Data transmission method, device and system

Abstract

A data transmission method, device and system, in the method, a first access network device sends first information, the first information indicates a first address of a first tunnel, and 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, the first address is associated with the first access network equipment; and establishing the first tunnel with the terminal device according to the first address. The method is used for designing a QUIC protocol suitable for being used between UE and access network equipment.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and particularly to a data transmission method, apparatus, and system. Background Art

[0002] In a wireless communication system, for example, in a new radio (NR) system, a user equipment (UE) may establish a protocol data unit (PDU) session with a data network (DN) element through a user plane function (UPF) element. The PDU session provides a data transmission service between the UE and the DN element. Among them, in order to support the UE to simultaneously transmit data between 3GPP and Non-3GPP accesses, a quick UDP internet connections (QUIC) protocol equivalent to TCP is used to establish a QUIC connection between the UE and the UPF element, and each connection may have different paths respectively carried on the 3GPP and Non-3GPP access paths. The QUIC protocol also has the characteristic of multi-stream multiplexing and can transmit data of multiple streams simultaneously.

[0003] In some current designs, in order to make full use of the multi-stream multiplexing and multi-path characteristics of QUIC, it is considered to introduce the QUIC protocol between the UE and an access network device (such as a RAN). However, due to the mobility of the UE, the RAN accessed by the UE often changes, and the protocol stack between the UE and the RAN is complex. The QUIC protocol applicable to the UE and the UPF element is not applicable to the UE and the RAN. Therefore, how to design a QUIC protocol applicable to the UE and the RAN is still an important problem to be solved urgently. Summary of the Invention

[0004] This application provides a data transmission method, apparatus, and system for designing a QUIC protocol applicable to a UE and an access network device.

[0005] In a first aspect, this application provides a data transmission method, which can be applied to a first access network device. The method may include: 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.

[0006] 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 improvement of the air interface transmission quality can be achieved based on the first tunnel.

[0007] In a possible implementation, the method may further include: 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 multiplex communication based on the first transport layer network protocol; configuring a first address of the first tunnel for the terminal device according to the first indication information.

[0008] In a possible implementation, the receiving the first indication information includes: receiving a first access layer message from the terminal device, where the first access layer message includes the first indication information; or receiving the first indication information from a core network element.

[0009] In a possible implementation, the method may further include: 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 a first address of the first tunnel for the terminal device according to the second indication information.

[0010] In a possible implementation, the receiving the second indication information includes: receiving a second access layer message from the terminal device, where the second access layer message includes the second indication information; or receiving the second indication information from the core network.

[0011] In a possible implementation, the first information further includes attribute information of the first tunnel, and 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.

[0012] In a possible implementation, the sending the first information includes: sending the first information to the terminal device; or sending the first information to the core network.

[0013] In a possible implementation, the method further includes: determining the attribute information of the first tunnel according to fourth indication information from a core network element, where the fourth indication information is used to indicate configuring the first address of the first tunnel; or receiving the attribute information of the first tunnel from the core network.

[0014] In a possible implementation, 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: receiving second information from the second access network device, where the second information includes a second identifier of the first tunnel, or the second information includes a 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.

[0015] In a possible implementation, 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 stratum message to the terminal device, where the third access stratum message includes the second identifier, or the third access stratum 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 message includes the second identifier and the second address.

[0016] In a possible implementation, 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.

[0017] In a possible implementation, the method further includes: sending 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 a fourth identifier of the first tunnel and a fourth address, and the fourth identifier and the fourth address are associated with the terminal device.

[0018] In a possible implementation, 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.

[0019] In a possible implementation, the method further includes: receiving 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 of the first tunnel and a third address of the first tunnel, 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; sending the third identifier to the terminal device, or sending the third identifier and the third address to the terminal device.

[0020] 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.

[0021] In a 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 stratum message to the terminal device, where the fourth access stratum message includes the third identifier, or the fourth access stratum message includes the third identifier and the third address; or sending 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.

[0022] In a 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, where the third communication path is associated with the third access network device; or migrating the first tunnel from a first communication path to the third communication path, where the third communication path is associated with the third access network device.

[0023] In a possible implementation, the method further includes: sending 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 of the first tunnel and a fourth address, and the fourth identifier and the fourth address are associated with the terminal device.

[0024] In a possible implementation, the method further includes: sending the context of the first tunnel to the third access network device.

[0025] Second aspect, the present application provides a data transmission method, which can be applied to a terminal device. The method includes: receiving 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 a 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 first access network device according to the first address.

[0026] In a possible implementation manner, the method further includes: sending 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 supports multiplex communication based on the first transport layer network protocol.

[0027] In a possible implementation manner, the sending of the first indication information includes: sending a first access layer message to the first access network device, where the first access layer message includes the first indication information; or sending a first non-access layer message to the core network, where the first non-access layer message includes the first indication information.

[0028] In a possible implementation manner, the method further includes: sending second indication information, where the second indication information indicates to establish the first tunnel between the terminal device and the first access network device.

[0029] In a possible implementation manner, the sending of the second indication information includes: sending a second access layer message to the first access network device, where the second access layer message includes the second indication information; or sending a second non-access layer message to the core network, where the second non-access layer message includes the second indication information.

[0030] In a possible implementation manner, the first information further includes attribute information of the first tunnel; the establishing of the first tunnel with the first access network device according to the first address includes: establishing the first tunnel with the first access network device according to the first address and the attribute information of the first tunnel.

[0031] In a possible implementation manner, the method further includes: determining the attribute information of the first tunnel according to the first information; receiving the attribute information of the first tunnel from the first access network device, where the attribute information of the first tunnel is carried in a downlink access layer message; receiving the attribute information of the first tunnel from a core network element.

[0032] In a possible implementation manner, the receiving of the first information includes: receiving the first information from a first access network device, where the first information is configured by the first access network device.

[0033] In a possible implementation, 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: receiving second information of the first tunnel from the first access network device, where the second information includes a second identifier of the first tunnel, or the second information includes a 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.

[0034] In a possible implementation, the receiving 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, where the third access layer message includes the second information; or receiving first control information from the first access network device through the first tunnel, where the first control information includes the second information.

[0035] 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.

[0036] In a possible implementation, 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.

[0037] In a possible implementation, the first access network device is the source access network device of the terminal device. 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, 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.

[0038] In a possible implementation, the receiving the third identifier of the first tunnel, or receiving the third identifier and the third address of the first tunnel includes: receiving 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; receiving 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.

[0039] 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, where the downlink data packet includes the third identifier and the third address.

[0040] In a possible implementation, 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.

[0041] In a third aspect, the present application provides a data transmission method, which can be applied to an SMF network element. The method includes: determining that a first tunnel needs to be established between a terminal device and a first access network device, where the first tunnel uses 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 fourth indication information to the first access network device, where the fourth indication information indicates configuring a first address of the first tunnel.

[0042] In a possible implementation, the method further includes: receiving first information from the first access network device, where the first information indicates a first address of the first tunnel; sending the first information to the terminal device through the first access network device.

[0043] In a possible implementation, the method further includes: sending attribute information of the first tunnel to the first access network device; or sending the attribute information of the first tunnel to the terminal device through the first access network device.

[0044] In a possible implementation, 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; the determining that a first tunnel needs to be established between the terminal device and the first access network device includes: determining that a first tunnel needs to be established between the terminal device and the first access network device according to the first indication information.

[0045] In a possible implementation, the determining that a first tunnel needs to be established between the terminal device and the first access network device includes: determining that a first tunnel needs to be established between the terminal device and the first access network device according to policy information from a PCF network element or subscription information from a UDM network element.

[0046] Fourthly, this application provides a data transmission method, which can be applied to a second access network device. The method includes: sending a second identifier of a first tunnel, or sending the second identifier and a second address of the first tunnel. The first tunnel is used for data transmission between the terminal device and the second access network device using a first transport layer network protocol. The second identifier and the second address are associated with a 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 for transmitting data between the terminal device and a first access network device. The first identifier and a 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 for transmitting data between the terminal device and the second access network device; receiving an uplink data packet from the terminal device, where the uplink data packet includes the second identifier and the second address.

[0047] In a possible implementation, the 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.

[0048] In a possible implementation, the method further includes: receiving sixth indication information from the first 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. The fourth identifier and the fourth address are associated with the terminal device; based on the fourth identifier and the fourth address, sending a downlink data packet to the terminal device, where the downlink data packet includes the second identifier and the second address.

[0049] In a possible implementation, 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.

[0050] Fifthly, this application provides a data transmission method, which can be applied to a third access network device. The method includes: sending a third identifier of a first tunnel, or sending the third identifier and a third address of the first tunnel. The first tunnel is used for data transmission between the terminal device and the third access network device using a first transport layer network protocol. 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; receiving an uplink data packet from the terminal device, where the uplink data packet includes the third identifier and the third address.

[0051] In a possible implementation, the third identifier of the first tunnel, or sending the third identifier and the 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 the third address of the first tunnel to the first access network device.

[0052] In a possible implementation, the method further includes: receiving fifth indication information from a first 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.

[0053] In a possible implementation, the method further includes: configuring the third address for the terminal device according to the indication information from the first access network device, or configuring the third identifier and the third address for the terminal device according to the indication information from the first access network device.

[0054] 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, where the downlink data packet includes the third identifier, the third address, and the fourth identifier and the fourth address.

[0055] In a possible implementation, the method further includes: receiving the context of the first tunnel from the first access network device.

[0056] In a possible implementation, the method further includes: instructing the first access network device to delete the context of the first tunnel.

[0057] In a sixth aspect, the present application provides a communication device, including at least one processor and an interface circuit, where the interface circuit is configured to provide data or code instructions for the at least one processor, and the at least one processor is configured to implement the method described in the first aspect and any possible design of the first aspect, 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 logic circuits or by executing code instructions.

[0058] In a seventh aspect, an embodiment of the present application provides a communication system, including a communication device for implementing the method described in the first aspect and any possible design of the first aspect above, or including a communication device for implementing the method described in the second aspect and any possible design of the second aspect above, or including a communication device for implementing the method described in the third aspect and any possible design of the third aspect above, or a communication device for implementing the method described in the fourth aspect and any possible design of the fourth aspect above, or a communication device for implementing the method described in the fifth aspect and any possible design of the fifth aspect above.

[0059] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium. The computer-readable medium stores program code. When the program code runs on a computer, it causes the computer to execute the method described in the first aspect and any possible design of the first aspect above. Or, when the program code runs on a computer, it causes the computer to execute the method described in the second aspect and any possible design of the second aspect above. Or, when the program code runs on a computer, it causes the computer to execute the method described in the third aspect and any possible design of the third aspect above. Or, when the program code runs on a computer, it causes the computer to execute the method described in the fourth aspect and any possible design of the fourth aspect above. Or, when the program code runs on a computer, it causes the computer to execute the method described in the fifth aspect and any possible design of the fifth aspect above.

[0060] In a ninth aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a computer, it causes the computer to execute the method described in the first aspect and any possible design of the first aspect above, or execute the method described in the second aspect and any possible design of the second aspect above, or execute the method described in the third aspect and any possible design of the third aspect above, or execute the method described in the fourth aspect and any possible design of the fourth aspect above, or execute the method described in the fifth aspect and any possible design of the fifth aspect above.

[0061] Based on the implementations provided in the above aspects of the present application embodiment, further combinations can be made to provide more implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1(a) - Figure 1(b) Shows a schematic diagram of a communication system applicable to an embodiment of the present application;

[0063] Figure 2 Shows a schematic diagram of the architecture of a protocol stack;

[0064] Figure 3 Shows a schematic diagram of the encapsulation mode of a QUIC data packet;

[0065] Figure 4 Schematic diagram showing the frame of a QUIC data packet;

[0066] Figure 5A Schematic diagram showing an address change;

[0067] Figure 5B Schematic diagram showing a terminal connecting to a server based on multiple access technologies;

[0068] Figure 5C Schematic diagram showing a DC scenario;

[0069] Figure 6 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0070] Figure 7 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0071] Figure 8 Schematic diagram showing multipath characteristics;

[0072] Figure 9 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0073] Figure 10 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0074] Figure 11 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0075] Figure 12 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0076] Figure 13 Schematic diagram showing the buffer state;

[0077] Figure 14 Schematic flow diagram showing the data transmission method according to an embodiment of the present application;

[0078] Figure 15 Schematic diagram showing the structure of a communication device;

[0079] Figure 16 Schematic diagram showing the structure of another communication device. Detailed implementation manners

[0080] To address the challenges of wireless broadband technology and maintain the leading edge of the 3rd generation partnership project (3GPP) network, the 3GPP standards group has developed the architecture of the Next Generation System for the next-generation mobile communication network, known as the 5G network architecture. This architecture not only supports the access of radio access technologies defined by the 3GPP standards group (such as long term evolution (LTE) access technology, 5G radio access network (RAN) access technology, etc.) to the 5G core network (CN), but also supports the access to the core network using non-3GPP access technologies through the non-3GPP interworking function (N3IWF) or the next generation packet data gateway (ngPDG).

[0081] Figure 1(a) is a schematic diagram of the 5G network architecture based on the service-based architecture. The 5G network architecture shown in Figure 1(a) may include access network devices and core network devices. The terminal device accesses the data network (DN) through the access network devices and core network devices. Among them, the core network devices include, but are 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 repository function (NRF) network element (not shown in the figure), network exposure function (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).

[0082] The terminal device can be a user equipment (UE), a mobile station, a mobile terminal device, etc. The terminal device can be widely applied to 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 city, etc. The terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, an urban air vehicle (such as an unmanned aircraft, a helicopter, etc.), a ship, a robot, a robotic arm, a smart home device, etc.

[0083] The access network device can be a radio access network (RAN) device or a wireline access network (FAN) device. Among them, the RAN device includes 3GPP access network devices, non-trusted non-3GPP access network devices, and trusted non-3GPP access network devices. The 3GPP access network devices include, but are not limited to: evolved NodeB (eNodeB) in LTE, next generation NodeB (gNB) in the 5G mobile communication system, base stations in future mobile communication systems, or modules or units that complete part of the base station functions, such as a central unit (CU), a distributed unit (DU), etc. The non-trusted non-3GPP access network devices include, but are not limited to: non-trusted non-3GPP access gateways or N3IWF devices, non-trusted wireless local area network (WLAN) access points (APs), switches, routers. The trusted non-3GPP access network devices include, but are not limited to: trusted non-3GPP access gateways, trusted WLAN APs, switches, routers. The wireline access network devices include, but are not limited to: wireline access gateways, fixed telephone network devices, switches, routers.

[0084] The access network device and the terminal device can be in a fixed position or movable. The access network device and the terminal device can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on airplanes, balloons, and artificial satellites in the air. The embodiments of this application do not limit the application scenarios of the access network device and the terminal device.

[0085] The AMF network element is responsible for the mobility management of the UE, including mobility state management, allocating a temporary identity identifier for the UE, authenticating and authorizing the UE.

[0086] The SMF network element is responsible for the selection of the UPF network element, the reselection of the UPF network element, IP address allocation, the establishment, modification, and release of the bearer, and quality of service (QoS) control.

[0087] The UPF network element supports all or part of the following functions: interconnecting the protocol data unit (PDU) session with the data network; packet routing and forwarding (for example, supporting the forwarding of traffic to the data network after uplink classification); packet detection.

[0088] The UDM network element is responsible for managing the subscribed data and notifying the corresponding network elements when the subscribed data is modified.

[0089] The UDR network element stores and retrieves subscribed data, policy data, and common architecture data, etc.; it provides relevant data for the UDM network element, the PCF network element, and the NEF network element. The UDR network element should be able to have different data access authentication mechanisms for different types of data such as subscribed data and policy data to ensure the security of data access; the UDR network element should be able to return a failure response with an appropriate cause value for illegal service-oriented operations or data access requests.

[0090] The NEF network element is used to support the opening of capabilities and events.

[0091] The AF network element transmits the requirements of the application side to the network side, for example, QoS requirements or user status event subscriptions, etc. The AF can be a third-party functional entity or an application service deployed by the operator, such as the IP Multimedia Subsystem (IMS) voice call service. Among them, the AF network element includes the AF network element within the core network (i.e., the operator's AF network element) and the third-party AF network element (such as the application server of a certain enterprise).

[0092] The PCF network element includes functions for policy control such as charging, QoS bandwidth guarantee, mobility management, and terminal device policy decision-making at the session and service flow levels. The PCF network element includes an access and mobility management policy control function (AM PCF) network element and a session management PCF (SM PCF) network element. Among them, the AM PCF network element is used to formulate AM policies for terminal devices, and the AM PCF network element can also be called a policy control network element (PCF for a UE) that provides services for terminal devices. The SM PCF network element is used to formulate session management policies (SM policies) for sessions, and the SM PCF network element can also be called a policy control network element (PCF for a PDU session) that provides services for sessions.

[0093] The NRF network element can be used to provide a network element discovery function and provide network element information corresponding to the network element type based on requests from other network elements. The NRF also provides network element management services such as network element registration, update, deregistration, and network element status subscription and push.

[0094] The BSF network element can provide functions such as BSF service registration / deregistration / update, connection detection with the NRF, creation of session binding information, acquisition of UE information, and query of session binding information with duplicate IP addresses.

[0095] The AUSF network element is responsible for authenticating the UE to determine whether to allow the UE to access the network.

[0096] The DN is a network outside the operator's network. The operator's network can access multiple DNs. Multiple services can be deployed on the DN, which can provide services such as data and / or voice for terminal devices. For example, the DN is a private network of a smart factory. The sensors installed in the workshop of the smart factory can be terminal devices. A control server for the sensors is deployed in the DN, and the control server can provide services for the sensors. The sensors can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions. Another example is that the DN is the internal office network of a company. The mobile phones or computers of the company's employees can be terminal devices, and the mobile phones or computers of the employees can access information, data resources, etc. on the company's internal office network.

[0097] In Figure 1(a), Npcf, Nufr, Nudm, Naf, Namf, and Nsmf are service-oriented interfaces provided by the above 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 the meanings of these interface serial numbers are as follows:

[0098] 1) N1: The interface between AMF and terminal devices, which can be used to transmit non-access stratum (NAS) signaling (such as QoS rules from AMF) to terminal devices.

[0099] 2) N2: The interface between AMF and access network equipment, which can be used to transmit wireless bearer control information from the core network side to the access network equipment.

[0100] 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.

[0101] 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.

[0102] 5) N6: The interface between UPF and DN, used to transfer the uplink and downlink user data flows between UPF and DN.

[0103] Figure 1(b) is a schematic diagram of a 5G network architecture based on a point-to-point interface. The functions of the network elements therein can be referred to the functions of the corresponding network elements in Figure 1(a), and will not be repeated here. The main difference between Figure 1(b) and Figure 1(a) is that the interface between the control plane network elements in Figure 1(a) is a service-oriented interface, while the interface between the control plane network elements in Figure 1(b) is a point-to-point interface.

[0104] In the architecture shown in Figure 1(b), the interface names and functions between the network elements are as follows:

[0105] 1) For the meanings of the N1, N2, N3, N4 and N6 interfaces, please refer to the above description.

[0106] 2) N5: The interface between the AF network element and the PCF network element, which can be used to send application service requests and report network events.

[0107] 3) N7: The interface between PCF network element and SMF network element, which can be used to send PDU session granularity and service data flow granularity control strategy.

[0108] 4) N8: The interface between the AMF network element and the UDM network element can be used for the AMF network element to obtain subscription data and authentication data related to access and mobility management from the UDM network element, and for the AMF network element to register information related to the mobility management of the terminal device with the UDM network element, etc.

[0109] 5) N9: The user plane interface between UPF network elements is used to transfer uplink and downlink user data streams between UPF network elements.

[0110] 6) N10: The interface between the SMF network element and the UDM network element can be used for the SMF network element to obtain subscription data related to session management from the UDM network element, and for the SMF network element to register information related to the session of the terminal device with the UDM network element, etc.

[0111] 7) N11: The interface between the SMF network element and the AMF network element can be used to transfer PDU session tunnel information between the access network device and the UPF, transfer control messages sent to the terminal device, transfer radio resource control information sent to the access network device, etc.

[0112] 8) N15: The interface between the PCF network element and the AMF network element can be used to issue policies related to terminal device policies and access control.

[0113] 9) N35: The interface between the UDM network element and the UDR network element can be used for the UDM network element to obtain user subscription data information from the UDR network element.

[0114] 10) N36: The interface between the PCF network element and the UDR network element can be used for the PCF network element to obtain policy-related subscription data and information related to application data from the UDR network element.

[0115] It can be understood that the above network elements or functions can be either network components in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (such as a cloud platform). Optionally, the above network elements or functions can be implemented by one device, jointly implemented by multiple devices, or can also be a functional module within one device. The embodiments of the present application do not make specific limitations in this regard.

[0116] 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 network elements with the functions of the above AMF network element, SMF network element, UDM network element, and NRF network element in future communications such as 6G networks. This application does not limit this. In the embodiments of this application, an example 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 is described. Moreover, the AMF network element, SMF network element, UDM network element, and NRF network element are abbreviated as AMF, SMF, UDM, and NRF respectively.

[0117] For ease of explanation, specific examples of the base station and UE as the access network device and terminal device respectively are used in the embodiments of this application for illustration. The base station and UE that appear at any subsequent position can be replaced with the access network device and terminal device respectively.

[0118] To facilitate understanding of the content of this application, the relevant background involved in the embodiments of this application is introduced below.

[0119] I. Quick UDP Internet Connections (QUIC) protocol:

[0120] The QUIC protocol is a transport protocol equivalent to the Transmission Control Protocol (TCP). As Figure 2 shown in the protocol stack structure, the QUIC protocol is carried on the UDP protocol and absorbs the advantages of HTTP / 2 API, TLS, and TCP during the design process. Its goal is to optimize the overall latency and throughput and improve the performance during network handover.

[0121] The encapsulation mode of the QUIC data packet is as Figure 3 shown, including a header and a payload (or called load) part, following the principle of encrypting the payload and encrypting the header as much as possible, in order to avoid problems such as the parsing and interception of network traffic by network middleware and enhance the security of data transmission.

[0122] Among them, the header includes a UDP header and a common header, for example, including at least one public flag, connection ID (CID), QUIC version, sequence number, etc. The CID can be used to associate the same link data.

[0123] The payload part is the encrypted ciphertext, which can encapsulate the frame data of multiple streams. The frame can include type, stream identifier, offset value, data length, stream data, etc. For example Figure 4 As shown, taking the terminal device and the server as the sender and receiver of the QUIC data packet respectively as an example, for the QUIC connection between the terminal device and the server, the QUIC data packet 1, QUIC data packet 2, and QUIC data packet 3 can be associated based on CID1. In a certain frame of the QUIC data packet 1 (for example, represented as 2QUIC frame), the data of stream 1 and stream 2 can be encapsulated. In a certain frame of the QUIC data packet 2 (for example, represented as 3QUIC frame), the data of stream 1, stream 2, and stream 3 can be encapsulated. In a certain frame of the QUIC data packet 3 (for example, represented as 1QUIC frame), the data of stream 2 can be encapsulated.

[0124] It should be understood that Figure 3 - Figure 4 The above is only an example description of the QUIC data packet format rather than any limitation. The width of the rectangular box is only an example and does not represent the length of each content in the data packet. For example, in specific implementation, the QUIC data packet can be a long header data packet or a short header data packet. The long header data packet contains the source CID and destination CID fields. The destination CID is specified by the receiver and used to provide stable routing for the data packet. The source CID is set as the destination CID by the peer. These fields can be used to set the CID of the new connection. The short header data packet only contains the destination CID and omits the explicit length. The length of the destination CID field is considered to be known to the peer.

[0125] II. QUIC Tunnel and CID:

[0126] Each connection between the terminal device and the server, also called a QUIC tunnel (hereinafter, "tunnel" and "connection" can be used interchangeably), usually can have a group of CIDs, denoted as CIDs. Each CID can identify the QUIC tunnel.

[0127] Among them, the CID can be independently selected by the terminal device. Each terminal device selects a CID for the peer to use. The main function of the CID is to ensure that when the address of the underlying protocol (such as UDP protocol, IP protocol, or a lower-level protocol stack) changes, the data packets of a QUIC connection will not be transmitted to the wrong QUIC terminal device, and it can support connection migration without the application (APP) being aware of it. The terminal device can select the CID in a special implementation (and possibly special deployment) manner, which will enable the data packets with this CID to be routed back to the terminal device and be correctly recognized when received.

[0128] The terminal device can maintain a set of CIDs received from the peer, and each CID can be used to send QUIC packets. The terminal device can impose restrictions on the use of CIDs. For example, the same CID can 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.

[0129] The terminal device can change the CID it interacts with the peer to another available CID at any time during the QUIC connection with the server. When the peer performs connection migration, the CID published by the terminal device will be consumed, that is, the use of this CID will stop. When the terminal device wants to stop using a certain 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 at the same time requests the peer to replace it with a new CID through a new CID frame.

[0130] For example, taking long-header packets as an example, during the handshake, the QUIC packets with long headers are used to set the CIDs used by both ends. The source CID of each end will be used as the destination CID of the packets sent to that end. After processing the first initial packet, each end sets the value of the destination CID field of the subsequent sent packets to the value of the source CID field it received.

[0131] In the embodiments of this application, only the negotiation and use of the CIDs of the QUIC connection between the UE and the RAN are concerned, and the packet format is not concerned.

[0132] III. QUIC Path Migration and QUIC Multipath Features:

[0133] The destination CID sent by the terminal device can change during the lifetime of a QUIC connection, especially in response to connection migration. For a mobile communication network, the following two features of QUIC: QUIC path migration and QUIC multipath, among which the QUIC multipath feature is more significant for a mobile communication network.

[0134] (1) QUIC Path Migration: Applicable when the UE's location moves / or the UE's access changes, resulting in a change in the UE's IP address. For a TCP connection, after the communication quadruple (including source IP, source port, destination IP, destination port) changes, the TCP connection will be interrupted, causing the interruption of the application layer service and thus affecting the user experience. However, in the QUIC protocol, the concept of "connection" is used, and with the CID, as long as the CID remains unchanged, even if the network switches, the connection can be ensured not to be interrupted, that is, the connection between these communication endpoints will not be interrupted due to the change of the quadruple. Therefore, 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 Figure 5A shown, different quadruples can correspond to one connection, and any change in any element of the quadruple (such as the change of the source IP) will not affect the application layer service.

[0135] ① Initiating connection migration: The terminal can migrate the connection by sending a data packet containing a non-probe frame from the new local address.

[0136] ② Responding 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 acknowledges this migration, it must send subsequent data packets to the new peer address, and if it has not initiated yet, it must initiate path verification (see the explanation below) to verify the peer's ownership of that address. If the receiver does not have an unused CID from the peer, then it will not be able to send any data on the new path until the peer provides one.

[0137] Each terminal will verify the peer's address during the connection establishment. Therefore, the migrating terminal can send data to the peer on the premise of knowing that the peer is willing to receive data at its current address. Thus, the terminal does not need to verify the peer's address first to migrate to the new local address.

[0138] (2) QUIC Multipath: Applicable when the UE supports simultaneous access with multiple access technologies, or when the UE supports dual active protocol stack switching (dual active protocol stake, DAPS, also known as seamless handover without interruption) during the handover process, or when there can be multiple sessions. For example, in 5G session SSC mode 3, when the UE is switching, it can maintain two session connections simultaneously. At this time, there can be multiple paths from the UE to the application server (AS), such as Figure 5BAs shown, the intelligent terminal is connected to the server through two access technologies simultaneously, and there are two communication paths.

[0139] IV. Access Traffic Steering, Switching and Splitting (ATSSS) Rules:

[0140] The ATSSS rules specify the overall technical requirements for the access traffic steering, switching and splitting functions of the core network of the 5G mobile communication network, including the new technical function requirements of network elements such as PCF, AMF, SMF, UPF, NRF, etc. with respect to 5G network functions and interfaces.

[0141] Among them, the access traffic steering process is the process of guiding the flow. A new data flow selects an access network and transmits the traffic of the service flow on the specified access network. Access traffic steering is applicable between a Third Generation Partnership Project (3GPP) access and a non-3GPP (Non-3GPP) access.

[0142] The access traffic switching process is the process of switching the flow. In a way that maintains the continuity of the service flow, all the traffic of the ongoing service flow is switched from one access network to another access network. Access traffic switching is applicable between a 3GPP access and a non-3GPP access.

[0143] The access traffic splitting process is the process of splitting and dividing the flow. It is the process of separating the service data flow (flow splitting and dividing) between multiple access networks. When traffic splitting (flow splitting and dividing) is applied to a data flow, some traffic of the data flow is transmitted through one access, while other traffic of the same data flow is transmitted through another access. Access traffic splitting is applicable between a 3GPP access and a non-3GPP access.

[0144] In the embodiments of the present application, the terminal device can control the traffic steering of the service according to the ATSSS rules. For example, the terminal device determines that the data flow of the service is transmitted only through the 3GPP access technology, or only through the non-3GPP access technology, or transmitted through both the 3GPP access technology and the Non-3GPP access technology simultaneously, that is, traffic steering is performed through two access technologies.

[0145] V. Protocol Data Unit (PDU) Session:

[0146] One of the key tasks of 5GS session management is to provide a data connection to the DN for the terminal device. To establish a connection between the terminal device and the DN, a PDU session needs to be established. A PDU session is a logical connection between the terminal device and a specific DN, providing a user plane connection from the terminal device to the DN. Herein, "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 the IP-based PDU session type, the Ethernet PDU session type, and the 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 the unstructured PDU session, 5GS does not interpret the "PDU" it carries.

[0147] 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 the actual data, such as voice and video, etc. A terminal device can request to establish multiple PDU sessions simultaneously. These multiple PDU sessions can be connected to different DNs respectively. For example, when the UE needs an Internet connection and IMS services simultaneously, it can establish a PDU session from the terminal device to the Internet and a PDU session from the terminal device to the IMS simultaneously. Additionally, a terminal device can also request to establish multiple PDU sessions to a single DN simultaneously.

[0148] The specific procedures for session establishment or modification can refer to the relevant procedures in 4.3 of 3GPP standard protocol 23.502, which will not be elaborated 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, without constituting any limitation.

[0149] VI. Dual Connection (DC):

[0150] Dual connection means that the UE maintains connections with two access network devices simultaneously. The DC technology was initially developed to solve the coverage problem of users at the cell edge.

[0151] As Figure 5C shown, if the UE is at the edge of the signal coverage area of base station A (denoted as cell 1), if only relying on base station A to provide network access services for the UE, the signal strength may not be sufficient, which will affect the service implementation on the UE side. In this case, the network service operator can deploy base station B at the cell edge and configure base station A and base station B as DCs to enhance the coverage. The UE maintains connections with base station A and base station B simultaneously.

[0152] In the embodiments of the present application, only the DC 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 between the UE and the access network device, which does not constitute any limitation.

[0153] VII. Xn handover and NG handover:

[0154] NG handover refers to the handover performed in the 4G LTE network, where NG represents the next generation. NG handover is a handover method based on LTE technology and is usually used in the LTE network. NG handover can achieve seamless handover from one base station to another to provide better user experience and service quality.

[0155] Xn handover refers to the handover performed in the 5G network, where Xn represents the extended network. Xn handover is a handover method based on 5G technology and is used in the 5G network. Xn handover can achieve handover from one 5G base station to another or from 4G to 5G to support various different scenarios and application requirements.

[0156] In the embodiments of the present application, only the handover 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 between the UE and the access network device, which does not constitute any limitation.

[0157] Due to the complexity of the protocol stack between the UE and the access network device (such as the RAN), especially when transmitting traffic data such as QUIC packets, the multi-stream multiplexing at the application layer on one QUIC packet makes it impossible for the air interface to distinguish the data in multiple streams or datagrams in the transmitted QUIC packet.

[0158] The embodiments of the present application provide a data transmission method, apparatus and system for designing a QUIC protocol applicable between the UE and the access network device to better transmit traffic similar to QUIC. Among them, the method and the apparatus are based on the same technical concept. Since the principles of the method and the apparatus for solving problems are similar, the implementation of the apparatus and the method can be referred to each other, and the repeated parts will not be described again. Moreover, in each embodiment of the present application, if there is no special description and logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referred to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0159] It should be noted that in the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can represent: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0160] In addition, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish 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 indicating differences in the priority or importance of these two devices. For example, in some embodiments, the method steps executed by the first access network device and the second access network device can be interchanged. For example, in a handover scenario, the first access network device can be used as the source access network device of the UE, and the second access network device can be used as the target access network device of the UE. Conversely, the first access network device can be used as the target access network device of the UE, and the second access network device can be used as the source access network device of the UE.

[0161] Figure 6 The flowchart of the data transmission method according to the embodiments of the present application is shown. Among them, this method can be jointly implemented by a terminal device and a network-side device. In different embodiments, the specific implementation manner of the network-side device can be different. For example, in a PDU session scenario, the network-side device can include an SMF network element, etc. In a dual-connectivity (DC) scenario, the network-side device can include at least one access network device. In a mobile handover scenario, the network-side device can include a source access network device and a target access network device, etc.

[0162] Refer to Figure 6 As shown, the data transmission method may include the following steps:

[0163] S610 (optional step): The first access network device configures the first address of the first tunnel for the terminal device.

[0164] In an embodiment of the present application, the first tunnel may adopt a first transport layer network protocol and be used to transmit data between a terminal device and a first access network device. It can be understood that there is a protocol function layer based on the first transport layer network protocol between the terminal device and the first access network device, or it can be understood that the reference point protocol stack between the terminal device and the first access network device includes a first transport layer network protocol layer.

[0165] Exemplarily, the first transport layer network protocol may be the QUIC protocol introduced above, and the first tunnel is a QUIC tunnel, or is referred to as a QUIC connection. The first address includes the address of the first access network device for QUIC communication with the terminal device, for example, includes 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 with the functions described in the present invention, or other transport layer network protocols similar to the QUIC protocol. The first address may include the address information configured by the first access network device under the corresponding protocol, or may also be the address identifier for identifying the communication endpoint of the first transport layer network protocol or the address identifier of the lower layer protocol communication endpoint carrying the first transport layer network protocol, such as a tunnel identifier, a protocol layer identifier, a channel identifier, a logical channel identifier, etc. The embodiments of the present application do not limit this.

[0166] It should be noted that in an embodiment of the present application, "provision (or configure or allocate)" may be replaced by "generate and send", "allocate". For example, when the first access network device configures the first address for the terminal device, specifically, the first access network device may generate the first address for the terminal device and send the first address to the terminal device.

[0167] In specific implementation, the first access network device may be triggered to execute S610 in multiple ways to configure the first address of the first tunnel for the terminal device. Examples of triggering methods are introduced as follows:

[0168] (1) Method 1: The first access network device receives first indication information, and 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 executing S610, the first access network device may configure the first address of the first tunnel for the terminal device according to the first indication information.

[0169] In specific implementation, according to different interaction processes in different embodiments, the source of the first indication information may be the terminal device or a core network element.

[0170] For example, in Example 1 of Method 1, the terminal device may send a first access stratum message to the first access network device, and the first access stratum message includes first indication information. Correspondingly, the first access network device receives the first access stratum message from the terminal device and obtains the first indication information from the first access stratum message. The terminal device may send the first access stratum message to the first access network device after accessing the first access network device, during or after establishing a PDU session.

[0171] Among them, the first access stratum message may be any uplink radio resource control (RRC) message from the terminal device. For example, it is an additional 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 first indication information.

[0172] Or for example, the first access stratum message may be a reuse 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 of other information elements in the original uplink RRC message between the terminal device and the first access network device.

[0173] Or for example, in Example 2 of Method 1, the core network element may send the first indication information to the first access network device, and the first indication information may be included in a control message sent by the core network element to the first access network device. Correspondingly, 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 establishing a PDU session.

[0174] When implementing Example 2 of the first specific implementation manner, the control message may be an additional control message between the core network element and the first access network device. Or, the control message may also be a reuse of an existing control message between the core network element and the first access network device.

[0175] Exemplarily, for example, the core network element may be an SMF network element. The control message may be implemented as an additional control message from the SMF network element, and the additional 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. Or, the control message may be implemented as an Nx session message from the SMF network element for instructing to establish 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 an additional information element or container, or may also be a replacement of other information elements originally carried in the Nx session message.

[0176] Among them, the core network element can learn the tunneling capability of the terminal device when interacting with the terminal device, or the first access network device, or other core network elements.

[0177] For example, the terminal device carries first indication information in a first non-access stratum message sent to the core network element. For example, the terminal device carries first indication information in a (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. 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.

[0178] Or for example, the terminal device carries first indication information in a (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. 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 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.

[0179] (2) Method 2: The first access network device receives second indication information, and the second indication information indicates to establish a first tunnel between the terminal device and the first access network device. For example, the second indication information can be a request indicator, indicating a request or a need to establish a tunnel between the terminal device and the first access network device. For another example, it is requirement description information, indicating a stable delay requirement, thereby implicitly indicating to establish a first tunnel between the terminal device and the first access network device. When implementing S610, the first access network device can configure a first address of the first tunnel for the terminal device according to the second indication information.

[0180] Specifically, in implementation, according to different interaction processes in different implementation manners, the source of the second indication information can be the terminal device or the core network element.

[0181] For example, in Example 1 of Method 2, the terminal device may send a second access stratum message to the first access network device, and the second access stratum message includes second indication information. Correspondingly, the first access network device may receive the second access stratum message from the terminal device and obtain the second indication information from the second access stratum message. The terminal device may send the second access stratum message to the first access network device after accessing the first access network device, during or after establishing a PDU session.

[0182] Wherein, the second access stratum message may be any uplink RRC message from the terminal device. For example, it is 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 second indication information.

[0183] Or for example, the second access stratum message may be a reuse 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 of other information elements in the existing uplink RRC message between the terminal device and the first access network device.

[0184] Or for example, in Example 2 of Method 2, the core network element may send a control message to the first access network device, and the control message may include second indication information. Correspondingly, the first access network device receives the control message from the core network element and obtains the second indication information from the control message.

[0185] When implementing Example 2 of the specific implementation manner 2, 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 also be a reuse of the control message between the core network element and the first access network device.

[0186] Exemplarily, for example, the core network element may be an SMF network element, and the control message may be implemented as a newly added control message from the SMF network 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. Or, the control message may be implemented as an Nx session message from the SMF network element for instructing to establish a PDU session for the terminal device, and the second indication information may be carried in a reserved field of the Nx session message, or a newly added information element or container, or may also be a replacement of other information elements originally carried in the Nx session message.

[0187] Wherein, the core network element may learn about the tunnel capability of the terminal device when interacting with the terminal device, or the first access network device, or other core network elements.

[0188] For example, the terminal device carries second indication information in a second non-access stratum message sent to a core network element. For example, the terminal device carries second indication information in a (PDU) session message sent to the AMF network element through the N1 interface. The AMF network element may 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 may send the second indication information to the first access network device. When the SMF network element sends the second indication information to the first access network device, it may also be understood that the SMF network element may determine whether to establish a first tunnel between the terminal device and the first access network device, and then send the second indication information to the first access network device.

[0189] For example, the SMF network element may determine whether to establish a first tunnel between the terminal device and the first access network device. For example, the SMF network element may determine whether 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, and during the interaction with the terminal device, the first access network device, or other core network elements. If the SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device, the SMF network element may instruct the first access network device to configure the first address of the first tunnel for the terminal device.

[0190] Exemplarily, the SMF network element may receive first indication information from the terminal device. 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 multiplexed 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 according to the first indication information.

[0191] Alternatively, the SMF network element may also 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:

[0192] (1) The subscription information of the terminal device. Among them, the SMF network element may obtain the subscription information of the terminal device from the UDM network element. If the subscription information indicates that the terminal device requires stable latency, the subscription information indicates that a first tunnel is allowed to be established between the terminal device and the first access network device, and the SMF network element may determine that a first tunnel needs to be established between the terminal device and the first access network device.

[0193] (2) DNN / Slice information. The SMF network element can obtain the DNN / Slice information from the session request (such as a PDU session) from the terminal device. If the service corresponding to the DNN / Slice has a requirement for stable latency or a requirement for the first tunnel, the SMF network element can determine that it is necessary to establish a first tunnel between the terminal device and the first access network device.

[0194] (3) Policy information of the PCF network element. The SMF network element can obtain this policy information from the PCF network element. If the policy information indicates that the session of the terminal device (such as a PDU session) has a requirement for stable latency or a requirement for the first tunnel, the SMF network element can determine that it is necessary to establish a first tunnel between the terminal device and the first access network device.

[0195] (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.

[0196] It should be understood that the above are only examples of the information relied on by the SMF network element for making a decision on whether it is necessary to establish a first tunnel between the terminal device and the first access network device, rather than any 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 elaborated here.

[0197] In the embodiments of this 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 can send fourth indication information to the first access network device, and the fourth indication information can indicate the first address for configuring the first tunnel.

[0198] Among them, 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 this control message includes the fourth indication information. Similarly, this control message can be a newly added control message between the SMF network element and the first access network device, or a reuse of an existing message between the SMF network element and the first access network device. The fourth indication information can be carried in the reuse of the existing control message. For example, the fourth indication information can be carried in the reserved field of the existing control message, or the fourth indication information can be a replacement of other information elements in the existing control message. The first access network device can configure the first address for the terminal device according to the fourth indication information and feedback the first address to the SMF network element as an example of a response to the fourth indication information. For example, the first access network device can send first information to the SMF network element, and this first information indicates the address of the first tunnel.

[0199] In another example, the fourth indication information may be carried in, for example, an Nx session message sent by the SMF network element to the first access network device. The first access network device may configure a first address for the terminal device according to the fourth indication information and send the first information to the terminal device.

[0200] In an alternative implementation, the SMF network element may also send the attribute information of the first tunnel to the first access network device. Specifically, in implementation, the above-mentioned fourth indication information may also indicate the attribute information of the first tunnel. Or, 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 with different indication information. Or, the attribute information of the first tunnel and the fourth indication information may be carried in different control messages or Nx session messages. The embodiments of the present application do not limit the carrying manner of the fourth indication information and the attribute information of the first tunnel.

[0201] In another alternative implementation, the first transport layer network protocol may also stipulate the default attributes of the first tunnel. The SMF network element and / or the first access network device may determine the default attributes as the attributes of the first tunnel according to the protocol stipulation. Among them, if the SMF network element determines the attributes of the first tunnel, 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 first access network device determines the attributes of the first tunnel, 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 an answer example for the fourth indication information introduced above. Or, 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 elaborated here for the time being.

[0202] Alternatively, for example, the terminal device carries second indication information in a (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. The SMF network element obtains the second indication information from the (PDU) session message received from the AMF network element. The SMF network element may send the second indication information to the first access network device. For example, when 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, the first access network device, or other core network elements during the interaction with the terminal device, the first access network device, or other core network elements, the SMF network element sends the second indication information to the first access network device. For detailed implementation details, refer to the above introduction and will not be elaborated 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 does not parse the second indication information from the (PDU) session message received from the terminal device, but needs to be sent by the SMF network element.

[0203] It should be understood that the above first indication information and second indication information may be sent by the terminal device to the access network device in the same AS signaling, or may be sent by the core 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 may be the same message. Alternatively, the above first indication information and second indication information may be sent by the terminal device to the access network device in different AS signals at different times, or may be sent by the core network element to the access network device in different control messages at different times. The embodiments of the present application do not limit this.

[0204] Figure 6 The dashed arrows and dashed boxes in indicate optional steps / nodes. The process details under the above different triggering methods will be introduced below in combination with different embodiments and drawings and will not be elaborated here for the time being. When the source of the above first indication information or second indication information is the core network element, the first access network device may decide whether to send the first address of the first tunnel configured for the terminal device to the core network element according to the first transport layer network protocol and the received relevant indication information. For detailed details, refer to the detailed introduction in combination with different embodiments below and will not be elaborated here for the time being.

[0205] S620: The first access network device sends first information to the terminal device, and the first information indicates the first address of the first tunnel. Correspondingly, the terminal device may receive the first information.

[0206] Exemplarily, the first information may be carried in a downlink control message from a first access network device, such as a downlink RRC message. The following takes the RRC message as an example for illustration.

[0207] Among them, according to the different ways of triggering the configuration of the first address introduced when implementing S610, the downlink RRC message carrying the first information may be a response from the first access network device to the first access stratum message from the terminal device, or the downlink RRC message carrying the first information may be a corresponding control message sent by the first access network device to the terminal device according to relevant messages or relevant indication information from the core network element.

[0208] 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 introduced above, the SMF network element may send the second indication information to the first access network device, indicating that it is requested or necessary to establish a tunnel between the terminal device and the first access network device. The first access network device may configure the first address for the terminal device according to the second indication information, and feed back the first information as the response information for 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.

[0209] In other words, in the embodiments of the present application, the first access network device may directly send the first information to the terminal device, or indirectly send the first information to the terminal device. The embodiments of the present application do not limit this. Figure 6 The arrow corresponding to S620 in only indicates that the first access network device may send the first information to the terminal device, and does not limit the way 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 elements, which will not be elaborated here.

[0210] S630: The terminal device establishes a first tunnel with the first access network device according to the first address.

[0211] In the embodiments of the present application, S630 may be initiated by the terminal device or by the first access network device. The embodiments of the present application do not limit this.

[0212] Taking the terminal device initiating S630 as an example, S630 may include the following steps:

[0213] S631a: The terminal device sends an uplink initial data packet using the first transport layer network protocol to the first access network device according to 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 referred to as 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 this initial packet, the terminal device generates an unpredictable value S1 to fill the destination protocol address of the initial packet to be sent using the first transport layer network protocol, which can also be referred to as the destination connection identifier (DCID), and the terminal device sends the initial data packet to the first access network device.

[0214] 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 its source protocol address is the source protocol address S3 generated by the first access network device.

[0215] S633c: The terminal device receives the downlink initial data packet from the first access network device, and obtains its destination protocol address S3 from the downlink initial data packet. Subsequently, the terminal device uses this S3 as the destination protocol address to send a first transport layer network protocol data packet carrying upper layer protocol data to the first access network device. For the QUIC protocol, it is the data part of 1-RTT.

[0216] S634d: If the 1-RTT data sent by the terminal device is received, 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.

[0217] So far, the negotiation of the communication identifier and address based on the first tunnel between the terminal device and the first access network device is completed, and the establishment process of the first tunnel is completed.

[0218] In an alternative embodiment, the terminal device and the first access network device can also negotiate the CID using retry data packets. This process may include the following steps:

[0219] S631b: The terminal device sends an uplink initial data packet of the first transport layer network protocol to the first access network device according to the first address. The destination address of this initial data packet is set to the received first address, and the source protocol address of the first transport layer network protocol of this initial data packet is set to C1, where C1 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 the destination protocol address of the initial packet to be sent, and the terminal device sends this initial data packet to the first access network device.

[0220] S632b: The first access network device receives the initial data packet from the terminal device, parses out C1 from this 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 S2. The first access network device sends a downlink retry data packet to the terminal device. The destination protocol address (DCID) of this 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.

[0221] S633b: The terminal device receives the retry data packet and sends the initial data packet again. The destination protocol address (DCID) of this 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.

[0222] S634b: The first access network device receives the initial data packet from the terminal device, parses out C1 from this 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 this downlink initial data packet is the source protocol address C1 of the terminal, and its source protocol address is the source protocol address S3 generated by the first access network device.

[0223] S635b: The terminal device receives the downlink initial data packet from the first access network device and obtains its destination protocol address S3 from this downlink initial data packet. Subsequently, the terminal device uses S3 as the destination protocol address to send a first transport layer network protocol data packet carrying upper layer protocol data to the first access network device. For the QUIC protocol, it is the data part of 1-RTT.

[0224] S636b: If the 1-RTT data sent by the terminal device is received, 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.

[0225] So far, the negotiation of the communication identifier and address implemented based on the first tunnel between the terminal device and the first access network device is completed, and the establishment process of the first tunnel is completed.

[0226] In an alternative embodiment, the terminal device may also obtain the 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.

[0227] Among them, in one example, the first transport layer network protocol may stipulate 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 carrying 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, and this AS signaling is different from the AS signaling carrying the first information. The embodiments of the present application do not limit the implementation manner for the terminal device to obtain the attribute information of the first tunnel.

[0228] Similarly, if S630 is initiated by the first access network device, the first access network device may also obtain the attribute information of the first tunnel. Among them, the first transport layer network protocol may stipulate the default attributes of the first tunnel. The first access network device may determine that the default attributes are the attribute information of the first tunnel according to the received first indication information, or the first access network device may determine that the default attributes are the attribute information of the first tunnel according to the fourth indication information from the core network element, and this fourth indication information is used to indicate the configuration of the first address of the first tunnel. Alternatively, the attribute information of the first tunnel may also be configured by the core network element. The "configuration" here may be understood as being generated and sent by the core network. For example, the core 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 may be carried in the corresponding control message sent by the core network to the first access network device, and the first access network device may obtain the attribute information of the first tunnel from this control message. It should be understood that the core network element here may include the SMF network element or other core network elements. When interacting with different core network elements, the control messages received by the first access network device carrying the attribute information of the first tunnel may be different, and the embodiments of the present application do not limit this.

[0229] In an alternative embodiment, the data transmission solution of the embodiments of the present application can also be applied to the DC scenario. In the DC scenario, the first access network device can act as the master node (MN), and the second access network device can act as the secondary node (SN). The first transport layer network protocol can support multi-path characteristics. The first tunnel can include at least one communication path, such as the first communication path between the terminal device and the first access network device, and the second communication path between the terminal device and the second access network device. In order for the terminal device to simultaneously perform data transmission 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 perform information interaction with the terminal device or with the second access network device, so that the three parties mutually know part or all of the information of the second communication path of the first tunnel, facilitating the terminal device to communicate with the second access network device based on the information of the second communication path of the first tunnel.

[0230] For example, the information of the second communication path can include the second identifier and the second address of the first tunnel, and the second identifier and the second address are associated with the second access network device. The information of the second communication path can also include the fourth identifier and the fourth address of the first tunnel, and the fourth identifier and the fourth address are associated with the terminal device.

[0231] The first access network device can send an Xn signaling to the second access network device, instructing the second access network device to configure (or understood as allocate or generate) the second identifier and / or the second address of the first tunnel. Among them, the first access network device can send the 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 embodiments of the present application do not limit the triggering time of this Xn signaling.

[0232] In one example, the first access network device may allocate a second identifier for the first tunnel. The first access network device may carry the second identifier in the Xn signaling sent to the second access network device, indicating that the second access network device configures 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. 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 alternative embodiment, the Xn instruction from the first access network device further includes the tunnel identifier and address information of the terminal device, denoted as the fourth identifier and the 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 embodiments of the present application do not limit the timing for the first access network device to announce the fourth identifier and the fourth address to the second access device

[0233] 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 carry a second identifier when sending the second address. Specifically, for example, the second access network device may 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 second identifier in a response message to the Xn signaling sent by the first access network device. It should be noted 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. Among them, it may be a communication system-level design. For example, the MN initiates the path addition process, or 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 send the second address and the second identifier to the MN. If the SN initiates the addition of the second communication path, the SN does not need to additionally send the second address, or the second address and the second identifier to the MN. Instead, when the SN initiates the addition of the second communication path, it can synchronize the information of the second communication path to the MN. The information of the second communication path may include the second identifier and / or the second address, etc. In an alternative embodiment, it may also be dynamically specified in the communication system which node initiates the path addition. At this time, for example, the MN may decide which node initiates the path addition. If the MN chooses to initiate the path addition by itself, it can default that the message sent to the SN indicates 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 may indicate in the message sent to the SN that the SN initiates the subsequent path addition. Exemplarily, for example, this indication may be indicated by the fourth identifier and the fourth address of the terminal device, or there is an independent indication message 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 by itself according to 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.

[0234] In another example, the first access network device may send Xn signaling to the second access network device to instruct the second access network device to configure the second identifier and the second address of the first tunnel. Alternatively, it can be understood that the Xn signaling instructs the second access network device to configure the second identifier and 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. Optionally, the Xn instruction from the first access network device may further include the tunnel identifier and address information of the terminal device, denoted as the fourth address and the fourth identifier. 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 embodiments of the present application do not limit the timing for the first access network device to announce the fourth identifier and the fourth address to the second access device.

[0235] Optionally, the second access network device may send the second identifier and the second address to the first access network device. For example, the second access network device may send the second address and the second identifier in the 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 the second identifier to the first access network device may refer to the relevant descriptions in the foregoing embodiments. The implementation details of the second communication path addition process can be found in the following introduction and will not be elaborated here.

[0236] In another example, the first access network device may send Xn signaling to the second access network device to instruct the second access network device to configure the second identifier of the first tunnel. Alternatively, 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 further include the tunnel identifier and address information of the terminal device, denoted as the fourth identifier and the 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 embodiments of the present application do not limit the timing for the first access network device to announce the fourth identifier and the fourth address to the second access device. It should be understood that in this example, it may be the SN that defaults to initiate the process of adding the second communication path. The implementation details of the path addition process can be found in the following introduction 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, and the Xn signaling includes the fourth identifier and the fourth address of the terminal device. For example, the terminal device may carry the fourth identifier and the 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 the fourth address of the terminal device from the uplink AS signaling. Alternatively, the terminal device may carry the fourth identifier and the 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 the 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 the fourth address of the first tunnel, and the first access network device may obtain the fourth identifier and the fourth address from the uplink data packet. The fourth identifier and the fourth address are associated with the second communication path. It should be noted that the fourth address may also be associated with the first communication path, that is, it is understood that the first identifier and the fourth address are associated with the first communication path. Optionally, the Xn signaling may trigger the second access network device to add the second communication path. The implementation details of the second communication path addition process can be found in the following description and will not be elaborated here.

[0238] It should be understood that in the above description, "indicate" can also be equivalently understood as "request", and the embodiments of the present application do not specifically limit the meaning of the Xn signaling.

[0239] If the second access network device and the terminal device are to communicate based on the second communication path of the first tunnel, then before data transmission between the terminal device and the second access network device, it is also necessary to add the second communication path to the first tunnel. In the embodiments of the present application, the process of adding the second communication path to the first tunnel may be initiated by the first access network device, or by the second access network device, or by the terminal device.

[0240] The following is an example introduction to the interaction process involved when different initiators add the second communication path.

[0241] Taking the process of the first access network device initiating to add the second communication path to the first tunnel as an example, the first access network device may obtain the information of the second communication path in the previous interaction process with the terminal device and the second access network device, and initiate the process of adding the second communication path to the first tunnel.

[0242] The first access network device may receive second information of a first tunnel from the second access network device. The second information may include a second identifier of the first tunnel, or the second information may include a second address of the first tunnel, or the second information may include both the second identifier and the second address of the first tunnel. According to the solution introduced above, 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 both the second identifier and the second address, the second information from the second access network device may include both the second identifier and the second address.

[0243] When the first access network device initiates the process of adding a second communication path to the first tunnel, it may send the second identifier to the terminal device before adding the second communication path, or send both the second identifier and the second address to the terminal device. Specifically, in one example, the first access network device may send a third access stratum message to the terminal device. The third access network message may include the second identifier, or the third access network message may include both 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. 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 both 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. The downlink data packet includes the second identifier and the second address of the first tunnel.

[0244] Then the first access network device sends a downlink data packet to the terminal device. The downlink data packet includes the fourth identifier and the fourth address of the terminal device, the second identifier and the second address, and the downlink data packet is used to add the second communication path. After receiving the downlink data, the terminal device may send an uplink data packet to the second access network device. The uplink data packet includes the fourth identifier and the fourth address of the terminal device, the second identifier and the second address. When the terminal device sends the uplink data packet, it indicates that the terminal device accepts the second communication path. Then the second access network device may send subsequent downlink data packets to the terminal device to implement data transmission with the terminal device. At this time, the first access network device and the second access network device need to share information such as packet space, path identifier, packet sequence number, and congestion window 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. The information about the second communication path may include, for example, the packet number space, path identifier, packet sequence number, congestion window, etc. associated with the data packets transmitted between the terminal device and the second access network device. Among them, the first access network device may send Xn signaling to the second access network device, and the Xn signaling may include information about the second communication path.

[0245] In an alternative embodiment, the first access network device and the second access network device also need to share the context of the first tunnel, and the context of the first tunnel may include at least one of the following information: the configuration / attributes of QUIC, the security context;

[0246] The last packet number of the transceiver of the QUIC protocol in the uplink and downlink;

[0247] Stream / Connection flow control status: the offset of data consumed per stream;

[0248] The buffer status, as Figure 13 shown;

[0249] Multipath status: PID, PN, the packet numbers of the last packet sent and received on each communication path.

[0250] Taking the process of the second access network device initiating to add a second communication path to the first tunnel as an example, the second access network device may obtain the 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.

[0251] For example, the first access network device may send sixth indication information to the second access network device, and the sixth indication information may indicate the fourth identifier of the first tunnel, or the sixth indication information indicates the fourth identifier and the fourth address of the first tunnel. Among them, the sixth indication information may be carried in the Xn signaling from the first access network device. In other words, according to the previously introduced solution, the first access network device may trigger the process of adding a second communication path to the first tunnel when sending the information of the terminal device to the second access network device.

[0252] Optionally, before the second access network device initiates to add a second communication path to the first tunnel, in one implementation, it may directly send the second identifier to the terminal device, or directly send the second identifier and the 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 send the second identifier and the 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 the 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 the second address in the Xn signaling or the response message of the Xn signaling sent to the first access network device. The first access network device sends the second identifier, or sends the second identifier and the second address to the terminal device according to the received information.

[0253] Then, the second access network device can send a downlink data packet to the terminal device. The downlink data packet includes the fourth identifier and fourth address of the terminal device, and the second identifier and second address. The downlink data packet is used to add a 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 fourth identifier and fourth address of the terminal device, and the second identifier and second address. When the terminal device sends the uplink data packet, it indicates that the terminal device accepts the second communication path. Then, the second access network device can send subsequent downlink data packets to the terminal device to implement data transmission with the terminal device. At this time, the first access network device and the second access network device need to share information such as packet space, path identifier, packet sequence number, and congestion window 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. The information about the second communication path can include, for example, the packet number space, path identifier, packet sequence number, congestion window, etc. associated with the data packets transmitted between the terminal device and the second access network device. Among them, the second access network device can send Xn signaling to the first access network device, and the Xn signaling can include information about the second communication path.

[0254] In an alternative embodiment, 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 referred to the relevant introduction above and will not be elaborated here.

[0255] Taking the process of the terminal device initiating to add a second communication path in the first tunnel as an example, the terminal device can receive the second identifier and / or the second address from the first access network device or the second access network device. Among them, the terminal device can receive the second identifier in the AS signaling from the first access network device, or receive the second identifier and the second address. Or the terminal device can receive the second identifier in the control information on the first communication path of the first tunnel, or receive the second identifier and the second address. Or the terminal device can receive the second identifier and the second address in the AS signaling from the second access network device. The embodiments of the present application do not limit the manner in which the terminal device obtains the second identifier and / or the second address.

[0256] Furthermore, the terminal device can initiate the process of adding a second communication path by sending an uplink data packet to the second access network device. Among them, the uplink data packet can include the second identifier and the second address. Or, the uplink data packet can also include the fourth identifier and the fourth address, and the fourth identifier and the fourth address are associated with the terminal device.

[0257] After the second communication path is successfully added, data can be transmitted between the terminal device and the second access network device based on this second communication path. For example, the terminal device can send an uplink data packet to the second access network device. The uplink data packet can include a destination identifier and a destination address, such as a second identifier and a second address. Or the uplink data packet can also include a source identifier and a source address, such as a fourth identifier and a fourth address. Or, the second access network device can send a downlink data packet to the terminal device. The downlink data packet can include a source identifier and a source address, such as a second identifier and a second address. Or the downlink data packet can also include a destination identifier and a destination address, such as a fourth identifier and a fourth address.

[0258] At this time, the terminal device needs to share information such as the packet space, path identifier, packet sequence number, congestion window, etc. 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 the information of the second communication path to the first access network device. The information of the second communication path can include, for example, the packet number space, path identifier, packet sequence number, congestion window, etc. associated with the data packets transmitted between the terminal device and the second access network device. Or, for example, the terminal device can send the information of the second communication path to the second access network device. The information of the second communication path can include, for example, the packet number space, path identifier, packet sequence number, congestion window, etc. associated with the data packets transmitted between the terminal device and the second access network device. Among them, the terminal device can send an AS signaling to the first access network device or the second access network device, and the AS signaling can include the information of the second communication path. In an optional implementation manner, 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 refer to the relevant introduction above and will not be elaborated here.

[0259] It should be understood that due to the multi-path characteristic, in the above DC scenario, either 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 for data transmission between the terminal device and different access network devices.

[0260] In another optional implementation manner, the data transmission solution of the embodiments of the present application can also be applied to a handover scenario. In the handover scenario, the first access network device can be used as the source access network device, and the third access network device can be used as the target access network device. When the terminal device needs to hand over 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-path communication based on the first transport layer network protocol, the first access network device also needs to perform information interaction with the terminal device or with the third access network device to mutually know how to migrate the first tunnel based on the first transport layer network protocol.

[0261] 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, during the tunnel migration in the handover 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, in one implementation, the first access network device can choose to first add the third communication path to the first tunnel and transmit the same data on the first communication path and the third communication path simultaneously for a period of time, and then abolish the first communication path to implement 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 embodiments, and the implementation details of deleting the first communication path can refer to the description of deleting the first communication path during tunnel migration below, which will not be elaborated here for the time being.

[0262] In another implementation based on DAPS, the first access network device can decide to adopt the tunnel migration method, that is, the tunnel migration solution introduced in the following embodiments. If the first access network device and the third access network device both support the DC scenario introduced above, during the tunnel migration in the handover 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 associating the fifth identifier and the fifth address of the first tunnel with the fourth access network device, where 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 previous text, and reference can be made to the relevant introduction in the previous text, which will not be elaborated here. It can be understood that in the embodiments 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 the third communication path to the first tunnel, and the third communication path is associated with the third access network device; or migrates 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.

[0263] The first access network device can send an Xn signaling to the third access network device to instruct the third access network device to configure (or understood as allocate or generate) the third identifier and / or the third address of the first tunnel. Among them, the first access network device can send the Xn signaling to the third access network device when determining that it needs to handover to the third access network device. The embodiments of the present application do not limit the triggering timing of this Xn signaling.

[0264] In one example, the first access network device may allocate a third identifier, and the first access network device may carry the third identifier in the Xn signaling sent to the third access network device, indicating that the third access network device configures a 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 a 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 alternative embodiment, the Xn instruction from the first access network device further includes a fourth identifier and a fourth address of the terminal device. Alternatively, the first access network device may 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 embodiments of the present application do not limit the timing for the first access network device to disclose the fourth identifier and the fourth address to the third access device. Exemplarily, the above Xn signaling may be implemented as a handover request from the first access network device.

[0265] 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 to the Xn signaling sent by the first access network device, or send the third address and the third identifier in a response message to the Xn signaling sent by the first access network device. It should be noted that in the embodiments of this 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. For example, the first access network device initiates tunnel migration, or the third access network device initiates tunnel migration, or the terminal device initiates 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 send the third address and the third identifier to the source access network device. If the target access network device initiates tunnel migration, the target access network device does not need to additionally send the third address, or the third address and the third identifier to the source access network device. Instead, when the target access network device initiates this process, it 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 alternative embodiment, it may also be dynamically specified in the communication system which node initiates the tunnel migration. At this time, 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, it can default that the message sent to the target access network device indicates 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 initiate the tunnel migration by the target access network device, the source access network device can indicate in the message sent to the target access network device that the target access network device initiates the subsequent tunnel migration. Exemplarily, for example, this indication may be indicated by the fourth identifier and the fourth address of the terminal device, or there is an independent indication message for requesting the SN to initiate path addition. At this time, the target access network device does not return the third identifier and / or the third address to the source access network device, but initiates the tunnel migration by itself according to the received information. The implementation details of the tunnel migration process (i.e., updating the packet identifier and address) can be referred to the following description and will not be elaborated here.

[0266] In another example, the first access network device may send Xn signaling to the third access network device to instruct the third access network device to configure the third identifier and the third address of the first tunnel. Alternatively, it can be understood that the Xn signaling instructs the third access network device to configure the third identifier and the third address of the first tunnel for the terminal device. The third identifier and the third address are associated with the third access network device. Optionally, the Xn instruction from the first access network device may further include the fourth address and the fourth identifier of the terminal device. Alternatively, the first access network device may 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 embodiments of the present application do not limit the timing for the first access network device to announce the fourth identifier and the fourth address to the third access device.

[0267] Optionally, the third access network device may send the third identifier and the third address to the first access network device. For example, the third access network device may 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 this 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 this process, the target access network device does not need to additionally send the third address and the third identifier to the source access network device. Instead, when the target access network device initiates this process, it can send 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 the third address, etc. The implementation details of the path migration process can be seen in the following introduction and will not be elaborated here.

[0268] In another example, the first access network device may send Xn signaling to the third access network device to instruct the third access network device to configure the third identifier of the first tunnel. Alternatively, 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 further include the fourth identifier and the fourth address of the terminal device. Alternatively, the first access network device may 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 embodiments of the present application do not limit the timing for the first access network device to announce the fourth identifier and the fourth address to the third access device. It should be understood that in this example, it may be default that the target access network device initiates the path process. The implementation details of the path migration process can be seen in the following introduction and will not be elaborated here.

[0269] In another example, the first access network device may send Xn signaling to the third access network device, and the Xn signaling includes a fourth identifier and a fourth address of the terminal device. For example, the terminal device may carry the fourth identifier and the 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 the fourth address of the terminal device from the uplink AS signaling. Alternatively, the terminal device may carry the fourth identifier and the 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 the 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 the fourth address of the first tunnel, and the first access network device may obtain the fourth identifier and the fourth address from the uplink data packet. The fourth identifier and the fourth address are associated with the second communication path. It should be noted that the fourth address may also be associated with the first communication path, that is, it is understood that the first identifier and the fourth address are associated with the first communication path.

[0270] It should be understood that in the above description, "indicate" may also be equivalently understood as "request", and the embodiments of the present application do not specifically limit the meaning of the Xn signaling.

[0271] In the embodiments of the present application, any one of the terminal device, the first access network device, or the third access network device may be the initiator to trigger the path migration process of the first tunnel.

[0272] The following is an example introduction to the interaction process involved when there are different initiators.

[0273] Taking the process of the first access network device initiating the path migration of the first tunnel as an example, when the first access network device determines that the terminal device needs to hand over (HO) to the third access network device, it may receive the third information of the first tunnel from the third access network device. The third information may include the third identifier of the first tunnel, or the first tunnel may include the third address of the first tunnel, or the first tunnel may include the third identifier and the third address of the first tunnel. According to the scheme introduced 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 may 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 may include the third identifier and the third address.

[0274] When the first access network device initiates the path migration process, it may send the third identifier to the terminal device, or send the third identifier and the third address. Specifically, in one example, the first access network device may send a fourth access stratum 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 a handover command, for example. In another example, the first access network device may send the second control information to the terminal device through the first tunnel. 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.

[0275] The first access network device may also send the context of the first tunnel to the third access network device. Exemplarily, taking the QUIC protocol as an example, the context of the first tunnel may include the following content:

[0276] QUIC configuration / attributes, security context;

[0277] The last packet number of the QUIC protocol for uplink and downlink transmissions and receptions;

[0278] Stream / Connection flow control status: offset of data consumed per stream;

[0279] Buffer status, as Figure 13 shown;

[0280] Multipath status: PID, PN, the packet numbers of the last packet sent and received on each communication path.

[0281] It should be understood that the above path migration process may be applicable to the handover process where there is a connection between access network devices, or may also be applicable to the handover process where there is no connection between access network devices and a handover needs to be performed via the core network. The first access network device may send the context of the first tunnel to the third access network device through a direct forwarding tunnel or an indirect forwarding tunnel between the first access network device and the third access network device.

[0282] Before the terminal device switches to the third access network device (for example, before the first access network device sends a handover command to the terminal device), a downlink data packet is sent to the terminal device, and the downlink data packet includes the fourth identifier and the fourth address of the terminal device, the third identifier and the third address.

[0283] 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 the fourth address of the terminal device, the third identifier and the third address, indicating that the terminal device accepts path migration.

[0284] It should be understood that the above examples are only illustrative examples of the interaction processes that may be involved in the process of the first access network device initiating the path migration of the first tunnel, rather than any limitations.

[0285] 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 the information associated with the terminal device, such as the fourth identifier and the fourth address of the terminal device, during the interaction process with the terminal device and the first access network device, and initiate the path migration process of the first tunnel.

[0286] For example, the first access network device may send the 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 the fourth address of the first tunnel. Among them, the fifth indication information may be carried in the Xn signaling from the first access network device. Exemplarily, the fifth indication information may be carried in the handover request sent by the first access network device.

[0287] Optionally, before the third access network device initiates path migration, it may send the third identifier to the terminal device through the first access network device, or send the third identifier and the third address to the terminal device through the first access network device. The first access network device may send the third identifier to the terminal device, or the first access network device may send the third identifier and the third address to the terminal device. Among them, in an optional implementation manner, the first access network device may send a fourth access stratum message to the terminal device. The fourth access stratum message includes the third identifier, or the fourth access stratum message includes the third identifier and the third address. Specifically, the fourth access stratum message may be a handover command. In another optional implementation manner, the first access network device may send 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 manner, the first access network device may send a downlink data packet to the terminal device. The downlink data packet may include the third identifier and the third address. Exemplarily, the third access network device may carry the third identifier in the handover request response message sent to the first access network device, or carry the third identifier and the third address in the handover request response message sent to the first access network device. The first access network device may carry the third identifier in the handover command sent to the terminal device, or carry the third identifier and the third address.

[0288] 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 referred to the foregoing introduction and will not be elaborated here.

[0289] 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. The downlink data packet includes the fourth identifier and fourth address of the terminal device, the third identifier and third address. The terminal device may also 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 the path migration.

[0290] Taking the path migration of the first tunnel initiated by the terminal device as an example, the terminal device may receive the third identifier and / or third address of the third access network device through the first access network device. Among them, the terminal device may obtain the third identifier and third address in the handover command from the first access network device. Or, the terminal device may obtain the third identifier in the AS signaling from the first access network device, or obtain the third identifier and third address in the AS signaling. Specifically, the AS signaling may be a handover command or a new AS signaling. Or, the terminal device may receive control information from the first access network device through the first tunnel. The control information may include the third identifier, or the control information may include the third identifier and third address. The embodiments of the present application do not limit the manner in which the terminal device obtains the third identifier and / or 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 referred to the foregoing introduction and will not be elaborated here.

[0292] After the terminal device switches to the third access network device, it may 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 the path migration.

[0293] It should be understood that the above process is only an example of the information interaction involved in the path migration process initiated by different initiators rather than any limitation. In other embodiments, there may be other interaction processes between the first access network device, the third access network device and the terminal device, which will not be elaborated here.

[0294] In an alternative implementation, if the terminal device only supports single-path communication with the access network device, the terminal device may freeze the uplink and downlink transmissions based on the first tunnel after receiving the handover command. After switching to the third access network device, the terminal device may restore the context of the first tunnel and restart the 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.

[0295] In another alternative implementation, if the terminal device, the first access network device, and the third access network device all support DAPS, it may also support the realization of zero-interruption tunnel migration. The first access network device may also indicate to the terminal device the data transmission rules on the first communication path (or referred to as the source path, old path, etc.) and the third communication path (or referred to as the target path, new path, etc.) of the first tunnel. The data transmission rules may include, for example, any one of the following transmission modes:

[0296] (1) Replication mode, that is, the same data is transmitted simultaneously on the first communication path and the third communication path.

[0297] (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 preferentially sent on the new path, and when uplink transmission cannot be performed on the new path, uplink data is sent on the old path.

[0298] (3) Proportional transmission mode, that is, the proportion 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 proportion.

[0299] (4) Transmission quality-based transmission mode, that is, the transmission quality 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 transmission quality.

[0300] Correspondingly, 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 rules and the corresponding transmission mode.

[0301] Any one of the terminal device, the first access network device, or the third access network device can decide whether it is necessary 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 itself.

[0302] For example, the third access network device can decide whether to delete the source path. For example, in the case of the replication mode, the third access network device can determine that the source path needs to be deleted when it is determined that the uplink data sent through the source path and the target path has 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 can determine 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 can determine that the source path needs to be deleted. In the case where it is determined that the source path needs to be deleted, in one implementation, the third access network device can send indication information to the terminal device, and this indication information instructs the terminal device to delete the first communication path between the terminal device 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 indication information to the first access network device, and this indication information instructs the first access network device to delete the first communication path between the first access network device 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.

[0303] Or, for example, the first access network device can decide whether to delete the source path. For example, the first access network device can determine that the source path needs to be deleted when there is no data to be transmitted on the source path. In the case where it is determined that the source path needs to be deleted, the first access network device sends indication information to the terminal device, and this indication information instructs the terminal device to delete the first communication path between the terminal device and the first access network device. At the same time, the first access network device deletes the context of the first communication path and sends indication information to the third access network device, and this indication information indicates that the context related to the source path has been deleted.

[0304] Or, for example, the terminal device can decide whether to delete the source path. For example, when the terminal device determines that it no longer needs the first communication path, it sends indication information to the third access network device, and this indication information 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. Or, when the terminal device determines that it no longer needs the first communication path, it sends indication information to the first access network device, and this indication information 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.

[0305] For ease of understanding, the implementation details of the data transmission method of the embodiments of the present application will be introduced below in combination with different embodiments.

[0306] Embodiment 1:

[0307] In the first embodiment, during the session establishment process between the terminal device and the core network, the SMF network element may request the first access network device to configure the first address of the first tunnel for the terminal device, and the SMF network element may send 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 a 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.

[0308] As Figure 7 shown, the data transmission method may include the following steps:

[0309] 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 for indicating the establishment of a session for the terminal device, such as establishing a PDU session. Alternatively, the session message may be a session modification message, such as a PDU session modification message. The embodiments of the present application do not limit this.

[0310] Correspondingly, the AMF network element may receive the session message and forward the session message to the SMF network element. The "forwarding" here may also be understood as "transparent transmission", that is, the AMF network element only performs format conversion on the session message and does not parse this message. For relevant explanations, reference can be made to the relevant introductions above and will not be elaborated here.

[0311] In the embodiments of the present application, the session message may be represented as a first non-access stratum message, and the session message may include first indication information. 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 multiplex communication based on the first transport layer network protocol. The terminal device may send the 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. Correspondingly, the SMF network element may receive the session message from the AMF network element and obtain the first indication information from the session message. The SMF network element may decide whether to support the establishment of a first tunnel using the first transport layer network protocol between the terminal device and the first access network device based on the first indication information, or decide whether to support multiplex communication between the terminal device and the first access network device based on the first transport layer network protocol based on the first indication information.

[0312] In an alternative embodiment, the session message may be represented as a second non-access stratum message, and the session message may include second indication information for indicating the establishment of a first tunnel 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 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.

[0313] It should be understood that in the embodiments of the present application, the first indication information and the second indication information may be carried in the same message or in different messages, and the embodiments of the present application do not limit this.

[0314] S702: Signing processing, policy processing, authentication / authorization processing, user plane function processing, etc. are implemented among the terminal device, the first access network device, and multiple network elements of the core network (such as including AMF network element, SMF network element, PCF network element, UDM network element, etc.). For detailed implementation details, reference may be made to the relevant standard documents of 3GPP, which will not be elaborated here.

[0315] S703: The SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device.

[0316] In the embodiments 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 according to the content in the session message received from the terminal device in S701. For example, when the second indication information is carried in the session message, the SMF network element may determine that a first tunnel needs to be established between the terminal device and the first access network device according to the second indication information. Or for example, when the first indication information is carried in the session message, 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 multiplexed 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.

[0317] Alternatively, in the implementation process of S702, the SMF network element can determine 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 elements. For example, in the implementation process of S702, the SMF network element can also receive other request information from the terminal device, such as DNN or Slice information, etc. The SMF network element can determine the need to establish a first tunnel between the terminal device and the first access network device in combination with DNN or Slice information, etc. Or for example, in the implementation process of S702, the SMF network element can also receive policy information from the PCF network element or subscription 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 according to the received policy information or subscription information.

[0318] S704: The SMF network element sends tunnel address configuration indication information to the first access network device. This 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 this 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.

[0319] In an alternative implementation, the tunnel address configuration indication information from the SMF network element can be represented as second indication information, and the second indication information indicates the establishment of the first tunnel between the terminal device and the first access network device. This second indication information can be carried in a control message from the SMF network element. This control message can be a newly added control plane message. The SMF network element can send this control message to the AMF network element through the N11 interface, and the AMF network element can send this control message to the first access network device through the N2 interface. It can be understood that the message carrying this second indication information can be a control message of the SMF network element.

[0320] In an alternative 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 default mode of the first tunnel according to the fourth indication information and the agreement of the first transport layer network protocol. This attribute information can include, for example, any one of the following transport modes: data packet mode, flow mode, or security mode. In another alternative implementation, the tunnel address configuration indication information from the SMF network element can also indicate the attribute information of the first tunnel. The first access network device can obtain the attribute information of the first tunnel from this tunnel address configuration indication information. This attribute information can include, for example, any one of the following transport modes: data packet mode, flow mode, or security mode.

[0321] In an alternative embodiment, the above tunnel address configuration indication information may further include the IP address of the terminal device, and the IP address of the terminal device can be used by the first access network device to initiate the process of establishing the first tunnel to the terminal device actively.

[0322] In another alternative embodiment, in the DC scenario, the communication system may further include a second access network device. The first access network device is the primary node of the terminal device, and the second access network device is the secondary node of the terminal device. The first access network device and the second access network device may also cooperate to execute the following S705a and / or S705b to configure the second identifier and the second address of the first tunnel for the terminal device, so as to extend the multi-path characteristic of the first tunnel in the DC scenario:

[0323] 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 the second address of the first tunnel for the terminal device. Correspondingly, the second access network device may configure the second address of the first tunnel for the terminal device according to the received Xn signaling, or configure the second identifier and the second address of the first tunnel for the terminal device. The number of the second identifiers may be one or more. The second address may include the IP address and port number provided by the second access network device for the first tunnel.

[0324] S705b (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 may include the second address. Or the Xn signaling response may include the second identifier and the second address. Correspondingly, the first access network device receives and saves 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, and in another embodiment, both S705a and S705b may be implemented simultaneously. For implementation details, please refer to the previous introduction and will not be elaborated here.

[0325] S706: The first access network device sends a response message for the tunnel address configuration indication information to the SMF network element through the AMF network element. Correspondingly, the SMF network element receives the response message from the first access network device.

[0326] The response message may include the first identifier and the first address of the first tunnel. In the 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.

[0327] 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 the first address of the first tunnel from the response message. In an optional DC scenario, obtain the first identifier, the first address, the second identifier, and the second address of the first tunnel.

[0328] S707: The SMF network element sends an Nx session message to the first access network device through the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0329] In the embodiments of the present application, the SMF network element can send a session message to the AMF network element through the N11 interface. The session message carries a cell sent to the terminal device, and the cell sent to the terminal device includes the first address of the first tunnel reported by the first access network device. In an optional implementation manner, the cell sent to the terminal device includes the attribute information of the first tunnel reported by the first access network device. In an optional DC scenario, the cell sent to the terminal device can include the first address and the second address of the first tunnel reported by the first access network device.

[0330] The AMF network element sends a session message to the first access network device through the N2 interface. The session message carries a cell sent to the terminal device, and the cell sent to the terminal device includes the first address of the first tunnel reported by the first access network device. In an optional implementation manner, the cell sent to the terminal device includes the attribute information of the first tunnel reported by the first access network device. In an optional DC scenario, the cell sent to the terminal device can include the first address and the second address of the first tunnel reported by the first access network device.

[0331] 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.

[0332] In the embodiments of the present application, the first information is carried in a downlink RRC message from the first access network device, and the first information can indicate the first address of the first tunnel. The response information for the first information can be carried in an uplink RRC message from the terminal device, and the response information for the first information can indicate that the first address of the first tunnel is received.

[0333] In an optional implementation manner, when implementing S708, the first access network device can also send the attribute information of the first tunnel to the terminal device. Wherein, the first information can include the attribute information of the first tunnel. Or the first information can be carried in the same downlink RRC message as the attribute information of the first tunnel, or can be carried in a different downlink RRC message.

[0334] 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 of the first tunnel and the second attribute, where the second attribute is associated with the second communication path between the terminal device and the second access network device.

[0335] The RRC message transmitted between the first access network device and the terminal device may be a newly added access stratum message, or it may also be a reuse of an existing access stratum 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 stratum message, or it may be a replacement of other information elements in the existing access stratum message. The embodiments of the present application do not make any limitations in this regard.

[0336] S709: The first access network device feeds back an Nx session response message to the SMF network element through the AMF network element. Correspondingly, the SMF network element receives the Nx session response message from the first access network device.

[0337] S710: The SMF network element performs the remaining steps of PDU session establishment with other core network elements. For detailed implementation details, reference can be made to the relevant standard documents of 3GPP, which will not be elaborated here.

[0338] S711: A first tunnel using the first transport layer network protocol is established between the terminal device and the first access network device.

[0339] In one implementation, it may be that the terminal device initiates S711 according to 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.

[0340] In another implementation, it may be that the first access network device initiates S711 according to the received information.

[0341] For the specific implementation details of S711, reference can be made to 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 elaborated here.

[0342] After that, the terminal device can perform data transmission with the first access network device based on the first tunnel.

[0343] In an optional DC scenario, it is also necessary to add a second communication path to the first tunnel so that the terminal device can perform data transmission with the second access network device based on the second communication path. In this case, the first access network device may also perform the following optional steps:

[0344] S712 (Optional step): 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 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 also be obtained in other previous interaction processes. This application embodiment does not make any limitations in this regard. That is, the execution timing of S712 is not limited.

[0345] Interactions are also required among the terminal device, the first access network device, and the second access network device to add a second communication path to the first tunnel. Among them, the process of adding the second communication path may be initiated by the first access network device, or may be initiated by the second access network device, or may also be initiated by the terminal device.

[0346] Exemplarily, if the process of adding the second communication path is initiated by the first access network device to the terminal device, the following optional steps may also be included after S711:

[0347] S713 (Optional step): The first access network device initiates a path addition operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0348] In one example, S713 may be implemented via AS signaling. For example, the first access network device may send a third access stratum message to the terminal device, and the second identifier is included in the third access stratum message, or the second identifier and the second address are included in the third access stratum message.

[0349] In another example, S713 may be implemented via the first tunnel. For example, the first access network device may send first control information to the terminal device via the first tunnel, and the second identifier may be included in the first control information, or the second identifier and the second address may be included in the first control information. Specifically, the first access network may send the first control information to the terminal device via the first communication path of the first tunnel.

[0350] Here, different from the multi-path feature of the general QUIC protocol, the two endpoints of the multi-path feature of the general QUIC protocol are the same entity (or node), and it is caused by the change of the address of the terminal device (for example, the IP address of the UE changes due to handover in the technologies of 3GPP and WIFI). In this case, it is caused by the data transmission between the terminal device and different access network devices. As Figure 8As shown in the figure, the terminal device can perform data transmission with different access network devices through different paths in the same QUIC tunnel. For example, data transmission is performed with the first access network device through the first communication path (e.g., denoted as path 1), the first identifier, and the first address in the same QUIC tunnel, and data transmission is performed with the second access network device through the second communication path (e.g., denoted as path 2), the second identifier, and the second address.

[0351] S714 (optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface. The Xn signaling includes information about the second communication path, such as the second identifier, packet number space, packet sequence number, etc.

[0352] Exemplarily, if the process of adding the second communication path is initiated by the second access network device to the terminal device, the following optional steps may further be included after S711:

[0353] S715 (optional step): The second access network device initiates a path addition operation to the terminal device.

[0354] Among them, S715 can be implemented through the first tunnel. For example, the second access network device can send the 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 further includes the fourth identifier and the fourth address of the first tunnel. The source path identifier of the third control information is the first identifier or the second identifier, and the target path identifier of the third control information is the fourth identifier.

[0355] S716 (optional step): The second access network device synchronizes the information of the second communication path, such as the second identifier, packet number space, packet sequence number, etc., to the first access network device.

[0356] Based on the above Embodiment 1, by designing the interaction between the terminal device, 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 communication paths of QUIC are 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.

[0357] Embodiment 2:

[0358] In the second embodiment, during the session establishment process between the terminal device and the core network, the SMF network element may instruct the first access network device to configure the first address of the first tunnel for the terminal device and inform the terminal device, so as to introduce a 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.

[0359] As Figure 9 shown, the data transmission method may include the following steps:

[0360] 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 establishing a PDU session. Correspondingly, the AMF network element may receive the session message and forward the session message to the SMF network element. For the detailed implementation details, refer to the introduction in combination with S701 above, which will not be elaborated here.

[0361] S902: Signing processing, policy processing, authentication / authorization processing, user plane function processing, etc. are implemented among the terminal device, the first access network device, and multiple network elements of the core network (such as including the AMF network element, the SMF network element, the PCF network element, the UDM network element, etc.). For the detailed implementation details, refer to the introduction in combination with S702 above, which will not be elaborated here.

[0362] S903: The SMF network element determines that it is necessary to establish a first tunnel between the terminal device and the first access network device. For the detailed implementation details, refer to the introduction in combination with S703 above, which will not be elaborated here.

[0363] S904: The SMF network element sends an Nx session message to the first access network device through the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0364] In the embodiment of the present application, the SMF network element may send an N11 session message to the AMF network element through the N11 interface. 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. 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.

[0365] In an alternative implementation, the tunnel address configuration indication information from the SMF network element may be represented as second indication information, and the second indication information indicates to establish the first tunnel between the terminal device and the first access network device. The second indication information may be carried in a fourth non-access stratum message from the SMF network element, and the fourth non-access stratum message may be a newly added control plane message. The SMF network element may send the fourth non-access stratum message to the AMF network element through the N11 interface, and the AMF network element may send the fourth non-access stratum message to the first access network device through the N2 interface.

[0366] 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.

[0367] In an alternative implementation, the tunnel address configuration indication information from the SMF network element may 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 may also determine the attribute information of the default mode as the first tunnel according to 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 transport modes: data packet mode, flow mode, or security mode.

[0368] In another alternative implementation, the tunnel address configuration indication information from the SMF network element may include the attribute information of the first tunnel. When implementing S905, the first access network device may also 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 transport modes: data packet mode, flow mode, or security mode.

[0369] In the DC scenario, the communication system may further include a second access network device. The first access network device is the primary node of the terminal device, and the second access network device is the secondary node of the terminal device. The first access network device and the second access network device may also cooperate to execute the following S906a and S906b to configure the second identifier and the second address of the first tunnel for the terminal device, so as to extend the multi-path characteristic of the first tunnel in the DC scenario. Among them, the detailed implementation details of S906a can be referred to the introduction in combination with S705a above, and the detailed implementation details of S906b can be referred to the introduction in combination with S705b above, which will not be elaborated here.

[0370] S907: The first access network device sends the first information to the terminal device. Correspondingly, the terminal device feeds back the response information for the first information to the first access network device. The detailed implementation details can be referred to the introduction in combination with S708 above, which will not be elaborated here.

[0371] 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.

[0372] S909: The SMF network element and other core network elements perform the remaining steps of PDU session establishment. For detailed implementation details, please refer to the relevant standard documents of 3GPP, which will not be elaborated here.

[0373] S910: A first tunnel using the first transport layer network protocol is established between the terminal device and the first access network device.

[0374] In one implementation, it can be that the terminal device initiates S910 according to the received information. In an optional DC scenario, the first access network device can also send a second identifier of the first tunnel to the terminal device.

[0375] In another implementation, it can be that the first access network device initiates S910 according to the received information.

[0376] For the specific implementation details of S910, please refer to 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 elaborated here.

[0377] After that, the terminal device can perform data transmission with the first access network device based on the first tunnel. In an optional DC scenario, the terminal device can perform data transmission with the first access network device or the second access network device respectively 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 performs data transmission 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 performs data transmission with the second access network device through the second communication path.

[0378] In an optional DC scenario, the first access network device can also perform the following optional steps:

[0379] S911 (optional step): The first access network device sends sixth indication information to the second access network device via the Xn interface. The sixth indication information can indicate the fourth identifier of the first tunnel, or the sixth indication information can 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 can be obtained by the first access network device in S910.

[0380] Interactions are also required among the terminal device, the first access network device, and the second access network device to add a second communication path in the first tunnel. Among them, 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.

[0381] 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:

[0382] S912 (optional step): The first access network device initiates a path addition operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0383] In one example, S912 can be implemented through AS signaling. For example, the first access network device can send a third access stratum message to the terminal device, and the second identifier is included in the third access stratum message, or both the second identifier and the second address are included in the third access stratum message.

[0384] In another example, S912 can be implemented through the first tunnel. For example, the first access network device can send the first control information to the terminal device through the first tunnel, and the second identifier can be included in the first control information, or both the second identifier and the second address can be included in the first control information.

[0385] Here, different from the multi-path feature of the general QUIC protocol, the two endpoints of the multi-path feature of the general QUIC protocol are the same entity (or node), and it is caused by the change of the UE's address (for example, the UE's IP address changes due to handover in the technologies of 3GPP and WIFI). In this case, it is caused by the data transmission between the terminal device and different access network devices. As Figure 8 shown, the UE performs data transmission with different access network devices through different paths in the same QUIC tunnel. For example, the UE performs data transmission with the first access network device through the first communication path (for example, denoted as path 1), the first identifier, and the first address in the same QUIC tunnel, and performs data transmission with the second access network device through the second communication path (for example, denoted as path 2), the second identifier, and the second address.

[0386] S913 (optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface. The Xn signaling includes information about the second communication path, such as the second identifier, the packet number space, the packet sequence number, etc.

[0387] 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 S910:

[0388] S914 (Optional step): The second access network device initiates a path addition operation to the terminal device.

[0389] Among them, S914 can be implemented through the first tunnel. For example, the second access network device can send third control information to the terminal device through the first tunnel. The third control information may include a second identifier, or the third control information may include a second identifier and a second address. Optionally, the third control information further includes a fourth identifier and a fourth address of the first tunnel. The source path identifier of the third control information is the first identifier or the second identifier, and the destination path identifier of the third control information is the fourth identifier.

[0390] S915 (Optional step): The second access network device synchronizes the information of the second communication path to the first access network device, such as the second identifier, packet number space, packet sequence number, etc.

[0391] Based on the above Embodiment 1, by designing the interaction between the terminal device, 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 communication paths of QUIC are 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.

[0392] Embodiment 3:

[0393] In this Embodiment 3, when the terminal device determines that it is necessary to establish a first tunnel with the first access network device according to 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 a 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.

[0394] As Figure 10 shown, the data transmission method may include the following steps:

[0395] 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 establishing a session for the terminal device, such as establishing a PDU session. Correspondingly, the AMF network element can receive the session message and forward the session message to the SMF network element. For the detailed implementation details, refer to the introduction in conjunction with S701 above, which will not be elaborated here.

[0396] S1002: Between the terminal device, the first access network device, and multiple network elements of the core network (such as including the AMF network element, SMF network element, PCF network element, UDM network element, etc.), subscription processing, policy processing, authentication / authorization processing, user plane function processing, etc. are implemented. For the detailed implementation details, refer to the introduction in combination with S702 above, which will not be elaborated here.

[0397] S1003: The SMF network element determines that a first tunnel needs to be established between the terminal device and the first access network device. For the detailed implementation details, refer to the introduction in combination with S703 above, which will not be elaborated here.

[0398] S1004: The SMF network element sends an Nx session message to the first access network device through the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0399] In the embodiment of this application, the SMF network element can send an N11 session message to the AMF network element through the N11 interface, and the N11 session message can 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 can 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.

[0400] In an optional implementation manner, the tunnel indication information from the SMF network element may include the attribute information of the first tunnel. The attribute information may include, for example, any one of the following transmission modes: data packet mode, flow mode, or security mode.

[0401] S1005: The first access network device sends tunnel indication information to the terminal device. Correspondingly, the terminal device receives the tunnel indication information from the first access network device.

[0402] 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 implementation manner, the tunnel indication information from the first access network device may include the attribute information of the first tunnel. The attribute information may include, for example, any one of the following transmission modes: data packet mode, flow mode, or security mode.

[0403] S1006: The first access network device sends an Nx session response message to the SMF network element through the AMF network element. Correspondingly, the SMF network element receives the Nx session response message from the first access network device.

[0404] S1007: The SMF network element and other core network elements execute the remaining steps of PDU session establishment. For the detailed implementation details, refer to the relevant standard documents of 3GPP, which will not be elaborated here.

[0405] 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.

[0406] The second indication information may be carried in a second access stratum message from the terminal device. The second access stratum 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 stratum message, or in replacement of other information elements in the original access stratum message.

[0407] 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 the attribute parameters of the first tunnel with the first access network device.

[0408] 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 the establishment of the first tunnel with the terminal device.

[0409] 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.

[0410] In a DC scenario, the communication system may further include a second access network device. The first access network device is the primary node of the terminal device, and the second access network device is the secondary node of the terminal device. The first access network device and the second access network device may also cooperate to perform the following S1010a and S1010b to configure a second identifier and a second address of the first tunnel for the terminal device, so as to expand the multi-path feature of the first tunnel in the DC scenario. Among them, for the detailed implementation details of S1010a, reference may be made to the introduction in conjunction with S705a above, and for the detailed implementation details of S1010b, reference may be made to the introduction in conjunction with S705b above, which will not be elaborated here.

[0411] S1011: Establish a first tunnel using a first transport layer network protocol between the terminal device and the first access network device.

[0412] In one implementation, it may be that the terminal device initiates S1011 according to the received information. In an optional DC scenario, the first access network device may further send a second identifier of the first tunnel to the terminal device.

[0413] In another implementation, it may be that the first access network device initiates S910 according to the received information.

[0414] For the specific implementation details of S1011, refer to 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 elaborated here.

[0415] After that, the terminal device can perform data transmission with the first access network device based on the first tunnel. In an optional DC scenario, the terminal device can perform data transmission with the first access network device or the second access network device respectively 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 performs data transmission 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 performs data transmission with the second access network device through the second communication path.

[0416] In an optional DC scenario, the first access network device can also perform the following optional steps:

[0417] S1012 (optional step): The first access network device sends sixth indication information to the second access network device through the Xn interface. The sixth indication information can indicate the fourth identifier of the first tunnel, or the sixth indication information can 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 and can be obtained by the first access network device in S1011.

[0418] Interactions are also required among the terminal device, the first access network device, and the second access network device to add a second communication path to the first tunnel. Among them, the process of adding the second communication path can be initiated by the first access network device, or by the second access network device, or by the terminal device.

[0419] If the process of adding the second communication path is initiated by the first access network device to the terminal device, the following optional steps can also be included after S1011:

[0420] S1013 (optional step): The first access network device initiates a path addition operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0421] In an example, S1013 can be implemented through AS signaling. For example, the first access network device can send a third access layer message to the terminal device, and the third access layer message includes the second identifier, or the third access layer message includes the second identifier and the second address.

[0422] In another example, S1013 can be implemented through the first tunnel. For example, the first access network device can send the first control information to the terminal device through the first tunnel, and the first control information may include a second identifier, or the first control information may include a second identifier and a second address.

[0423] Here, different from the multi-path feature of the general QUIC protocol, the two endpoints of the multi-path feature of the general QUIC protocol are the same entity (or node), and it is caused by the change of the UE's address (for example, the UE's IP address changes due to handover in the technologies of 3GPP and WIFI). In this case, it is caused by the data transmission between the terminal device and different access network devices. As Figure 8 shown, the UE performs data transmission with different access network devices through different paths in the same QUIC tunnel. For example, the UE performs data transmission with the first access network device through the first communication path (for example, denoted as path 1), the first identifier, and the first address in the same QUIC tunnel, and performs data transmission with the second access network device through the second communication path (for example, denoted as path 2), the second identifier, and the second address.

[0424] S1014 (optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface. The Xn signaling includes information about the second communication path, such as the second identifier, the packet number space, the packet sequence number, etc.

[0425] If the process of adding the second communication path is initiated by the second access network device to the terminal device, the following optional steps may also be included after S1011:

[0426] S1015 (optional step): The second access network device initiates a path addition operation to the terminal device.

[0427] Among them, S1015 can be implemented through the first tunnel. For example, the second access network device can send the third control information to the terminal device through the first tunnel, and the third control information may include a second identifier, or the third control information may include a second identifier and a second address. Optionally, the third control information further includes a fourth identifier and a fourth address of the first tunnel. The source path identifier of the third control information is the first identifier or the second identifier, and the target path identifier of the third control information is the fourth identifier.

[0428] S1016 (optional step): The second access network device synchronizes the information of the second communication path, such as the second identifier, the packet number space, the packet sequence number, etc., to the first access network device.

[0429] Based on the above-mentioned First Embodiment, by designing the interaction between the terminal device, 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. Meanwhile, in an optional DC scenario, by designing the interaction between the second access network device and the first access network device or the terminal device, different communication paths of QUIC are 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.

[0430] Fourth Embodiment:

[0431] In this Fourth Embodiment, during the session establishment process between the terminal device and the core network, the first access network device configures the first address of the first tunnel for the terminal device according to the tunnel capability information reported by the terminal device, and notifies the SMF network element in the uplink message. The SMF network element notifies the terminal device in the downlink NAS message, so as to introduce a 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.

[0432] As Figure 11 shown, the data transmission method may include the following steps:

[0433] S1101: The terminal device sends an uplink RRC message or a session message to the first access network device. Correspondingly, the first access network device receives the RRC message or the session message from the terminal device and sends session-related content to the SMF network element.

[0434] In an example, the RRC message or the session message may include first indication information, and 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 multiplex communication based on the first transport layer network protocol. The first access network device may, according to the first indication information, configure the first address of the first tunnel for the terminal device when necessary. For example, if the first access network device also supports the first transport layer network protocol or supports multiplex 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.

[0435] The first access network device may carry the first indication information in the 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 multiplex communication based on the first transport layer network protocol. The N1 message may also carry the first address of the first tunnel.

[0436] The AMF network element sends a session establishment request message to the SMF network element. The session establishment request message may include first indication information and may also carry the first address of the first tunnel. In an optional implementation, the session establishment request message may further include attribute information of the first tunnel. The attribute information may, for example, include any one of the following transmission modes: data packet mode, stream mode, or security mode.

[0437] S1102: Between the terminal device, the first access network device, and multiple network elements of the core network (such as including the AMF network element, the SMF network element, the PCF network element, and the UDM network element, etc.), subscription processing, policy processing, authentication / authorization processing, user plane function processing, etc. are implemented. For detailed implementation details, refer to the introduction in conjunction with S702 above, which will not be elaborated here.

[0438] S1103: The SMF network element determines that it is necessary to establish a first tunnel between the terminal device and the first access network device. For detailed implementation details, refer to the introduction in conjunction with S703 above, which will not be elaborated here.

[0439] S1104: The SMF network element sends an Nx session message to the first access network device through the AMF network element. Correspondingly, the first access network device receives the Nx session message from the SMF network element.

[0440] In an example, the SMF network element sends a session message to the AMF network element through the N11 interface. The session message may include information to be sent to the terminal device, such as the first address of the first tunnel, attribute information, etc. The session message may further include information to be sent to the first access network device, such as indication information, for example, indicating authorization for the terminal device to establish a first tunnel with the first access network device.

[0441] The AMF network element sends indication information to the first access network device through the N1 interface, indicating authorization for the terminal device to establish a first tunnel with the first access network device.

[0442] S1105: The AMF network element sends information to be sent to the terminal device to the terminal device, such as first information, including the first address of the first tunnel. Or the first information may further include attribute information of the first tunnel. Or the AMF network element may also send attribute information of the first tunnel to be sent to the terminal device to the terminal device.

[0443] Among them, the AMF network element may send a session message to the first access network device through the N2 interface. The first access network device may send the first information and / or the second information to the terminal device through a downlink RRC message.

[0444] 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.

[0445] S1107: The SMF network element and other core network elements perform the remaining steps of PDU session establishment. For detailed implementation details, reference can be made to the relevant standard documents of 3GPP, which will not be elaborated here.

[0446] In the DC scenario, the communication system may further include a second access network device. The first access network device is the primary node of the terminal device, and the second access network device is the secondary node of the terminal device. The first access network device and the second access network device may also cooperate to perform the following S1108a and S1108b to configure the second identifier and the second address of the first tunnel for the terminal device, so as to expand the multi-path characteristics of the first tunnel in the DC scenario. Among them, for the detailed implementation details of S1108a, reference can be made to the introduction in combination with S705a above, and for the detailed implementation details of S1108b, reference can be made to the introduction in combination with S705b above, which will not be elaborated here.

[0447] S1109: A first tunnel using the first transport layer network protocol is established between the terminal device and the first access network device.

[0448] In one implementation, it may be that the terminal device initiates S1109 according to the received information. In the optional DC scenario, the first access network device may also send the second identifier of the first tunnel to the terminal device.

[0449] In another implementation, it may be that the first access network device initiates S1109 according to the received information.

[0450] For the specific implementation details of S1109, reference can be made to 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 elaborated here.

[0451] After that, the terminal device can perform data transmission with the first access network device based on the first tunnel. In the optional DC scenario, the terminal device can perform data transmission with the first access network device or the second access network device respectively 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 performs data transmission 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 performs data transmission with the second access network device through the second communication path.

[0452] In the optional DC scenario, the first access network device may also perform the following optional steps:

[0453] S1110 (Optional step): 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 the fourth address of the first tunnel. The fourth identifier and the fourth address are associated with the terminal device and may be obtained by the first access network device in S1109.

[0454] Interactions are also required among the terminal device, the first access network device, and the second access network device to add a second communication path to the first tunnel. Among them, the process of adding the second communication path may be initiated by the first access network device, or by the second access network device, or by the terminal device.

[0455] If the process of adding the second communication path is initiated by the first access network device to the terminal device, the following optional steps may also be included after S1109:

[0456] S1111 (Optional step): The first access network device initiates a path addition operation to the terminal device based on the second identifier and the second address of the first tunnel.

[0457] In one example, S1111 can be implemented via AS signaling. For example, the first access network device may send a third access stratum message to the terminal device, and the third access stratum message includes the second identifier, or the third access stratum message includes the second identifier and the second address.

[0458] In another example, S1111 can be implemented via the first tunnel. For example, the first access network device may send first control information to the terminal device via 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.

[0459] Here, different from the multi-path feature of the general QUIC protocol, the two endpoints of the multi-path feature of the general QUIC protocol are the same entity (or node), and it is caused by the change of the UE's address (for example, the UE's IP address changes due to handover in the technologies of 3GPP and WIFI). In this case, it is caused by the data transmission between the terminal device and different access network devices. As Figure 8 shown, the UE performs data transmission with different access network devices through different paths in the same QUIC tunnel. For example, the UE performs data transmission with the first access network device through the first communication path (for example, denoted as path 1), the first identifier, and the first address in the same QUIC tunnel, and performs data transmission with the second access network device through the second communication path (for example, denoted as path 2), the second identifier, and the second address.

[0460] S1112 (Optional step): The first access network device sends Xn signaling to the second access network device through the Xn interface. The Xn signaling includes information about the second communication path, such as a second identifier, a packet number space, a packet sequence number, etc.

[0461] If the second access network device initiates a process of adding a second communication path to the terminal device, the following optional steps may also be included after S1109:

[0462] S1113 (Optional step): The second access network device initiates a path addition operation to the terminal device.

[0463] Among them, S914 can be implemented through a first tunnel. For example, the second access network device can send third control information to the terminal device through the first tunnel. The third control information may include a second identifier, or the third control information may include a second identifier and a second address. Optionally, the third control information further includes a fourth identifier and a fourth address of the first tunnel. The source path identifier of the third control information is the first identifier or the second identifier, and the destination path identifier of the third control information is the fourth identifier.

[0464] S1114 (Optional step): The second access network device synchronizes information about the second communication path, such as a second identifier, a packet number space, a packet sequence number, etc., to the first access network device.

[0465] Based on the above Embodiment 1, by designing the interaction between the terminal device, 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 an optional DC scenario, by designing the interaction between the second access network device and the first access network device or the terminal device, different communication paths of QUIC are 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.

[0466] Embodiment 5:

[0467] Embodiment 5 can be a further supplement to the above Embodiments 1-4 to perform tunnel migration between the terminal device and different base stations in a scenario involving base station handover, 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.

[0468] As Figure 12 shown, the data transmission method may include the following steps:

[0469] S1201: The terminal device and the first access network device initiate a measurement process. The first access network device is the source access network device of the terminal device. For detailed implementation details, please refer to the relevant standard documents of 3GPP, which will not be elaborated here.

[0470] S1202: The first access network device determines, based on the measurement results, that the terminal device needs to be switched to the third access network device. The third access network device is the target access network device of the terminal.

[0471] 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.

[0472] The handover request may carry the parameters required in the mobile handover process. For detailed implementation details, please refer to the relevant standard documents of 3GPP, which will not be elaborated here.

[0473] When designing the QUIC protocol in the handover scenario of the embodiments of this application, the handover request may further include the context information of the first tunnel. The context information of the first tunnel may include, for example: the fourth identifier and the fourth address of the first tunnel, and the fourth identifier and the fourth address are associated with the terminal device. The context information of the first tunnel may further include, for example:

[0474] QUIC configuration / attributes, security context

[0475] The last packet number of the QUIC protocol for uplink and downlink transmission and reception;

[0476] Stream / Connection flow control status: per stream offset of data consumed;

[0477] Buffer status, such as Figure 13 shown;

[0478] Multipath status: PID, PN, and the packet numbers of the last packets sent and received on the given paths.

[0479] 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.

[0480] The above S1203 and S1204 are applicable to the handover scenario where there is a connection between the terminal device and the base station (such as the first access network device), and are also applicable to the handover scenario where there is no connection between the terminal device and the base station (such as the first access network device) and the handover needs to be performed through the core network.

[0481] S1205: The first access network device initiates a tunnel migration to the terminal device.

[0482] Among them, if S1206 is executed according to the existing QUIC protocol, the first access network device may send a data packet of a new non-probe frame based on the second address configured by the third access network device to migrate the context information of the first tunnel.

[0483] Or, if it is a 3GPP custom tunnel protocol, when executing S1206, the first access network device may initiate a path switch on the control plane, or a similar mechanism.

[0484] In an optional implementation manner, before S1205, the first access network device may also perform the following steps:

[0485] S1206: The first access network device sends a path detection process or a path verification process to the terminal device, that is, sends a data packet of a probe frame to the terminal device (using the endpoint address of the tunnel allocated by the target RAN), and after the verification is completed, initiates the tunnel migration process of S1205.

[0486] S1207: The first access network device sends a handover command to the terminal device.

[0487] In an optional implementation manner, the handover command may include the third identifier of the first tunnel. Or, the handover command may include the third address of the first tunnel.

[0488] In another optional implementation manner, the third identifier of the first tunnel may be carried in a downlink RRC message different from the handover command, such as S1209.

[0489] In another optional implementation manner, if the available fourth identifier provided by the terminal device has been included in S1203, S1208 may not be implemented. Conversely, the terminal device may also execute S1208 to publish the available identifier of the terminal device to the first access network device or the third access network device.

[0490] S1210: After receiving the handover command, the terminal device freezes the uplink transmission based on the first tunnel.

[0491] S1211: The terminal device accesses the third access network device.

[0492] S1212: Restore the context of the first tunnel and restart the uplink transmission based on the first tunnel, and use the third identifier and the third address of the first tunnel to perform data transmission with the third access network device.

[0493] For example, the terminal device sends an uplink data packet to a third access network device, and the uplink data packet includes a third identifier and a third address. Optionally, the uplink data packet may further include a fourth identifier and a fourth address.

[0494] Or for example, the terminal device receives a downlink data packet from a third access network device, and the downlink data packet includes a third identifier and a third address. Optionally, the downlink data packet may further include a fourth identifier and a fourth address.

[0495] Embodiment 6:

[0496] Embodiment 6 may also be a further supplement to the above Embodiments 1-4 to perform tunnel migration between different base stations of the terminal device in a scenario where the terminal device, the source access network device, and the target access network device all support multi-path communication based on the QUIC protocol and are involved in base station handover and DAPS, so as to introduce a first tunnel using a 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.

[0497] As Figure 14 shown, the data transmission method may include the following steps:

[0498] S1401: The terminal device and the first access network device start a measurement process, and the first access network device is the source access network device of the terminal device. For detailed implementation details, reference can be made to the relevant standard documents of 3GPP, which will not be elaborated here.

[0499] S1402: The first access network device determines, according to the measurement result, that the terminal device needs to be switched to a third access network device, and the third access network device is the target access network device of the terminal.

[0500] 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.

[0501] The handover request may carry the parameters required in the mobile handover process. For detailed implementation details, reference can be made to the relevant standard documents of 3GPP, which will not be elaborated here.

[0502] When designing the QUIC protocol in the handover scenario of the embodiments of the present application, the handover request may further include the context information of the first tunnel. The context information of the first tunnel may include, for example: the fourth identifier and the fourth address of the first tunnel, and the fourth identifier and the fourth address are associated with the terminal device. The context information of the first tunnel may further include, for example:

[0503] QUIC configuration / attributes, security context

[0504] The last packet number for transmission and reception in the uplink and downlink of the QUIC protocol;

[0505] Stream / Connection flow control status: offset of data consumed per stream;

[0506] Buffer status, such as Figure 13 as shown;

[0507] Multipath status: PID, PN, the packet numbers of the last packets sent and received on the given paths.

[0508] 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.

[0509] The above S1403 and S1404 can be applicable to the handover 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 handover scenario where there is no connection between the terminal device and the base station (such as the first access network device) and handover needs to be performed via the core network.

[0510] S1405: The first access network device initiates a tunnel context migration to the terminal device.

[0511] When the first access network device supports the DSPA capability, the first access network device obtains the DAPS capability of the terminal device or the third access network device.

[0512] For example, the terminal device sends the DAPS capability of the terminal device to the first access network device in the uplink RRC message, and the first access network device obtains the DAPS capability of the third access network device in the signaling interaction related to the execution of handover with the third access network device (such as sending a request message to the target RAN to inquire whether it supports DAPS, 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 the acquisition of the DAPS capability).

[0513] 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:

[0514] S1406: The first access network device initiates a path addition operation to the terminal device.

[0515] For example, the first access network device may send a 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 use the connection identifier CID(s) assigned by the third access network device as the source CID.

[0516] In an alternative implementation, the first access network device also indicates to the terminal device the rules for data transmission on the two paths, such as the replication mode (i.e., transmitting the same data on both paths), or new path priority (i.e., only data that cannot be sent on the new path is sent on the old path), or setting the ratio of data transmission on the two paths, or allocating according to the transmission quality on the two paths. Among them, the new path refers to the communication path between the terminal device and the third access network device using the target transport layer network protocol, and the old path refers to the communication path between the terminal device and the first access network device using the target transport layer network protocol.

[0517] Among them, in order to implement the path addition operation in the first tunnel, a group handover connection ID (CID) is required. Then, 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 timing and message mechanisms.

[0518] For example, the first access network device may carry the third identifier in the handover command sent to the terminal device. Or for example, the first access network device may carry the third identifier in the existing AS signaling sent by the terminal device other than the handover command. Or for example, the first access network device may carry the third identifier in the new AS signaling sent by the terminal device.

[0519] S1407: The first access network device sends a handover command to the terminal device.

[0520] S1410: After receiving the handover command, the terminal device connects to the third access network device and transmits data on one or both paths according to the indication of the data transmission mode on the two paths.

[0521] S1411: Taking the replication mode as an example, the terminal device duplicates the uplink data twice and performs uplink transmission on the two paths.

[0522] S1412: When the third access network device determines that the source path can be deleted (for example, the data on the two paths has been synchronized, or no context information has been received from the first access network device within a set time, or an end marker sent from the first access network device is received), the third access network device may send a path deletion message to the terminal device to delete the path between the terminal device and the first access network device.

[0523] In another implementation, the third access network device may 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 on its own that there is no data to be transmitted on this path, it sends a path deletion message to the terminal device to delete the source path and notifies the third access network device.

[0524] In another implementation, if the terminal device determines that the source path is no longer needed, the terminal device sends a path deletion message to the third access network device to delete the path between the terminal device and the first access network device. The third access network device sends a notification message to the first access network device indicating that the path has been deleted. The first access network device releases relevant resources such as the QUIC protocol stack context. Or send a path deletion to the first access network device. After deletion, notify the third access network device that the path has been deleted.

[0525] S1413: The terminal device transmits data to the third access network device only on the target path.

[0526] Note: During the handover process in Embodiment 5 and Embodiment 6, if the third access network device supports DC, it can refer to the descriptions in the previous Embodiments 1 to 4 and send the SN information to the terminal device during the handover process. Or it can also add the SN of DC again after the handover is completed and execute the steps related to the DC scenario in the foregoing embodiments, which will not be elaborated here.

[0527] The embodiments of the present application also provide a communication device for executing the methods performed 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 foregoing method embodiments. For related features, refer to the foregoing method embodiments and will not be elaborated here.

[0528] As Figure 15 shown, the communication device 1500 may include: a processing unit 1501 and a communication unit 1502.

[0529] When the communication device 1500 is used to execute the method performed by the first access network device, the communication unit 1502 is configured to send first information indicating a first address of a first tunnel. 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. The first address is associated with the first access network device; and establish the first tunnel with the terminal device according to the first address. For specific implementation manners, refer to the method steps implemented by the first access network device in the foregoing method embodiments and will not be elaborated here.

[0530] When the communication device 1500 is used to execute the method performed by the terminal device, the communication unit 1502 is configured to receive first information, where the first information indicates a first address of a first tunnel, the first tunnel uses 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; the processing unit 1501 is configured to establish the first tunnel with the first access network device according to the first information. For the specific implementation manner, please refer to the method steps implemented by the terminal device in the above method embodiment, which will not be elaborated here.

[0531] When the communication device 1500 is used to execute the method performed by the SMF network element, the communication unit 1502 is configured to receive first information, where the first information indicates a first address of a first tunnel, the first tunnel is used to transmit data 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; and establish the first tunnel with the first access network device according to the first address. For the specific implementation manner, please refer to the method steps implemented by the SMF network element in the above method embodiment, which will not be elaborated here.

[0532] When the communication device 1500 is used to execute the method performed by the second access network device, the communication unit 1502 is configured to send a second identifier of the first tunnel, or send the second identifier and a 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 a first transport layer network protocol, the second identifier and the second address are associated with a second communication path of the first tunnel, 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 a first access network device, a first identifier and a first address of the first tunnel 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; and receive an uplink data packet from the terminal device, where the uplink data packet includes the second identifier and the second address. For the specific implementation manner, please refer to the method steps implemented by the second access network device in the above method embodiment, which will not be elaborated here.

[0533] When the communication device 1500 is used to execute the method performed 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 of the first tunnel and the third address. The first tunnel is used for data transmission between the terminal device and the third access network device using the first transport layer network protocol. 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. The communication unit 1502 is further used to receive an uplink data packet from the terminal device, where the uplink data packet includes the third identifier and the third address. For the specific implementation, please refer to the method steps implemented by the third access network device in the above method embodiments, which will not be elaborated here.

[0534] It should be understood that the division of each unit in the above device is only a logical function division. In actual implementation, all or part of them can be integrated into a physical entity, or physically separated. In addition, the units in the device can be implemented in the form of a processor invoking software. For example, the device includes a processor, the processor is connected to a memory, and instructions are stored in the memory. The processor invokes the instructions stored in the memory to implement any of the above methods or the functions of each unit of the device. 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 inside or outside the device. Alternatively, the units in the device can be implemented in the form of a hardware circuit, and the functions of some or all of the units can be implemented through the design of the hardware circuit. 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), and the functions of some or all of the above units are implemented through the design of the logical relationship of the components in the circuit. Again, 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 through a configuration file to implement the functions of some or all of the above units. All units of the above device can be implemented entirely in the form of a processor invoking software, or entirely in the form of a hardware circuit, or part in the form of a processor invoking software and the remaining part in the form of a hardware circuit.

[0535] In an embodiment of the present application, a processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and running capabilities, such as a CPU, a microprocessor, a graphics processing unit (GPU) (which can be understood as a type of microprocessor), or a digital signal processor (DSP), etc.; in another implementation, the processor can implement certain functions through the logical relationship of a hardware circuit, and the logical relationship of this hardware circuit is fixed or can be reconfigured. For example, the processor is a hardware circuit implemented by an ASIC or a PLD, such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document to implement the configuration of the hardware circuit 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 a type of ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0536] 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.

[0537] In addition, each unit in the above device can be fully or partially integrated together, or can be independently implemented. In one implementation, these units are integrated together and implemented in the form of a system-on-a-chip (SOC). The SOC can include at least one processor for implementing any of the above methods or implementing the functions of each unit of the device. The types of the at least one processor can be different, such as including a CPU and an FPGA, a CPU and an artificial intelligence processor, a CPU and a GPU, etc.

[0538] In a simple embodiment, those skilled in the art can think that the communication devices in the above embodiments can all adopt Figure 16 the form shown.

[0539] As Figure 16 shown in the device 1600, it includes at least one processor 1610 and a communication interface 1630. In an optional design, a memory 1620 can also be included.

[0540] In the embodiments of the present application, the specific connection medium between the above-mentioned processor 1610 and the memory 1620 is not limited.

[0541] In a device such as Figure 16 When the processor 1610 communicates with other devices, data transmission can be performed through the communication interface 1630.

[0542] When the communication device adopts Figure 16 the form shown, Figure 16 the processor 1610 in can execute any of the above method embodiments by calling the computer-executable instructions stored in the memory 1620, so that the device 1600 can execute.

[0543] The embodiments of the present application also relate 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.

[0544] In a possible implementation manner, the processor can be coupled to the memory through an interface.

[0545] In a possible implementation manner, the chip system may also directly include a memory, and the memory stores a computer program or computer instructions.

[0546] Exemplarily, the memory can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DRRAM).

[0547] An embodiment of the present application further relates to a processor, which is used to call a computer program or computer instructions stored in the memory, so that the processor executes the method described in any one of the above embodiments.

[0548] Exemplarily, in the embodiments of the present application, the processor is an integrated circuit chip with the ability to process signals. For example, the processor can be an FPGA, a general-purpose processor, a DSP, an ASIC, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or can also be a system on chip (SoC), can also be a CPU, can also be a network processor (NP), can also be a microcontroller unit (MCU), can also be a PLD or other integrated chips, 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, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by a hardware decoding processor, or can be executed and completed by a combination of hardware and software modules in the decoding processor. The software module can be located in a random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, and other mature storage media in the art. This storage media is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0549] It should be understood that the embodiments of the present application can be provided as a method, a system, or a computer program product.

[0550] In a possible implementation manner, the embodiments of the present application provide a computer-readable storage medium, and the computer-readable storage medium stores program codes. When the program codes run on the computer, the computer is enabled to execute the above method embodiments.

[0551] In a possible implementation manner, the embodiments of the present application provide a computer program product. When the computer program product runs on the computer, the computer is enabled to execute the above method embodiments.

[0552] Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0553] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in one process or multiple processes of the flowchart and / or one block or multiple blocks of the block diagram.

[0554] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are executed on the computer or other programmable apparatus to produce a computer-implemented process, thereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one flow or more flows of the flowchart and / or one block or more blocks of the block diagram.

[0555] 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 equivalent technologies, the present application also intends to include these changes and modifications. In each embodiment of the present application, if there is no special description and logical conflict, the terms and / or descriptions between the 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 to 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. The first communication path in the at least one communication path is used for transmitting 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 for transmitting data 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, wherein 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, 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, wherein The method further includes: Send 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 supports multiplexed 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, where the second indication information indicates 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 second information is included in the third access layer message; or, Receive the first control information from the first access network device through the first tunnel, where the second information is included in the first control information.

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

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 second identifier and the second address of the first tunnel are included in the uplink data packet.

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 third identifier is included in the fourth access layer message, or the third identifier and the third address are included in the fourth access layer message; Receive the second control information from the first access network device through the first tunnel, where the third identifier is included in the second control information, or the third identifier and the third address are included in the first control information.

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 third identifier and the third address are included in the downlink data packet.

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 third identifier and the third address are included in the uplink data packet.

27. A communication device, characterized in that, Comprising at least one processor and interface circuitry, the interface circuitry 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 or the method according to any one of claims 14-26 through logic circuitry or by executing code instructions.

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 that, 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 is run 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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