Train communication method and device

Abstract

The application discloses a train communication method and device, relates to the technical field of train communication, and mainly aims to improve the adaptability between transmission time delay and network environment and reduce the risk of safety accidents. The main technical scheme of the application is as follows: an RSSP-1 message package of a sending end is received, which contains message content, a message serial number and a message timestamp. The message type is determined according to the message content, and the maximum allowed transmission time delay parameter and the standard transmission time delay parameter corresponding to the type are obtained. The network quality is determined according to the current multi-dimensional network state information, and the target transmission time delay parameter is selected from the maximum allowed and standard transmission time delay parameters. The RSSP-1 message package is encapsulated into a TRDP packet, and the target transmission time delay parameter is embedded. Finally, the TRDP packet is sent according to a preset transmission strategy, so that the receiving end can determine whether to respond to the message content based on the target transmission time delay parameter, the message serial number and the message timestamp.

Description

Technical Field

[0001] This invention relates to the field of train communication technology, and in particular to a train communication method and device. Background Technology

[0002] With the gradual development of trains towards automatic driving, a highly reliable data exchange channel needs to be established between critical onboard safety equipment (such as braking systems and automatic train protection systems) to ensure train operation safety. Currently, trains use Railway Signal Safety Protocol-1 (RSSP-1) as the communication scheme. This protocol, as a dedicated secure communication mechanism for Safety Integrity Level 4 (SIL4), effectively defends against data deletion, insertion, replay, and delay attacks through strict sequence number increment verification and a timestamp verification mechanism based on a synchronization clock, ensuring the integrity, order, and timeliness of messages.

[0003] However, RSSP-1's security mechanism has a rigid dependence on deterministic transmission latency—the receiver, when verifying message validity, requires that the deviation between the message timestamp and the local synchronization clock be strictly controlled within a preset threshold. This characteristic makes it extremely sensitive to fluctuations in network transmission latency. However, in the case of freight trains, especially in complex terrain environments such as tunnels and mountainous areas, the wireless channel is susceptible to obstruction effects, multipath propagation interference, and Doppler shift, leading to a significant increase in end-to-end transmission latency that frequently exceeds the preset threshold. Once a message arrives outside the time window allowed by RSSP-1, even if its content is complete and its sequence number is consecutive and valid, it will be judged as an "expired message" and discarded directly by the receiver.

[0004] This mechanism may cause serious safety hazards in certain scenarios: for example, when a real emergency braking command has a slight transmission delay due to wireless channel jitter, the receiving end may incorrectly reject the valid command due to the excessive timestamp deviation, resulting in the braking action not being executed, which may lead to major safety accidents such as train rear-end collisions and derailments. Summary of the Invention

[0005] In view of the above problems, the present invention provides a train communication method and device, the main purpose of which is to improve the adaptability between transmission latency and network environment and reduce the risk of safety accidents.

[0006] To solve the above-mentioned technical problems, the present invention proposes the following solution: In a first aspect, the present invention provides a train communication method, the method comprising: Receive RSSP-1 message packets sent by the sending end, wherein the RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number and message timestamp; The message type corresponding to the RSSP-1 message packet is determined based on the message content, and the maximum allowable transmission delay parameter and standard transmission delay parameter corresponding to the message type are determined. The maximum allowable transmission delay parameter is used to characterize the maximum end-to-end delay allowed from the sending end to the receiving end processing the message. The current network quality is determined based on the current multidimensional network status information, and a target transmission delay parameter is selected from the maximum allowable transmission delay parameter and the standard transmission delay parameter based on the current network quality. The standard transmission delay parameter is used to characterize the expected standard end-to-end transmission delay from the sending end to the receiving end. The RSSP-1 message packet is encapsulated into a TRDP message, and the target transmission delay parameter is embedded in the TRDP message; The TRDP message is sent to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, the message sequence number and the message timestamp.

[0007] In a second aspect, the present invention provides a train communication device, the device comprising: The message receiving unit is used to receive RSSP-1 message packets sent by the sending end. The RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number, and message timestamp. The parameter determination unit is used to determine the message type corresponding to the RSSP-1 message packet based on the message content in the RSSP-1 message packet received by the message receiving unit, and to determine the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type. The maximum allowable transmission delay parameter is used to characterize the maximum end-to-end delay allowed from the sending end to the receiving end processing the message. The quality determination unit is used to determine the current network quality based on the current multidimensional network state information, and select the target transmission delay parameter from the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type determined by the parameter determination unit based on the current network quality. The standard transmission delay parameter is used to characterize the expected standard end-to-end transmission delay from the sending end to the receiving end. The message encapsulation unit is used to encapsulate the RSSP-1 message packet into a TRDP message and embed the target transmission delay parameter selected by the quality determination unit into the TRDP message; The message sending unit is used to send the TRDP message encapsulated by the message encapsulation unit to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, the message sequence number and the message timestamp.

[0008] To achieve the above objectives, according to a third aspect of the present invention, a storage medium is provided, the storage medium including a stored program, wherein, when the program is executed, the device on which the storage medium is located controls the execution of the train communication method of the first aspect.

[0009] To achieve the above objectives, according to a fourth aspect of the present invention, a processor is provided for running a program, wherein the program executes the train communication method of the first aspect described above.

[0010] By employing the above technical solution, the present invention provides a train communication method and apparatus that effectively solves the problem of safety-critical messages being mistakenly discarded and leading to safety accidents in complex wireless channel environments due to the use of rigid delay thresholds in the existing RSSP-1 protocol by introducing a target transmission delay parameter mechanism based on message type dynamic adaptation. Specifically, after receiving an RSSP-1 message packet sent by the sender, the type of the message can be identified based on its message content. For different message types, the system pre-configures corresponding maximum allowable transmission delay parameters and standard transmission delay parameters. The maximum allowable transmission delay parameter characterizes the maximum end-to-end transmission delay allowed from the sender to the receiver, while the standard transmission delay parameter characterizes the expected end-to-end transmission delay under normal network conditions. Subsequently, the network quality is evaluated by combining the current multi-dimensional network state information, and a target transmission delay parameter that adapts to the current network conditions is selected between the maximum allowable transmission delay parameter and the standard transmission delay parameter. The target transmission delay parameter is embedded in the encapsulated TRDP message, and the TRDP message is sent to the receiving end according to the preset transmission strategy corresponding to the TRDP message. When verifying the validity of the message, the receiving end no longer relies on a fixed preset time window, but makes a comprehensive judgment based on the target transmission delay parameter, message sequence number, and message timestamp carried in the message: only when the actual transmission delay does not exceed the target transmission delay parameter and the message sequence number meets the expectation is the RSSP-1 message packet considered valid, and a response is made to its message content. Thus, while fully retaining the original security mechanisms of RSSP-1 (such as sequence number increment verification, timestamp anti-replay, etc.), this scheme enables the determination of transmission delay to adapt to changes in the network environment, effectively preventing the erroneous discarding of safety-critical commands such as emergency braking due to channel fluctuations, thereby significantly reducing the risk of major safety accidents such as train rear-end collisions and derailments, and providing reliable protection for high-safety-level communication in train automatic driving systems. Furthermore, this invention encapsulates RSSP-1 message packets into Train Real-Time Data Protocol (TRDP) messages and sends them to the receiving end according to the preset transmission strategy corresponding to the TRDP messages. The TRDP message refers to a network transmission unit formed by encapsulating RSSP-1 message packets according to the Train Real-Time Data Protocol (TRDP) format. By using the TRDP protocol as the bearer mechanism, its real-time communication capabilities optimized for train Ethernet can be fully utilized, effectively suppressing additional uncontrollable delays introduced by queuing, scheduling, or bandwidth contention during the transmission of messages carrying dynamic delay parameters within the onboard network.Especially for high-safety-level commands such as emergency braking, TRDP can ensure rapid and reliable transmission within the onboard network segment through mechanisms such as priority scheduling and deterministic forwarding. This ensures that the actual end-to-end transmission delay observed by the receiver primarily reflects the true transmission status of the wireless channel, rather than being affected by uncertainties in the transmission within the onboard network. Consequently, the receiver's validity assessment based on the target transmission delay parameter is more accurate, further enhancing the reliability of safety-critical communications in automatic train operation scenarios.

[0011] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0012] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a train communication method provided by an embodiment of the present invention is shown; Figure 2 A flowchart of another train communication method provided by an embodiment of the present invention is shown; Figure 3 This diagram illustrates a block diagram of a train communication device provided in an embodiment of the present invention. Figure 4 A block diagram of another train communication device provided in an embodiment of the present invention is shown. Detailed Implementation

[0013] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0014] To address the mismatch between the rigid latency threshold and the complex dynamic characteristics of wireless channels in the existing Railway Signal Safety Communication Protocol-1 (RSSP-1) during automatic train operation—specifically manifested in the significant fluctuations in end-to-end transmission latency caused by obstruction, multipath effects, and Doppler effects in harsh operating environments such as tunnels and mountainous areas—this invention proposes a train communication method that dynamically adapts transmission latency tolerance based on message type and network status.

[0015] This method is implemented by a security gateway. Deployed within the onboard network, the security gateway communicates with both the sending and receiving ends, collaboratively processing, encapsulating, and forwarding messages. The sending end includes, but is not limited to, safety-critical subsystems such as the Automatic Train Protection (ATP) system, Brake Control Unit (BCU), axle temperature / vibration safety monitoring module, door safety controller, and train integrity detection device. The receiving end comprises onboard equipment that needs to process such safety messages, such as the Brake Execution Unit (responding to emergency braking commands), the Central Safety Computer (processing status alarm information), and the Automatic Train Protection (responding to train integrity loss signals). By using the security gateway to perform type identification, dynamic configuration of latency parameters, and TRDP encapsulation of safety messages from different sources, reliable protection of high-security communication is achieved in uncertain network environments.

[0016] Next, combined Figure 1 The present invention provides a train communication method, the specific execution steps of which are as follows: Figure 1 As shown, it includes: 101. Receive RSSP-1 message packets sent by the sender. The RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number, and message timestamp.

[0017] In this invention, the sending end can generate message content with safety semantics based on the current train operating status or equipment monitoring results. Typical examples include, but are not limited to, "emergency braking," "axle temperature exceeding limit," "door unlocked," and "train integrity loss." Each message content conforms to the RSSP-1 protocol's requirements for application layer data format.

[0018] Subsequently, the sending end can assign a monotonically increasing sequence number to the message to be sent. This sequence number is automatically incremented by 1 each time a new message is generated, ensuring global uniqueness and non-reversibility, thus meeting the security requirements of the RSSP-1 protocol for preventing replay and insertion attacks.

[0019] Meanwhile, the sending end obtains the current time based on the train's onboard synchronization clock (such as a high-precision time synchronization system implemented via GPS) and embeds it as a message timestamp in the message. This timestamp is used by the receiving end to verify the timeliness of the message.

[0020] The sending end encapsulates the generated message content, sequence number, and timestamp according to the frame structure specified in the RSSP-1 protocol to form a complete RSSP-1 message packet, and sends the message packet to the security-service gateway through the vehicle internal communication channel (such as vehicle Ethernet or shared memory).

[0021] Furthermore, to further enhance fault isolation capabilities, different categories of safety messages can use independent sequence number counters. For example, "emergency braking" messages use counter A, "axle temperature exceeding limit" messages use counter B, and "door status" messages use counter C, with each counter incrementing independently. In this way, an anomaly in the transmission of one type of message (such as frequent triggering) will not affect the sequential continuity of other types of messages, allowing the receiver to more accurately identify local communication faults while still meeting the RSSP-1 safety requirements for the sequential order of each message stream.

[0022] Upon receiving the RSSP-1 message packet, the security-service gateway can parse the message content, sequence number, and timestamp from it, which will serve as input for subsequent steps.

[0023] 102. Determine the message type corresponding to the RSSP-1 message packet based on the message content, and determine the maximum allowable transmission delay parameter and standard transmission delay parameter corresponding to the message type.

[0024] In this embodiment, after receiving an RSSP-1 message packet, the security-service gateway first parses the message content and identifies the message type based on the content. Message type identification is necessary because different security messages have significantly different tolerances for transmission timeliness: for example, the "emergency braking" command is directly related to train operation safety and must be processed by the receiving end even under poor network conditions. Therefore, configuring latency tolerance according to message type is a crucial prerequisite for achieving high reliability of safety-critical communications and efficient utilization of non-critical communication resources.

[0025] After determining the message type, the security-service gateway further obtains two preset latency parameters associated with that type: the maximum allowed transmission latency parameter and the standard transmission latency parameter.

[0026] The maximum permissible transmission delay parameter characterizes the maximum end-to-end transmission delay allowed from the sender to the receiver for successful processing. Its core function is to provide a safety net for the receiver: as long as the actual transmission delay does not exceed this value, even if there is temporary network congestion or wireless channel fluctuations (such as a train entering a tunnel), the receiver should still consider the message valid and respond to it. This prevents genuinely valid safety-critical instructions (such as emergency braking) from being mistakenly judged as "expired" and discarded due to reasonable delays.

[0027] Standard transmission delay parameters characterize the expected end-to-end transmission delay under normal network conditions, typically corresponding to performance metrics in ideal or typical operating environments. This parameter is primarily used for fine-grained scheduling and resource optimization when network quality is good, such as selecting more energy-efficient transmission strategies or reducing redundancy.

[0028] The two parameters mentioned above are not dynamically calculated, but are pre-configured and stored in the local preset mapping table of the security-service gateway during the system deployment phase based on the message's Safety Integrity Level (SIL), functional criticality, and relevant railway industry standards.

[0029] For safety control messages, such as emergency braking, the maximum permissible transmission delay parameter is typically set to cover the most unfavorable but acceptable end-to-end transmission scenarios (e.g., maximum wireless link jitter, maximum queuing delay in the vehicular network, and protocol processing overhead), with a typical value of, for example, 500ms. The standard transmission delay parameter reflects the typical delay under good channel conditions, such as 100ms. For non-critical data messages, the maximum permissible transmission delay can be appropriately relaxed. This preset mapping table uses "message type" as the index key, supporting quick lookup.

[0030] 103. Determine the current network quality based on the current multidimensional network status information, and select the target transmission delay parameter from the maximum allowable transmission delay parameter and the standard transmission delay parameter based on the current network quality.

[0031] In this embodiment, the security-service gateway can assess the current network quality based on the current multidimensional network status information, and select the target transmission delay parameter between the maximum allowable transmission delay parameter and the standard transmission delay parameter accordingly.

[0032] Multidimensional network status information refers to key indicators that comprehensively reflect the real-time performance of the vehicular communication link, specifically including: Available bandwidth utilization: refers to the percentage of bandwidth currently occupied in the communication link relative to the total available bandwidth, used to measure the degree of network congestion; Network latency jitter: refers to the fluctuation range of end-to-end transmission delay of consecutive messages, used to reflect the stability of network latency; Link connectivity status: refers to whether the communication link is in a normal connected state, which can be determined by the heartbeat mechanism of Train Real-Time Data Protocol (TRDP), the status of Ethernet physical layer, or the connection status of wireless communication modules (such as 5G-R or GSM-R terminals).

[0033] The above information can be collected in real time by the security-service gateway through the vehicular network interface, TRDP protocol stack, or wireless communication module. When assessing the current network quality based on multi-dimensional network status information, any of the following implementation methods can be used: Method 1: Discrete Grading Method Based on Preset Thresholds A pre-configured set of judgment rules divides network quality into several levels (e.g., "high," "medium," and "low"). Each level corresponds to a set of judgment conditions regarding available bandwidth utilization, network latency jitter, and link connectivity. During actual evaluation, if the current metric meets any of the conditions defined for a certain level, the network quality is determined to belong to that level. This method has clear logic, low computational overhead, and is suitable for resource-constrained embedded platforms.

[0034] Method 2: Continuous evaluation method based on weighted scoring The security-service gateway normalizes available bandwidth utilization, network latency jitter, and link connectivity status, and assigns corresponding weights based on the impact of each indicator on communication reliability. It then calculates a network quality score between 0 and 1, with a higher score indicating a better network condition.

[0035] In addition, link connectivity status can be set as a key factor: if the link is interrupted, the score is directly set to the lowest value (e.g., 0) regardless of other indicators. This method can more finely reflect the gradual changes in network status and is suitable for security gateways with strong processing capabilities.

[0036] The two methods described above are alternative implementation methods and can be flexibly selected according to the actual needs of system resources, real-time requirements and deployment scenarios.

[0037] 104. Encapsulate the RSSP-1 message packet into a TRDP message and embed the target transmission delay parameter in the TRDP message.

[0038] 105. The TRDP message is sent to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, message sequence number and message timestamp.

[0039] In this invention, once the security-service gateway determines the target transmission delay parameters, it can perform message encapsulation and sending operations. The specific process is as follows: First, the RSSP-1 message packet is encapsulated into a Train Real-Time Data Protocol (TRDP) message. Specifically, the security-service gateway uses the original RSSP-1 message packet (containing message content conforming to the RSSP-1 protocol format, message sequence number, and message timestamp) as the application layer payload, encapsulates it according to the frame structure specified by the TRDP protocol, and generates a standard TRDP message. During this process, the aforementioned determined target transmission delay parameters are embedded into the application layer extended field of the TRDP message as metadata for the message, which is used by the receiving end during security verification.

[0040] Subsequently, the TRDP message is sent to the receiving end according to the preset transmission policy corresponding to it. The preset transmission policy is a communication rule pre-configured in the security-service gateway, which can use User Datagram Protocol (UDP) as the underlying transmission protocol to meet TRDP's requirements for low latency and high efficiency.

[0041] In addition, high priority can be marked in the IP header or Ethernet VLAN tag (e.g., IEEE 802.1 QPCP value set to 6 or 7) to ensure that the packet is scheduled in a high-priority queue in the vehicle switch. Of course, for SIL4 level critical messages (such as emergency braking), a dual-channel redundant transmission mechanism can be enabled, that is, the same TRDP message is sent simultaneously through two physically isolated Ethernet channels (such as network A and network B) to improve delivery reliability.

[0042] By employing the aforementioned preset transmission strategy, it is ensured that security messages carrying dynamic latency parameters receive transmission guarantees matching their security level within the vehicle Ethernet, effectively suppressing transmission failures or additional delays caused by competition from ordinary service traffic or single-point link failures.

[0043] Upon receiving a TRDP message, the receiving end can perform the following security verification and response process: 1. Extract key fields: Parse the original RSSP-1 message packet from the TRDP message, and further extract the message content, message sequence number, message timestamp, and embedded target transmission delay parameters.

[0044] 2. Determine if the sequence number of the current message is strictly greater than the sequence number of the last successfully received message, and if there is no duplication. If the sequence numbers are not consecutive or are duplicated, a replay or out-of-order attack is suspected, and the verification fails. Of course, if the sender classifies the sequence numbers according to message type, the receiver must also refer to this classification during verification.

[0045] 3. Compare the message timestamp with the local synchronization clock, calculate the absolute value of the deviation between the two, and determine whether the deviation is less than or equal to the target transmission delay parameter.

[0046] The receiving end considers the RSSP-1 message packet valid only when both the sequence number verification and the timestamp verification pass, and performs corresponding security functions (such as applying braking, recording faults, triggering alarms, etc.) according to the message content; if either verification fails, the message is discarded, no control action is performed, and only the abnormal event is recorded in the local security log for subsequent fault tracing and security auditing.

[0047] Based on the above Figure 1As can be seen from the implementation, the train communication method provided by this invention effectively solves the problem of safety-critical messages being mistakenly discarded and leading to safety accidents in complex wireless channel environments due to the use of rigid delay thresholds in the existing RSSP-1 protocol by introducing a target transmission delay parameter mechanism based on message type dynamic adaptation. Specifically, after receiving an RSSP-1 message packet sent by the sender, the type of the message can be identified based on its message content. For different message types, the system pre-configures corresponding maximum allowable transmission delay parameters and standard transmission delay parameters. The maximum allowable transmission delay parameter characterizes the maximum end-to-end transmission delay allowed from the sender to the receiver, while the standard transmission delay parameter characterizes the expected end-to-end transmission delay under normal network conditions. Subsequently, the network quality is evaluated based on the current multi-dimensional network state information, and a target transmission delay parameter that adapts to the current network conditions is selected between the maximum allowable transmission delay parameter and the standard transmission delay parameter. The target transmission delay parameter is embedded in the encapsulated TRDP message, and the TRDP message is sent to the receiving end according to the preset transmission strategy corresponding to the TRDP message. When verifying the validity of the message, the receiving end no longer relies on a fixed preset time window, but makes a comprehensive judgment based on the target transmission delay parameter, message sequence number, and message timestamp carried in the message: only when the actual transmission delay does not exceed the target transmission delay parameter and the message sequence number meets the expectation is the RSSP-1 message packet considered valid, and a response is made to its message content. Thus, while fully retaining the original security mechanisms of RSSP-1 (such as sequence number increment verification, timestamp anti-replay, etc.), this scheme enables the determination of transmission delay to adapt to changes in the network environment, effectively preventing the erroneous discarding of safety-critical commands such as emergency braking due to channel fluctuations, thereby significantly reducing the risk of major safety accidents such as train rear-end collisions and derailments, and providing reliable protection for high-safety-level communication in train automatic driving systems. Furthermore, this invention encapsulates RSSP-1 message packets into Train Real-Time Data Protocol (TRDP) messages and sends them to the receiving end according to the preset transmission strategy corresponding to the TRDP messages. The TRDP message refers to a network transmission unit formed by encapsulating RSSP-1 message packets according to the Train Real-Time Data Protocol (TRDP) format. By using the TRDP protocol as the bearer mechanism, its real-time communication capabilities optimized for train Ethernet can be fully utilized, effectively suppressing additional uncontrollable delays introduced by queuing, scheduling, or bandwidth contention during the transmission of messages carrying dynamic delay parameters within the onboard network.Especially for high-safety-level commands such as emergency braking, TRDP can ensure rapid and reliable transmission within the onboard network segment through mechanisms such as priority scheduling and deterministic forwarding. This ensures that the actual end-to-end transmission delay observed by the receiver primarily reflects the true transmission status of the wireless channel, rather than being affected by uncertainties in the transmission within the onboard network. Consequently, the receiver's validity assessment based on the target transmission delay parameter is more accurate, further enhancing the reliability of safety-critical communications in automatic train operation scenarios.

[0048] Furthermore, as a response to Figure 1 Further refinement and extension of the illustrated embodiment, this invention also provides another train communication method, such as... Figure 2 As shown, the specific steps are as follows: 201. Receive RSSP-1 message packets sent by the sending end. The RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number, and message timestamp.

[0049] 202. Determine the message type corresponding to the RSSP-1 message packet based on the message content, and determine the maximum allowable transmission delay parameter and standard transmission delay parameter corresponding to the message type.

[0050] The implementation methods of steps 201-202 are the same as those of steps 101-102, and can achieve the same technical effect and solve the same technical problem, so they will not be repeated here.

[0051] In this embodiment, it should be noted that the system is pre-configured with a preset mapping table, in which the maximum allowed transmission delay parameter and the standard transmission delay parameter are associated with each type of message. In practical applications, the security-service gateway can identify the message type based on the message content in the RSSP-1 message packet, and use the message type as an index to query the preset mapping table to obtain the corresponding maximum allowed transmission delay parameter and standard transmission delay parameter.

[0052] The message types are divided into two main categories: safety control messages and non-critical data messages. Typical safety control messages include emergency braking commands, train integrity loss alarms, and emergency door unlocking requests, which are directly related to train operation safety. Non-critical data messages include ambient temperature monitoring data and operation logs, which are mainly used for status monitoring or maintenance analysis and do not directly affect real-time safety control.

[0053] In terms of parameter configuration, the maximum allowable transmission delay parameter for security control messages is greater than that for non-critical data messages. This is because, although security control messages have extremely high timeliness requirements, they also have a high security level. If they are discarded due to momentary network fluctuations (such as a wireless interruption caused by a train entering a tunnel), it could lead to a serious security incident. Therefore, a relatively lenient "fallback" upper limit needs to be set for them to ensure that, under extreme but acceptable network conditions, the receiving end can still determine that they are valid and respond accordingly, thereby avoiding the accidental loss of genuine and valid security commands.

[0054] Meanwhile, the standard transmission delay parameter for safety control messages is less than that for non-critical data messages. This is because, under normal network conditions, safety control messages must be transmitted end-to-end with the lowest possible latency to meet the stringent requirements for rapid response in scenarios such as automatic train protection and emergency braking; while non-critical data messages have a higher tolerance for real-time performance and can be transmitted within a slightly longer time window. Therefore, their standard transmission delay parameter can be appropriately relaxed to reduce system scheduling pressure and improve resource utilization efficiency.

[0055] Through the above differentiated configuration, the system not only ensures the reliable delivery of high-security commands, but also achieves refined latency management for different business types, balancing security, real-time performance, and communication efficiency.

[0056] 203. Determine the current network quality based on the current multidimensional network status information, and select the target transmission delay parameter from the maximum allowable transmission delay parameter and the standard transmission delay parameter based on the current network quality.

[0057] In this embodiment, when determining the current network quality based on the current multidimensional network status information, the security-service gateway first obtains the network latency jitter, available bandwidth utilization, and link connectivity status from the multidimensional network status information.

[0058] Subsequently, all indicators are converted into uniform dimensionless values ​​(typically ranging from 0 to 1) to facilitate subsequent weighted fusion. Among them, network latency jitter and available bandwidth utilization are reverse normalized (i.e., the smaller the value, the better the performance), while link connectivity status is mapped to binary values ​​(connectivity is 1, interruption is 0).

[0059] Subsequently, according to the preset weight allocation algorithm, corresponding weight coefficients can be assigned to the three normalized indicators respectively. The preset weight allocation algorithm can be pre-configured based on the security level of the message type or system deployment experience. For example, for security control messages (such as emergency braking commands), due to their high dependence on communication reachability, the link connectivity status can be given the highest weight (e.g., 0.5). In some implementations, a veto mechanism is even introduced—if the link is interrupted (normalized value is 0), the network quality is directly determined to be the lowest level, because it directly determines whether communication is reachable.

[0060] Meanwhile, network latency jitter is the second most important factor (e.g., a weight of 0.3), reflecting the impact of latency stability on the execution of secure commands; available bandwidth utilization has the lowest weight (e.g., a weight of 0.2), as it mainly affects the concurrency capabilities of non-critical services.

[0061] For non-critical data messages (such as device self-test reports), the link connectivity weight can be appropriately reduced and the bandwidth utilization weight increased to optimize resource utilization efficiency.

[0062] After weight allocation, the three normalized indicators are multiplied by their corresponding weights and summed to obtain a network quality score ranging from 0 to 1. A higher score indicates a better current network condition. Finally, according to a preset level mapping rule, the score is converted into a corresponding network quality level. For example, a score ≥ 0.8 can be set as "high," 0.5 ≤ score < 0.8 as "medium," and a score < 0.5 as "low." Through this mechanism, the system achieves a quantitative mapping from multi-dimensional network state information to network quality levels, providing a scientific basis for subsequent dynamic latency parameter adaptation.

[0063] Subsequently, when selecting the target transmission delay parameter from the maximum permissible transmission delay parameter and the standard transmission delay parameter based on the current network quality, it can be: If the current network quality level is high, the standard transmission delay parameter is set as the target transmission delay parameter; if the current network quality level is medium or low, the maximum allowable transmission delay parameter is set as the target transmission delay parameter.

[0064] This is done because a "high" network quality level indicates that the current communication link is stable, with low latency jitter, sufficient bandwidth, and reliable link connectivity, meeting the conditions for supporting high-time-sensitivity communication. Using a standard transmission latency parameter (i.e., the expected latency under normal operating conditions) as the judgment threshold at this time helps the receiving end verify the validity of messages with stricter timeliness standards, thereby improving system response speed, avoiding unnecessary redundancy tolerance, and optimizing overall communication efficiency.

[0065] When the network quality level is "medium" or "low", it usually means that there is a certain degree of network congestion, increased latency fluctuations, or decreased link reliability (e.g., trains entering tunnels, mountainous areas, or areas with severe multipath interference).

[0066] In such scenarios, if strict standard transmission delay parameters are still used, safety-critical messages that should be valid (such as emergency braking commands) may be misjudged as "timeout" and discarded due to reasonable but increased transmission delays, thereby causing safety hazards.

[0067] Therefore, switching to the maximum allowable transmission delay parameter (i.e., the safety fallback threshold) can provide greater tolerance for message validity judgment, ensuring that under harsh but acceptable network conditions, genuine and valid security instructions can still be correctly identified and executed by the receiving end, thereby enhancing the system's adaptability to complex operating environments without sacrificing functional safety.

[0068] Through the aforementioned dynamic selection mechanism, the system achieves adaptive adjustment of latency tolerance driven by network state awareness, effectively balancing the contradiction between real-time communication and robustness, and is particularly suitable for the safe and reliable operation requirements of automated freight trains in long-distance, variable channel environments.

[0069] 204. Encapsulate the RSSP-1 message packet into a TRDP message and embed the target transmission delay parameter in the TRDP message.

[0070] 205. The TRDP message is sent to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, message sequence number and message timestamp.

[0071] The implementation methods of steps 204-205 are the same as those of steps 104-105, and can achieve the same technical effect and solve the same technical problem, so they will not be repeated here.

[0072] 206. If no feedback message is received from the receiver for the TRDP message within the preset time period, the retransmission mechanism will be executed.

[0073] In this embodiment, to improve the reliable delivery rate of messages in complex vehicular network environments, a feedback-based TRDP message retransmission mechanism can be further introduced. Specifically, after sending a TRDP message, the security-service gateway starts a timer to detect whether an acknowledgment feedback message (such as a response message in the TRDP protocol) is received from the receiver within a preset time period.

[0074] If no feedback message is received within the preset time period, it is determined that the current transmission may have failed to complete successfully due to reasons such as momentary link interruption, message loss, or receiver processing delay. At this time, the security-service gateway will calculate the message retransmission interval (i.e., the time interval between two retransmissions) according to the preset interval determination policy.

[0075] Subsequently, the security-service gateway retrieves the original TRDP message from the retransmission buffer (which was temporarily stored during the initial transmission) and performs periodic retransmission operations according to the determined message retransmission interval. The retransmission process will continue until either of the following termination conditions is met: (1) a feedback message is successfully received from the receiver; (2) the number of retransmissions reaches the preset retransmission threshold (e.g., 3 times).

[0076] The reason for adopting the above retransmission mechanism is that in the actual operating environment of automated freight trains, the onboard communication network may be affected by factors such as tunnel obstruction, electromagnetic interference, multipath effects, or switch congestion caused by high-density train formation, resulting in the failure of a single TRDP message transmission. If critical safety messages (such as emergency braking commands) are not retried and only a single transmission is relied upon, there is a risk of losing valid commands, which may lead to serious safety accidents.

[0077] By introducing a controlled, limited-retransmission mechanism, the final delivery probability of messages can be significantly improved without significantly increasing end-to-end latency. Simultaneously, setting retransmission thresholds and feedback timeout mechanisms can prevent infinite retries from exhausting system resources or causing timing disruptions, ensuring that overall communication behavior remains within predictable and verifiable safety boundaries.

[0078] When determining the message retransmission strategy according to the preset interval, updated multi-dimensional network status information (including available bandwidth utilization, network latency jitter and link connectivity status) can be obtained, and the current network quality can be re-evaluated based on this information to obtain updated network quality evaluation results.

[0079] Subsequently, the preset time interval corresponding to the target transmission delay parameter associated with the TRDP message is adaptively adjusted according to the updated network quality, thereby accurately determining the actual message retransmission interval for this retransmission.

[0080] The process specifically includes the following steps: First, a network quality adjustment coefficient is obtained based on the updated network quality. This adjustment coefficient can be obtained through a preset mapping relationship. For example, if the updated network quality level is "high," indicating that the network condition is good, then the network quality adjustment coefficient takes a small value (such as 0.5); if the updated network quality level is "medium," then the adjustment coefficient takes a middle value (such as 0.8); if the updated network quality level is "low," indicating that the network is congested or unstable, then the adjustment coefficient takes a large value (such as 1.2 or 1.5).

[0081] The above mapping relationship can be stored in the configuration table of the security-service gateway to ensure that the adjustment coefficient is negatively correlated with network quality—that is, the worse the network quality, the larger the adjustment coefficient and the longer the retransmission interval; the better the network quality, the smaller the adjustment coefficient and the more timely the retransmission.

[0082] This design aims to: speed up retry speed to improve responsiveness when the network is good, and proactively lengthen the retry interval when the network is poor, so as to avoid exacerbating congestion or interfering with high-priority security traffic due to frequent retries.

[0083] Then, the preset time interval corresponding to the target transmission delay parameter is multiplied by the network quality adjustment coefficient to obtain the final message retransmission interval. For example, if the preset time interval is 100 milliseconds and the current adjustment coefficient is 1.2, then the actual retransmission interval is 120 milliseconds.

[0084] Through the above mechanism, under the premise of ensuring the overall security of the system, the optimization of differentiated retransmission strategies for different service flows is realized, taking into account both communication reliability and network resource efficiency.

[0085] Furthermore, as a response to the above Figure 1 In addition to the implementation of the method shown, this embodiment of the invention also provides a train communication device for the above-described method. Figure 1 The method shown is implemented accordingly. This device embodiment corresponds to the foregoing method embodiment. For ease of reading, this device embodiment will not repeat the details of the foregoing method embodiment, but it should be clear that the device in this embodiment can implement all the contents of the foregoing method embodiment. Figure 3 As shown, the device includes: Message receiving unit 301 is used to receive RSSP-1 message packets sent by the sending end. The RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number and message timestamp. The parameter determination unit 302 is used to determine the message type corresponding to the RSSP-1 message packet according to the message content in the RSSP-1 message packet received by the message receiving unit 301, and to determine the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type. The maximum allowable transmission delay parameter is used to characterize the maximum end-to-end delay allowed from the sending end to the receiving end processing the message. The quality determination unit 303 is used to determine the current network quality based on the current multidimensional network status information, and select the target transmission delay parameter from the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type determined by the parameter determination unit 302 based on the current network quality. The standard transmission delay parameter is used to characterize the expected standard end-to-end transmission delay from the sending end to the receiving end. The message encapsulation unit 304 is used to encapsulate the RSSP-1 message packet into a TRDP message and embed the target transmission delay parameter selected by the quality determination unit 303 into the TRDP message; The message sending unit 305 is used to send the TRDP message encapsulated by the message encapsulation unit 304 to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, the message sequence number and the message timestamp.

[0086] Furthermore, as a response to the above Figure 2 In addition to the implementation of the method shown, this embodiment of the invention also provides another train communication device for the above-described method. Figure 2 The method shown is implemented accordingly. This device embodiment corresponds to the foregoing method embodiment. For ease of reading, this device embodiment will not repeat the details of the foregoing method embodiment, but it should be clear that the device in this embodiment can implement all the contents of the foregoing method embodiment. Figure 4 As shown, the device includes: Message receiving unit 301 is used to receive RSSP-1 message packets sent by the sending end. The RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number and message timestamp. The parameter determination unit 302 is used to determine the message type corresponding to the RSSP-1 message packet according to the message content in the RSSP-1 message packet received by the message receiving unit 301, and to determine the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type. The maximum allowable transmission delay parameter is used to characterize the maximum end-to-end delay allowed from the sending end to the receiving end processing the message. The quality determination unit 303 is used to determine the current network quality based on the current multidimensional network status information, and select the target transmission delay parameter from the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type determined by the parameter determination unit 302 based on the current network quality. The standard transmission delay parameter is used to characterize the expected standard end-to-end transmission delay from the sending end to the receiving end. The message encapsulation unit 304 is used to encapsulate the RSSP-1 message packet into a TRDP message and embed the target transmission delay parameter selected by the quality determination unit 303 into the TRDP message; The message sending unit 305 is used to send the TRDP message encapsulated by the message encapsulation unit 304 to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, the message sequence number and the message timestamp.

[0087] In one optional implementation, the parameter determination unit 302 is specifically used for: Obtain a preset mapping table, wherein each message type in the preset mapping table has a corresponding maximum allowed transmission delay parameter and a standard transmission delay parameter; In the preset mapping table, the maximum allowed transmission delay parameter and the standard transmission delay parameter are queried using the message type as the index. The message type includes security control messages and non-critical data messages. The maximum allowed transmission delay parameter corresponding to the security control message is greater than the maximum allowed transmission delay parameter corresponding to the non-critical data message, and the standard transmission delay parameter corresponding to the security control message is less than the standard transmission delay parameter corresponding to the non-critical data message.

[0088] In one optional implementation, the quality determination unit 303 is specifically used for: Obtain network latency jitter, available bandwidth utilization, and link connectivity status from multi-dimensional network status information; According to the preset weight allocation algorithm, corresponding weight coefficients are assigned to the network latency jitter, the available bandwidth utilization, and the link connectivity status. The network latency jitter, the available bandwidth utilization, and the link connectivity status are normalized. The network quality score is obtained by weighting and summing the normalized network latency jitter, available bandwidth utilization, and link connectivity status according to the corresponding weighting coefficients. According to the preset network quality level mapping table, the network quality score is mapped to the corresponding network quality level, and the network quality level is determined as the current network quality.

[0089] In an optional implementation, the quality determination unit 303 is further configured to: If the current network quality level is high, then the standard transmission delay parameter is determined as the target transmission delay parameter; If the current network quality level is medium or low, then the maximum allowable transmission delay parameter is determined as the target transmission delay parameter.

[0090] In an optional implementation, after the message sending unit 305 sends the TRDP message to the receiving end according to a preset transmission strategy, the device further includes a message retransmission unit 306, which is specifically used for: Detect whether a feedback message is received from the receiving end for the TRDP message within a preset time period; If not, the message retransmission interval is determined according to the preset interval determination strategy; The TRDP message is retrieved from the retransmission buffer and retransmitted according to the message retransmission interval until the feedback message is received or the number of retransmissions reaches the preset retransmission threshold.

[0091] In one optional implementation, when determining the message retransmission interval according to the preset interval determination strategy, the message retransmission unit 306 is specifically used for: Obtain updated multidimensional network state information and determine the updated network quality based on the updated multidimensional network state information; The preset time interval corresponding to the target transmission delay parameter carried in the TRDP message is adjusted according to the updated network quality to obtain the message retransmission interval.

[0092] In an optional implementation, when the message retransmission unit 306 adjusts the preset time interval corresponding to the target transmission delay parameter carried in the TRDP message according to the updated network quality to obtain the message retransmission interval, it is specifically used for: The network quality adjustment coefficient is obtained based on the updated network quality. The message retransmission interval is obtained by multiplying the preset time interval corresponding to the target transmission delay parameter by the network quality adjustment coefficient. The network quality adjustment coefficient is negatively correlated with the updated network quality.

[0093] Furthermore, embodiments of the present invention also provide a storage medium for storing a computer program, wherein the computer program, when running, controls the device where the storage medium is located to execute the above-described... Figure 1-2 The train communication method described herein.

[0094] Furthermore, embodiments of the present invention also provide a processor for running a program, wherein the program executes the above-described... Figure 1-2 The train communication method described herein.

[0095] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0096] It is understood that the relevant features in the above methods and apparatus can be referenced interchangeably. Furthermore, the terms "first," "second," etc., in the above embodiments are used to distinguish between embodiments and do not represent the superiority or inferiority of any particular embodiment.

[0097] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0098] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, this invention is not directed to any particular programming language. It should be understood that the contents of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0099] In addition, the memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0100] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0101] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0102] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0103] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0104] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0105] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0106] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0107] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0108] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0109] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A train communication method, characterized in that, The method includes: Receive RSSP-1 message packets sent by the sending end, wherein the RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number and message timestamp; The message type corresponding to the RSSP-1 message packet is determined based on the message content, and the maximum allowable transmission delay parameter and standard transmission delay parameter corresponding to the message type are determined. The maximum allowable transmission delay parameter is used to characterize the maximum end-to-end delay allowed from the sending end to the receiving end processing the message. The current network quality is determined based on the current multidimensional network state information. A target transmission delay parameter is selected from the maximum allowable transmission delay parameter and the standard transmission delay parameter based on the current network quality. The standard transmission delay parameter characterizes the expected standard end-to-end transmission delay from message transmission at the sender to message processing at the receiver. Determining the current network quality based on the current multidimensional network state information includes: Obtain network latency jitter, available bandwidth utilization, and link connectivity status from multi-dimensional network status information; According to the preset weight allocation algorithm, corresponding weight coefficients are assigned to the network latency jitter, the available bandwidth utilization, and the link connectivity status. The network latency jitter, the available bandwidth utilization, and the link connectivity status are normalized. The network quality score is obtained by weighting and summing the normalized network latency jitter, available bandwidth utilization, and link connectivity status according to the corresponding weighting coefficients. According to the preset network quality level mapping table, the network quality score is mapped to the corresponding network quality level, and the network quality level is determined as the current network quality. Based on the current network quality, a target transmission delay parameter is selected from the maximum allowable transmission delay parameter and the standard transmission delay parameter, including: If the current network quality level is high, then the standard transmission delay parameter is determined as the target transmission delay parameter; If the current network quality level is medium or low, then the maximum allowable transmission delay parameter is determined as the target transmission delay parameter; The RSSP-1 message packet is encapsulated into a TRDP message, and the target transmission delay parameter is embedded in the TRDP message; The TRDP message is sent to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, the message sequence number and the message timestamp.

2. The method according to claim 1, characterized in that, Determining the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type includes: Obtain a preset mapping table, wherein each message type in the preset mapping table has a corresponding maximum allowed transmission delay parameter and a standard transmission delay parameter; In the preset mapping table, the maximum allowed transmission delay parameter and the standard transmission delay parameter are queried using the message type as the index. The message type includes security control messages and non-critical data messages. The maximum allowed transmission delay parameter corresponding to the security control message is greater than the maximum allowed transmission delay parameter corresponding to the non-critical data message, and the standard transmission delay parameter corresponding to the security control message is less than the standard transmission delay parameter corresponding to the non-critical data message.

3. The method according to claim 1, characterized in that, After sending the TRDP message to the receiving end according to the preset transmission strategy, the method further includes: Detect whether a feedback message is received from the receiving end for the TRDP message within a preset time period; If not, the message retransmission interval is determined according to the preset interval determination strategy; The TRDP message is retrieved from the retransmission buffer and retransmitted according to the message retransmission interval until the feedback message is received or the number of retransmissions reaches the preset retransmission threshold.

4. The method according to claim 3, characterized in that, The message retransmission interval is determined according to a preset interval determination strategy, including: Obtain updated multidimensional network state information and determine the updated network quality based on the updated multidimensional network state information; The preset time interval corresponding to the target transmission delay parameter carried in the TRDP message is adjusted according to the updated network quality to obtain the message retransmission interval.

5. The method according to claim 4, characterized in that, The preset time interval corresponding to the target transmission delay parameter carried in the TRDP message is adjusted according to the updated network quality to obtain the message retransmission interval, including: The network quality adjustment coefficient is obtained based on the updated network quality. The message retransmission interval is obtained by multiplying the preset time interval corresponding to the target transmission delay parameter by the network quality adjustment coefficient, wherein the network quality adjustment coefficient is negatively correlated with the updated network quality.

6. A train communication device, characterized in that, The device includes: The message receiving unit is used to receive RSSP-1 message packets sent by the sending end. The RSSP-1 message packets include message content conforming to the RSSP-1 protocol format, message sequence number, and message timestamp. The parameter determination unit is used to determine the message type corresponding to the RSSP-1 message packet based on the message content in the RSSP-1 message packet received by the message receiving unit, and to determine the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type. The maximum allowable transmission delay parameter is used to characterize the maximum end-to-end delay allowed from the sending end to the receiving end processing the message. The quality determination unit is used to determine the current network quality based on the current multidimensional network state information, and to select a target transmission delay parameter from the maximum allowable transmission delay parameter and the standard transmission delay parameter corresponding to the message type determined by the parameter determination unit based on the current network quality. The standard transmission delay parameter is used to characterize the expected standard end-to-end transmission delay from the sending end to the receiving end. Specifically, the quality determination unit is used to: Obtain network latency jitter, available bandwidth utilization, and link connectivity status from multi-dimensional network status information; According to the preset weight allocation algorithm, corresponding weight coefficients are assigned to the network latency jitter, the available bandwidth utilization, and the link connectivity status. The network latency jitter, the available bandwidth utilization, and the link connectivity status are normalized. The network quality score is obtained by weighting and summing the normalized network latency jitter, available bandwidth utilization, and link connectivity status according to the corresponding weighting coefficients. According to the preset network quality level mapping table, the network quality score is mapped to the corresponding network quality level, and the network quality level is determined as the current network quality. The quality determination unit is also used for: If the current network quality level is high, then the standard transmission delay parameter is determined as the target transmission delay parameter; If the current network quality level is medium or low, then the maximum allowable transmission delay parameter is determined as the target transmission delay parameter; The message encapsulation unit is used to encapsulate the RSSP-1 message packet into a TRDP message and embed the target transmission delay parameter selected by the quality determination unit into the TRDP message; The message sending unit is used to send the TRDP message encapsulated by the message encapsulation unit to the receiving end according to the preset transmission strategy corresponding to the TRDP message, so that the receiving end can determine whether to respond to the message content in the RSSP-1 message packet based on the target transmission delay parameter, the message sequence number and the message timestamp.

7. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, it controls the device where the storage medium is located to perform the train communication method as described in any one of claims 1 to 5.

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