High-speed train wireless communication sensing network system and testing method thereof

Abstract

The present application relates to the technical field of wireless communication, in particular to a high-speed train wireless communication sensing network system and a testing method thereof, the network system comprising three-layer communication network buses of train level, vehicle level and device level; wireless network bridges are used to replace traditional Ethernet wire connections, join sensing networks, use various sensors such as LoRa and WiFi to detect the state inside and outside the train, and determine the overall network topology structure; the testing method sends and receives data through the network to be tested, and applies time stamps on the application layer, transmits the data to the PC end for calculation, so as to obtain the time delay and fluctuation of the network; the present application simplifies the network system arrangement, realizes real-time monitoring and feedback of the environment inside and outside the train, and meets the demand of high-speed trains for stable and efficient communication.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more particularly to a high-speed train wireless communication perception network system and a testing method thereof. Background Art

[0002] With the rapid development of high-speed train technology, the CR400 intelligent EMU, a key representative of modern railway transportation, features advanced powertrain systems, onboard control systems, and network communication capabilities. Traditional train networks based on wired connections often face the risk of network failures caused by abnormal terminal devices. For example, if a terminal device on an Ethernet network fails and sends a large number of broadcast packets, these broadcast data consumes a significant amount of network bandwidth, preventing normal control data from being processed in a timely manner, increasing the likelihood of network outages. Furthermore, the fixed wiring structure of wired connections limits the network's flexibility and adaptability. This is especially true when faced with unique environmental factors such as vibration and electromagnetic interference during train operation. Wired connections are susceptible to problems such as loose connectors and aging shielding, further reducing the reliability and stability of network communications. These issues not only increase the complexity and cost of network operations and maintenance, but also limit the network's ability to adapt to dynamic environmental changes and rapidly deploy new technologies.

[0003] Therefore, in order to address the above problems and to provide further development space in the future, the CR400 intelligent EMU urgently needs a more flexible and intelligent, more perceptive and more scalable wireless communication perception network system and its testing method. Summary of the Invention

[0004] In view of this, the present invention provides a high-speed train wireless communication perception network system and a testing method thereof, which can improve the reliability and stability of train network communications.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a high-speed train wireless communication perception network system, comprising a three-layer communication network bus at the train level, vehicle level, and device level;

[0007] The train-level bus uses the backbone Ethernet bus ETB. Each carriage is equipped with a backbone network switch ETBN, and each backbone network switch ETBN is connected to the backbone Ethernet bus ETB.

[0008] The vehicle-level bus uses the marshaling Ethernet bus (ECN). Each carriage is equipped with two marshaling network switches (ECNN), one of which serves as the master switch and the other as the slave switch. When the master switch fails, communication automatically switches to the slave switch. Both marshaling network switches (ECNN) in each carriage are connected to the marshaling Ethernet bus (ECN).

[0009] Each device in the carriage is connected point-to-point to the corresponding marshaling network switch using a star topology, and the two switch machines in the same carriage share a virtual MAC address and IP address;

[0010] For each carriage, a firewall is added between the backbone network switch ETBN and the marshalling network switch ECNN to isolate and control access to network data.

[0011] Furthermore, the system also includes a LoRa communication gateway, which is used for information exchange between different train groups, collision warning, and node data forwarding for narrowband, low-power, long-distance wireless node networking communications.

[0012] Furthermore, the system also includes a global satellite navigation GNSS module and a WiFi AP. The global satellite navigation GNSS module is used to provide timing, positioning and speed information; the WiFi AP is used for WiFi coverage under the vehicle, on the roof and inside the vehicle, for access by train staff handheld terminals and passengers' mobile devices.

[0013] In a second aspect, the present invention provides a method for testing a high-speed train wireless communication perception network system, comprising:

[0014] Two Ethernet testers (NDTs) are connected to the marshaling network switches (ECNNs) at both ends of the system under test via Ethernet cables. One of the two Ethernet testers (NDTs) serves as the master NDT, and the other as the slave NDT. The master NDT includes both local and remote ports, while the slave NDT only writes local ports. The remote port number is obtained by the master NDT initiating communication with the slave NDT. The master NDT receives information from all IP addresses, while the slave NDT only receives information from the master NDT.

[0015] The master NDT actively initiates a data request to the slave NDT, first allocates buffer space for the data, then fills the buffer with data, and releases the buffer space after sending the data request; and when sending the data request, records the application layer timestamp T APP1 ;

[0016] After receiving the data request from the master NDT, the slave NDT responds and sends a reply message. When the master NDT receives the returned data, it records the application layer timestamp T app4 ;

[0017] The polling information time delay of the slave NDT using the master NDT is taken as the internal processing time delay of the NDT;

[0018] After the master NDT sends information to the slave NDT for the first time, the slave NDT obtains the port number of the master NDT and starts sending a data request to the master NDT; when the master NDT receives the data request, the master NDT records the time stamp T app2 of the application layer, sends reply information, and records the time stamp T app3 of the application layer;

[0019] T app4 -T app1 and T app3 -T app2 are output to the PC end through a serial port, and the PC end calculates the time delay and fluctuation of the system to be tested.

[0020] Further, in the test method, two PCs are connected to a marshalling network switch ECNN of the system to be tested through an Ethernet, one as a master and the other as a slave.

[0021] Further, the system to be tested is tested by the two PCs, including:

[0022] A connection is established through the IP addresses of the two PCs, parameters of a data script are set according to required data characteristics, and the size of the data used for testing is finally determined;

[0023] To ensure that the system to be tested is full, a plurality of data streams in the same direction are copied for testing;

[0024] If bidirectional throughput needs to be tested, a reverse data stream needs to be established and copied again;

[0025] If there are bidirectional data streams, the data streams are grouped according to the direction;

[0026] The time when the test is stopped is set as the moment when any data stream is completed;

[0027] After the test is completed, the maximum instantaneous throughput T max , the minimum instantaneous throughput T min , the average throughput T, the actual transmission data amount D, the theoretical maximum bandwidth B max and the transmission time t are viewed according to groups, and the throughput fluctuation R and the bandwidth efficiency E are calculated according to the above data.

[0028] Further, the calculation formula of the throughput fluctuation R is:

[0029] R = T max -T min

[0030] The calculation formula of the bandwidth efficiency E is:

[0031]

[0032] Furthermore, the total data volume D used in the test is calculated as follows:

[0033] D=file_size*transactions*number_of_records

[0034] Among them, file_size indicates the size of a single data transaction; transactions is the number of transactions, indicating how much data of file_size is contained in each record; number_of_records indicates the number of records ultimately generated.

[0035] Furthermore, the calculation formula for the time delay of the system under test is:

[0036] τ=[(T app4 -T app1 )-(T app3 -T app2 )]

[0037] The jitter calculation formula of the system under test is:

[0038]

[0039] Among them, n is the total number of polling times in this test, τ i is the one-way transmission delay of the i-th polling data, and τ is the average one-way transmission delay of this test.

[0040] Furthermore, the Ethernet tester includes: a single chip microcomputer, a power management module, an Ethernet interface module, a lora wireless remote communication radio frequency module and an interface module;

[0041] The Ethernet interface module contains an Ethernet interface, which is connected to the Ethernet controller through HR601850 to achieve network communication and POE power supply;

[0042] The power management module uses a DC24 chip to convert the 48V input voltage provided by the POE power supply into a stable 5V voltage to power the lora wireless remote communication RF module; then the LM1117 linear regulator converts the 5V into 3.3V to power the microcontroller and interface module.

[0043] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0044] This invention addresses the issues of wired connections being susceptible to loose connectors and aging shielding layers during the operation of CR400 high-speed trains, such as vibration and electromagnetic interference. A high-speed train wireless communication sensing network was invented. This network uses wireless technology to replace traditional wired connections, simplifying system deployment and maintenance. It also uses various sensors to provide real-time monitoring and feedback of the train's internal and external environments. Network expansion is facilitated through the use of network bridges, open WiFi APs, and LoRa communication nodes, leaving room for future development and enabling faster deployment of new modules. Furthermore, the network incorporates various sensors, such as LoRa and WiFi, that can monitor the train's internal and external conditions in real time, such as temperature, vibration, and air pressure. This helps the network better adapt to changes in the dynamic external environment, improves the network's ability to perceive these changes, and enhances its flexibility and adaptability.

[0045] In addition, the present invention also proposes a testing method to comprehensively test the performance of the constructed perception network, such as latency and jitter, and further collect throughput data to calculate data such as throughput fluctuation and bandwidth efficiency, ensuring the stability and reliability of network communications, meeting the needs of modern high-speed trains for stable and efficient communications, and at the same time providing new solutions and innovative paths for the technological progress and market competitiveness of future railway transportation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0047] Figure 1 This is a schematic diagram of the structure of the high-speed train wireless communication sensing network system provided by the present invention;

[0048] Figure 2 This is a flow chart of the testing method for the high-speed train wireless communication perception network system provided by the present invention. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] like Figure 1As shown, the embodiment of the present invention discloses a high-speed train wireless communication perception network system, including a three-layer communication network bus at the train level, vehicle level and device level;

[0051] Taking the CR400 intelligent EMU as an example, it consists of eight carriages, with four carriages forming a traction unit, consisting of one traction carriage and three ordinary carriages. The eight carriages are thus evenly divided into two groups, which can be reconnected and run together. The train-level bus uses the backbone Ethernet bus ETB, with each carriage equipped with a backbone network switch ETBN, and each backbone network switch ETBN is connected to the backbone Ethernet bus ETB.

[0052] The vehicle-level bus uses the marshaling Ethernet bus (ECN). Each carriage is equipped with two marshaling network switches (ECNN), one serving as the master switch and the other as the slave switch. The two switches in the same carriage share a virtual MAC address and IP address. If the master switch fails, communication automatically switches to the slave switch. Both marshaling network switches (ECNN) in each carriage are connected to the marshaling Ethernet bus (ECN).

[0053] Each device in the carriage is point-to-point connected to the corresponding marshaling network switch using a star topology; the devices in the carriage include: traction control unit (DCU), central control unit (CCU), train control unit (TCU), human-machine interface display (HMI), passenger information system (PIS), input and output module (IOM), etc.

[0054] Among them, the backbone Ethernet bus ETB uses bridge equipment to connect the ETBN between trains, realizing wireless communication between the backbone network switches ETBN between carriages of different traction units. In a single-section train, a bridge is also used to connect the marshaling network switch of each carriage with the on-board equipment, realizing a wireless communication system between the on-board equipment and the marshaling network switch ECNN of each carriage.

[0055] For each carriage, a firewall is added between the backbone network switch ETBN and the marshalling network switch ECNN to isolate and control access to network data; combined with multi-level security measures such as encrypted communication, authentication and authorization, intrusion detection and prevention, network segmentation and VLAN, security protocols and standards, it effectively improves the security and reliability of the network.

[0056] The sensing network also includes a LoRa communication gateway for information exchange between different train groups, collision warnings, and node data forwarding for narrowband, low-power, long-range wireless node networking. The LoRa sensor sensing network includes wireless infrared axle temperature sensors, wireless vibration sensors, wireless temperature and humidity sensors, and wireless air pressure and altitude sensors installed on the tracks.

[0057] In addition, the perception network also includes a global satellite navigation GNSS module and a WiFi AP. The global satellite navigation GNSS module is used to provide timing, positioning, and speed information; the WiFi AP is used for WiFi coverage under the vehicle, on the roof, and inside the carriage, for access by train staff handheld terminals and passengers' mobile devices.

[0058] At this point, the entire perception network topology has been completed. A wireless bridge is used to replace the traditional Ethernet cable connection, and various sensors such as LoRa and WiFi are used to detect the status inside and outside the vehicle, realizing comprehensive and real-time detection of the environment inside and outside the vehicle.

[0059] like Figure 2 As shown, the present invention also provides a testing method for a high-speed train wireless communication perception network system, which sends and receives data through the network system to be tested, and timestamps it at the application layer, and transmits the data to the PC for calculation, thereby obtaining the network's delay and fluctuation. The above-mentioned embedded Ethernet channel delay and jitter tester NDT uses the Modbus-UDP protocol for communication. The master NDT IP is 192.168.0.100, and the slave NDT IP is 192.168.5. The timestamp position of receiving and sending information is at the application layer, and the time accuracy is at the us level. The time interval for the master NDT to send polling information to the slave NDT is 100ms. The transmission rate of the Ethernet interface is 100Mbps, and it supports automatic adaptation of the working mode and transmission rate to communicate with network devices of different rates. Use a micro-USB interface for power supply and data transmission. Specifically including the following steps:

[0060] 1) Initialize the NDT and timer: Connect two PCs to the marshaling network switch ECNN of the system under test via Ethernet, one as the master and the other as the slave, and set the corresponding IP addresses.

[0061] Two Ethernet testers (NDTs) are connected to the marshaling network switches (ECNNs) at both ends of the system under test via Ethernet cables. One Ethernet tester acts as the master NDT and the other as the slave NDT. The two NDTs communicate using the Modbus-UDP protocol. The NDTs are connected to a PC via Micro-USB. A serial port debugging assistant is run on the PC to read information transmitted through the NDT serial port.

[0062] The purpose and application of this invention's dual-PC setup is to enable bidirectional testing and monitoring of the network under test, ensuring accurate and comprehensive network performance data. The master and slave PCs are configured to establish end-to-end data communication for testing performance such as throughput, latency, and variability. This setup enables bidirectional data streaming.

[0063] The distinction between master and slave mainly refers to the distinction between the console end (master) and the endpoint end (slave) in the flow test software and the distinction between the master NDT and the slave NDT. The PC connected to the master NDT is the master PC, which serves as the console end in the flow test. The slave NDT is connected to the slave PC, which serves as the endpoint end in the flow test.

[0064] In traffic testing, the console is the user interface for managing and controlling the test, also known as the console. It is used to configure test parameters, manage endpoints, start and stop tests, and display test results. Through the console, users can set the test type, data volume, transmission protocol, and other parameters, and analyze and report performance results. Endpoints are the devices or processes responsible for sending and receiving test traffic. These endpoints can be deployed at locations within the network where performance testing is required.

[0065] 2) Define the port numbers at both ends. The master NDT includes the local port and the remote port, while the slave NDT only writes the local port. The remote port number is obtained after the master NDT initiates communication with the slave NDT. The master NDT receives information from all IP addresses, while the slave NDT only receives information from the master NDT.

[0066] 3) The master NDT actively initiates a data request to the slave NDT, first allocates buffer space for the data, then fills the buffer data, and obtains the IP address of the master NDT from the slave NDT; after the master NDT sends the data request, it releases the buffer space; and when sending the data request, it records the timestamp T of the MAC layer and application layer MAC1 and T APP1 .

[0067] 4) After receiving the data request from the master NDT, the slave NDT responds and sends a reply message. When the master NDT receives the returned data, it records the timestamp T of the MAC layer and application layer. MAC4 and T app4 .

[0068] 5) Since the accuracy requirement does not reach the microsecond level, there is no need to accurately correspond to the processing delay of each piece of data; the internal processing delay of the NDT will not fluctuate significantly; and the two NDTs have the same configuration and basically the same internal processing delay. Therefore, the polling information delay of the master NDT processing the slave NDT is used as the internal processing delay of the NDT.

[0069] 6) After the first connection is established, when the master NDT sends information to the slave NDT for the first time, the slave NDT obtains the port number of the master NDT and starts sending data requests to the master NDT; when the master NDT receives the data request, it records the application layer timestamp T app2 , send a reply message and record the application layer timestamp Tapp3 .

[0070] 7) Output T through the serial port app4 -T app1 and T app3 -T app2 To the PC, the PC calculates the delay and fluctuation of the system under test.

[0071] The exported serial port information contains two data: the time when the main NDT sends the polling data in the application layer timestamp T app1 Time T to receive NDT data app4 The time difference T app4 -T app1 , Time T when the master NDT receives the polling information sent by the slave NDT app2 Time T for the main NDT to send a reply message app3 The time difference T app3 -T app2 .

[0072] After processing the exported data and removing the NDT internal processing delay, the formula for calculating the one-way transmission delay τ of the system under test is:

[0073] τ=[(T app4 -T app1 )-(T app3 -T app2 )]

[0074] The jitter calculation formula of the system under test is:

[0075]

[0076] Among them, n is the total number of polling times in this test, τ i is the one-way transmission delay of the i-th polling data, and τ is the average one-way transmission delay of this test.

[0077] In another embodiment, the present invention further installs traffic testing software on a PC to perform traffic testing on the system to be tested, collects throughput data and calculates throughput utilization, throughput fluctuation and bandwidth efficiency.

[0078] Specifically include:

[0079] Establish a connection through the IP addresses of the two PCs, set the parameters of the data script according to the required data characteristics, and finally determine the amount of data used for the test; the total amount of data D used in the test is calculated as follows:

[0080] D=file_size*transactions*number_of_records

[0081] Among them, file_size indicates the size of a single data transaction; transactions is the number of transactions, indicating how much data of file_size is contained in each record; number_of_records indicates the number of records ultimately generated.

[0082] To ensure that the bandwidth to be tested is fully utilized, multiple data streams with the same direction are copied for testing;

[0083] If you need to test bidirectional throughput, you need to establish a reverse data flow and replicate it.

[0084] If there is bidirectional data flow, the data flow is grouped according to direction;

[0085] Set the test stop time to the moment when any data stream completes transmission;

[0086] After the test is completed, view the maximum instantaneous throughput T by group. max , minimum instantaneous throughput T min As well as the average throughput T, the actual amount of data transmitted D, and the theoretical maximum bandwidth B max and transmission time t, and calculate the throughput fluctuation R and bandwidth efficiency E based on the above data.

[0087] The calculation formula for throughput fluctuation R is:

[0088] R=T max -T min

[0089] The calculation formula for bandwidth efficiency E is:

[0090]

[0091] This test method, based on the STM32H7 single-chip microcontroller and communicating via the Modbus-UDP protocol, features high-precision timestamp recording and supports microsecond accuracy. Compared to traditional operating system software testing, this method reduces the impact of operating system latency. By combining an embedded tester with traffic testing software, it provides a comprehensive network performance testing method for more accurate network performance testing.

[0092] In a specific embodiment, the Ethernet tester NDT includes: an STM32H7 single-chip microcomputer, a power management module, an Ethernet interface module, a lora wireless remote communication RF module and an interface module; it also supports POE and Micro USB power supply, Micro USB serial port data printing, long-distance communication with other devices, and microsecond-level precise timing.

[0093] The Ethernet interface module contains an Ethernet interface, which is connected to the Ethernet controller through HR601850 to achieve network communication and POE power supply;

[0094] The power management module uses a DC24-5 chip to convert the 48V input voltage provided by the POE power supply into a stable 5V voltage to power the lora wireless remote communication RF module; then the LM1117 linear regulator converts the 5V into 3.3V to power the microcontroller and interface module.

[0095] The interface module contains a MicroUSB interface, which is connected to the USB pin of the STM32H7 microcontroller to realize the printing of data via the MicroUSB serial port.

[0096] At the same time, the peripheral circuit uses multiple filter capacitors and resistors to stabilize and decouple the signal.

[0097] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0098] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-speed train wireless communication sensing network system, characterized in that: Including three-layer communication network bus at train level, vehicle level and equipment level; The train-level bus uses the backbone Ethernet bus ETB. Each carriage is equipped with a backbone network switch ETBN, and each backbone network switch ETBN is connected to the backbone Ethernet bus ETB. The vehicle-level bus uses the marshaling Ethernet bus (ECN). Each carriage is equipped with two marshaling network switches (ECNN), one of which serves as the master switch and the other as the slave switch. When the master switch fails, communication automatically switches to the slave switch. Both marshaling network switches (ECNN) in each carriage are connected to the marshaling Ethernet bus (ECN). Each device in the carriage is connected point-to-point to the corresponding marshaling network switch using a star topology, and the two switch machines in the same carriage share a virtual MAC address and IP address; For each carriage, a firewall is added between the backbone network switch ETBN and the marshalling network switch ECNN to isolate and control access to network data.

2. The high-speed train wireless communication sensing network system according to claim 1, characterized in that: It also includes a LoRa communication gateway, which is used for information exchange between different train groups, collision warning, and node data forwarding for narrowband, low-power, long-distance wireless node networking communications.

3. The high-speed train wireless communication sensing network system according to claim 1, characterized in that: It also includes a global satellite navigation GNSS module and WiFi AP. The global satellite navigation GNSS module is used to provide timing, positioning and speed information; the WiFi AP is used for WiFi coverage under the vehicle, on the roof and inside the carriage, for access by train staff's handheld terminals and passengers' mobile devices.

4. A method for testing a high-speed train wireless communication perception network system, characterized in that: include: Two Ethernet testers (NDTs) are connected to the marshaling network switches (ECNNs) at both ends of the system under test via Ethernet cables. One of the two Ethernet testers (NDTs) serves as the master NDT, and the other as the slave NDT. The master NDT includes both local and remote ports, while the slave NDT only writes local ports. The remote port number is obtained by the master NDT initiating communication with the slave NDT. The master NDT receives information from all IP addresses, while the slave NDT only receives information from the master NDT. The master NDT actively initiates a data request to the slave NDT, first allocates buffer space for the data, then fills the buffer with data, and releases the buffer space after sending the data request; and when sending the data request, records the application layer timestamp T APP1 ; After receiving the data request from the master NDT, the slave NDT responds and sends a reply message. When the master NDT receives the returned data, it records the application layer timestamp T app4 ; Use the master NDT's processing delay of the slave NDT's polling information as the NDT's internal processing delay; After the master NDT sends information to the slave NDT for the first time, the slave NDT obtains the port number of the master NDT and starts sending data requests to the master NDT. When the master NDT receives the data request, it records the application layer timestamp T app2 , send a reply message and record the application layer timestamp T app3 ; Output T through the serial port app4 -T app1 and T app3 -T app2 To the PC, the PC calculates the delay and fluctuation of the system under test.

5. The method for testing a high-speed train wireless communication perception network system according to claim 4, characterized in that: Two PCs are connected to the marshaling network switch ECNN of the system under test via Ethernet, one as the host and the other as the slave.

6. The method for testing a high-speed train wireless communication perception network system according to claim 4, characterized in that: The flow test of the system under test is performed using two PCs, including: Establish a connection through the IP addresses of the two PCs, set the parameters of the data script according to the required data characteristics, and finally determine the amount of data used for the test; To ensure that the bandwidth to be tested is fully utilized, multiple data streams with the same direction are copied for testing; If you need to test bidirectional throughput, you need to establish a reverse data flow and replicate it. If there is bidirectional data flow, the data flow is grouped according to direction; Set the test stop time to the moment when any data stream completes transmission; After the test is completed, view the maximum instantaneous throughput T by group. max , minimum instantaneous throughput T min and average throughput Actual data transmission volume D, theoretical maximum bandwidth B max and transmission time t, and calculate the throughput fluctuation R and bandwidth efficiency E based on the above data.

7. The method for testing a high-speed train wireless communication perception network system according to claim 6, characterized in that: The calculation formula for throughput fluctuation R is: R=T max -T min The calculation formula for bandwidth efficiency E is:

8. The method for testing a high-speed train wireless communication perception network system according to claim 6, characterized in that: The calculation formula for the total data volume D used in the test is: D=file_size*transactions*number_of_records Among them, file_size indicates the size of a single data transaction; transactions is the number of transactions, indicating how much data of file_size is contained in each record; number_of_records indicates the number of records ultimately generated.

9. The method for testing a high-speed train wireless communication perception network system according to claim 4, characterized in that: The calculation formula for the time delay of the system under test is: τ=[(T app4 -T app1 )-(T app3 -T app2 )] The jitter calculation formula of the system under test is: Among them, n is the total number of polling times in this test, τ i is the one-way transmission delay of the i-th polling data, is the average one-way transmission delay of this test.

10. The method for testing a high-speed train wireless communication perception network system according to claim 4, characterized in that: The Ethernet tester includes: a single chip microcomputer, a power management module, an Ethernet interface module, a lora wireless remote communication radio frequency module and an interface module; The Ethernet interface module contains an Ethernet interface, which is connected to the Ethernet controller through HR601850 to achieve network communication and POE power supply; The power management module uses a DC24 chip to convert the 48V input voltage provided by the POE power supply into a stable 5V voltage to power the lora wireless remote communication RF module; then the LM1117 linear regulator converts the 5V into 3.3V to power the microcontroller and interface module.

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