Data transmission method and wireless communication system

Abstract

The invention provides a data transmission method and a wireless communication system. Wherein the terminal equipment supports the establishment of 3GPP connection and non-3GPP connection with the network equipment at the same time; and under the condition that the terminal equipment moves from the first area to a second area covered by the 3GPP network and the non-3GPP network, sending a second data packet to the network equipment through the established 3GPP connection, and sending a third data packet which is completely the same as the second data packet to the network equipment through the established non-3GPP connection. And enabling the network equipment to perform data transmission with the server equipment based on the first arriving data packet in the second data packet and the third data packet, and discarding the later arriving data packet. Thus, when the terminal equipment enters the second area from the first area, tedious network switching and other operations are not needed for the transmission of the uplink data packet, the flow of data transmission between the terminal equipment and the server equipment is simplified, and thus the transmission delay of the uplink data packet is shortened.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a data transmission method and a wireless communication system. Background Art

[0002] An Automated Guided Vehicle (AGV) is a transport vehicle equipped with an electromagnetic or optical automatic navigation device that can travel along a specified navigation path. It can be used in material handling and transportation in various industries. A warehouse control system (Warehouse Control System, WCS) is an information system used to control logistics warehousing operations. It is used to coordinate the operation of AGVs and other logistics equipment. When AGV is working, it needs to communicate with WCS in real time.

[0003] In the working environment of AGV, there are areas covered only by the network based on the fifth generation mobile communication technology (5th Generation Mobile Communication Technology) for data transmission (referred to as 5G network), areas covered only by the network based on wireless fidelity technology (Wireless Fidelity, Wi-Fi) for data transmission (referred to as Wi-Fi network), and areas covered by both 5G network and Wi-Fi network. When AGV moves from an area covered by a single network or an area without network coverage to an area covered by both 5G network and Wi-Fi network, in the prior art, for data transmission between AGV and WCS, AGV will perform network selection or network switching operations for 5G network and Wi-Fi network, making the data transmission process more complicated, thus increasing the delay of data transmission. Summary of the invention

[0004] The present application provides a data transmission method and a wireless communication system, wherein a terminal device supports establishing a 3rd Generation Partnership Project (3GPP) connection and a non-3GPP connection with a network device at the same time. When the terminal device moves from a first area to a second area covered by a 3GPP network and a non-3GPP network, the terminal device sends the same uplink data packet to the network device through the established 3GPP and non-3GPP connections, respectively, so that the network device communicates with the server device based on the data packet that arrives first. In this way, when the terminal device moves to the second area to send an uplink data packet, it does not need to perform network selection or network switching operations in the two networks, which simplifies the data transmission process and thus shortens the data transmission delay.

[0005] In a first aspect, the present application provides a data transmission method, which is applied to a terminal device, the method comprising: when the terminal device moves from a first area to a second area, the terminal device establishes or maintains a first connection with a network device, and the terminal device establishes or maintains a second connection with the network device; wherein, there is 3GPP network coverage in the first area, or there is non-3GPP network coverage in the first area, or there is no network coverage in the first area; there is 3GPP network coverage and non-3GPP network coverage in the second area; the first connection is established between the terminal device and the network device based on 3GPP wireless access technology, and the second connection is established between the terminal device and the network device based on non-3GPP wireless access technology; the terminal device generates a second data packet and a third data packet based on a first data packet to be sent; wherein the second data packet is exactly the same as the third data packet; the terminal device sends the second data packet to the network device through the first connection, and the terminal device sends the third data packet to the network device through the second connection, so that the network device performs data transmission with a server device based on the first data packet that arrives first among the second data packet and the third data packet, and discards the second first data packet that arrives first.

[0006] In some embodiments, the terminal device generates a second data packet and a third data packet based on a first data packet to be sent, including: the terminal device generates a fourth data packet that is exactly the same as the first data packet; the terminal device obtains the second data packet by adding a first sequence number and a redundant identifier to the first data packet; the terminal device obtains the third data packet by adding the first sequence number and the redundant identifier to the fourth data packet; wherein the redundant identifier is used to verify the second data packet and the third data packet, and the first sequence number is used by the network device to determine whether the first data packet or the second data packet is the first data packet to arrive.

[0007] In some embodiments, the terminal device obtains the second data packet based on adding the first sequence number and the redundant identifier to the first data packet, including: the terminal device adds the first sequence number and the redundant identifier to the first data packet to obtain a fifth data packet; the terminal device adds the Media Access Control Address (MAC) of the wireless access point of the non-3GPP network to the fifth data packet to obtain the second data packet; the terminal device obtains the third data packet based on adding the first sequence number and the redundant identifier to the fourth data packet, including: the terminal device adds the first sequence number and the redundant identifier to the fourth data packet to obtain a sixth data packet; the terminal device adds the MAC of the wireless access point of the non-3GPP network to the sixth data packet to obtain the third data packet; wherein the MAC is used to indicate that the second data packet and the third data packet are data packets sent to the server device.

[0008] In some embodiments, the terminal device sends the second data packet to the network device through the first connection, including: when the terminal device detects that the reference signal receiving power (RSRP) of the reference signal received based on the first connection is greater than a first preset threshold, the terminal device sends the second data packet to the network device through the first connection; the terminal device sends the third data packet to the network device through the second connection, including: when the terminal device detects that the strength of the access point (AP) beacon received based on the second connection is greater than a second preset threshold, the terminal device sends the third data packet to the network device through the second connection.

[0009] In a second aspect, the present application provides a data transmission method, which is applied to a network device, the method comprising: the network device receives a second data packet sent by a terminal device in a second area through a first connection; wherein the first connection is established between the terminal device and the network device based on 3GPP wireless access technology, and the network device determines whether a third data packet is received through the second connection before receiving the second data packet; wherein the second connection is established between the terminal device and the network device based on non-3GPP wireless access technology; when the terminal device moves from the first area to the second area, the terminal device establishes or maintains the first connection with the network device, and the terminal device establishes or maintains the second connection with the network device; wherein there is 3GPP network coverage in the first area, or there is non-3GPP network coverage in the first area, or there is no network coverage in the first area; there is 3GPP network coverage and non-3GPP network coverage in the second area; if the network device does not receive the third data packet before receiving the second data packet, the network device performs data transmission with a server device based on the second data packet; if the network device receives the third data packet before receiving the second data packet, the network device discards the second data packet.

[0010] In some embodiments, the network device determines whether a third data packet is received through a second connection before receiving the second data packet, including: the network device performs a decapsulation operation based on the second data packet to obtain a first serial number; the network device determines whether there is a serial number identical to the first serial number among the second serial numbers corresponding to at least one seventh data packet received historically; if there is a serial number identical to the first serial number among at least one of the second serial numbers, the network device determines that the third data packet is received before receiving the second data packet; if there is no serial number identical to the first serial number among at least one of the second serial numbers, the network device determines that the third data packet is not received before receiving the second data packet.

[0011] In some embodiments, the network device performs a decapsulation operation based on the second data packet and also obtains a first data packet, and the network device performs data transmission with a server device based on the second data packet; including: the network device sends the first data packet to the server device.

[0012] In some embodiments, before the network device decapsulates the second data packet, the method further includes: the network device detects the second data packet, determines that the second data packet is encapsulated using an encapsulation protocol agreed upon by the terminal device and the network device, and that the second data packet carries the MAC of the wireless access point of the non-3GPP network.

[0013] In some embodiments, the method further includes: receiving an eighth data packet; upon detecting that the source Internet Protocol (IP) address carried in the eighth data packet is the same as the source IP address of the server device, generating a ninth data packet and a tenth data packet based on the eighth data packet; wherein the ninth data packet and the tenth data packet are exactly the same; sending the ninth data packet to the terminal device via the first connection, and sending the tenth data packet to the terminal device via the second connection, so that the terminal device performs data transmission with a control device corresponding to the terminal device based on the first arriving data packet between the ninth data packet and the tenth data packet, and discards the second first arriving data packet.

[0014] In a third aspect, the present application provides a data transmission device, comprising a device for executing the data transmission method described in the first aspect or the second aspect.

[0015] In a fourth aspect, the present application provides a chip comprising an interface circuit and a logic circuit, wherein the interface circuit is used to receive signals from other chips outside the chip and transmit them to the logic circuit, or to send signals from the logic circuit to other chips outside the chip, and the logic circuit is used to implement the data transmission method described in the first aspect or the second aspect.

[0016] In a fifth aspect, the present application provides a terminal device, comprising a memory and a processor, wherein the memory stores a computer program that can be executed on the processor, and wherein the processor implements the data transmission method described in the first aspect when executing the program.

[0017] In a sixth aspect, the present application provides a network device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and wherein the processor implements the data transmission method described in the second aspect when executing the program.

[0018] In a seventh aspect, the present application provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the data transmission method as described in the first aspect or the second aspect.

[0019] In an eighth aspect, the present application provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the steps of the data transmission method described in the first aspect or the second aspect.

[0020] In a ninth aspect, the present application provides a wireless communication system, comprising the terminal device described in the fifth aspect and the network device described in the sixth aspect.

[0021] The present application provides a data transmission method and a wireless communication system. Among them, the terminal device supports establishing a 3GPP connection and a non-3GPP connection with a network device at the same time; when the terminal device moves from a first area to a second area covered by a 3GPP network and a non-3GPP network, the first data packet to be sent is copied to obtain a completely identical second data packet and a third data packet, and the second data packet is sent to the network device through the established 3GPP connection, and the third data packet is sent to the network device through the established non-3GPP connection. The network device is enabled to perform data transmission with the server device based on the first data packet that arrives between the second data packet and the third data packet, and discard the data packet that arrives later. In this way, when the terminal device enters the second area from the first area, for the transmission of uplink data packets, there is no need to perform cumbersome network selection or network switching operations in the 3GPP network and the non-3GPP network, which simplifies the process of data transmission between the terminal device and the server device, thereby shortening the transmission delay of the uplink data packet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a wireless communication system provided in an embodiment of the present application;

[0023] Figure 2 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0024] Figure 3 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0025] Figure 4 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0026] Figure 5 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0027] Figure 6 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0028] Figure 7 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0029] Figure 8A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0030] Fig. 9 A flowchart for implementing the data transmission method provided in the embodiment of the present application;

[0031] Fig.10 A structural diagram of a data transmission device provided in an embodiment of the present application;

[0032] Fig.11 A structural diagram of a data transmission device provided in an embodiment of the present application;

[0033] Fig.12 A structural diagram of a terminal device provided in an embodiment of the present application;

[0034] Fig.13 A structural diagram of a network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0036] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0037] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] Wireless network technology plays an important role in the working scenarios of AGVs, especially when it comes to the seamless roaming capabilities of AGVs when they move between different network coverage areas. Next, we will first introduce some key wireless network technologies and roaming protocols, which are essential to ensuring the efficiency and reliability of AGV work.

[0039] (1) IEEE 802.11 standard: It is the basic standard for wireless LAN communication. It includes a variety of different technologies, such as 802.11a / b / g / n / ac / ax, etc. Each technology has a specific rate, frequency band and usage scenario.

[0040] (2) Wireless Industrial Automation-Fixed Access (WIA-FA) for industrial process automation: It is a wireless communication technology designed specifically for industrial environments. It provides high reliability and real-time performance and is suitable for AGV-related systems in industrial automation.

[0041] (3) Wi-Fi 6 (IEEE 802.11ax): A new generation of Wi-Fi technology, Wi-Fi 6 provides higher data transmission rates, improved performance in high-density environments, and support for more concurrent users.

[0042] (4) Fast roaming protocols: including 802.11k, 802.11v, and 802.11r. These protocols optimize roaming performance in wireless networks and reduce roaming delay and packet loss rate.

[0043] Among them, 802.11k provides improvements to wireless networks, including the broadcast of channel usage information to help clients scan and select the best AP more quickly.

[0044] 802.11v adds network assistance features, such as fast initial connection of clients and neighbor lists (BSS transmission), to help clients manage their connection status more intelligently.

[0045] 802.11r introduces Fast BSS Transmission (FT), which allows clients to quickly switch to a new AP while maintaining upper layer connections, reducing interruption time during roaming.

[0046] (5) Hierarchical State Routing (HSR) Protocol and Parallel Redundancy Protocol (PRP): It is not a roaming protocol, but a redundancy protocol used to create a high-availability network. It prevents single point failure by creating two independent paths in the network.

[0047] (6) Seamless roaming technology: By optimizing the scanning and switching process of wireless signals, it reduces packet loss and delay during roaming.

[0048] The key to roaming protocols and technologies is the ability to provide a fast and seamless switching experience, which allows the AGV to maintain a stable connection with the relevant control system during movement.

[0049] Among them, seamless roaming technology includes the following key functions:

[0050] a1) Roaming trigger mechanism: The device decides whether to roam based on signal strength, signal quality or other network parameters, which involves continuous monitoring of the signals of the currently connected AP and neighboring APs.

[0051] a2) Fast Scan: The terminal device can quickly scan available wireless networks to quickly find the best new AP when the current connection weakens.

[0052] a3) Neighbor List (BBS Transmission): The BSS transition function defined in the 802.11v standard allows the AP to provide the client with information about nearby APs, helping the client make better roaming decisions.

[0053] a4) Fast BSS Transfer (FT): FT defined in the 802.11r standard allows devices to quickly switch to a new AP while maintaining session continuity, reducing interruption time during roaming.

[0054] a5) Pre-authentication: Before roaming to a new AP, the device can pre-authenticate with the potential new AP so that once the decision to roam is made, the handover process can be completed faster.

[0055] a6) Signal strength threshold: The terminal device will decide whether to start the roaming process based on the preset signal strength threshold. The setting of the threshold needs to balance fast response and avoid frequent switching.

[0056] a7) Switching time: The goal of seamless roaming is to minimize the switching time and ensure the continuity of data transmission and service quality.

[0057] Continuity of data transmission: To achieve seamless roaming, data packets may be buffered and then forwarded after successful handover to the new AP to avoid data loss.

[0058] a8) Quality of Service (QoS): During roaming, it is important to maintain the quality of service, especially for applications with high real-time requirements.

[0059] a9) Network Management System: The network management system can monitor roaming events, analyze roaming performance, and adjust network configuration as needed.

[0060] a10) Collaboration between client and AP: The client and AP need to work together to ensure the accuracy of roaming decisions and the smoothness of the handover process.

[0061] a11) Multi-band and multi-radio support: Devices that support multiple bands and radios can more flexibly select the best AP and channel for better roaming performance.

[0062] (7) 5G key technologies for AGV:

[0063] 5G technology is the latest generation of mobile communication technology. It not only provides services for smartphones and mobile devices, but also brings revolutionary changes to industrial automation and intelligent manufacturing. By integrating 5G technology, AGV-related systems can obtain the following advantages:

[0064] b1) High-speed transmission: 5G technology provides extremely high data transmission rates, which is important for AGV-related systems that require large amounts of data exchange.

[0065] b2) Low latency: The low latency characteristic of 5G technology (usually below 1ms) is very important for real-time control and fast response AGV systems, which can improve operational accuracy and efficiency.

[0066] b3) High reliability: 5G networks have designed a variety of mechanisms to ensure the reliability of data transmission, which is more important for command transmission and status monitoring in AGV systems.

[0067] b4) Large connection capacity: 5G technology supports the connection of a large number of devices and is suitable for factory or warehouse environments where AGV systems are deployed on a large scale.

[0068] b5) Network slicing: 5G allows the creation of multiple virtual network switches, each of which can be optimized based on specific service requirements, such as creating a high-priority network slice for the AGV system.

[0069] b6) Mobility management: 5G technology is designed with high-speed mobility in mind, which means that it can ensure a stable network connection while the AGV is moving.

[0070] b7) Edge computing: Combining 5G and edge technology, data processing and analysis can be performed at the edge of the network, reducing the delay in data transmission to the central server and providing faster decision support for AGV.

[0071] b8) Security: 5G networks provide enhanced security features, including data encryption and network security mechanisms, which can protect the communications of the AGV system from attacks.

[0072] b9) Guarantee of service quality: 5G networks can provide differentiated service quality according to different types of traffic, ensuring that key personnel’s AGV communications obtain the necessary bandwidth and priority.

[0073] b10) Improvement of spectrum efficiency: 5G technology improves spectrum efficiency through advanced modulation and coding technologies, allowing more AGV systems to be supported with limited spectrum resources.

[0074] b11) Compatibility and interoperability: 5G is designed with backward compatibility features and can coexist with existing 4G (The 4th Generation Mobile Communication Technology, 4G) or Long Term Evolution (Long Term Evolution, LTE) networks to ensure the smooth operation of the AGV system during the transition period.

[0075] (8) 3GPP heterogeneous networking

[0076] In the 3GPP 5G network architecture, the non-3GPP interworking function (N3IWF) and non-5G-capable over WLAN (N5CW) devices can support heterogeneous networking of non-3GPP network technologies (such as WLAN) and 5G networks.

[0077] Next, we will introduce N3IWF and N5CW:

[0078] Among them, N3IWF is a key component in the 3GPP 5G network architecture to support interoperability between non-3GPP access networks (such as WLAN) and the core network. It is mainly responsible for the following functions:

[0079] c1) As the gateway of the 3GPP access network, it supports control plane and user plane connections with the 5G core network.

[0080] c2) It connects to the control plane and user plane functions of the 5G core network through the N2 and N3 interfaces respectively.

[0081] c3) Establish an Internet Protocol Security (IPSec) tunnel with the terminal to ensure the security of connecting to the 5G core network through an untrusted non-3GPP access network.

[0082] c4) Supports Extensible Authentication Protocol (EAP-AKA') authentication, allowing the terminal to use the authentication mechanism of the 5G core network for authentication.

[0083] c5) is responsible for relaying non-access stratum signaling between the terminal and the Access and Mobility Management Function (AMF).

[0084] c6) Manage Protocol Data Unit (PDU) sessions and QoS, including establishing IPsec security associations to support PDU session traffic.

[0085] N5CW refers to devices that do not support 5G core network NAS signaling, and they connect to the 5G core network through the WLAN access network. For such devices, 3GPP defines the Trusted WLAN Interworking Function (TWIF) to support their access.

[0086] d1) TWIF acts as an agent for the N5CW device and is responsible for interacting with the 5G core network.

[0087] d2) TWIF terminates the N1, N2 and N3 interfaces, implements the AMF selection steps, and exchanges NAS messages with AMF on behalf of the N5CW device.

[0088] d3) On the user plane, TWIF relays PDU units between the Yw interface and the N3 interface.

[0089] d4) TWIF is also responsible for the authentication of N5CW devices, which may involve Yw reference point interaction with trusted WLAN access points TWAP.

[0090] d5) Application scenarios of N3IWF and N5CW / TWIF include but are not limited to: Public WLAN hotspots, such as airports and shopping malls, provide 5G network services. In enterprise or home environments, user devices access the 5G core network through WLAN. Specific industry applications, such as industrial automation, use WLAN to connect to the 5G network for remote control and data collection.

[0091] Since non-3GPP access networks may not be managed by 5G network operators, N3IWF ensures the security of data transmission by establishing IPsec tunnels. For N5CW devices, TWIF may use different mechanisms during the authentication process, but security must also be guaranteed.

[0092] The above introduces the relevant network technology and wireless roaming technology of the AGV system. During the operation, the AGV may pass through areas covered only by 3GPP networks, or may pass through areas covered only by non-3GPP networks, or may pass through areas covered by both 3GPP and non-3GPP networks. When the AGV moves from an area covered by a single network or no network to an area covered by 3GPP and non-3GPP networks, the wireless roaming technology introduced above may be used to perform network switching, or to select a suitable network access from the two networks. In this case, the AGV needs to perform wireless signal scanning, repeatedly optimize the signal reception threshold in the overlapping area, and other operations, and the execution process is relatively complicated.

[0093] Based on this, the present application provides a data transmission method, in which the terminal device supports establishing connections with both the 3GPP network and the non-3GPP network at the same time. In this way, when moving from a first area covered by a single network or no network to an area covered by a 3GPP network and a non-3GPP network, two identical data packets are sent based on the 3GPP network and the non-3GPP network, respectively, so that the network device will communicate with the server device based on the first received data packet and discard the second first received data packet. In this way, when the terminal device enters the second area from the first area, for the transmission of the uplink data packet, there is no need to perform cumbersome network switching or select a suitable network access operation, and there is no need to repeatedly adjust the signal reception threshold in the second area, etc. The execution process is relatively simple, thus simplifying the process of data transmission between the terminal device and the server device, thereby shortening the transmission delay of the uplink data packet.

[0094] The data transmission method of the present application is applicable to Figure 1 The wireless communication system shown.

[0095] like Figure 1As shown, the wireless communication system includes terminal equipment, access network, core network and server equipment; wherein the access network equipment can be composed of multiple nodes, and the multiple nodes include one or more wireless access points of 3GPP networks, and one or more access points of non-3GPP access networks.

[0096] The 3GPP network may be a 5G network, a 4G network, a 3G network, etc. Exemplarily, the 3GPP network is a 5G network, and the wireless access point of the 3GPP network is a Next Generation Radio Access Network (NG-RAN) node, such as a next generation base station or a 5G base station.

[0097] Among them, the next generation base station includes but is not limited to the new radio base station (NR nodeB, gNB), the next generation evolved base station (NG-eNB), the gNB in ​​the form of a central unit (CU) and a distributed unit (DU) separated from the central unit, etc.), a transmission receive point (TRP), a transmission point (TP) or other nodes.

[0098] The non-3GPP network may be a WLAN network. Exemplarily, the WLAN network is a network that performs data transmission based on Wi-Fi technology, and the wireless access point of the non-3GPP network may be a Wi-Fi AP device.

[0099] Among them, the terminal device is connected to the core network through NG-RAN to form a 3GPP network. And the terminal device is connected to the core network through Wi-Fi AP to form a non-3GPP network. That is, not only a 3GPP connection (5G connection) is established between the terminal device and the core network, but also a non-3GPP connection (Wi-Fi connection) is established.

[0100] like Figure 1The core network includes multiple functional units such as AMF network element, session management function (Session Management Function, SMF) network element, user plane function (User Plane Function, UPF) network element, authentication server function (Authentication Server Function, AUSF) network element, policy control function (Policy Control Function, PCF) network element, application function (Application Function, AF) network element, unified data management function (unified data management, UDM) network element, network slice selection function (Network Slice Selection Function, NSSF) network element, network storage function (Network Repository Function, NRF) network element, and network exposure function (Network Exposure Function, NEF) network element.

[0101] Among them, the AMF network element is mainly responsible for services such as mobility management and access management. The SMF network element is mainly responsible for session management, terminal address management and allocation, dynamic host configuration protocol functions, selection and control of user plane functions, etc. The UPF is mainly responsible for external connection to the data network (DN) and the user plane data packet routing forwarding, message filtering, and execution of quality of service (QoS) control related functions. The AUSF is mainly responsible for the authentication function of the terminal device, etc. The PCF network element is mainly responsible for providing a unified policy framework for network behavior management, providing policy rules for control plane functions, and obtaining registration information related to policy decisions.

[0102] Among them, the terminal can transmit control plane messages with the AMF network element through the N1 interface, the NG-RAN node can establish a user plane data transmission channel with the UPF through the N3 interface, the NG-RAN node can establish a control plane signaling connection with the AMF network element through the N2 interface, and the UPF can exchange information with the SMF network element through the N4 interface.

[0103] Some network elements in the core network are connected via buses. Figure 1As shown, AUSF network elements, AMF network elements, SMF network elements, AF network elements, NEF network elements, NRF network elements, UDM, PCF network elements and NSSF network elements are interconnected through a bus. When the above network elements are interconnected through the bus, a service-oriented interface is adopted. For example, the AUSF network element is connected to the bus through a Nausf interface, the AMF network element is connected to the bus through a Namf interface, the SMF network element is connected to the bus through an Nsmf interface, the AF network element is connected to the bus through a NAF network element interface, the UDM is connected to the bus through a Nudm interface, the PCF network element is connected to the bus through an NPCF network element interface, the NRF is connected to the bus through an Nnrf interface, the NEF is connected to the bus through an Nnef interface, and the NSSF is connected to the bus through an Nnssf interface.

[0104] The embodiments of the present application do not limit the specific technology and specific device form used by the network device. For the convenience of description, in all embodiments of the present application, the above-mentioned device that provides wireless communication function for the terminal device is collectively referred to as a network device.

[0105] In the embodiment of the present application, the terminal device may be any terminal, for example, the terminal device may be a user equipment of machine type communication. The terminal device may also be referred to as user equipment (user equipment, terminal), mobile station (mobilestation, MS), mobile terminal (mobile terminal), terminal, etc.

[0106] Exemplarily, the terminal device may be an AGV, or the terminal device may be deployed on an AGV, and the terminal device implements the scheduling and operation of the AGV by performing data transmission with the server device.

[0107] The WCS is deployed on the server device.

[0108] Figure 2 A schematic diagram of the implementation flow of the data transmission method provided in the embodiment of the present application; Figure 2 As shown, the method includes:

[0109] S201. When a terminal device moves from a first area to a second area, the terminal device establishes or maintains a first connection with a network device, and the terminal device establishes or maintains a second connection with the network device.

[0110] Among them, the first area includes 3 situations, namely:

[0111] Case 1: There is 3GPP network coverage and no non-3GPP network coverage in the first area, or there is only 3GPP network coverage in the first area.

[0112] In the case that a 3GPP network exists in the first area, the terminal device establishes a first connection with the network device based on the 3GPP wireless access technology in the first area.

[0113] In the embodiment of the present application, the network device may specifically be a UPF. When the 3GPP network is a 5G network, the terminal device establishes a first connection with the network device through the 3GPP wireless access technology. Specifically, Figure 1 As shown, the terminal device establishes the first connection with UPF through the 5G interface and NG-RAN.

[0114] Case 2: There is non-3GPP network coverage and no 3GPP network coverage in the first area, or there is only non-3GPP network coverage in the first area.

[0115] The non-3GPP network may be a Wi-Fi network. In this case, the terminal device establishes a second connection with the network device in the first area through the non-3GPP access technology. Specifically, the terminal device establishes a second connection with the UPF through the Wi-Fi interface and the Wi-Fi AP.

[0116] Case 3: There is no network coverage in the first area.

[0117] In this case, the terminal device cannot establish a network connection in the first area.

[0118] The second area is covered by not only 3GPP networks but also non-3GPP networks.

[0119] If the first area is covered by a 3GPP network, when the terminal device moves from the first area to the second area, the terminal device maintains the first connection and establishes a second connection with the network device.

[0120] If there is non-3GPP network coverage in the first area, when the terminal device moves from the first area to the second area, the terminal device maintains the second connection and establishes the first connection with the network device.

[0121] If there is no network coverage in the first area, when the terminal device moves from the first area to the second area, the terminal device establishes a first connection with the network device and establishes a second connection with the network device.

[0122] In some embodiments, the target device may determine whether the target device has moved to the second area based on simultaneously detecting a specific reference signal broadcast by a wireless access point of a 3GPP network and a specific reference signal broadcast by a wireless access point of a non-3GPP network.

[0123] S202. The terminal device generates a second data packet and a third data packet based on the first data packet to be sent.

[0124] The second data packet and the third data packet are completely identical.

[0125] The present application does not limit the method for generating the second data packet and the third data packet. In some embodiments, the terminal device may first copy the first data packet to obtain two identical data packets, and then encapsulate the two identical data packets according to the same encapsulation format to obtain the second data packet and the third data packet. The specific implementation method for generating the second data packet and the third data packet is described in the following embodiment and will not be repeated here.

[0126] The above encapsulation protocol is an encapsulation protocol pre-negotiated by the terminal device and the server device.

[0127] As described above, the terminal device can be an AGV or a device deployed on the AGV. Accordingly, an AGV controller is also deployed on the AGV, and the first data packet is generated by the AGV controller. The first data packet includes the posture and position information of the AGV, and the first data packet is used by the server device to schedule and control the operating status of the AGV.

[0128] S203: The terminal device sends a second data packet to the network device through the first connection, and the terminal device sends a third data packet to the network device through the second connection.

[0129] Specifically, the terminal device sends the second data packet to the wireless access point of the 3GPP network, and the wireless access point of the 3GPP network forwards the second data packet to the network device.

[0130] The terminal device sends a third data packet to the wireless access point of the non-3GPP network, and the wireless access point of the non-3GPP network forwards the third data packet to the network device.

[0131] The second data packet and the third data packet both include the MAC of the wireless access point of the non-3GPP network. The MAC of the wireless access point of the non-3GPP network is used to indicate the network device, and the data packet is a data packet sent to the server device.

[0132] Specifically, the terminal device and the network device are both provided with dual-transmit and selective-receive modules, and the terminal device and the network device process, send and receive data packets transmitted between the network device and the server device by their respective corresponding dual-transmit and selective-receive modules.

[0133] Exemplarily, the dual-transmit selective receiving module in the terminal device performs an operation of generating a second data packet and a third data packet based on the first data packet; when the network device detects that the second data packet and the third data packet include the MAC of a wireless access point of a non-3GPP network, the dual-transmit selective receiving module performs an operation of sending the second data packet or the third data packet to the server device.

[0134] In this way, this solution does not require complex firmware protocol stack updates for AGV terminals, next-generation base stations, and Wi-Fi APs, reducing the cost and complexity of equipment modification.

[0135] S204: The network device forwards the first arriving data packet of the second data packet and the third data packet to the server device, and discards the second first arriving data packet.

[0136] Specifically, when the network device receives the second data packet and the third data packet, it parses the received data packets according to the encapsulation protocol, and determines based on the parsed information whether a data packet identical to the data packet has been received before the data packet is received.

[0137] If the network device has not received the data packet, the network device will transmit data with the server device based on the data packet to ensure the timeliness of data transmission; if the network device has received the data packet, the network device will discard the data packet to avoid repeated transmission of the data packet to save transmission resources.

[0138] In an embodiment of the present application, the terminal device supports establishing a 3GPP connection and a non-3GPP connection with a network device at the same time; when the terminal device moves from a first area to a second area covered by a 3GPP network and a non-3GPP network, the first data packet to be sent is copied to obtain a completely identical second data packet and a third data packet, and the second data packet is sent to the network device through the established 3GPP connection, and the third data packet is sent to the network device through the established non-3GPP connection. This enables the network device to perform data transmission with the server device based on the first data packet that arrives between the second data packet and the third data packet, and discards the data packet that arrives first. In this way, when the terminal device enters the second area from the first area, for the transmission of uplink data packets, there is no need to perform cumbersome network selection or network switching operations in the 3GPP network and the non-3GPP network, and there is no need to perform abnormal link detection and other operations, which simplifies the process of data transmission between the terminal device and the server device, thereby shortening the transmission delay of the uplink data packet.

[0139] As described above, after the terminal device moves to the second area, the first connection is established or maintained, and the second connection is established or maintained. Afterwards, the first data packet is transmitted between the terminal device and the network device. Before the first data packet is transmitted, the second data packet and the third data packet are generated based on the first data packet.

[0140] Next, through Figure 3 The embodiment specifically describes how the terminal device generates the second data packet and the third data packet based on the first data packet.

[0141] Figure 3The implementation flow chart of the data transmission method provided in the embodiment of the present application is as follows: Figure 3 As shown, S202 can be implemented through the following steps.

[0142] S2021. The terminal device generates a fourth data packet that is exactly the same as the first data packet.

[0143] S2021 is a copy operation of the first data packet.

[0144] The first data packet is completely identical to the fourth data packet, which means that each field in the first data packet is completely identical to that in the fourth data packet, including the content of each field, byte length and other information are completely identical.

[0145] S2022. The terminal device obtains a second data packet based on adding the first sequence number and the redundant identifier to the first data packet, and obtains a third data packet based on adding the first sequence number and the redundant identifier to the fourth data packet.

[0146] An encapsulation protocol is pre-negotiated between the terminal device and the server device. The terminal device can encapsulate the first data packet based on the encapsulation protocol pre-negotiated between the terminal device and the server device to obtain a second data packet.

[0147] Furthermore, the terminal device may encapsulate the fourth data packet based on an encapsulation protocol pre-negotiated between the terminal device and the server device to obtain a third data packet.

[0148] This application does not limit the format of the encapsulation protocol.

[0149] With respect to encapsulating the first data packet, specifically, the terminal device adds the first sequence number and the redundant identifier to the first data packet to implement encapsulation of the first data packet.

[0150] Regarding the encapsulation of the fourth data packet, specifically, the terminal device adds the first sequence number and the redundant identifier to the fourth data packet to implement the encapsulation of the fourth data packet.

[0151] It should be noted that the first sequence number encapsulating the first data packet and the fourth data packet is exactly the same. The redundant identifier is also exactly the same. In this way, the consistency of the first data packet and the fourth data packet can be guaranteed. That is, the first data packet and the fourth data packet are also exactly the same.

[0152] The redundant identifier is used to verify the second data packet and the third data packet.

[0153] The first sequence number is used to identify the second data packet and the third data packet, so that the network device determines whether the second data packet or the third data packet is the first received data packet based on the first sequence number.

[0154] In this embodiment, in the process of generating the second data packet and the third data packet, the first data packet and the fourth data packet obtained by copying the first data packet are encapsulated based on the encapsulation protocol pre-negotiated by the terminal device and the network device. Specifically, the first sequence number is added to the first data packet and the fourth data packet respectively to obtain the second data packet and the third data packet. In this way, the second data packet and the third data packet are completely identical, and the first sequence number used for encapsulation can simultaneously identify the second data packet and the third data packet. In this way, the network device can determine whether the second data packet or the third data packet is the first data packet received based on the first sequence number.

[0155] In some embodiments, after the terminal device encapsulates the first data packet and the fourth data packet, it is necessary to add the MAC of the wireless access point of the non-3GPP network so that the data packet received by the network device is the data packet to be sent to the server device and the subsequent downlink data is sent.

[0156] Based on this, the present application provides a data transmission method, and the data transmission method provided by the present application is used to introduce how to obtain the second data packet and the third data packet based on the encapsulated first data packet and the encapsulated fourth data packet.

[0157] Figure 4 Flowchart for implementing the data transmission method provided in the embodiment of the present application; Figure 4 As shown, S2022 can be implemented through steps a1 to a4.

[0158] Step a1: The terminal device adds the first sequence number and the redundant identifier to the first data packet to obtain a fifth data packet.

[0159] That is to say, after the terminal device encapsulates the first data packet, the fifth data packet is obtained.

[0160] Step a2: The terminal device adds the MAC address of the wireless access point of the non-3GPP network to the first data packet to obtain a second data packet.

[0161] The MAC address of the wireless access point of the non-3GPP network may be the MAC address of the Wi-Fi AP.

[0162] In some embodiments, MAC may be used to instruct the network device to determine whether the second data packet is a data packet sent to the server device.

[0163] If the network device detects the MAC, the network device determines that the second data packet is a data packet sent to the server device, and the network device performs a determination as to whether the second data packet is the first data packet to arrive.

[0164] Step a3: The terminal device adds the first serial number and the redundant identifier to the fourth data packet to obtain a sixth data packet.

[0165] That is to say, after the terminal device encapsulates the fourth data packet, six data packets are obtained.

[0166] Step a4: The terminal device adds the MAC of the wireless access point of the non-3GPP network to the fourth data packet to obtain a third data packet.

[0167] MAC is used to instruct the network device to determine whether the fourth data packet is a data packet sent to the server device.

[0168] If the network device detects the MAC, the network device determines that the fourth data packet is a data packet sent to the server device, and then the network device determines whether the fourth data packet is the first data packet to arrive.

[0169] In this embodiment, after the terminal device encapsulates the first data packet and the fourth data packet, it also adds the MAC of the Wi-Fi AP, so that the network device recognizes that the first data packet and the fourth data packet are data packets that need to be sent to the server device, and enables the network device to record the address of the Wi-Fi AP sent to the server device.

[0170] It should be noted that in this embodiment, the execution order of steps a1 to a2 and steps a3 to a4 is not limited. In some embodiments, steps a1 to a2 are performed before steps a3 to a4; in other embodiments, steps a3 and a4 are performed before steps a1 to a2.

[0171] In some embodiments, before sending the second data packet and the third data packet, the terminal device needs to detect the signal strength corresponding to the first connection and the second connection, and send when the signal strength meets the conditions to ensure the reliability of data transmission.

[0172] Based on this, the present application provides a data transmission method, which is used to illustrate the specific conditions for a terminal device to send a second data packet and a third data packet.

[0173] Figure 5 A schematic diagram of the implementation flow of the data transmission method provided in the embodiment of the present application is shown in FIG. Figure 5 As shown, S203 can be realized by S2031 and S2032:

[0174] S2031. The terminal device detects that the RSRP of the reference signal received based on the first connection is greater than a first preset threshold, and sends the second data packet to the network device through the first connection.

[0175] As described above, the terminal device establishes a first connection with the network device through a wireless access point of the 3GPP network. The reference signal is sent by the wireless access point of the 3GPP network.

[0176] It can be seen that before executing S203, the terminal device detects the reference signal sent by the wireless access point of the 3GPP network in real time, and does not execute the operation of sending the second data packet when it is detected that the RSRP of the reference signal is less than or equal to the first preset threshold; the operation of sending the second data packet is executed only after it is detected that the RSRP of the reference signal is greater than the first preset threshold.

[0177] S2032: When the terminal device detects that the strength of the AP beacon received based on the second connection is greater than a second preset threshold, the terminal device sends a third data packet to the network device through the second connection.

[0178] As described above, the terminal device establishes a second connection with the network device through the wireless access point of the non-3GPP network. The AP beacon is sent by the wireless access point of the non-3GPP network.

[0179] It can be seen that before executing S203, the terminal device detects the AP beacon sent by the wireless access point of the non-3GPP network in real time. When it is detected that the strength of the AP beacon is less than or equal to the second preset threshold, the operation of sending the third data packet is not executed; the operation of sending the third data packet is executed only after it is detected that the RSRP of the reference signal is greater than the second preset threshold.

[0180] In this embodiment, the operation of sending the second data packet will be executed only when the RSRP is greater than the first threshold, and the operation of sending the third data packet will be executed only when the strength of the AP beacon is greater than the second preset threshold. In this way, the reliability of the transmission of the second data packet and the third data packet can be guaranteed.

[0181] As described above, the network device will forward the first received data packet to the server device and discard the second first received data packet. In S204, after receiving the second data packet and the third data packet, the network device will determine whether they are the first received data packets, and perform subsequent operations based on the determination results.

[0182] Next, taking the second data packet as an example, Figure 6 Examples to Figure 8 The embodiment illustrates the processing operation of the network device with respect to the received second data packet.

[0183] The present application provides a data transmission method, which is used for the network device in S204 to process the second data packet when receiving the second data packet.

[0184] Figure 6The implementation flow chart of the data transmission method provided in the embodiment of the present application is as follows: Figure 6 As shown, S204 includes:

[0185] S2041. The network device receives a second data packet sent by a terminal device in a second area through a first connection.

[0186] As described above, the first connection is established between the terminal device and the network device based on the 3GPP wireless access technology.

[0187] S2042. The network device determines whether the third data packet is received through the second connection before the second data packet is received; if so, execute S2043; otherwise, execute S2044.

[0188] As described above, the second connection is established between the terminal device and the network device based on the non-3GPP wireless access technology.

[0189] S2043: The network device discards the second data packet.

[0190] It can be understood that if the network device has received the third data packet before receiving the second data packet, the network device must have performed an operation of data transmission with the server device based on the third data packet. The network device will then discard the second data packet to avoid repeated transmission of data packets, thereby saving transmission resources.

[0191] S2044: The network device transmits data with the server device based on the second data packet.

[0192] It can be understood that if the network device does not receive the third data packet before receiving the second data packet, the network device will promptly transmit data with the server device based on the second data packet, and discard the second data packet when the third data packet is subsequently received.

[0193] In this embodiment, when the network device receives the second data packet, it determines whether the second data packet is received first. If so, it transmits data with the server device based on the second data packet to ensure timely transmission of the data. If not, it discards the second data packet to avoid repeated transmission of data packets to save transmission resources.

[0194] It should be noted that the network device can not only receive the second data packet, but also receive the third data packet; when the network device receives the third data packet, it will also process the third data packet.

[0195] The processing operation of the network device when receiving the third data packet is similar to the processing operation of receiving the second data packet. Figures 6 to 8The embodiment takes the processing operation of the network device when receiving the second data packet as an example. The processing operation of the network device when receiving the third data packet may also be based on Figures 6 to 8 The steps of the embodiment are carried out and will not be described in detail here.

[0196] Next, the determination of whether the network device receives the third data packet before receiving the second data packet is described in detail.

[0197] Figure 7 Flowchart for implementing the data transmission method provided in the embodiment of the present application; Figure 7 As shown, S2042 can be implemented by following steps b1 to b3:

[0198] Step b1: The network device detects the second data packet and determines that the second data packet is encapsulated using the encapsulation protocol agreed upon by the terminal device and the network device, and that the second data packet carries the MAC of the wireless access point of the non-3GPP network.

[0199] It can be understood that if the second data packet is encapsulated using the encapsulation protocol agreed upon by the terminal device and the network device, and the second data packet carries the MAC of the wireless access point of the non-3GPP network, it proves that the second data packet is a data packet that needs to be sent to the server device. The network device will perform data transmission with the server device based on the second data packet.

[0200] Specifically, when the network device detects that the second data packet is encapsulated using the above-mentioned encapsulation protocol, the second data packet can be sent to an internal dual-transmit and selective-receive module specifically used to process data transmission between the terminal device and the server device. The dual-transmit and selective-receive module detects whether the second data packet carries the MAC of a wireless access point of a non-3GPP network.

[0201] After the network device detects the MAC of the wireless access point of the non-3GPP network in the second data packet, it records the IP address (AGV_IP) and the MAC (Wi-Fi_AP_MAC) of the terminal device. The IP address of the terminal device can be obtained by reading the source IP address in the second data packet.

[0202] If the network device detects that the received data packet is not encapsulated using the encapsulation protocol, or does not carry the MAC of a wireless access point of a non-3GPP network, then the data packet is not a data packet transmitted between the terminal device and the server device. After receiving the data packet, the network device performs other processing on the data packet.

[0203] Step b2: The network device performs a decapsulation operation based on the second data packet to obtain a first serial number and a first data packet.

[0204] In some embodiments, the network device removes the MAC address of the wireless access point of the non-3GPP network from the second data packet to obtain a fifth data packet, and then performs a decapsulation operation on the fifth data packet.

[0205] The manner in which the network device performs a decapsulation operation on the fifth data packet corresponds to the manner in which the terminal device performs an encapsulation operation on the first data packet.

[0206] The network device decapsulates the fifth data packet based on the encapsulation protocol agreed upon by the terminal device and the network device to obtain the first serial number and the first data packet.

[0207] In some embodiments, the network device performs a decapsulation operation on the second data packet and also obtains a redundant identifier. The network device determines whether an abnormality occurs during the transmission of the second data packet based on the redundant identifier. If no abnormality occurs, subsequent operations can be performed.

[0208] Step b3: The network device determines whether there is a sequence number identical to the first sequence number among the second sequence numbers corresponding to at least one seventh data packet received historically.

[0209] Among them, the seventh data packet is a data packet encapsulated by using an encapsulation protocol agreed upon by the terminal device and the network device, and carries the MAC of an access point of a non-3GPP network.

[0210] Every time the network device receives a seventh data packet, it performs decapsulation processing based on the seventh data packet to obtain the second sequence number corresponding to the seventh data packet, and stores the second sequence number corresponding to the seventh data packet.

[0211] It can be understood that if there is a sequence number identical to the first sequence number among at least one of the stored second sequence numbers, it means that the network device has received a third data packet identical to the second data packet and has performed data transmission with the server device for the third data packet. The network device then executes S2043 to discard the second data packet to avoid repeated transmission of the data packet.

[0212] If there is no sequence number identical to the first sequence number among at least one stored second sequence number, it means that the network device has not yet received a third data packet that is exactly the same as the second data packet. The network device then executes S2044 and promptly transmits data with the server device based on the second data packet.

[0213] An embodiment of the present application provides a data transmission method, which specifically describes how a network device performs a decapsulation operation based on a second data packet and then performs data transmission with a server device based on the second data packet.

[0214] Figure 8This is a flowchart of the implementation of the data transmission method provided in this application. Figure 8 As shown, in Figure 7 Based on S2044, S2044a can achieve:

[0215] S2044a. The network device sends the first data packet to the server device.

[0216] It can be understood that before sending the first data packet, the terminal device needs to encapsulate the first data packet and add MAC to the encapsulated fifth data packet to send the second data packet to the network device.

[0217] Accordingly, after the network device performs the decapsulation operation based on the second data packet in step b2, it obtains the first data packet. The first data packet is the original data packet sent by the terminal device to the server device. Therefore, the network device sends the first data packet obtained by decapsulation to the server device to realize data transmission between the terminal device and the server device.

[0218] Figures 2 to 8 The embodiment describes the process of uplink data transmission between the terminal device and the server device. The process of downlink data transmission between the server device and the terminal device is similar to the process of uplink data transmission.

[0219] Next, through Fig. 9 The embodiment describes the process of downlink data transmission between a server device and a terminal device.

[0220] Fig. 9 The implementation flow chart of the data transmission method provided in the embodiment of the present application is as follows: Fig. 9 As shown, after S204, the method further includes:

[0221] S205. The network device receives an eighth data packet.

[0222] In this embodiment, the terminal device has not moved out of the second area.

[0223] It can be understood that in the embodiment of the present application, the network device can not only receive data packets sent by the server device, but also receive data packets sent by other devices, but the network device only performs the following dual-send selective reception operation on the data packets sent by the server device.

[0224] Therefore, after receiving the eighth data packet, the network device first detects the eighth data packet to determine whether the eighth data packet is sent by the server device.

[0225] Specifically, the network device detects whether the source IP address carried in the eighth data packet is the same as the source IP address of the server device. If they are the same, the eighth data packet is sent by the server device; if they are different, the eighth data packet is not sent by the server device.

[0226] S206: When the network device detects that the IP address carried in the eighth data packet is the same as the IP address of the server device, the network device generates a ninth data packet and a tenth data packet based on the eighth data packet.

[0227] It can be understood that the eighth data packet is sent by the server device, and the server device uses the dual-send and selective-receive protocol to transmit the eighth data packet to the terminal device, that is, the server device uses the first connection and the second connection to transmit the eighth data packet to the terminal device as described below.

[0228] The network device generates the ninth data packet and the tenth data packet based on the eighth data packet. Specifically, the network device copies the eighth data packet to obtain the eleventh data packet. The network device encapsulates the eighth data packet according to the encapsulation protocol agreed upon by the terminal device and the network device to obtain the ninth data packet. The network device encapsulates the eleventh data packet according to the encapsulation protocol agreed upon by the terminal device and the network device to obtain the tenth data packet.

[0229] The encapsulation operation for the eighth data packet is as follows: the network device adds the redundancy identifier and the third sequence number to the eighth data packet to obtain a ninth data packet.

[0230] The encapsulation operation for the eleventh data packet is as follows: the network device adds the redundancy identifier and the third sequence number to the eleventh data packet to obtain the tenth data packet.

[0231] The redundant identifier and the third sequence number used to encapsulate the eighth data packet are exactly the same as the redundant identifier and the third sequence number used to encapsulate the eleventh data packet.

[0232] That is, the ninth data packet and the tenth data packet are exactly the same.

[0233] If the eighth data packet is not sent by the server device, the server device does not generate the ninth data packet and the tenth data packet based on the eighth data packet. The network device directly forwards the eighth data packet to the wireless access point of the 3GPP network, and the wireless access point performs corresponding forwarding operations on the eighth data packet.

[0234] S207. The network device sends the ninth data packet to the terminal device via the first connection, and sends the tenth data packet to the terminal device via the second connection.

[0235] Specifically, with respect to the sending of the ninth data packet, the network device sends the ninth data packet to a wireless access point of the 3GPP network, and the wireless access point sends the ninth data packet to the terminal device based on the stored IP address (AGV_IP) of the terminal device.

[0236] Regarding the sending of the tenth data packet, the network device sends the tenth data packet to the wireless access point of the non-3GPP network based on the MAC of the wireless access point of the non-3GPP network stored in the network device, and the wireless access point of the non-3GPP network forwards the tenth data packet to the terminal device.

[0237] S208: The terminal device sends the first arriving data packet of the ninth data packet and the tenth data packet to the control device of the terminal device, and discards the second first arriving data packet.

[0238] When the terminal device is an AGV or a device on the AGV, the control device is an AGV controller. The AGV controller controls the running state of the AGV based on the ninth data packet or the tenth data packet.

[0239] The way in which the terminal device determines which of the ninth and tenth data packets arrives first is consistent with the way in which the network device determines which of the second and third data packets arrives first, both of which involve decapsulating the received data packet (the ninth or tenth data packet), obtaining the third sequence number, and making a judgment based on the third sequence number. For details, please refer to the way in which the network device determines which of the second and third data packets arrives first based on the first sequence number, which will not be described in detail here.

[0240] In this embodiment, when receiving a downlink data packet, the network device also sends the same downlink data packet to the terminal device based on the first connection and the second connection based on the dual-transmission and selective reception protocol. In this way, neither the network device nor the terminal device needs to perform complex network selection or network switching operations, simplifying the sending process for the downlink data packet.

[0241] It should be noted that although the steps of the method in the present application are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.; or, steps in different embodiments may be combined into a new technical solution.

[0242] Based on the foregoing embodiments, an embodiment of the present application provides a data transmission device, which includes the modules included and the units included in the modules, and can be implemented by a processor; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA), etc.

[0243] Fig.10 A schematic diagram of the structure of a data transmission device provided in an embodiment of the present application is shown in FIG. Fig.10 As shown, the data transmission device 100 includes a connection establishment module 1001, a first generation module 1002 and a first sending module 1003, wherein:

[0244] A connection establishment module 1001 is used to establish or maintain a first connection with a network device, and to establish or maintain a second connection with the network device when the terminal device moves from a first area to a second area; wherein, there is 3GPP network coverage in the first area, or there is non-3GPP network coverage in the first area, or there is no network coverage in the first area; there is 3GPP network coverage and non-3GPP network coverage in the second area; the first connection is established between the terminal device and the network device based on 3GPP wireless access technology, and the second connection is established between the terminal device and the network device based on non-3GPP wireless access technology;

[0245] A first generating module 1002, configured to generate a second data packet and a third data packet based on the first data packet to be sent; wherein the second data packet is identical to the third data packet;

[0246] The first sending module 1003 is used to send the second data packet to the network device through the first connection, and to send the third data packet to the network device through the second connection, so that the network device transmits data with the server device based on the first data packet arriving between the second data packet and the third data packet, and discards the second first arriving data packet.

[0247] In some embodiments, the first generation module 1002 is specifically used to generate a fourth data packet that is exactly the same as the first data packet; based on adding the first sequence number and the redundant identifier to the first data packet, the second data packet is obtained; based on adding the first sequence number and the redundant identifier to the fourth data packet, the third data packet is obtained; wherein the redundant identifier is used to verify the second data packet and the third data packet, and the first sequence number is used by the network device to determine whether the first data packet or the second data packet is the first data packet to arrive.

[0248] In some embodiments, the first generation module 1002 is specifically used to add the first serial number and the redundant identifier to the first data packet to obtain a fifth data packet; add the MAC of the wireless access point of the non-3GPP network to the fifth data packet to obtain the second data packet; add the first serial number and the redundant identifier to the fourth data packet to obtain a sixth data packet; add the MAC of the wireless access point of the non-3GPP network to the sixth data packet to obtain the third data packet; wherein the MAC is used to indicate that the second data packet and the third data packet are data packets sent to the server device.

[0249] In some embodiments, the first sending module 1003 is specifically used to send the second data packet to the network device through the first connection when it is detected that the RSRP of the reference signal received based on the first connection is greater than a first preset threshold; and send the third data packet to the network device through the second connection when it is detected that the strength of the AP beacon received based on the second connection is greater than a second preset threshold.

[0250] Based on the foregoing embodiments, an embodiment of the present application provides a data transmission device, which includes the modules included and the units included in the modules, and can be implemented by a processor; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA), etc.

[0251] Fig.11 A schematic diagram of the structure of a data transmission device provided in an embodiment of the present application is shown in FIG. Fig.11 As shown, the data transmission device 110 includes a receiving module 1101, a judging module 1102 and a second sending module 1103; wherein,

[0252] The receiving module 1101 is configured to receive a second data packet sent by a terminal device in a second area through a first connection; wherein the first connection is established between the terminal device and the network device based on a 3GPP wireless access technology;

[0253] The judgment module 1102 is used to judge whether a third data packet is received through a second connection before the second data packet is received; wherein the second connection is established between the terminal device and the network device based on a non-3GPP wireless access technology; when the terminal device moves from a first area to a second area, the terminal device establishes or maintains the first connection with the network device, and the terminal device establishes or maintains the second connection with the network device; wherein there is 3GPP network coverage in the first area, or there is non-3GPP network coverage in the first area, or there is no network coverage in the first area; there is 3GPP network coverage and non-3GPP network coverage in the second area;

[0254] The second sending module 1103 is specifically used to transmit data with the server device based on the second data packet if the network device has not received the third data packet before receiving the second data packet; if the network device receives the third data packet before receiving the second data packet, discard the second data packet.

[0255] In some embodiments, the judgment module 1102 is specifically used to perform a decapsulation operation based on the second data packet to obtain a first serial number; determine whether there is a serial number identical to the first serial number among the second serial numbers corresponding to at least one seventh data packet received historically; if there is a serial number identical to the first serial number among at least one of the second serial numbers, determine that the third data packet is received before the second data packet is received; if there is no serial number identical to the first serial number among at least one of the second serial numbers, determine that the third data packet is not received before the second data packet is received.

[0256] In some embodiments, the network device performs a decapsulation operation based on the second data packet and obtains a first data packet. The second sending module 1103 is specifically configured to send the first data packet to the server device.

[0257] In some embodiments, the data transmission device 110 also includes a detection module, which is used to detect the second data packet to determine that the second data packet is encapsulated using an encapsulation protocol agreed upon by the terminal device and the network device, and that the second data packet carries the MAC of the wireless access point of the non-3GPP network.

[0258] In some embodiments, the receiving module 1101 is further used to receive an eighth data packet. The data transmission device 110 further includes a second generation module, which is used to generate a ninth data packet and a tenth data packet based on the eighth data packet when it is detected that the source IP address carried in the eighth data packet is the same as the source IP address of the server device; wherein the ninth data packet and the tenth data packet are exactly the same; the second sending module 1103 is further used to send the ninth data packet to the terminal device through the first connection, and to send the tenth data packet to the terminal device through the second connection, so that the terminal device performs data transmission with the control device corresponding to the terminal device based on the first data packet that arrives between the ninth data packet and the tenth data packet, and discards the second first data packet that arrives.

[0259] It should be noted that in the embodiments of this application Fig.10 and Fig.11 The division of modules in the data transmission device shown is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit. It may also be implemented in the form of a combination of software and hardware.

[0260] The present application embodiment provides a terminal device, Fig.12 A schematic diagram of the hardware entity of the terminal device according to an embodiment of the present application is shown in FIG. Fig.12 As shown, the terminal device 120 includes a memory 121 and a processor 122, the memory 121 stores a computer program that can be run on the processor 122, and the processor 122 implements the steps in the method provided in the above embodiment when executing the program.

[0261] It should be noted that the memory 121 is configured to store instructions and applications executable by the processor 122, and can also cache data to be processed or processed by various modules in the processor 122 and the terminal device 120 (for example, image data, audio data, voice communication data, and video communication data), which can be implemented through flash memory (FLASH) or random access memory (Random Access Memory, RAM).

[0262] The present application embodiment provides a network device, Fig.13 A schematic diagram of the hardware entity of the network device of the embodiment of the present application is shown as follows: Fig.13As shown, the network device 130 includes a memory 131 and a processor 132. The memory 131 stores a computer program that can be run on the processor 132. When the processor 132 executes the program, the steps in the method provided in the above embodiment are implemented.

[0263] It should be noted that the memory 131 is configured to store instructions and applications executable by the processor 132, and can also cache data to be processed or processed by the processor 132 and various modules in the network device 130 (for example, image data, audio data, voice communication data, and video communication data), which can be implemented through flash memory (FLASH) or random access memory (Random Access Memory, RAM).

[0264] An embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps in the data transmission method provided in the above embodiment are implemented.

[0265] An embodiment of the present application provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the steps of the data transmission method provided in the above method embodiment.

[0266] The present application provides a communication system, such as Figure 1 As shown, it includes the terminal device and network device of the embodiment of the present application.

[0267] It should be noted here that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium, storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

Claims

1. A data transmission method, characterized in that: Applied to a terminal device, the method comprises: In the case where the terminal device moves from the first area to the second area, the terminal device establishes or maintains a first connection with the network device, and the terminal device establishes or maintains a second connection with the network device; wherein, there is a Third Generation Partnership Project 3GPP network coverage in the first area, or there is a non-3GPP network coverage in the first area, or there is no network coverage in the first area; the 3GPP network coverage and the non-3GPP network coverage exist in the second area; the first connection is established between the terminal device and the network device based on the 3GPP wireless access technology, and the second connection is established between the terminal device and the network device based on the non-3GPP wireless access technology; The terminal device generates a second data packet and a third data packet based on the first data packet to be sent; wherein the second data packet is completely identical to the third data packet; The terminal device sends the second data packet to the network device through the first connection, and the terminal device sends the third data packet to the network device through the second connection, so that the network device performs data transmission with the server device based on the first data packet arriving between the second data packet and the third data packet, and discards the second first data packet arriving.

2. The method according to claim 1, characterized in that The terminal device generates a second data packet and a third data packet based on a first data packet to be sent, including: The terminal device generates a fourth data packet that is identical to the first data packet; The terminal device obtains the second data packet based on adding the first sequence number and the redundancy identifier to the first data packet; The terminal device obtains the third data packet based on adding the first sequence number and the redundant identifier to the fourth data packet; The redundant identifier is used to verify the second data packet and the third data packet, and the first sequence number is used by the network device to determine whether the first data packet or the second data packet is the first data packet to arrive.

3. The method according to claim 2, characterized in that The terminal device obtains the second data packet based on adding the first sequence number and the redundancy identifier to the first data packet, including: The terminal device adds the first sequence number and the redundant identifier to the first data packet to obtain a fifth data packet; The terminal device adds the media access address MAC of the wireless access point of the non-3GPP network to the fifth data packet to obtain the second data packet; The terminal device obtains the third data packet based on adding the first sequence number and the redundant identifier to the fourth data packet, including: The terminal device adds the first sequence number and the redundant identifier to the fourth data packet to obtain a sixth data packet; The terminal device adds the MAC of the wireless access point of the non-3GPP network to the sixth data packet to obtain the third data packet; The MAC is used to indicate that the second data packet and the third data packet are data packets sent to the server device.

4. The method according to claim 1, characterized in that: The terminal device sending the second data packet to the network device through the first connection includes: When the terminal device detects that a reference signal received power RSRP of a reference signal received based on the first connection is greater than a first preset threshold, the terminal device sends the second data packet to the network device through the first connection; The terminal device sending the third data packet to the network device through the second connection includes: When the terminal device detects that the strength of the access point AP beacon received based on the second connection is greater than a second preset threshold, the terminal device sends the third data packet to the network device through the second connection.

5. A data transmission method, characterized in that: Applied to a network device, the method comprises: The network device receives a second data packet sent by the terminal device in the second area through a first connection; wherein the first connection is established between the terminal device and the network device based on 3GPP wireless access technology; The network device determines whether a third data packet is received through a second connection before receiving the second data packet; wherein the second connection is established between the terminal device and the network device based on a non-3GPP wireless access technology; when the terminal device moves from a first area to the second area, the terminal device establishes or maintains the first connection with the network device, and the terminal device establishes or maintains the second connection with the network device; wherein there is 3GPP network coverage in the first area, or there is non-3GPP network coverage in the first area, or there is no network coverage in the first area; and there is both the 3GPP network coverage and the non-3GPP network coverage in the second area; If the network device does not receive the third data packet before receiving the second data packet, the network device performs data transmission with the server device based on the second data packet; If the network device receives the third data packet before receiving the second data packet, the network device discards the second data packet.

6. The method according to claim 5, characterized in that The network device determines whether a third data packet is received through the second connection before receiving the second data packet, including: The network device performs a decapsulation operation based on the second data packet to obtain a first sequence number; The network device determines whether there is a sequence number identical to the first sequence number among the second sequence numbers corresponding to at least one seventh data packet received historically; If at least one of the second sequence numbers includes a sequence number that is the same as the first sequence number, the network device determines that the third data packet is received before the second data packet is received; If there is no sequence number identical to the first sequence number in at least one of the second sequence numbers, the network device determines that the third data packet has not been received before the second data packet is received.

7. The method according to claim 6, characterized in that The network device performs a decapsulation operation based on the second data packet to obtain a first data packet. The network device performs data transmission with the server device based on the second data packet; comprising: The network device sends the first data packet to the server device.

8. The method according to claim 5, characterized in that Before the network device performs a decapsulation operation on the second data packet, the method further includes: The network device detects the second data packet and determines that the second data packet is encapsulated using an encapsulation protocol agreed upon by the terminal device and the network device, and that the second data packet carries the MAC of the wireless access point of the non-3GPP network.

9. The method according to claim 5, characterized in that The method further comprises: The network device receives an eighth data packet; When the network device detects that the source Internet Protocol IP address carried in the eighth data packet is the same as the source IP address of the server device, the network device generates a ninth data packet and a tenth data packet based on the eighth data packet; wherein the ninth data packet and the tenth data packet are exactly the same; The network device sends the ninth data packet to the terminal device via the first connection, and sends the tenth data packet to the terminal device via the second connection, so that the terminal device performs data transmission with the control device corresponding to the terminal device based on the first data packet that arrives between the ninth data packet and the tenth data packet, and discards the second first data packet.

10. A wireless communication system, characterized in that: It comprises a terminal device and a network device; wherein the terminal device is used to execute the method described in any one of claims 1 to 4, and the network device is used to execute the method described in any one of claims 5 to 9.

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