A system and method for wia-fa and 5g fusion

Abstract

The application relates to a WIA-FA and 5G fusion system and method. The system comprises field devices, access devices, a central gateway device and a host computer; the central gateway device is responsible for WIA-FA network management and security management, allocates a unique short address for each device, allocates channel time slot resources for WIA-FA device communication, manages keys of the whole network, and authenticates all field devices accessing the WIA-FA network; a key management mechanism including key establishment and key update in the WIA-FA system is utilized to mutually authenticate the central gateway device; when a gateway is online, the WIA-FA-IF device is authenticated, then the IF device performs identity authentication on the gateway, and the two times of authentication are both passed through the gateway, so that the IF device can normally access the network; the central gateway device and the field device are internally provided with a root key, which is used as a voucher for authentication and verification of the core network; 5G core network management and a security mechanism across the WIA-FA system are realized.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, and relates to the application of WIA-FA communication networks in industrial field wireless systems, and particularly to a system and method for integrating WIA-FA (Wireless Networks for Industrial Automation - Factory Automation) with 5G. Background Technology

[0002] In industrial applications, especially within factories and workshops, the interconnection of numerous sensors, controllers, and mobile devices places high demands on communication networks for reliability, low latency, and high security. While fifth-generation mobile communication technology (5G) offers advantages such as high speed, large bandwidth, and low latency, it still faces limitations in practical industrial scenarios, including high deployment costs, limited indoor coverage, insufficient equipment compatibility, and spectrum interference.

[0003] Wireless Local Access Networks (WLANs), especially high-security field-grade WLANs, can compensate for the shortcomings of 5G networks in industrial field applications. WLANs are characterized by low cost, ease of deployment, and communication privacy, meeting the high reliability and flexibility requirements of industrial environments. However, field-grade WLANs also have some problems, such as susceptibility to spectrum interference, limited coverage, and insufficient capacity. These problems are particularly prominent in industrial environments because industrial equipment typically requires stable communication connections, while wireless signals are easily affected by environmental factors. Therefore, a complementary system and method integrating high-security field-grade WLANs and 5G private networks needs to be considered to achieve more efficient and secure industrial communication.

[0004] Industrial wireless LAN technologies such as WIA-FA (Wireless Networks for Industrial Automation - Factory Automation) provide highly reliable, low-latency communication services, suitable for scenarios such as industrial automation control. Furthermore, the deployment cost of wireless LANs is relatively low, making them suitable for large-scale deployment within factory workshops, thereby reducing overall communication costs. While 5G private networks provide high-bandwidth, wide-connectivity, and highly reliable communication services for industrial scenarios, wireless LANs can compensate for the shortcomings of 5G private networks in terms of coverage and deployment cost. Combining the two to build a hybrid communication network satisfies the high reliability and low latency requirements of industrial equipment while also considering cost-effectiveness and deployment flexibility.

[0005] Therefore, considering factors such as the specific scenarios in existing industrial applications, 5G private network policies, usage costs, and data security, current networks are not suitable for all industrial application scenarios. The interconnection of numerous sensors, controllers, and mobile devices within factory workshops is better suited to WLAN communication. WLAN's low cost, ease of deployment, and communication privacy can compensate for the shortcomings of 5G networks in industrial field applications. However, field-level WLAN also suffers from issues such as spectrum susceptibility to interference and limitations in coverage and capacity.

[0006] In existing technologies, WIA-FA systems and 5G networks lack an effective integration mechanism, making it difficult to achieve unified management of multiple WIA-FA systems by the 5G core network. Furthermore, the security mechanisms across WIA-FA systems are inadequate. Therefore, a system and method for integrating WIA-FA and 5G are urgently needed to address these technical issues. Summary of the Invention

[0007] The purpose of this invention is to address the problems of existing wireless local area networks, such as susceptibility to spectrum interference, coverage limitations, and capacity constraints, by providing a system and method for integrating WIA-FA and 5G. Based on the fact that WIA-FA gateway devices already have the ability to authenticate field devices, the integration of WIA-FA and 5G enables the 5G core network to uniformly manage multiple WIA-FA systems, builds a security mechanism across WIA-FA systems, effectively supplements the application of 5G networks in indoor industrial scenarios, and reduces the investment and deployment costs and maintenance difficulties of network construction.

[0008] To achieve the above objectives, the present invention adopts the following technical solution.

[0009] In a first aspect, this invention proposes a WIA-FA integrated system with 5G, referred to as the WIA-FA system, which adopts an enhanced star topology and includes: field devices, access devices, a central gateway device, and a main control computer. The main control computer is connected to the central gateway device, and the central gateway device is connected to multiple access devices, with each access device wirelessly connected to multiple field devices.

[0010] The central gateway device includes a network management module and a security management module. The network management module is responsible for allocating a unique short address and WIA-FA communication channel time slot resources to each device. The security management module is responsible for key management and access authentication for the entire network; key management includes key establishment and key updates.

[0011] Preferably, the system adopts an enhanced star topology, wherein the central gateway device is connected to multiple access devices via a wired connection, and the access devices are connected to multiple field devices via a wireless connection.

[0012] Preferably, the system further includes a WIA-FA Interworking Function (WIA-FA-IF). The WIA-FA-IF connects multiple central gateway devices via wired connections, enabling multiple WIA-FA systems to access the 5G core network. The WIA-FA-IF communicates with the Access and Mobility Management Function (AMF) on the signaling plane via the N2 interface and with the User Plane Function (UPF) on the user plane via the N3 interface.

[0013] Preferably, the WIA-FA-IF has an N2 / N3 interface protocol stack defined by 3GPP. The N2 interface protocol stack adopts the NG-AP protocol, with SCTP as the transport layer, and manages the NAS signaling connection with the AMF through a NAS (Non-Access Stratum) layer at the upper layer. The N3 interface protocol stack adopts the GRE (Generic Routing Encapsulation) protocol to implement Ethernet sessions for upper-layer protocol data units. The UPF implements user plane functions, including packet routing and forwarding, policy enforcement, traffic reporting, and QoS (Quality of Service) processing.

[0014] Preferably, both the central gateway device and the field devices have a built-in 3GPP-defined root key as the authentication credential provided by the 5G core network. The WIA-FA-IF utilizes the WIA-FA system's key management mechanism for bidirectional authentication with the central gateway device. The WIA-FA-IF performs initial authentication on the online central gateway. After the initial authentication is successful, the central gateway performs secondary authentication with the WIA-FA-IF. After both authentications are successful, the central gateway can be connected to the network normally.

[0015] Preferably, for the central gateway device that has joined the network, the WIA-FA-IF acquires and stores data from its downstream devices, including the identification information, root key, and device status information of the central gateway device and the field devices, to achieve security information synchronization.

[0016] A second aspect of this invention proposes a method for integrating WIA-FA with 5G, implemented based on the aforementioned system, including a 5G-AKA (5G Authentication and Key Agreement) authentication process and a session management process. Specifically, 5G-AKA authentication is implemented through a WIA-FA-IF device, and the 5G-AKA authentication process and session management process are executed by proxy by obtaining the device's root key and device identification information.

[0017] The 5G-AKA authentication process is executed by the WIA-FA-IF proxy. Whenever a field device comes online, the WIA-FA-IF obtains the device's root key and device identification information, and performs the following steps: S1. The WIA-FA-IF sends an authentication request to the AMF through the N2 interface; S2. The AMF queries the Unified Data Management (UDM) function of the home network to obtain the Authentication Vector (AV). The Authentication Vector includes a random number (RAND), expected response (XRES), key sequence (KASME), and authentication token (AUTN). S3. After receiving the authentication vector, the WIA-FA-IF uses the root key of the corresponding device and the RAND to calculate the actual response (RES). S4. Compare the RES with the XRES. If the match is successful, the authentication is passed and the session management process begins. If the match fails, the process is terminated and the exception is recorded.

[0018] Preferably, the session management process is completed collaboratively by the Session Management Function (SMF) and the UPF, and the WIA-FA-IF agent executes it, including the following steps: Step 1: After the device completes 5G authentication, it requests a session request from the WIA-FA-IF. The WIA-FA-IF proxy device then sends a PDU (Protocol Data Unit) session request to the AMF. Step 2: The AMF selects the SMF, the SMF assigns a PDU session ID and requests the UPF to configure the data path; Step 3: The UPF creates a GTP-U (GPRS Tunneling Protocol for User Plane) tunnel or PFCP (Packet Forwarding Control Protocol) session, prepares to forward data, and returns a confirmation that the session has been successfully established; Step 4: The WIA-FA-IF interacts with the UPF through the N3 interface, establishing a user plane tunnel using GRE encapsulation. After the session management process is completed, the device transmits data normally, and the UPF takes over the user plane functions.

[0019] Preferably, the authentication process between the WIA-FA-IF and the central gateway device is executed before the 5G-AKA authentication process. The WIA-FA-IF performs the initial authentication on the online central gateway; after the initial authentication is successful, the central gateway performs a secondary authentication with the WIA-FA-IF; after both authentications are successful, the central gateway is successfully connected to the network, and its downstream field devices trigger the 5G-AKA authentication process.

[0020] Preferably, after the central gateway joins the network, the WIA-FA-IF acquires and stores its downstream device data, including the identification information, root key, and device status information of the central gateway device and the field device. When the field device comes online, the WIA-FA-IF extracts the root key of the corresponding device from the stored data for RES calculation in the 5G-AKA authentication process.

[0021] Beneficial effects This invention proposes a system and method for integrating WIA-FA with 5G, which has the following advantages compared with existing technologies: 1. The system proposed is designed for industrial applications and combines the advantages of two networks to propose a network architecture, data interoperability and security mechanism. It not only effectively supplements the application of 5G network in indoor scenarios, but also reduces the investment and deployment costs and maintenance difficulty of 5G network construction. 2. The fusion method provides higher indoor coverage density, lower wireless transmission latency guarantee, and higher reliability, forming a wireless interconnection that can be practically implemented and effectively solve the problem of intelligent upgrading of enterprises, and solving the integrated application of high-security wireless local area network WIA-FA and 5G network system in industrial sites; 3. The integrated system combines the high real-time performance, high reliability, and high security of locally deployed systems with the high bandwidth and large capacity advantages of 5G wide area networks to achieve precise control within the workshop and collaborative operations across factory areas; 4. The integrated system reduces terminal network maintenance costs: WIA-FA local area network has low deployment cost, is easy to expand and maintain in the workshop and does not rely on the core network, which can greatly alleviate the problems of high deployment cost and high maintenance difficulty of 5G network in fixed areas. 5. The fusion method described above can achieve better data security protection. Specifically, it transmits data within the WIA-FA local area network and implements differentiated encryption according to the enterprise, effectively protecting the security of enterprise industrial production data. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the composition and connection principle of a WIA-FA and 5G converged system according to an embodiment of the present invention. Figure 2 This is an application scenario architecture for a specific implementation of a WIA-FA and 5G converged system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a WIA-FA-IF device in a specific implementation of a WIA-FA and 5G convergence system according to an embodiment of the present invention. Figure 4 This is a flowchart illustrating the authentication and session process of the WIAFA system and the 5G core network convergence system in a specific implementation of a WIA-FA and 5G convergence method according to an embodiment of the present invention. Detailed Implementation

[0023] The following detailed description of the specific implementation of a WIA-FA and 5G convergence system and method of the present invention, with reference to the accompanying drawings and embodiments, is provided in detail.

[0024] To facilitate a clear description of the technical solutions in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0025] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0026] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c" can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0027] Example 1 This invention provides a system and method for integrating WIA-FA and 5G in industrial applications. Combining the advantages of both networks, it proposes a network architecture, key data interoperability technologies, and security mechanisms. This effectively complements 5G network technology in indoor applications, reducing the investment and deployment costs and maintenance difficulties of 5G network construction. It also provides higher indoor coverage density, lower wireless transmission latency, and higher reliability, forming a wireless interconnection system and method that can be practically implemented and effectively solve the challenges of intelligent upgrading for enterprises. This invention addresses the integrated application of high-security wireless LAN WIA-FA and 5G network systems in industrial settings.

[0028] This invention provides a system and method based on the convergence of WIA-FA network and 5G. Since the WIA-FA gateway device already has the ability to authenticate field devices, by integrating WIA-FA and 5G, the 5G core network can manage multiple WIA-FA systems and build a security mechanism across WIA-FA systems.

[0029] The specific components of the WIA-FA system are as follows: Figure 1 As shown, the system consists of field devices, access devices, a gateway device, and a main control computer. It employs an enhanced star topology, where a central gateway device connects to multiple access devices via wired connections, and these access devices then wirelessly connect to multiple field devices. The gateway device is responsible for WIA-FA network management and security management. Specifically, the network management module is responsible for assigning unique short addresses to each device and allocating communication channels and time slots for WIA-FA devices; the security management module is responsible for key management (including key establishment and key updates) and authenticating all field devices accessing the WIA-FA network. This invention utilizes a WIA-FA Interworking Function (WIA-FA-IF) module to connect multiple WIA-FA systems via a wired connection to a central gateway device, enabling unified management of multiple WIA-FA systems accessing the 5G core network. The 5G core network includes WIA-FA-IF, AMF, UPF, SMF, AUSF (Authentication Server Function), UDM, and PCF (Policy Control Function). The WIA-FA-IF connects to the AMF via the N2 interface and to the UPF via the N3 interface. The AMF, UPF, SMF, AUSF, UDM, and PCF are each connected to a bus. The 5G core network system is connected to a main control computer. The WIA-FA-IF acts as a proxy device for interconnecting the WIA-FA system's central gateway device with the 5G core network. It performs signaling plane communication with the AMF via the N2 interface and uplink / downlink user plane data transmission with the UPF via the N3 interface, thus serving as a user terminal device for network access.

[0030] like Figure 2 The application scenario architecture shown is as follows: WIA-FA-IF connects multiple WIA-FA systems via wired gateway devices, enabling multiple WIA-FA systems to access the 5G core network for management. It realizes signaling plane communication transmission with AMF through the N2 interface and uplink and downlink user plane data transmission with UPF through the N3 interface, thus serving as a user terminal device to access the network.

[0031] The schematic diagram of the WIA-FA-IF device is as follows: Figure 3 As shown.

[0032] WIA-FA-IF utilizes the key management mechanism in the WIA-FA system to achieve mutual authentication between WIA-FA-IF and gateway devices: when a gateway comes online, it authenticates with the WIA-FA-IF device. After the gateway authentication is successful, the WIA-FA-IF device authenticates its identity with the gateway. After both authentications are successful, the device can access the network normally.

[0033] Gateway devices and field devices have a built-in 3GPP-defined root key, which serves as the core network's authentication credential. For network access gateway devices, WIA-FA-IF can obtain data from downstream devices of the gateway device and store it as a data list or database, including information such as the gateway device and field device identifiers, root keys, and device status.

[0034] WIA-FA-IF features a 3GPP-defined N2 / N3 interface protocol stack, serving as a proxy device for interconnecting the WIA-FA system gateway with the 5G core network. Above the common physical, data link, and network layers: the N2 interface uses the NGAP protocol, and the transport layer is SCTP.

[0035] Upper-layer users can establish and release NAS signaling connections with the AMF at the NAS non-access layer; the N3 interface uses the GRE general routing encapsulation protocol to implement Ethernet sessions of upper-layer protocol data units, and the UPF further implements user plane functions, including packet routing and forwarding, policy enforcement, traffic reporting, QoS processing, etc.

[0036] WIA-FA-IF implements the 5G-AKA authentication algorithm. Using the obtained device root key and device identification information, it proxies the execution of the 5G-AKA authentication and session management processes: Whenever a field device comes online, WIA-FA-IF first sends an authentication request to the AMF via the N2 interface. The AMF queries its home network (e.g., UDM) to obtain the authentication vector (AV), which includes: RAND (random number), XRES (expected response), KASME (key sequence), and AUTN (authentication token). After receiving the AV returned by the AMF, WIA-FA-IF uses the corresponding device's root key and RAND to calculate the actual response RES. The calculated RES is compared with the XRES provided by the AMF. If a match is found, authentication is successful, and the device enters the session management phase, allowing it to access core network services. If a mismatch occurs, authentication fails, the process terminates, and an exception is recorded.

[0037] Session management is handled collaboratively by the SMF (Session Management Function) and UPF (User Plane Function), with WIA-FA-IF acting as the proxy: After the device completes 5G authentication, it immediately requests a session from the WIA-FA-IF. The WIA-FA-IF then proxies the device to send a PDU Session Request (e.g., an Ethernet session) to the AMF. The AMF selects the SMF, which assigns a PDU Session ID and requests the UPF to configure the data path. The UPF creates a GTP-U tunnel (or PFCP session), prepares to forward data, and returns a confirmation of successful session establishment. The WIA-FA-IF interacts with the UPF through the N3 interface (GRE encapsulation) to establish the user plane tunnel. The device can then transmit data normally, and the UPF takes over the user plane functions.

[0038] The end-to-end transmission latency of standalone 5G networks is constrained by base station relay and operator network relay, and can only reach an average of tens of milliseconds, which is difficult to meet the communication latency requirements of control data in factory automation. The high real-time and high reliability characteristics of WIA-FA technology are more suitable for application in factory automation communication, with an air interface latency as low as 100us, which is more in line with industrial application terminals than the minimum 1m of 5G.

[0039] The specific implementation of the authentication and session flowchart of the WIAFA system and the 5G core network convergence system is as follows: Figure 4 As shown. WIA-FA-IF utilizes the key management mechanism in the WIA-FA system to achieve mutual authentication between WIA-FA-IF and gateway devices: when a gateway comes online, it authenticates with the WIA-FA-IF device. After successful gateway authentication, the WIA-FA-IF device authenticates its identity with the gateway. Only after both authentications pass the gateway can the device successfully access the network. Similarly, access devices and field devices can access the WIA-FA network through the two-way authentication function. Gateway devices and field devices have a built-in root key defined by 3GPP, which serves as the core network's authentication credential. For network access gateway devices, WIA-FA-IF can obtain data from downstream devices of the gateway device and store it as a data list or database, including information such as the gateway device and field device identifiers, root keys, and device status, and synchronize security information.

[0040] Whenever a field device comes online, WIA-FA-IF first sends an Authentication Request to the AMF via the N2 interface. The AMF queries its home network (e.g., UDM) to obtain the Authentication Vector (AV), which includes: RAND (random number), XRES (expected response), KASME (key sequence), and AUTN (authentication token). After receiving the AV returned by the AMF, WIA-FA-IF uses the root key and RAND of the corresponding device to calculate the RES (actual response). The calculated RES is compared with the XRES provided by the AMF. If they match, authentication is successful, and the device enters the session management phase, allowing it to access core network services. If they do not match, authentication fails, the process terminates, and an exception is logged.

[0041] After the device completes 5G authentication, it immediately requests a session from WIA-FA-IF. WIA-FA-IF then proxies the device to send a PDU Session Request (e.g., an Ethernet session) to the AMF. The AMF selects the SMF, which assigns a PDU SessionID and requests the UPF to configure the data path. The UPF creates a GTP-U tunnel (or PFCP session), prepares to forward data, and returns a confirmation of successful session establishment. WIA-FA-IF interacts with the UPF through the N3 interface (GRE encapsulation) to establish a user plane tunnel. The device can then transmit data normally, and the UPF takes over the user plane functions.

[0042] The end-to-end transmission latency of standalone 5G networks is limited by base station relay and operator network relay, and can only reach an average of tens of milliseconds, which is difficult to meet the communication latency requirements of control data in factory automation. The high real-time and high reliability characteristics of WIA-FA technology are more suitable for use in automated communication in factory scenarios. The air interface latency can be as low as 100 μs, which is more in line with the stringent latency requirements of industrial application terminals compared to 5G's minimum of 1 ms.

[0043] The WIA-FA and 5G convergence system and method provided by this invention can be widely applied to industrial scenarios such as intelligent manufacturing, industrial automation, energy and power, and rail transportation, to achieve high real-time control communication within the workshop's WIA-FA local area network; 5G wide-area collaborative communication across workshops and factories; unified security management and core network authentication; and flexible expansion of multi-system convergence deployment.

[0044] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the description of the drawings, in carrying out the claimed invention. In this specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can implement several of the functions listed in the specification. While certain measures are described in different embodiments, this does not mean that these measures cannot be combined to produce good results.

[0045] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the invention and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications fall within the scope of the invention and its equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A WIA-FA integrated 5G system, characterized in that, The system includes: a main control computer, a central gateway device, access devices, and field devices; The main control computer is connected to the central gateway device, and the central gateway device is connected to multiple access devices, each of which is wirelessly connected to multiple field devices; The central gateway device includes a network management module and a security management module. The network management module is responsible for allocating a unique short address and WIA-FA communication channel time slot resources to each device. The security management module is responsible for key management and access authentication for the entire network. Key management includes key establishment and key update.

2. The system according to claim 1, characterized in that, The system adopts an enhanced star topology, and the central gateway device is connected to multiple access devices via wired connection, while the access devices are connected to multiple field devices via wireless connection.

3. The system according to claim 1, characterized in that, The system also includes a WIA-FA interconnection function module, namely WIA-FA-IF, which connects multiple central gateway devices via wired means to enable multiple WIA-FA systems to access the 5G core network; The WIA-FA-IF communicates with the access and mobility management functions via the N2 interface for signaling plane communication and with the user plane functions via the N3 interface for user plane data transmission.

4. The system according to claim 3, characterized in that, The WIA-FA-IF has an N2 / N3 interface protocol stack defined by 3GPP; the N2 interface protocol stack adopts the NG-AP protocol, the transport layer is SCTP, and the upper layer manages the NAS signaling connection with the AMF through the NAS non-access layer; the N3 interface protocol stack adopts the GRE general routing encapsulation protocol to realize the Ethernet session of the upper layer protocol data unit, and the UPF implements the user plane functions, including packet routing forwarding, policy enforcement, traffic reporting and QoS processing.

5. The system according to claim 3, characterized in that, The central gateway device and the field devices have a built-in root key defined by 3GPP, which serves as the authentication credential for the 5G core network. The WIA-FA-IF utilizes the key management mechanism of the WIA-FA system to perform two-way authentication with the central gateway device. The WIA-FA-IF performs an initial authentication on the central gateway. After the initial authentication is successful, the central gateway performs a secondary authentication with the WIA-FA-IF. After both authentications are successful, the central gateway is successfully connected to the network.

6. The system according to claim 5, characterized in that, For the central gateway device that joins the network, the WIA-FA-IF acquires and stores data from its downstream devices, including the identification information, root key, and device status information of the central gateway device and the field devices, to achieve security information synchronization.

7. A method for integrating WIA-FA with 5G, based on the system implementation as described in any one of claims 1 to 6, including 5G-AKA authentication and session management, characterized in that, The 5G-AKA authentication process is executed by WIA-FA-IF proxy. Whenever a field device comes online, WIA-FA-IF obtains the device's root key and device identification information, and performs the following steps: S1. The WIA-FA-IF sends an authentication request to the Access and Mobility Management Function (AMF) through the N2 interface; S2. The AMF queries the User Data Management Function (UDM) of the home network to obtain the authentication vector, which includes a random number, expected response XRES, key sequence and authentication token. After receiving the authentication vector returned by AMF, S3 and WIA-FA-IF use the root key of the corresponding device and a random number to calculate the actual response RES. S4. Compare the RES with the XRES. If a match is found, authentication is successful, and the session management process begins. If a match fails, the process is terminated and the exception is logged.

8. The method according to claim 7, characterized in that, The session management process is completed collaboratively by the Session Management Function (SMF) and the User Plane Function (UPF), and is executed by the WIA-FA-IF proxy, including the following steps: Step 1: After the device completes 5G authentication, it requests a session request from the WIA-FA-IF. The WIA-FA-IF proxy device then sends a PDU session request to the AMF. Step 2: The AMF selects the SMF, and the SMF assigns a PDU session identifier and requests the UPF to configure the data path; Step 3: The UPF creates a GTP-U tunnel or PFCP session, prepares to forward data, and returns a confirmation that the session has been successfully established. Step 4: The WIA-FA-IF interacts with the UPF through the N3 interface and establishes a user plane tunnel using GRE encapsulation; After the session management process is completed, the device transmits data normally, and the UPF takes over the user plane function.

9. The method according to claim 8, characterized in that, The authentication process between the WIA-FA-IF and the central gateway device is executed before the 5G-AKA authentication process, including: The WIA-FA-IF performs initial authentication on the central gateway. After the initial authentication is successful, the central gateway performs secondary authentication with the WIA-FA-IF. After both authentications are successful, the central gateway is able to access the network normally, and its downstream field devices trigger the 5G-AKA authentication process.

10. The method according to claim 9, characterized in that, After the central gateway joins the network, the WIA-FA-IF acquires and stores its downstream device data, including the identification information, root key and device status information of the central gateway device and the field device; When the field device comes online, the WIA-FA-IF extracts the root key of the corresponding device from the stored data, which is used for RES calculation in the 5G-AKA authentication process.

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