Railway signal system mobile internet business continuity assurance system supporting 5g and 4g dual-mode switching

Abstract

The application discloses a railway signal system mobile internet business continuity guarantee system supporting 5G and 4G dual-mode switching, comprising: a network state real-time monitoring unit, used for collecting 5G network and 4G network communication parameters of a target area in a railway signal system mobile internet scene, wherein the communication parameters at least include 5G / 4G signal strength, network coverage range, transmission delay; a 5G-4G mode switching control unit, electrically connected with the network state real-time monitoring unit, receiving the communication parameters and generating a mode switching instruction. Through the setting of the network state real-time monitoring unit and the 5G-4G mode switching control unit, a precise dual-mode switching mechanism is constructed, the signal strength, coverage range, transmission delay and other parameters of the 5G and 4G networks can be collected in real time, and the switching instruction is generated based on the preset threshold, so that the automatic switching of the 5G and 4G modes is realized, and the mechanism can adapt to the network coverage differences of different areas in the railway signal system mobile internet scene.

Description

Technical Field

[0001] This invention relates to the field of railway signaling system technology, specifically to a railway signaling system mobile internet service continuity assurance system that supports 5G and 4G dual-mode switching. Background Technology

[0002] The railway signaling system is a key technical equipment for ensuring train operation safety and improving transportation efficiency. It covers multiple subsystems such as station signal control system, section signal control system, and train operation control system. Its network architecture adopts an internal dedicated network. Except for the on-board system, which accesses the dedicated mobile network through the railway dedicated GSM-R, the rest of the ground equipment relies on wired networks. Furthermore, the business data interaction between the subsystems is achieved through firewalls or network gateways.

[0003] While this dedicated network architecture ensures the stability and security of the railway signaling system to a certain extent, it also brings significant limitations: First, the maintenance of the railway signaling system's network and equipment relies on internal maintenance equipment and terminals. Maintenance personnel need to obtain data and alarm information through periodic review and inspection, resulting in data acquisition delays and the potential for missing important alarm information, which can escalate into malfunctions. Second, during on-site outdoor operations, workers are limited by fixed management terminals and cannot view the necessary auxiliary data in a timely manner. Furthermore, it is difficult to confirm the equipment's recovery status in real time after maintenance, leading to low maintenance efficiency. Third, the closed nature of the signaling system restricts the value mining of signaling data and hinders the innovative development of the signaling system in the directions of intelligence, automation, and informatization.

[0004] With the rapid development of network security, computer communication, and mobile internet technologies, extending signaling systems from dedicated networks to mobile terminals through secure interconnection and data transfer technologies has become a trend. However, mobile communication inherently possesses characteristics such as terminal mobility, network openness, and the vulnerability of wireless transmission. Mobile terminal access faces challenges including terminal security risks, untrusted access users, threats to communication links, and application-level security risks. Simultaneously, current mobile networks are evolving towards a coexistence of 5G and 4G. In the context of mobile internet in railway signaling systems, a single network standard is insufficient to adapt to the network coverage of different areas. Network standard switching can easily lead to communication link interruptions and data transmission stagnation, failing to meet the high requirements of service continuity for railway signaling systems. Therefore, a mobile internet system that supports dual-standard switching between 5G and 4G and ensures service continuity is urgently needed to achieve stable operation of mobile internet services in railway signaling systems while ensuring security. Summary of the Invention

[0005] The purpose of this invention is to provide a mobile internet service continuity assurance system for railway signaling systems that supports 5G and 4G dual-mode switching, so as to solve the problems existing in the prior art mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a mobile internet service continuity assurance system for railway signaling systems supporting 5G and 4G dual-mode switching, comprising:

[0007] A real-time network status monitoring unit is used to collect 5G and 4G network communication parameters of the target area in the mobile Internet scenario of the railway signaling system. The communication parameters include at least 5G / 4G signal strength, network coverage, and transmission latency.

[0008] The 5G-4G standard switching control unit is electrically connected to the network status real-time monitoring unit, receives the communication parameters and generates standard switching instructions, including 5G network access instructions, 4G network access instructions and 5G fallback to 4G automatic switching instructions.

[0009] A dedicated mobile safety smart terminal is communicatively connected to the 5G-4G standard switching control unit, responds to the standard switching command to realize automatic switching between 5G and 4G standards, and is used to acquire and interact with railway signal system data;

[0010] The mobile virtual private network is built on the operator's 5G / 4G core network and is isolated from the public network using APN / VPDN technology. Under the control of the standard switching command, it provides a dual-standard dedicated communication link for the dedicated mobile security smart terminal and supports seamless connection of the communication link during the switching process.

[0011] The safe one-way ferry subsystem connects the mobile virtual private network with the railway signaling system and maintains railway signal data transmission when the dedicated mobile safety smart terminal switches between 5G and 4G standards.

[0012] The security management subsystem is communicatively connected to the network status real-time monitoring unit, the 5G-4G standard switching control unit, the dedicated mobile security smart terminal, the mobile virtual private network, and the security one-way transfer subsystem to monitor the 5G-4G standard switching status and the service transmission status during the switching process.

[0013] The switching logic of the 5G-4G standard switching control unit is as follows:

[0014] When the 5G signal strength collected by the real-time network status monitoring unit meets the preset threshold and the target area is within the 5G network coverage area, a 5G network access command is generated.

[0015] When the 5G signal strength is lower than the preset threshold or there is no 5G network coverage in the target area, and the 4G signal strength meets the communication requirements, a 5G fallback to 4G automatic switching command or a 4G network access command is generated.

[0016] When the 5G network recovers to meet the preset threshold and coverage requirements, a command is generated to switch back to the 5G network.

[0017] Preferably, the dedicated mobile security smart terminal includes customized hardware, security-hardened components, and a dedicated SIM card with a national cryptographic chip, wherein:

[0018] The dedicated mobile security smart terminal has a built-in signal receiving module, which is used to receive 5G / 4G signal data fed back by the network status real-time monitoring unit, and cooperate with the 5G-4G standard switching control unit to realize standard switching;

[0019] The dedicated SIM card and the dedicated mobile security smart terminal are bound one-to-one, and identity authentication is completed through a national cryptographic chip during the switching process.

[0020] Preferably, during the 5G-4G standard switching process, the mobile virtual private network maintains the virtual tunnel encryption state based on IPSec. The virtual tunnel encryption adopts the national cryptographic algorithm, and the mobile virtual private network only allows dedicated mobile security smart terminals configured with the dedicated SIM card to access it. The isolation state between the private network and the public network is not changed during the switching.

[0021] Preferably, the 5G-4G standard switching control unit presets a 5G signal strength threshold of ≥-90dBm and a 4G signal strength threshold of ≥-100dBm, wherein:

[0022] When the real-time network status monitoring unit detects that the 5G signal strength is <-90dBm and the 4G signal strength is ≥-100dBm, it generates a 5G fallback to 4G automatic switching command.

[0023] When the 5G signal strength is detected to recover to ≥-90dBm and remain so for more than 3 seconds, a command to switch back to the 5G network is generated.

[0024] Preferably, the secure one-way transfer subsystem includes a front-end protocol interface unit, a forward digital diode, a reverse digital diode, and a rear-end protocol interface unit. During the 5G-4G standard switching process, the secure one-way transfer subsystem maintains the current data transmission direction, records the identifiers of transmitted data blocks through the front-end protocol interface unit, and resumes the transmission of incomplete data based on the data block identifiers after the switch is completed.

[0025] Preferably, the security management subsystem monitors the handover duration in real time during the 5G-4G standard handover process, wherein:

[0026] If the switching time exceeds 3 seconds, a switching anomaly alarm will be pushed to the operation and maintenance terminal. The switching anomaly alarm includes the location of the dedicated mobile security smart terminal, the current network standard, and the reason for the switching failure.

[0027] The security management subsystem records the switching process log, including the switching time, triggering conditions, and data transmission status.

[0028] Preferably, the security hardening component of the dedicated mobile safety smart terminal maintains control over the terminal's Bluetooth and Wi-Fi during the 5G-4G standard switch. This control state allows the terminal to connect only to railway-specific Bluetooth devices and railway-dedicated Wi-Fi networks, while prohibiting connection to unauthorized Bluetooth devices and public Wi-Fi networks. Furthermore, the dedicated mobile safety smart terminal has a built-in GPS positioning module that continuously reports its location to the safety management subsystem during the switchover process.

[0029] If the terminal is outside the preset service area and is in the process of switching between service systems, it will trigger the area-de-zone offline function and clear the locally cached railway signal sensitive data.

[0030] Preferably, during the 5G-4G standard switch, the mobile virtual private network uses a connection mechanism between a primary security authentication on the operator side and a secondary access control on the platform side, wherein:

[0031] The operator-side security authentication verifies the legitimacy of the dedicated SIM card, while the platform-side secondary access control completes the terminal identity verification before the handover and verifies the terminal's current network identifier during the handover process.

[0032] Preferably, when the safe one-way ferry subsystem is in one-way transmission mode, during the 5G-4G standard switching process, the reverse digital diode remains in the conducting state, and the front-end protocol interface unit prioritizes the transmission of fault alarm data and real-time monitoring data of the railway signaling system, wherein...

[0033] The unidirectional transmission mode is as follows: only the reverse digital diode is turned on, and data flows from the railway signaling system to the dedicated mobile safety intelligent terminal.

[0034] Preferably, the real-time network status monitoring unit collects 5G / 4G communication parameters at a frequency of 1 second / time, and the real-time network status monitoring unit performs data verification with the signal receiving module of the dedicated mobile security smart terminal.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] 1) This application constructs a precise dual-mode switching mechanism by setting up a real-time network status monitoring unit and a 5G-4G mode switching control unit. It can collect parameters such as signal strength, coverage, and transmission latency of 5G and 4G networks in real time, and generate switching commands based on preset thresholds to realize automatic switching between 5G and 4G modes. This mechanism can adapt to the network coverage differences in different areas under the mobile Internet scenario of railway signaling system. When the 5G network signal strength is lower than the threshold or there is no coverage, it automatically switches to the 4G network. When the 5G network recovers to meet the requirements, it automatically switches back to the 5G network, avoiding service interruption caused by insufficient adaptation of a single network mode, and providing a stable network foundation for the mobile Internet service of railway signaling system.

[0037] 2) The mobile virtual private network in this application system is built on the operator's 5G / 4G core network, and is isolated from the public network by using APN / VPDN technology. During the handover process, it maintains the encrypted state of the virtual tunnel based on IPSec and the isolation state from the public network, allowing only terminals configured with dedicated SIM cards to access. At the same time, the dedicated mobile security smart terminal achieves security protection through customized hardware, security hardening components and dedicated SIM cards with national cryptographic chips, and is bound one-to-one with the dedicated SIM card. During the handover process, identity authentication is completed through the national cryptographic chip. The multiple security designs form a full-link security protection system from the terminal to the network, which effectively solves the problems of terminal security risks, untrusted access users and communication link threats faced by mobile terminal access, and ensures the security of railway signal data transmission and the credibility of terminal access.

[0038] 3) During the 5G-4G standard switching process, the secure one-way transfer subsystem of this application maintains the current data transmission direction, records the identifier of the transmitted data block through the front-end protocol interface device, and resumes the transmission of incomplete data based on the identifier after the switch is completed, so as to avoid data transmission interruption or loss during the switch. The dedicated mobile security smart terminal responds to the switching command to realize automatic standard switching. The mobile virtual private network supports seamless connection of communication links during the switching process. The security management subsystem monitors the switching status and service transmission status in real time. All components work together to maintain the continuity of railway signal data transmission during the standard switching process, ensure the stable transmission of key business data such as fault alarms and real-time monitoring data, meet the high requirements of the railway signal system for business continuity, and improve the timeliness of data acquisition and maintenance efficiency of on-site operators.

[0039] 4) The overall design of this application system aligns with the business needs and safety standards of railway signaling systems. The safety management subsystem can monitor the switching duration, and when the switching duration exceeds the limit, it will push an abnormal alarm and record the switching log, facilitating timely problem handling and subsequent auditing by maintenance personnel. The security hardening component of the dedicated mobile security smart terminal maintains control over Bluetooth and WIFI during switching, and triggers off-zone offline and clears sensitive data when the terminal exceeds the preset business area, further enhancing system security. At the same time, the system is compatible with the existing architecture of railway signaling systems and can achieve data interaction with TDCS / CTC systems, centralized signal monitoring systems, etc. On the basis of ensuring safety and business continuity, it promotes the extension of railway signaling systems to mobile terminals, provides support for the value mining of signal data and the intelligent upgrading of the system, and helps to improve the intelligent management and maintenance level of railway signaling equipment. Attached Figure Description

[0040] Figure 1 This is a flowchart of this application. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of the invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] In the description of the invention, it should be noted that the execution order of the steps is not limited by the sequence number. The possible changes in the order of some steps, the synchronous execution of steps, and the split execution of steps are all within the scope of protection of this application.

[0045] Please see Figure 1 This invention provides a technical solution: a railway signaling system mobile internet service continuity assurance system supporting 5G and 4G dual-mode switching, comprising:

[0046] The real-time network status monitoring unit is used to collect 5G and 4G network communication parameters of the target area in the mobile Internet scenario of the railway signaling system. The communication parameters include at least 5G / 4G signal strength, network coverage, and transmission latency.

[0047] The 5G-4G standard switching control unit is electrically connected to the real-time network status monitoring unit. It receives communication parameters and generates standard switching commands, including 5G network access commands, 4G network access commands, and 5G fallback to 4G automatic switching commands.

[0048] A dedicated mobile safety smart terminal communicates with the 5G-4G standard switching control unit, responds to standard switching commands to realize automatic switching between 5G and 4G standards, and is used to acquire and interact with railway signal system data;

[0049] Mobile Virtual Private Network (VPN) is built on the operator's 5G / 4G core network and uses APN / VPDN technology to isolate it from the public network. Under the control of the standard switching command, it provides a dual-standard dedicated communication link for dedicated mobile security smart terminals and supports seamless connection of communication links during the switching process.

[0050] The safe one-way ferry subsystem connects the mobile virtual private network and the railway signaling system, and maintains railway signal data transmission when the dedicated mobile safe smart terminal switches between 5G and 4G standards.

[0051] The security management subsystem communicates with the real-time network status monitoring unit, the 5G-4G standard switching control unit, the dedicated mobile security smart terminal, the mobile virtual private network, and the security one-way transfer subsystem to monitor the 5G-4G standard switching status and the service transmission status during the switching process.

[0052] The switching logic of the 5G-4G standard switching control unit is as follows:

[0053] When the 5G signal strength collected by the real-time network status monitoring unit meets the preset threshold and the target area is within the 5G network coverage area, a 5G network access command is generated.

[0054] When the 5G signal strength is lower than the preset threshold or there is no 5G network coverage in the target area, and the 4G signal strength meets the communication requirements, a 5G fallback to 4G automatic switching command or a 4G network access command is generated.

[0055] When the 5G network recovers to meet the preset threshold and coverage requirements, a command is generated to switch back to the 5G network.

[0056] Specifically, by integrating core components such as a real-time network status monitoring unit and a 5G-4G standard switching control unit, this invention solves the problems of insufficient single-network standard adaptation and service interruption caused by standard switching in the mobile internet scenario of railway signaling systems. In existing technologies, while the original network structure of railway signaling systems ensures security, it suffers from untimely data acquisition, low on-site operational efficiency, and risks such as network openness in mobile access. Furthermore, the coexistence of 5G and 4G necessitates addressing differences in network coverage. In this application, the real-time network status monitoring unit dynamically collects key parameters such as 5G and 4G signal strength and coverage area, ensuring accurate capture of network status changes and providing data support for switching decisions. The 5G-4G standard switching control unit generates switching commands based on preset thresholds, adapting to different regional network coverage conditions and preventing mobile terminal disconnection due to weak or nonexistent 5G signals. This solves the problem in existing technologies where on-site outdoor workers cannot promptly view data. Furthermore, the mobile virtual private network (VPN) uses APN / VPDN technology to isolate itself from the public network, ensuring the security of mobile internet. The secure one-way transfer subsystem maintains data transmission during handover, and combined with the security management subsystem's monitoring of the handover status, it enables stable transmission of railway signal data during dual-system handover. This not only meets the needs of extending the signal system to mobile terminals but also ensures business continuity. It provides a stable network foundation for maintenance personnel to obtain alarm information in real time and for on-site workers to view auxiliary data in a timely manner, helping to improve the maintenance efficiency and informatization level of the railway signal system.

[0057] The dedicated mobile secure smart terminal includes customized hardware, security-hardened components, and a dedicated SIM card with a national cryptographic chip, among which:

[0058] The dedicated mobile security smart terminal has a built-in signal receiving module, which is used to receive 5G / 4G signal data fed back by the network status real-time monitoring unit, and to achieve standard switching in conjunction with the 5G-4G standard switching control unit.

[0059] A dedicated SIM card and a dedicated mobile security smart terminal are bound one-to-one, and identity authentication is completed through a national cryptographic chip during the switching process.

[0060] Specifically, existing technologies require measures such as customized terminals, national cryptographic chips, and SIM card binding to ensure terminal security. In this application, the customized hardware of the dedicated mobile security smart terminal can block the access path of general devices, reducing the potential attack surface. The dedicated SIM card with a national cryptographic chip can provide digital certificate management, encryption and decryption functions, providing cryptographic services for terminal identity authentication and data transmission, thus solving the risk of untrusted access users. In addition, the terminal's built-in signal receiving module can work with the switching control unit to achieve system switching, ensuring accurate response to switching commands and avoiding switching delays caused by untimely terminal signal reception. The one-to-one SIM card binding design strictly follows the security requirements of SIM card binding, preventing unauthorized terminals from accessing the system by changing SIM cards and eliminating unauthorized access. At the same time, identity authentication is completed through the national cryptographic chip during the switching process, avoiding authentication failure caused by switching, ensuring that the terminal is in a trusted state before and after the dual-system switching. This not only ensures the security of the terminal itself but also provides terminal-level support for the smooth execution of dual-system switching, enabling the mobile terminal to stably participate in railway signal data interaction. This avoids the impact of terminal security issues or switching authentication failures on on-site operation data acquisition and business operations, further improving the level of intelligent equipment management and maintenance.

[0061] During the 5G-4G standard transition, the mobile virtual private network maintains the encrypted state of the virtual tunnel based on IPSec. The virtual tunnel encryption adopts the national cryptographic algorithm, and the mobile virtual private network only allows dedicated mobile secure smart terminals configured with dedicated SIM cards to access it. The isolation state between the private network and the public network is not changed during the transition.

[0062] Specifically, since mobile virtual private networks (MVPBs) need to be isolated from public networks and communication links need to be encrypted, this application uses APN / VPDN technology to isolate the MVPB from the public network, allowing only terminals configured with dedicated SIM cards to access it. This fully complies with the design requirements for isolating MVPBs from the mobile internet and illegal networks, blocking unauthorized device access at the network level and solving the communication link threat problem caused by the vulnerability of wireless transmission in existing technologies. During the dual-mode handover process, the MVPB maintains an IPSec-based virtual tunnel encryption state and uses national cryptographic algorithms. This is consistent with the security specifications of existing technologies that use IPSec virtual tunnel technology to achieve transmission encryption and comply with the basic requirements of cryptographic applications in information systems. This ensures the confidentiality and integrity of railway signal data transmission during the handover process and prevents data from being leaked or tampered with due to link encryption interruption during the handover. Meanwhile, the isolation between the private network and the public network is not changed during the switch, and an independent security system is always maintained. This not only ensures the security of network communication during the dual-system switch, but also avoids the risk of network isolation failure caused by the switch. It ensures that sensitive data of the railway signaling system is not illegally obtained during transmission, provides a network security barrier for business continuity under dual-system switch, and supports maintenance personnel to obtain signaling system data securely and stably through mobile terminals.

[0063] The 5G-4G standard switching control unit has a preset 5G signal strength threshold of ≥-90dBm and a 4G signal strength threshold of ≥-100dBm, where:

[0064] When the real-time network status monitoring unit detects that the 5G signal strength is <-90dBm and the 4G signal strength is ≥-100dBm, it generates a 5G fallback to 4G automatic switching command.

[0065] When the 5G signal strength is detected to recover to ≥-90dBm and remain so for more than 3 seconds, a command to switch back to the 5G network is generated.

[0066] Specifically, this application addresses the issue of ensuring a smooth network transition during the coexistence of 5G and 4G in existing technologies. In this application, the 5G signal strength threshold is no less than -90dBm, and the 4G signal strength threshold is no less than -100dBm. This threshold setting is based on the real-time data transmission requirements of railway signaling systems. Since railway signaling systems need to ensure the timely transmission of critical services such as fault alarms and real-time monitoring data, the -90dBm 5G threshold ensures that the 5G network possesses high-speed, low-latency characteristics, meeting the transmission requirements of critical services. Meanwhile, the -100dBm 4G threshold can cover areas with weak 5G signals, preventing frequent disconnections caused by excessively high signal thresholds. Meanwhile, when the real-time network status monitoring unit detects that the 5G signal strength is below -90dBm and the 4G signal strength is not below -100dBm, it generates a 5G fallback to 4G automatic switching command. When it detects that the 5G signal strength has recovered to not below -90dBm and has lasted for more than 3 seconds, it generates a command to switch back to the 5G network. This logic avoids erroneous switching caused by brief fluctuations in the 5G signal and can promptly restore high-speed transmission after the 5G network stabilizes. This switching logic enables the system to dynamically adjust the access standard according to the actual network status, avoiding service interruptions caused by signal problems under a single standard. It ensures that maintenance personnel can continuously obtain signal data through mobile terminals in different areas, solving the problem in existing technologies where on-site personnel cannot promptly view the required auxiliary data. This provides accurate and stable switching control support for the continuous operation of mobile internet services in railway signaling systems.

[0067] The secure one-way transfer subsystem includes a front-end protocol interface unit, a forward digital diode, a reverse digital diode, and a rear-end protocol interface unit. During the 5G-4G standard switching process, the secure one-way transfer subsystem maintains the current data transmission direction, records the identifiers of transmitted data blocks through the front-end protocol interface unit, and resumes the transmission of incomplete data based on the data block identifiers after the switch is completed.

[0068] Specifically, the secure one-way import system consists of a front-end protocol interface unit, a digital diode, and a rear-end protocol interface unit. It undertakes the core functions of blocking unauthorized access and ensuring one-way or bidirectional data transmission. The structural design of the secure one-way ferry subsystem in this application completely follows this architecture, ensuring compatibility with the original security protection system of the signal system. In the critical scenario of dual-mode handover, the system maintains the current data transmission direction to avoid transmission direction disorder caused by the handover. The front-end protocol interface unit records the identifiers of transmitted data blocks and resumes transmission of incomplete data after the handover, solving the problem of data loss due to link interruption in existing mobile transmission technologies. Through data block identification and the continuation mechanism, it ensures that critical information such as fault alarms and real-time monitoring data are not lost during the handover process. For example, when maintenance personnel access centralized signal monitoring data via a mobile terminal, if a 5G to 4G handover occurs, the front-end protocol interface unit can record the transmitted monitoring data blocks and directly resume transmission of the untransmitted portions after the handover, without needing to download again. This saves network resources and ensures that maintenance personnel can continuously obtain complete data, improving fault diagnosis efficiency.

[0069] During the 5G-4G standard handover process, the security management subsystem monitors the handover duration in real time, including:

[0070] If the switching time exceeds 3 seconds, a switching anomaly alarm will be pushed to the operation and maintenance terminal. The switching anomaly alarm will include the location of the dedicated mobile security smart terminal, the current network standard, and the reason for the switching failure.

[0071] The security management subsystem records the switchover process log, including the switchover time, triggering conditions, and data transmission status.

[0072] Specifically, in existing technologies, security management systems are unified management platforms for backend maintenance and security control, used for implementing security policies, status monitoring, and security auditing. In this application, the security management subsystem monitors the switching time in real time during dual-mode switching. When it exceeds 3 seconds, it pushes an anomaly alarm, and the alarm information includes the location of the dedicated mobile security smart terminal, the current network standard, and the reason for the switching failure. This design allows maintenance personnel to quickly locate the terminal with switching anomalies and the root cause of the problem, promptly identify and resolve system issues, and avoid terminal disconnection due to prolonged unresolved switching anomalies, which could affect on-site operations. Furthermore, the function of recording switching process logs, including switching time, triggering conditions, and data transmission status, complies with security audit requirements, facilitating subsequent tracing of the cause of switching anomalies and optimization of switching strategies. It also meets the compliance requirements for log retention and auditing in the basic requirements of network security level protection for information security technology. For example, when the switching time of a certain field operation terminal exceeds the limit, the operation and maintenance personnel can quickly determine the location of the terminal and the reason for the switching failure through the alarm information, and adjust the relevant parameters or dispatch a backup terminal in a timely manner. This avoids the inability of the operation personnel to obtain fault data due to the terminal disconnection, effectively ensuring the stability of the mobile Internet service of the railway signaling system, and at the same time providing data support for the long-term operation and maintenance and safety optimization of the system.

[0073] During the 5G-4G standard switch, the security hardening components of the dedicated mobile safety smart terminal maintain control over the terminal's Bluetooth and Wi-Fi. This control ensures that the terminal can only connect to railway-specific Bluetooth devices and the railway-dedicated Wi-Fi network, while prohibiting connection to unauthorized Bluetooth devices and public Wi-Fi networks. Furthermore, the dedicated mobile safety smart terminal has a built-in GPS positioning module that continuously reports its location to the safety management subsystem during the switchover process.

[0074] If the terminal is outside the preset service area and is in the process of switching between service systems, it will trigger the area-de-zone offline function and clear the locally cached railway signal sensitive data.

[0075] Specifically, mobile terminals require security hardening, including Bluetooth control, Wi-Fi network access authorization, and automatic offline protection in case of out-of-area conditions. The security hardening components maintain control over Bluetooth and Wi-Fi during switching, preventing unauthorized devices from accessing the terminal and stealing data due to the loss of control during system switching. This addresses the security risks associated with terminal mobility in existing technologies, ensuring the terminal remains under secure control during the dynamic process of switching. Simultaneously, the terminal's built-in GPS positioning module continuously reports its location during switching, and triggers offline protection and clears sensitive data when it exceeds the preset service area. This prevents the terminal from carrying sensitive signal data out of the work area, avoiding the risk of data leakage and meeting the data leakage prevention requirements of the basic requirements for network security level protection in information security technology. For example, when operators carry terminals outside the station's operating area, even if the terminal is in the process of switching from 5G to 4G, the system can still promptly trigger off-grid offline, clearing the train operation control data cached in the terminal and preventing the leakage of sensitive information. Maintaining Bluetooth and WIFI control during the switch can prevent other unrelated devices at the work site from intruding into the terminal through wireless connection, ensuring that the terminal always accesses the railway signal mobile internet system as a trusted node. This provides full-scenario protection for terminal security under dual-mode switching, ensuring the security of railway signal data and the compliance of the operation process.

[0076] During the 5G-4G standard transition, mobile virtual private networks (VPNs) employ a mechanism that connects primary security authentication on the operator's side with secondary access control on the platform's side.

[0077] The operator performs a first-pass security authentication to verify the legitimacy of the dedicated SIM card, while the platform performs a second-pass access control to verify the terminal's identity before the handover and to verify the terminal's current network identifier during the handover process.

[0078] Specifically, the operator performs a primary authentication to verify the legitimacy of the dedicated SIM card, while the platform performs a secondary access control to verify the terminal's identity before the handover. During the handover, only the terminal's current network identifier is verified. This adheres to the security principle of dual authentication while avoiding delays caused by repeatedly executing the complete authentication process during the handover. This connection mechanism ensures the legitimacy of the terminal SIM card through operator-side authentication and ensures that the terminal's identity matches its service permissions through platform-side pre-verification. The simplified authentication steps during the handover can complete identity verification within 1 to 2 seconds, avoiding service interruptions due to excessive authentication time. This resolves the contradiction between security and efficiency in existing mobile internet technologies. For example, when maintenance personnel are working in a section with their terminals, they may trigger a handover when moving from a 5G coverage area to a 4G coverage area. In this case, the platform does not need to re-verify the terminal's identity; it only needs to verify the terminal's current 4G network identifier to complete the access, ensuring a rapid handover process. Maintenance personnel can continuously view the status data of signal equipment, avoiding missing fault alarm processing opportunities due to authentication delays. This not only ensures the security of network access but also improves the efficiency of dual-mode handover, providing authentication-level support for the continuity of mobile internet services in railway signaling systems.

[0079] When the safe one-way ferry subsystem is in one-way transmission mode, during the 5G-4G standard switching process, the reverse digital diode remains in the conducting state, and the front-end protocol interface unit prioritizes the continued transmission of fault alarm data and real-time monitoring data from the railway signaling system.

[0080] The unidirectional transmission mode is as follows: only the reverse digital diode is turned on, and data flows from the railway signaling system to the dedicated mobile safety intelligent terminal.

[0081] Specifically, the one-way interaction mode is suitable for signal systems with high data and system security levels, and information security must be ensured according to different business methods to prevent the leakage of sensitive information. When the system is in one-way transmission mode, the reverse digital diode remains in the conducting state during the handover process to ensure that the data transmission link from the signal system to the terminal is not interrupted, avoiding the interruption of sensitive data transmission such as scheduling instructions and fault alarms of high-security systems due to the handover. The front-end protocol interface unit prioritizes the continuation of fault alarm data and real-time monitoring data. Maintenance personnel are prone to overlooking important alarm information, which may lead to the escalation of hidden dangers. Prioritizing the continuation of key data can ensure that maintenance personnel do not miss core alarm information during the handover process and can promptly grasp the fault status of signal equipment. When a handover occurs, if the signal system is pushing a blockage fault alarm for a certain section, the front-end protocol interface unit can prioritize the transmission of the alarm data, ensuring that maintenance personnel can obtain it and carry out fault investigation as soon as possible, avoiding alarm delay reception due to the handover, which may lead to safety risks.

[0082] The real-time network status monitoring unit collects 5G / 4G communication parameters at a frequency of once per second, and performs data verification with the signal receiving module of the dedicated mobile security smart terminal. Specifically, the monitoring unit collects parameters once per second, which can capture the dynamic changes of 5G and 4G signals at a high frequency, avoiding missing critical nodes such as sudden drops in signal strength due to excessively long collection intervals. This ensures that switching commands can be generated in a timely manner. For example, when the terminal enters a 5G signal blind zone, the once-per-second collection frequency can quickly detect that the 5G signal is below the threshold and promptly trigger a switch to 4G, preventing the terminal from being in a signal-less state for a long time. This solves the problem in existing technologies where on-site personnel cannot check data in a timely manner. At the same time, the monitoring unit performs data verification with the terminal's signal receiving module, which can eliminate signal data errors. This is because wireless transmission is vulnerable and easily affected by interference, leading to data distortion. Data verification can eliminate false data caused by signal interference, avoiding triggering erroneous switching based on incorrect data. For example, when the 5G signal strength collected by the monitoring unit is inconsistent with the feedback from the terminal's receiving module, verification can confirm the actual signal situation, preventing the triggering of erroneous switching commands and avoiding service fluctuations caused by frequent switching. This design ensures the timeliness of network status monitoring through high-frequency acquisition and guarantees the accuracy of monitoring data through data verification. It provides reliable data support for the 5G-4G standard switching control unit, avoids erroneous switching or switching delays, further improves the stability of dual-standard switching, and lays a data foundation for the continuous development of mobile Internet services in the railway signaling system.

[0083] Example 1: Dual-system switching application in the scenario of mobile maintenance of signaling equipment in high-speed railway sections

[0084] This embodiment demonstrates a system applied to a mobile maintenance scenario for signaling equipment on a high-speed railway section. The specific configuration and operation process are as follows:

[0085] I. System Component Deployment and Configuration

[0086] 1. Real-time Network Status Monitoring Unit: One base station-side monitoring module is deployed every 5 kilometers along the high-speed railway section. Simultaneously, a terminal-side monitoring module is integrated into a dedicated mobile security smart terminal. Both modules collect 5G / 4G communication parameters (signal strength, coverage, transmission latency) at a frequency of 1 second per instance. The data collected by the base station-side module and the terminal-side module are verified in real time. Only when the difference in signal strength between the two modules at the same frequency band is ≤ ±3dBm is the data considered valid and uploaded to the 5G-4G standard switching control unit.

[0087] 2.5G-4G Standard Switching Control Unit: Deployed in the railway signal area operation and maintenance center, with preset 5G signal strength thresholds ≥ -90dBm and transmission latency ≤ 50ms, and 4G signal strength thresholds ≥ -100dBm and transmission latency ≤ 100ms. After receiving valid monitoring data, it generates a switching command according to preset logic, and the command is pushed to a dedicated mobile security smart terminal and mobile virtual private network through an encrypted signaling channel.

[0088] 3. Dedicated Mobile Safety Smart Terminal: Utilizing a customized PAD with a dedicated SIM card containing a built-in SM4 chip (a national standard for cryptographic standards), achieving a one-to-one device-SIM card binding; equipped with security hardening components to maintain control over Bluetooth and Wi-Fi (allowing connection only to railway-specific wireless devices), and a built-in GPS positioning module with preset operating area range. Upon receiving a switching command, the terminal automatically switches between 5G and 4G standards within 1.5 seconds, continuously reporting its location to the safety management subsystem during the switching process.

[0089] 4. Mobile Virtual Private Network: Based on the operator's 5G / 4G core network, a dedicated channel is constructed using APN / VPDN technology, which is completely isolated from the public network. During the handover process, the IPSec virtual tunnel is kept encrypted (using the national cryptographic SM2 / SM3 algorithm), and only terminals configured with dedicated SIM cards are allowed to access the network, without changing the isolation status from the public network.

[0090] 5. Secure One-Way Shuttle Subsystem: Deployed in the section signal control room, it consists of a front-end protocol interface unit, forward digital diodes, reverse digital diodes, and a rear-end protocol interface unit. The rear-end protocol interface unit connects to the section signal centralized monitoring system via a serial port, while the front-end protocol interface unit interfaces with the platform's secure access subsystem via an encrypted link. During the switching process, a bidirectional transmission mode is maintained (both forward and reverse diodes are conducting). The front-end protocol interface unit records the identifiers of transmitted data blocks (each 50KB is one block), and resumes transmission of incomplete data based on the identifiers after the switch is completed.

[0091] II. Actual Operation Process

[0092] When maintenance personnel are working on normal sections of the tunnel with a dedicated mobile safety smart terminal, the real-time network status monitoring unit collects data showing a 5G signal strength of -82dBm and a transmission latency of 42ms. After valid data verification, the 5G-4G switching control unit generates a 5G access command, and the terminal receives turnout action data from the centralized signal monitoring system via the 5G network. When maintenance personnel enter a long tunnel, the monitoring unit collects data showing a 5G signal strength dropping to -96dBm and a transmission latency of 65ms, and a 4G signal strength of -93dBm and a transmission latency of 85ms. After valid data verification, a 5G fallback to 4G switching command is generated, and the terminal switches to the 4G network upon receiving the command. During the switching process, the mobile virtual private network maintains tunnel encryption, and the safe one-way transfer subsystem records that 18 data blocks have been transmitted. After the switch is complete, the remaining 7 data blocks are transmitted, and the terminal experiences no data interruption. If maintenance personnel mistakenly take the terminal away from the preset work area, even if the terminal is in the process of switching from 4G to 5G, the GPS positioning module detects an abnormal location and immediately triggers offline detection and clears the locally cached section block data, meeting the terminal safety protection requirements.

[0093] Example 2: Application of one-way transmission and dual-mode switching in the mobile terminal dispatching scenario of the TDCS system in a hub station

[0094] This embodiment applies the system to a mobile terminal dispatching scenario of the TDCS system at a railway hub station, as detailed below:

[0095] I. System Component Deployment and Configuration

[0096] 1. Real-time Network Status Monitoring Unit and Switching Control Unit: Three base station-side monitoring modules are deployed within the hub station area and a 3-kilometer radius. The terminal-side monitoring module is integrated into the dispatcher's dedicated mobile terminal. Both work together to collect and verify 5G / 4G parameters. The 5G-4G switching control unit has preset 5G signal strength thresholds of ≥-88dBm and 4G signal strength thresholds of ≥-98dBm. When the 5G signal strength within the station area meets the thresholds, the terminal prioritizes 5G access; when the 5G signal strength is insufficient at the station edge, it switches to 4G.

[0097] 2. Mobile Virtual Private Network and Authentication Mechanism: A dedicated APN channel is constructed based on the operator's core network, employing a "one-time authentication on the operator side + two-time access control on the platform side" connection mechanism. The operator side verifies the legitimacy of the dedicated SIM card, while the platform side verifies the dispatcher's identity (requiring matching dispatch permissions) before handover. During the handover process, only the terminal's current network identifier is verified, eliminating the need for repeated full authentication.

[0098] 3. Secure One-Way Transfer Subsystem: As the TDCS system is a high-security system, it is set to a one-way transmission mode (only the reverse digital diode is turned on, and the data flows from the TDCS system to the terminal). The front-end protocol interface machine is equipped with a data priority scheduling module, which divides the TDCS data into "fault alarm / real-time scheduling data (level 1)" and "historical scheduling data (level 2)". When switching, the level 1 data is resumed first.

[0099] 4. Safety Management Subsystem: Deployed in the station dispatch center, it monitors the handover duration in real time (preset threshold 3 seconds), pushes alarms when handover is abnormal (including terminal location and cause of failure), and records handover logs (handover time, triggering conditions, data transmission status). The logs are kept for 6 months to meet safety audit requirements.

[0100] II. Actual Operation Process

[0101] When a dispatcher uses a dedicated mobile terminal in the station dispatch room, the 5G signal strength is -85dBm. The network status monitoring unit verifies the data, and the switching control unit generates a 5G access command. The terminal receives train operation plan data from the TDCS system via the 5G network. The data is transmitted to the terminal via the safety one-way transfer subsystem (reverse diode conduction). When the dispatcher moves to the signal tower at the station edge, the monitoring unit collects 5G signal strength of -92dBm and 4G signal strength of -95dBm, generating a switching command. During the switching process, the mobile virtual private network completes the terminal's 4G access authentication within 1 second through the authentication connection mechanism, without needing to repeatedly verify the dispatcher's identity. The safety one-way transfer subsystem maintains the reverse diode conduction, suspends the transmission of historical dispatch data, and prioritizes the resumption of the "train delay alarm" level-one data pushed by the TDCS system, ensuring no critical information interruption on the terminal. If the switching time reaches 3.5 seconds, the safety management subsystem immediately pushes an alarm to the maintenance terminal (location: station signal tower, reason: 4G base station switching delay), and records the switching log. Maintenance personnel can quickly troubleshoot base station faults through the log, ensuring the continuity of dispatch services.

[0102] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A railway signaling system supporting 5G and 4G dual-mode switching for mobile internet service continuity assurance, characterized in that: include: A real-time network status monitoring unit is used to collect 5G and 4G network communication parameters of the target area in the mobile Internet scenario of the railway signaling system. The communication parameters include at least 5G / 4G signal strength, network coverage, and transmission latency. The 5G-4G standard switching control unit is electrically connected to the network status real-time monitoring unit, receives the communication parameters and generates standard switching instructions, including 5G network access instructions, 4G network access instructions and 5G fallback to 4G automatic switching instructions. A dedicated mobile safety smart terminal is communicatively connected to the 5G-4G standard switching control unit, responds to the standard switching command to realize automatic switching between 5G and 4G standards, and is used to acquire and interact with railway signal system data; The mobile virtual private network is built on the operator's 5G / 4G core network and is isolated from the public network using APN / VPDN technology. Under the control of the standard switching command, it provides a dual-standard dedicated communication link for the dedicated mobile security smart terminal and supports seamless connection of the communication link during the switching process. The safe one-way ferry subsystem connects the mobile virtual private network with the railway signaling system and maintains railway signal data transmission when the dedicated mobile safety smart terminal switches between 5G and 4G standards. The security management subsystem is communicatively connected to the network status real-time monitoring unit, the 5G-4G standard switching control unit, the dedicated mobile security smart terminal, the mobile virtual private network, and the security one-way transfer subsystem to monitor the 5G-4G standard switching status and the service transmission status during the switching process. The switching logic of the 5G-4G standard switching control unit is as follows: When the 5G signal strength collected by the real-time network status monitoring unit meets the preset threshold and the target area is within the 5G network coverage area, a 5G network access command is generated. When the 5G signal strength is lower than the preset threshold or there is no 5G network coverage in the target area, and the 4G signal strength meets the communication requirements, a 5G fallback to 4G automatic switching command or a 4G network access command is generated. When the 5G network recovers to meet the preset threshold and coverage requirements, a command to switch back to the 5G network is generated. The dedicated mobile security smart terminal includes customized hardware, security-hardened components, and a dedicated SIM card with a national cryptographic chip, wherein: The dedicated mobile security smart terminal has a built-in signal receiving module, which is used to receive 5G / 4G signal data fed back by the network status real-time monitoring unit, and cooperate with the 5G-4G standard switching control unit to realize standard switching; The dedicated SIM card is bound to the dedicated mobile security smart terminal in a one-to-one manner, and identity authentication is completed through a national cryptographic chip during the switching process. The 5G-4G standard switching control unit has a preset 5G signal strength threshold of ≥-90dBm and a 4G signal strength threshold of ≥-100dBm, wherein: When the real-time network status monitoring unit detects that the 5G signal strength is <-90dBm and the 4G signal strength is ≥-100dBm, it generates a 5G fallback to 4G automatic switching command. When the 5G signal strength is detected to recover to ≥-90dBm and last for more than 3 seconds, a command to switch back to the 5G network is generated. The secure one-way transfer subsystem includes a front-end protocol interface unit, a forward digital diode, a reverse digital diode, and a rear-end protocol interface unit. During the 5G-4G standard switching process, the secure one-way transfer subsystem maintains the current data transmission direction, records the identifiers of transmitted data blocks through the front-end protocol interface unit, and resumes the transmission of incomplete data based on the data block identifiers after the switch is completed. During the 5G-4G standard switch, the mobile virtual private network (VPN) uses a connection mechanism between primary security authentication on the operator side and secondary access control on the platform side, wherein: The operator-side security authentication verifies the legitimacy of the dedicated SIM card, while the platform-side secondary access control completes the terminal identity verification before the handover and verifies the terminal's current network identifier during the handover process. The real-time network status monitoring unit collects 5G / 4G communication parameters at a frequency of 1 second / time, and the real-time network status monitoring unit performs data verification with the signal receiving module of the dedicated mobile security smart terminal.

2. The railway signaling system mobile internet service continuity assurance system supporting 5G and 4G dual-mode switching as described in claim 1, characterized in that, During the 5G-4G standard switching process, the mobile virtual private network maintains the virtual tunnel encryption state based on IPSec. The virtual tunnel encryption adopts the national cryptographic algorithm, and the mobile virtual private network only allows dedicated mobile security smart terminals configured with the dedicated SIM card to access it. The isolation state between the private network and the public network is not changed during the switching.

3. The railway signaling system mobile internet service continuity assurance system supporting 5G and 4G dual-mode switching as described in claim 1, characterized in that, The security management subsystem monitors the handover duration in real time during the 5G-4G standard handover process, including: If the switching time exceeds 3 seconds, a switching anomaly alarm will be pushed to the operation and maintenance terminal. The switching anomaly alarm includes the location of the dedicated mobile security smart terminal, the current network standard, and the reason for the switching failure. The security management subsystem records the switching process log, including the switching time, triggering conditions, and data transmission status.

4. The railway signaling system mobile internet service continuity assurance system supporting 5G and 4G dual-mode switching as described in claim 1, characterized in that, During the 5G-4G standard switch, the security hardening component of the dedicated mobile safety smart terminal maintains control over the terminal's Bluetooth and Wi-Fi. This control state allows the terminal to connect only to railway-specific Bluetooth devices and dedicated railway Wi-Fi networks, while prohibiting connection to unauthorized Bluetooth devices and public Wi-Fi networks. Furthermore, the dedicated mobile safety smart terminal has a built-in GPS positioning module that continuously reports its location to the safety management subsystem during the switchover process. If the terminal is outside the preset service area and is in the process of switching between service systems, it will trigger the area-de-zone offline function and clear the locally cached railway signal sensitive data.

5. The railway signaling system mobile internet service continuity assurance system supporting 5G and 4G dual-mode switching as described in claim 1, characterized in that, When the safety unidirectional ferry subsystem is in unidirectional transmission mode, during the 5G-4G standard switching process, the reverse digital diode remains in the conducting state, and the front-end protocol interface unit prioritizes the continued transmission of fault alarm data and real-time monitoring data from the railway signaling system. The unidirectional transmission mode is as follows: only the reverse digital diode is turned on, and data flows from the railway signaling system to the dedicated mobile safety intelligent terminal.

Images