional): The second access network device synchronizes information about the second communication path with the first access network device. For example, the second access network device sends Xn signaling to the first access network device via an Xn interface. The Xn signaling includes information about the second communication path, such as the second identifier, the packet number space, and the packet sequence number.

[0396] Based on the above-mentioned embodiment 1, by designing the interaction between the terminal device and the first access network device and some core network elements, a tunnel using the QUIC protocol can be introduced between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device. At the same time, in the optional DC scenario, by designing the interaction between the second access network device and the first access network device or the terminal device, different QUIC communication paths can be introduced between the terminal device and the second access network device to ensure the communication quality between the terminal device and the second access network device.

[0397] Example 3:

[0398] In this third embodiment, when the terminal device determines that it is necessary to establish a first tunnel with the first access network device based on the received indication, after establishing a PDU session between the terminal device and the core network, the terminal device requests the first access network device to configure the first address of the first tunnel, so as to introduce the first tunnel using the first transport layer network protocol between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device.

[0399] As shown in FIG10 , the data transmission method may include the following steps:

[0400] S1001: The terminal device sends a session message to the SMF network element through the AMF network element. The session message is used to indicate the establishment of a session for the terminal device, such as the establishment of a PDU session. Accordingly, the AMF network element can receive the session message and forward it to the SMF network element. Detailed implementation details can be found in the above description of S701 and will not be repeated here.

[0401] S1002: The terminal device, the first access network device, and multiple network elements of the core network (for example, including AMF network elements, SMF network elements, PCF network elements, and UDM network elements) implement contract processing, policy processing, authentication / authorization processing, user plane function processing, etc. Detailed implementation details can be found in the introduction of S702 above and will not be repeated here.

[0402] S1003: The SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device. Detailed implementation details can be found in the above description in conjunction with S703 and will not be repeated here.

[0403] S1004: The SMF network element sends an Nx session message to the first access network device via the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0404] In an embodiment of the present application, the SMF network element may send an N11 session message to the AMF network element through the N11 interface, and the N11 session message may carry tunnel indication information. The AMF network element sends an N2 session message to the first access network device through the N2 interface, and the N2 session message may carry tunnel indication information. The tunnel indication information is used to indicate that the terminal device needs to establish a first tunnel with the first access network device.

[0405] In an optional implementation, the tunnel indication information from the SMF network element may include attribute information of the first tunnel. The attribute information may include, for example, any one of the following transmission modes: data packet mode, stream mode, or security mode.

[0406] S1005: The first access network device sends tunnel indication information to the terminal device, which is represented as second indication information. Correspondingly, the terminal device receives the second indication information from the first access network device.

[0407] The tunnel indication information is used to indicate that the terminal device needs to establish a first tunnel with the first access network device. In an optional embodiment, the tunnel indication information from the first access network device may include attribute information of the first tunnel. The attribute information may include, for example, any of the following transmission modes: data packet mode, stream mode, or security mode.

[0408] S1006: The first access network device feeds back an Nx session response message to the SMF network element via the AMF network element. Correspondingly, the SMF network element receives the Nx session response message from the first access network device.

[0409] S1007: The SMF network element and other core network elements execute the remaining steps of establishing the PDU session. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be repeated here.

[0410] S1008: The terminal device sends second indication information to the first access network device, where the second indication information indicates to establish the first tunnel between the terminal device and the first access network device.

[0411] The second indication information may be carried in a second access layer message from the terminal device. The second access layer message may be a newly added control plane message. Alternatively, the second indication information may be carried in a reserved field of the original access layer message, or may replace other information elements in the original access layer message.

[0412] In an optional implementation, when implementing S1008, the terminal device may further send attribute information of the first tunnel to the first access network device, so as to negotiate attribute parameters of the first tunnel with the first access network device.

[0413] In another optional implementation, when implementing S1008, the terminal device may further send session information associated with the first tunnel to the first access network device for the first access network device to perform authorization judgment to allow establishment of the first tunnel with the terminal device.

[0414] S1009: The first access network device configures a first address of the first tunnel for the terminal device and sends first information to the terminal device, where the first information indicates the first address of the first tunnel. Correspondingly, the terminal device receives the first information from the first access network device.

[0415] In the DC scenario, the communication system may further include a second access network device (SN), wherein the first access network device is a primary node of the terminal device, and the second access network device is a secondary node of the terminal device. The first access network device and the second access network device may further collaboratively execute the following S1010a and S1010b to configure the second identifier and the second address of the first tunnel for the terminal device, thereby extending the multipath characteristics of the first tunnel in the DC scenario. The detailed implementation details of S1010a may be found in the above description in conjunction with S705a, and the detailed implementation details of S1010b may be found in the above description in conjunction with S705b, which will not be repeated here.

[0416] S1010a (optional step): The first access network device sends an Xn signaling to the second access network device through the Xn interface. The Xn signaling is used to request configuration of a communication path with the SN.

[0417] S1010b (optional step): The second access network device sends an Xn signaling response to the first access network device through the Xn interface. The Xn signaling response is used to configure a communication path with the SN.

[0418] S1011: A first tunnel using a first transport layer network protocol is established between the terminal device and the first access network device.

[0419] In one implementation, the terminal device may initiate S1011 based on the received information. In an optional DC scenario, the first access network device may further send the second identifier of the first tunnel to the terminal device.

[0420] In another implementation, the first access network device may initiate S910 according to the received information.

[0421] The specific implementation details of S1011 can be found in the connection establishment process of the first transport layer network protocol, such as the connection establishment process of the QUIC protocol, which will not be repeated here.

[0422] After that, the terminal device can transmit data with the first access network device based on the first tunnel. In the optional DC scenario, the terminal device can transmit data with the first access network device or the second access network device based on multiple communication paths of the first tunnel. For example, the first identifier and the first address of the first tunnel are associated with the first communication path of the first tunnel, and the terminal device transmits data with the first access network device through the first communication path. The second identifier and the second address of the first tunnel are associated with the second communication path of the first tunnel, and the terminal device transmits data with the second access network device through the second communication path.

[0423] In the optional DC scenario, the first access network device may further perform the following optional steps:

[0424] S1012 (optional step): The first access network device sends Xn signaling to the second access network device via the Xn interface to notify the terminal device of the CID. For example, the first access network device sends sixth indication information to the second access network device via the Xn interface. The sixth indication information may indicate the fourth identifier of the first tunnel, or the sixth indication information may indicate the fourth identifier and fourth address of the first tunnel. The fourth identifier and fourth address are associated with the terminal device and may be obtained by the first access network device in S1011.

[0425] The terminal device, the first access network device, and the second access network device need to interact to add a second communication path in the first tunnel. The process of adding the second communication path can be initiated by the first access network device, the second access network device, or the terminal device.

[0426] If the first access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be included after S1011:

[0427] S1013 (optional step): The first access network device initiates a path adding operation to the terminal device based on the address and CID of the SN. For example, the first access network device initiates a path adding operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0428] In one example, S1013 may be implemented through AS signaling. For example, the first access network device may send a third access layer message to the terminal device, where the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address.

[0429] In another example, S1013 may be implemented through the first tunnel. For example, the first access network device may send first control information to the terminal device through the first tunnel, and the first control information may include the second identifier, or the first control information may include the second identifier and the second address.

[0430] Here, unlike the multipath characteristics of the general QUIC protocol, the two endpoints of the multipath characteristics of the general QUIC protocol are the same entity (or node), and are caused by the change of the UE's address (for example, in the technologies of 3GPP and WIFI, the UE's IP address changes due to switching), while the situation here is caused by data transmission between the terminal device and different access network devices. As shown in Figure 8, the UE transmits data to different access network devices through different paths in the same QUIC tunnel, for example, through the first communication path (for example, represented by path 1), the first identifier, and the first address in the same QUIC tunnel to transmit data to the first access network device, and through the second communication path (for example, represented by path 2), the second identifier, and the second address to transmit data to the second access network device.

[0431] S1014 (optional step): The first access network device sends an Xn signaling to the second access network device via the Xn interface to notify the second access network device of information about the second communication path. For example, the Xn signaling includes information about the second communication path, such as the second identifier, packet number space, and packet sequence number.

[0432] If the second access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be included after S1011:

[0433] S1015 (optional step): The second access network device (SN) initiates a path adding operation to the terminal device.

[0434] S1015 may be implemented through the first tunnel. For example, the second access network device may send third control information to the terminal device through the first tunnel. The third control information may include the second identifier, or the third control information may include the second identifier and the second address. Optionally, the third control information may also include the fourth identifier and the fourth address of the first tunnel. The source path identifier of the third control information may be the first identifier or the second identifier, and the target path identifier of the third control information may be the fourth identifier.

[0435] S1016 (optional): The second access network device synchronizes information about the second communication path with the first access network device. For example, the second access network device sends Xn signaling to the first access network device via an Xn interface. The Xn signaling includes information about the second communication path, such as the second identifier, packet number space, and packet sequence number.

[0436] Based on the above-mentioned embodiment 1, by designing the interaction between the terminal device and the first access network device and some core network elements, a tunnel using the QUIC protocol can be introduced between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device. At the same time, in the optional DC scenario, by designing the interaction between the second access network device and the first access network device or the terminal device, different QUIC communication paths can be introduced between the terminal device and the second access network device to ensure the communication quality between the terminal device and the second access network device.

[0437] Example 4:

[0438] In this fourth embodiment, during the session establishment process between the terminal device and the core network, the first access network device may configure the first address of the first tunnel for the terminal device based on the tunnel capability information reported by the terminal device, and inform the SMF network element in the uplink message, and the SMF network element may inform the terminal device in the downlink NAS message to introduce the first tunnel using the first transport layer network protocol between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device.

[0439] As shown in FIG11 , the data transmission method may include the following steps:

[0440] S1101: The terminal device sends an uplink RRC message or a session message to the first access network device. Accordingly, the first access network device receives the RRC message or session message from the terminal device and sends session-related content to the SMF network element.

[0441] In one example, the RRC message or session message may include first indication information, which may indicate that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol. The first access network device may configure the first address of the first tunnel for the terminal device based on the first indication information, if necessary. For example, if the first access network device also supports the first transport layer network protocol, or supports multi-channel communication based on the first transport layer network protocol. The first access network device may configure the first address of the first tunnel for the terminal device.

[0442] The first access network device may carry first indication information in an N1 message sent to the AMF network element. The first indication information may indicate that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol. The N1 message may also carry the first address of the first tunnel.

[0443] The AMF network element sends a session establishment request message to the SMF network element. The session establishment request message may include the first indication information and may also carry the first address of the first tunnel. In an optional implementation, the session establishment request message may also include attribute information of the first tunnel. The attribute information may include, for example, any one of the following transmission modes: data packet mode, stream mode, or security mode.

[0444] S1102: The terminal device, the first access network device, and multiple network elements of the core network (for example, including AMF network elements, SMF network elements, PCF network elements, and UDM network elements) implement contract processing, policy processing, authentication / authorization processing, user plane function processing, etc. Detailed implementation details can be found in the introduction of S702 above and will not be repeated here.

[0445] S1103: The SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device. Detailed implementation details can be found in the above description in conjunction with S703 and will not be repeated here.

[0446] S1104: The SMF network element sends an Nx session message to the first access network device via the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0447] In one example, the SMF network element sends a session message to the AMF network element through the N11 interface. The session message may include information that needs to be sent to the terminal device, such as the first address and attribute information of the first tunnel. The session message may also include information that needs to be sent to the first access network device, such as instruction information, such as an instruction to authorize the terminal device to establish a first tunnel with the first access network device.

[0448] The AMF network element sends an indication message to the first access network device through the N1 interface, instructing the authorized terminal device to establish a first tunnel with the first access network device.

[0449] S1105: The AMF network element sends information to the terminal device, such as first information including the first address of the first tunnel. Alternatively, the first information may also include attribute information of the first tunnel. Alternatively, the AMF network element may further send the attribute information of the first tunnel to the terminal device.

[0450] Among them, the AMF network element can send a session message to the first access network device through the N2 interface. The first access network device can send the first information and / or the second information to the terminal device through a downlink RRC message.

[0451] S1106: The first access network device feeds back an Nx session response message to the SMF network element via the AMF network element. Correspondingly, the SMF network element receives the Nx session response message from the first access network device.

[0452] S1107: The SMF network element and other core network elements execute the remaining steps of establishing the PDU session. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be repeated here.

[0453] In the DC scenario, the communication system may further include a second access network device (SN), wherein the first access network device is a primary node of the terminal device, and the second access network device is a secondary node of the terminal device. The first access network device and the second access network device may further collaboratively execute the following S1108a and S1108b to configure the second identifier and the second address of the first tunnel for the terminal device, thereby extending the multipath characteristics of the first tunnel in the DC scenario. The detailed implementation details of S1108a may be found in the above description in conjunction with S705a, and the detailed implementation details of S1108b may be found in the above description in conjunction with S705b, which will not be repeated here.

[0454] S1109: A first tunnel using a first transport layer network protocol is established between the terminal device and the first access network device.

[0455] In one implementation, the terminal device may initiate S1109 based on the received information. In an optional DC scenario, the first access network device may further send the second identifier of the first tunnel to the terminal device.

[0456] In another implementation, the first access network device may initiate S1109 according to the received information.

[0457] The specific implementation details of S1109 can be found in the connection establishment process of the first transport layer network protocol, such as the connection establishment process of the QUIC protocol, which will not be repeated here.

[0458] After that, the terminal device can transmit data with the first access network device based on the first tunnel. In the optional DC scenario, the terminal device can transmit data with the first access network device or the second access network device based on multiple communication paths of the first tunnel. For example, the first identifier and the first address of the first tunnel are associated with the first communication path of the first tunnel, and the terminal device transmits data with the first access network device through the first communication path. The second identifier and the second address of the first tunnel are associated with the second communication path of the first tunnel, and the terminal device transmits data with the second access network device through the second communication path.

[0459] In the optional DC scenario, the first access network device may further perform the following optional steps:

[0460] S1110 (optional step): The first access network device sends Xn signaling to the second access network device via the Xn interface to notify the terminal device of the CID. For example, the first access network device sends sixth indication information to the second access network device via the Xn interface. The sixth indication information may indicate the fourth identifier of the first tunnel, or the sixth indication information may indicate the fourth identifier and fourth address of the first tunnel. The fourth identifier and fourth address are associated with the terminal device and may be obtained by the first access network device in S1109.

[0461] The terminal device, the first access network device, and the second access network device need to interact to add a second communication path in the first tunnel. The process of adding the second communication path can be initiated by the first access network device, the second access network device, or the terminal device.

[0462] If the first access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be included after S1109:

[0463] S1111 (optional step): The first access network device initiates a path adding operation to the terminal device based on the address and CID of the SN. For example, the first access network device initiates a path adding operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0464] In one example, S1111 may be implemented through AS signaling. For example, the first access network device may send a third access layer message to the terminal device, where the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address.

[0465] In another example, S1111 may be implemented through the first tunnel. For example, the first access network device may send first control information to the terminal device through the first tunnel, and the first control information may include the second identifier, or the first control information may include the second identifier and the second address.

[0466] Here, unlike the multipath characteristics of the general QUIC protocol, the two endpoints of the multipath characteristics of the general QUIC protocol are the same entity (or node), and are caused by the change of the UE's address (for example, in the technologies of 3GPP and WIFI, the UE's IP address changes due to switching), while the situation here is caused by data transmission between the terminal device and different access network devices. As shown in Figure 8, the UE transmits data to different access network devices through different paths in the same QUIC tunnel, for example, through the first communication path (for example, represented by path 1), the first identifier, and the first address in the same QUIC tunnel to transmit data to the first access network device, and through the second communication path (for example, represented by path 2), the second identifier, and the second address to transmit data to the second access network device.

[0467] S1112 (optional step): The first access network device sends Xn signaling to the second access network device via the Xn interface to notify the second access network device of information about the second communication path. For example, the Xn signaling includes information about the second communication path, such as the second identifier, packet number space, and packet sequence number.

[0468] If the second access network device initiates the process of adding the second communication path to the terminal device, the following optional steps may be included after S1109:

[0469] S1113 (optional step): The second access network device (SN) initiates a path adding operation to the terminal device.

[0470] S1113 may be implemented through the first tunnel. For example, the second access network device may send third control information to the terminal device through the first tunnel. The third control information may include the second identifier, or the third control information may include the second identifier and the second address. Optionally, the third control information may also include the fourth identifier and the fourth address of the first tunnel. The source path identifier of the third control information may be the first identifier or the second identifier, and the target path identifier of the third control information may be the fourth identifier.

[0471] S1114 (optional): The second access network device synchronizes information about the second communication path with the first access network device. For example, the second access network device sends Xn signaling to the first access network device via an Xn interface. The Xn signaling includes information about the second communication path, such as the second identifier, packet number space, and packet sequence number.

[0472] Based on the above-mentioned embodiment 1, by designing the interaction between the terminal device and the first access network device and some core network elements, a tunnel using the QUIC protocol can be introduced between the terminal device and the first access network device to ensure the communication quality between the terminal device and the first access network device. At the same time, in the optional DC scenario, by designing the interaction between the second access network device and the first access network device or the terminal device, different QUIC communication paths can be introduced between the terminal device and the second access network device to ensure the communication quality between the terminal device and the second access network device.

[0473] Embodiment 5:

[0474] Example 5 can be a further supplement to the above-mentioned Examples 1 to 4, so as to perform tunnel migration between the terminal device and different base stations in a scenario involving base station switching, so as to introduce a first tunnel using the first transport layer network protocol between the terminal device and the target access network device to ensure the communication quality between the terminal device and the target access network device and the source access network device.

[0475] As shown in FIG12 , the data transmission method may include the following steps:

[0476] S1201: The terminal device and the first access network device start a measurement process, where the first access network device is the source access network device of the terminal device. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be repeated here.

[0477] S1202: The first access network device determines, based on the measurement result, that the terminal device needs to be switched to a third access network device, where the third access network device is the target access network device of the terminal.

[0478] S1203: The first access network device sends a handover request to the third access network device. Correspondingly, the third access network device receives the handover request.

[0479] The handover request may carry parameters required in the mobile handover process. For detailed implementation details, please refer to the relevant standard documents of 3GPP, which will not be repeated here.

[0480] When designing the QUIC protocol in the handover scenario of the embodiment of the present application, the handover request may also include context information of the first tunnel. The context information of the first tunnel may include, for example: the fourth identifier and fourth address of the first tunnel, the fourth identifier and fourth address are associated with the terminal device. The context information of the first tunnel may also include, for example:

[0481] QUIC configuration / properties, security context

[0482] The last packet number sent or received in the upstream and downstream of the QUIC protocol;

[0483] Stream / Connection flow control status: offset of data consumed per stream;

[0484] The buffer state is shown in Figure 13;

[0485] Multipath status: PID, PN, and the packet number of the last packet sent or received on the given path.

[0486] S1204: The third access network device configures the second identifier and the second address of the first tunnel for the terminal device, and sends a handover response to the first access network device. The handover response may include the second identifier and the second address of the first tunnel.

[0487] The above S1203 and S1204 can be applicable to the switching scenario where there is a connection between the terminal device and the base station (such as the first access network device), and can also be applicable to the switching scenario where there is no connection between the terminal device and the base station (such as the first access network device) and switching needs to be performed through the core network.

[0488] S1205: The first access network device initiates tunnel migration to the terminal device.

[0489] Among them, if S1206 is executed according to the existing QUIC protocol, the first access network device may send a new non-detection frame data packet based on the second address configured by the third access network device to migrate the context information of the first tunnel.

[0490] Alternatively, if it is a 3GPP custom tunnel protocol, when executing S1206, the first access network device may initiate a control plane path switch, or a similar mechanism.

[0491] In an optional implementation, before S1205, the first access network device may also perform the following steps:

[0492] S1206: The first access network device initiates a path detection or verification process to the terminal device. Specifically, the first access network device sends a downlink detection frame data packet (using the tunnel endpoint address assigned by the target RAN) to the terminal device. This downlink data packet may include, for example, the third identifier and third address of the first tunnel. After verification is complete, the tunnel migration process of S1205 is initiated.

[0493] S1207: The first access network device sends a switching command to the terminal device.

[0494] In an optional implementation, the handover command may include the third identifier of the first tunnel. Alternatively, the handover command may include the third address of the first tunnel.

[0495] In another optional implementation, the third identifier of the first tunnel may be carried in a downlink RRC message different from the handover command, for example, S1209.

[0496] In another optional implementation, if the available fourth identifier provided by the terminal device is already included in S1203, S1208 may not be implemented. Otherwise, the terminal device may also execute S1208 to publish the available identifier of the terminal device, i.e., the new CID, to the first access network device or the third access network device.

[0497] S1208 (optional step): The terminal device sends a new CID to the first access network device, which is represented as a third identifier.

[0498] S1209 (optional step): The first access network device sends a new CID to the terminal device, which is represented as a third identifier.

[0499] S1210: After receiving the switching command, the terminal device freezes the uplink transmission based on the first tunnel.

[0500] S1211: The terminal device accesses the third access network device.

[0501] S1212: The terminal device restores the context of the first tunnel and restarts uplink transmission based on the first tunnel, using the new CID to transmit data with the third access network device. For example, in S1213, the terminal device transmits data with the third access network device based on the third identifier and third address of the first tunnel.

[0502] For example, the terminal device sends an uplink data packet to the third access network device, where the uplink data packet includes a third identifier and a third address. Optionally, the uplink data packet may also include a fourth identifier and a fourth address.

[0503] Or for example, the terminal device receives a downlink data packet from a third access network device, the downlink data packet including a third identifier and a third address. Optionally, the downlink data packet may also include a fourth identifier and a fourth address.

[0504] Example 6:

[0505] Example 6 can also be a further supplement to the above-mentioned Examples 1 to 4, so that the terminal device, the source access network device and the target access network device all support multi-channel communication based on the QUIC protocol, and in scenarios involving base station switching and DAPS, tunnel migration is performed between the terminal device and different base stations, so as to introduce a first tunnel using the first transport layer network protocol between the terminal device and the target access network device to ensure the communication quality between the terminal device and the target access network device and the source access network device.

[0506] As shown in FIG14 , the data transmission method may include the following steps:

[0507] S1401: The terminal device and the first access network device start a measurement process, where the first access network device is the source access network device of the terminal device. Detailed implementation details can be found in the relevant standard documents of 3GPP and will not be described here in detail.

[0508] S1402: The first access network device determines, based on the measurement result, that the terminal device needs to be switched to a third access network device, where the third access network device is the target access network device of the terminal.

[0509] S1403: The first access network device sends a handover request to the third access network device. Correspondingly, the third access network device receives the handover request.

[0510] The handover request may carry parameters required in the mobile handover process. For detailed implementation details, please refer to the relevant standard documents of 3GPP, which will not be repeated here.

[0511] When designing the QUIC protocol in the handover scenario of the embodiment of the present application, the handover request may also include context information of the first tunnel. The context information of the first tunnel may include, for example: the fourth identifier and fourth address of the first tunnel, the fourth identifier and fourth address are associated with the terminal device. The context information of the first tunnel may also include, for example:

[0512] QUIC configuration / properties, security context

[0513] The last packet number sent or received in the upstream and downstream of the QUIC protocol;

[0514] Stream / Connection flow control status: offset of data consumed per stream;

[0515] The buffer state is shown in Figure 13;

[0516] Multipath status: PID, PN, and the packet number of the last packet sent or received on the given path.

[0517] S1404: The third access network device configures the second identifier and the second address of the first tunnel for the terminal device, and sends a handover response to the first access network device. The handover response may include the second identifier and the second address of the first tunnel.

[0518] The above S1403 and S1404 can be applicable to the switching scenario where there is a connection between the terminal device and the base station (such as the first access network device), and can also be applicable to the switching scenario where there is no connection between the terminal device and the base station (such as the first access network device) and switching needs to be performed through the core network.

[0519] S1405: The first access network device initiates tunnel context migration to the terminal device.

[0520] When the first access network device supports the DSPA capability, the first access network device acquires the DAPS capability of the terminal device or the third access network device.

[0521] For example, the terminal device sends the DAPS capability of the terminal device to the first access network device in an uplink RRC message. The first access network device obtains the DAPS capability of the third access network device in the signaling interaction related to the execution of the handover with the third access network device (for example, sending a request message to the target RAN to inquire whether DAPS is supported, or inquiring the target RAN and the target RAN actively indicates to the source RAN that it supports DAPS). In addition, the first access network device can also obtain the MPQUIC capability of the third access network device (the acquisition method is similar to that of obtaining the DAPS capability).

[0522] When the first access network device, the third access network device, and the terminal device all support MPQUIC and DPSA, the data transmission method may further include the following steps:

[0523] S1406: The first access network device initiates a path addition operation to the terminal device. For example, the first access network device may send a downlink non-probing frame to the terminal device. The non-probing frame may use the endpoint address (IP address and port) assigned by the third access network device as the address of the new path and the connection identifier CID(s) assigned by the third access network device as the source CID.

[0524] In an optional implementation, the first access network device also indicates to the terminal device the rules for data transmission on the two paths, such as a replication mode (i.e., transmitting the same data on the two paths), or a new path priority (i.e., only data that cannot be sent on the new path is sent on the old path), or setting a ratio of data transmission on the two paths, or allocating data based on the transmission quality on the two paths. The new path refers to a communication path between the terminal device and the third access network device that uses the target transport layer network protocol, and the old path refers to a communication path between the terminal device and the first access network device that uses the target transport layer network protocol.

[0525] Among them, in order to implement the path addition operation in the first tunnel, a group switching connection ID (CID) is required, so the terminal device and the first access network device can exchange a new CID, that is, the third identifier of the third access network device, in the following multiple opportunities and message mechanisms.

[0526] For example, the first access network device may carry the third identifier in a handover command sent to the terminal device. Alternatively, the first access network device may carry the third identifier in existing AS signaling other than the handover command sent by the terminal device. Alternatively, the first access network device may carry the third identifier in newly added AS signaling sent by the terminal device.

[0527] S1407: The first access network device sends a switching command to the terminal device.

[0528] S1408 (optional step): The terminal device sends a new CID to the first access network device, which is represented as a third identifier.

[0529] S1409 (optional step): The first access network device sends a new CID to the terminal device, which is represented as a third identifier.

[0530] S1410: After receiving the switching command, the terminal device connects to the third access network device and transmits data according to the instructions on one or both paths based on the data transmission mode instructions on the two paths.

[0531] S1411: Taking the replication mode as an example, the terminal device replicates the uplink data into two copies and performs uplink transmission on both paths.

[0532] S1412: When the third access network device determines that the source path can be deleted (for example, the data on the two paths have been synchronized, or no context information is received from the first access network device within the set time, or an end marker sent by the first access network device is received), the third access network device can initiate a path deletion message to the terminal device to delete the path between the terminal device and the first access network device.

[0533] In another implementation, the third access network device can instruct the first access network device to delete the path between the terminal device and the first access network device, or when the first access network device determines that there is no data to be transmitted on the path, it initiates a path deletion message to the terminal device, deletes the source path, and notifies the third access network device.

[0534] In another implementation, if the terminal device determines that the source path is no longer needed, it sends a path deletion message to a third access network device to delete the path between the terminal device and the first access network device. The third access network device then sends a notification message to the first access network device indicating that the path has been deleted. The first access network device then releases related resources, such as the QUIC protocol stack context. Alternatively, it sends a path deletion message to the first access network device, and after deletion, notifies the third access network device of the path deletion.

[0535] S1413: The terminal device transmits data only on the target path, for example, transmits data only to the third access network device on the target path.

[0536] Note: During the handover process of Examples 5 and 6, if the third access network device supports DC, the SN information can be sent to the terminal device during the handover process, referring to the description in Examples 1 to 4. Alternatively, after the handover is completed, the DC SN can be added again, and the steps related to the DC scenario in the previous embodiments can be performed, which will not be repeated here.

[0537] An embodiment of the present application also provides a communication device for executing the method executed by the terminal device, or the first access network device, or the second access network device, or the third access network device, or the SMF network element in the above method embodiment. Relevant features can be found in the above method embodiment and will not be repeated here.

[0538] As shown in FIG. 15 , the communication device 1500 may include: a processing unit 1501 and a communication unit 1502 .

[0539] When communication device 1500 is used to execute the method performed by the first access network device, communication unit 1502 is configured to send first information, where the first information indicates a first address of a first tunnel, where the first tunnel is used to transmit data between the terminal device and the first access network device using a first transport layer network protocol, and the first address is associated with the first access network device; and establish the first tunnel with the terminal device based on the first address. For specific implementation methods, please refer to the method steps implemented by the first access network device in the above method embodiment, which will not be repeated here.

[0540] When the communication apparatus 1500 is used to execute the method executed by the terminal device, the communication unit 1502 is configured to receive first information, wherein the first information indicates a first address of a first tunnel, the first tunnel employing a first transport layer network protocol, and the first tunnel is used to transmit data between the terminal device and a first access network device; and the processing unit 1501 is configured to establish the first tunnel with the first access network device based on the first information. For specific implementation methods, please refer to the method steps implemented by the terminal device in the above method embodiment, and will not be repeated here.

[0541] When the communication device 1500 is used to execute the method executed by the SMF network element, the communication unit 1502 is used to receive first information, wherein the first information indicates a first address of a first tunnel, the first tunnel is used to transmit data between the terminal device and the first access network device using a first transport layer network protocol, and the first address is associated with the first access network device; and the first tunnel is established with the first access network device based on the first address. For specific implementation methods, please refer to the method steps implemented by the SMF network element in the above method embodiment, which will not be repeated here.

[0542] When the communication device 1500 is used to execute the method executed by the second access network device, the communication unit 1502 is used to send the second identifier of the first tunnel, or send the second identifier and second address of the first tunnel, the first tunnel is used to transmit data between the terminal device and the second access network device using the first transport layer network protocol, the second identifier and the second address are associated with the second communication path of the first tunnel, the first tunnel includes at least one communication path, the first communication path in the at least one communication path is used to transmit data between the terminal device and the first access network device, the first identifier and the first address of the first tunnel are associated with the first communication path, the second communication path in the at least one communication path is used to transmit data between the terminal device and the second access network device; receive an uplink data packet from the terminal device, the uplink data packet includes the second identifier and the second address. For specific implementation methods, please refer to the method steps implemented by the second access network device in the above method embodiment, which will not be repeated here.

[0543] When the communication device 1500 is used to execute the method executed by the third access network device, the communication unit 1502 is used to send the third identifier of the first tunnel, or send the third identifier and third address of the first tunnel, the first tunnel is used to use the first transport layer network protocol to transmit data between the terminal device and the third access network device, the third address is associated with the third access network device, and the third access network device is the target access network device of the terminal device; receive an uplink data packet from the terminal device, the uplink data packet includes the third identifier and the third address. For specific implementation methods, please refer to the method steps implemented by the third access network device in the above method embodiment, which will not be repeated here.

[0544] It should be understood that the division of the various units in the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into a physical entity, or they can be physically separated. In addition, the units in the device can be implemented in the form of a processor calling software; for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or realize the functions of the various units of the device, where the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units can be realized by designing the hardware circuits. The hardware circuit can be understood as one or more processors. For example, in one implementation, the hardware circuit is an application-specific integrated circuit (ASIC), which realizes the functions of some or all of the above units by designing the logical relationship of the components in the circuit. For another example, in another implementation, the hardware circuit can be implemented by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units. All units of the above devices can be implemented in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[0545] In an embodiment of the present application, a processor is a circuit with a signal processing capability. In one implementation, the processor may be a circuit with instruction reading and execution capability, such as a CPU, a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP); in another implementation, the processor may implement certain functions through the logical relationship of a hardware circuit, and the logical relationship of the hardware circuit is fixed or reconfigurable, such as a hardware circuit implemented by an ASIC or PLD, such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0546] It can be seen that each unit in the above device can be one or more processors (or processing circuits) configured to implement the above method, such as: CPU, GPU, NPU, TPU, DPU, microprocessor, DSP, ASIC, FPGA, or a combination of at least two of these processor forms.

[0547] In addition, the various units in the above devices can be fully or partially integrated together, or can be implemented independently. In one implementation, these units are integrated together and implemented in the form of a system-on-a-chip (SOC). The SOC may include at least one processor for implementing any of the above methods or implementing the functions of the various units of the device. The type of the at least one processor can be different, for example, including a CPU and FPGA, a CPU and an artificial intelligence processor, a CPU and a GPU, etc.

[0548] In a simple embodiment, those skilled in the art can imagine that the communication devices in the above embodiments may all adopt the form shown in FIG. 16 .

[0549] As shown in FIG16 , the apparatus 1600 includes at least one processor 1610 and a communication interface 1630. In an optional design, a memory 1620 may also be included.

[0550] The specific connection medium between the processor 1610 and the memory 1620 is not limited in the embodiment of the present application.

[0551] In the apparatus shown in FIG. 16 , the processor 1610 may transmit data through the communication interface 1630 when communicating with other devices.

[0552] When the communication device adopts the form shown in Figure 16, the processor 1610 in Figure 16 can call the computer execution instructions stored in the memory 1620, so that the device 1600 can execute any of the above method embodiments.

[0553] An embodiment of the present application also relates to a chip system, which includes a processor for calling a computer program or computer instructions stored in a memory so that the processor executes the method of any of the above embodiments.

[0554] In a possible implementation, the processor may be coupled to the memory through an interface.

[0555] In a possible implementation, the chip system may also directly include a memory, in which a computer program or computer instructions are stored.

[0556] For example, the memory may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache memory. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0557] An embodiment of the present application further relates to a processor, which is used to call a computer program or computer instruction stored in a memory so that the processor executes the method described in any of the above embodiments.

[0558] For example, in the embodiments of the present application, the processor is an integrated circuit chip with signal processing capabilities. For example, the processor can be an FPGA, a general-purpose processor, a DSP, an ASIC or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, a system on chip (SoC), a CPU, a network processor (NP), a microcontroller unit (MCU), a PLD or other integrated chip, and can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0559] It should be understood that the embodiments of the present application may be provided as methods, systems, or computer program products.

[0560] In one possible implementation, an embodiment of the present application provides a computer-readable storage medium, which stores program code. When the program code runs on the computer, the computer executes the above method embodiment.

[0561] In a possible implementation, an embodiment of the present application provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above method embodiment.

[0562] Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0563] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0564] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0565] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these changes and variations. In the various embodiments of the present application, unless otherwise specified or logically conflicting, the terms and / or descriptions between the various embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

Claims

1. A data transmission method, characterized in that, Applied to a first access network device, the method includes: Sending first information, where the first information indicates a first address of a first tunnel, and the first tunnel is used for data transmission between the terminal device and the first access network device using a first transport layer network protocol, and the first address is associated with the first access network device; Establishing the first tunnel with the terminal device according to the first address.

2. The method according to claim 1, characterized in that, The method further includes: Receiving first indication information, where the first indication information indicates that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal device supports multi-channel communication based on the first transport layer network protocol; Configuring the first address of the first tunnel for the terminal device according to the first indication information.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Receiving second indication information, where the second indication information indicates to establish the first tunnel between the terminal device and the first access network device; Configuring the first address of the first tunnel for the terminal device according to the second indication information.

4. The method according to any one of claims 1-3, characterized in that The first information further includes attribute information of the first tunnel, The establishing the first tunnel with the terminal device according to the first address includes: Establishing the first tunnel with the terminal device according to the first address and the attribute information of the first tunnel.

5. The method according to any one of claims 1-4, characterized in that, The sending the first information includes: Sending the first information to the terminal device; or, Sending the first information to the core network.

6. The method according to any one of claims 1 to 4, characterized in that The first tunnel includes at least one communication path. A first communication path in the at least one communication path is used for data transmission between the terminal device and the first access network device. The first identifier of the first tunnel and the first address are associated with the first communication path. A second communication path in the at least one communication path is used for data transmission between the terminal device and a second access network device. The method further includes: Receiving second information of the first tunnel from the second access network device, where the second information includes a second identifier of the first tunnel, or the second information includes the second identifier of the first tunnel and a second address of the first tunnel, and the second identifier and the second address are associated with the second communication path; Sending the second identifier to the terminal device, or sending the second identifier and the second address to the terminal device.

7. The method according to claim 6, characterized in that, The sending the second identifier to the terminal device, or sending the second identifier and the second address to the terminal device includes: Sending a third access layer message to the terminal device, where the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address; or, Sending first control information to the terminal device through the first tunnel, where the first control information includes the second identifier, or the first control information includes the second identifier and the second address.

8. The method according to claim 6 or 7, characterized in that, The method further includes: Sending a downlink data packet, where the downlink data packet includes the second identifier and the second address of the first tunnel.

9. The method according to any one of claims 6-8, characterized in that, The method further includes: Send sixth indication information to the second access network device, where the sixth indication information indicates a fourth identifier of the first tunnel, or the sixth indication information indicates the fourth identifier and a fourth address of the first tunnel, and the fourth identifier and the fourth address are associated with the terminal device.

10. The method according to any one of claims 1-9, characterized in that, The method further includes: Receive third information of the first tunnel from a third access network device, where the third information includes a third identifier of the first tunnel, or the third information includes the third identifier and a third address of the first tunnel, and the third identifier and the third address are associated with the third access network device, and the third access network device is a target access network device of the terminal device; Send the third identifier to the terminal device, or send the third identifier and the third address to the terminal device.

11. The method according to claim 10, characterized in that, The method further includes: Send a downlink data packet to the terminal device, where the downlink data packet includes the third identifier and the third address.

12. The method according to claim 10 or 11, characterized in that, Sending the third identifier to the terminal device, or sending the third identifier and the third address to the terminal device, includes: Send a fourth access layer message to the terminal device, where the fourth access layer message includes the third identifier, or the fourth access layer message includes the third identifier and the third address; or Send second control information to the terminal device through the first tunnel, where the second control information includes the third identifier, or the second control information includes the third identifier and the third address.

13. The method according to any one of claims 10-12, characterized in that, The method further includes: Send fifth indication information to the third access network device, where the fifth indication information indicates a fourth identifier of the first tunnel, or the fifth indication information indicates the fourth identifier and a fourth address of the first tunnel, and the fourth identifier and the fourth address are associated with the terminal device.

14. A data transmission method, characterized in that, Applied to a terminal device, the method includes: Receive first information, where the first information indicates a first address of a first tunnel for data transmission between the terminal device and a first access network device using a first transport layer network protocol, and the first address is associated with the first access network device; Establish the first tunnel with the first access network device according to the first address.

15. The method according to claim 14, characterized in that, The method further includes: Send first indication information indicating that the terminal device supports the first transport layer network protocol, or the first indication information indicates that the terminal supports multiplex communication based on the first transport layer network protocol.

16. The method according to claim 14 or 15, characterized in that, The method further includes: Send second indication information indicating the establishment of the first tunnel between the terminal device and the first access network device.

17. The method according to any one of claims 14 - 16, characterized in that, The first information further includes attribute information of the first tunnel, The establishing the first tunnel with the first access network device according to the first address includes: Establish the first tunnel with the first access network device according to the first address and the attribute information of the first tunnel.

18. The method according to any one of claims 14 - 17, characterized in that, The receiving the first information includes: Receive the first information from the first access network device, where the first information is configured by the first access network device.

19. The method according to any one of claims 14-18, characterized in that, The first tunnel includes at least one communication path. The first communication path in the at least one communication path is used to transmit data between the terminal device and the first access network device. The first identifier of the first tunnel and the first address are associated with the first communication path. The second communication path in the at least one communication path is used to transmit data between the terminal device and the second access network device. The method further includes: Receive the second information of the first tunnel from the first access network device, where the second information includes the second identifier of the first tunnel, or the second information includes the second identifier of the first tunnel and the second address of the first tunnel, and the second identifier and the second address are associated with the second communication path.

20. The method according to claim 19, wherein The receiving the second information of the first tunnel from the first access network device includes: Receive a third access layer message from the first access network device, where the third access layer message includes the second information; or, Receive the first control information from the first access network device through the first tunnel, where the first control information includes the second information.

21. The method according to claim 19 or 20, characterized in that, The method further includes: Receive a downlink data packet, where the downlink data packet includes the second identifier and the second address of the first tunnel.

22. The method according to any one of claims 19-21, characterized in that, The method further includes: Send an uplink data packet to the second access network device, where the uplink data packet includes the second identifier and the second address of the first tunnel.

23. The method according to any one of claims 14-22, characterized in that, The first access network device is the source access network device of the terminal device. The method further includes: Receive the third identifier of the first tunnel, or receive the third identifier and the third address of the first tunnel, where the third identifier and the third address are associated with the data transmitted between the terminal device and the third access network device in the first tunnel, and the third access network device is the target access network device of the terminal device.

24. The method according to claim 23, wherein The receiving the third identifier of the first tunnel, or receiving the third identifier and the third address of the first tunnel includes: Receive a fourth access layer message from the first access network device, where the fourth access layer message includes the third identifier, or the fourth access layer message includes the third identifier and the third address; Receive the second control information from the first access network device through the first tunnel, where the second control information includes the third identifier, or the first control information includes the third identifier and the third address.

25. The method according to claim 23 or 24, characterized in that, The method further includes: Receive a downlink data packet from the first access network device or receive a downlink data packet from the third access network device, where the downlink data packet includes the third identifier and the third address.

26. The method according to any one of claims 23-25, characterized in that, The method further includes: Send an uplink data packet to the third access network device, where the uplink data packet includes the third identifier and the third address.

27. A communication device, characterized in that, Comprising at least one processor and an interface circuit, the interface circuit being configured to provide data or code instructions for the at least one processor, the at least one processor being configured to implement the method according to any one of claims 1-13 through logic circuits or by executing code instructions, or to implement the method according to any one of claims 14-26.

28. A communication system, characterized in that, Comprising a communication device configured to implement the method according to any one of claims 1-13, or comprising a communication device configured to implement the method according to any one of claims 14-26.

29. A computer-readable storage medium, characterized in that, The computer-readable medium stores program code which, when run on a computer, causes the computer to execute the method according to any one of claims 1-13, or to execute the method according to any one of claims 14-26.

30. A computer program product, characterized in that, When the computer program product runs on a computer, it causes the computer to execute the method according to any one of claims 1-13, or to implement the method according to any one of claims 14-26.

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