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

Abstract

The invention relates to the technical field of wireless communication, in particular to a high-speed train wireless communication sensing network system and a test method thereof, and the network system comprises a train-level communication network bus, a vehicle-level communication network bus and an equipment-level communication network bus; a wireless network bridge is used for replacing traditional Ethernet cable connection, a sensing network is added, various sensors such as LoRa and WiFi are used for detecting the internal and external states of a vehicle, and the overall network topology structure is determined. The test method comprises the following steps: sending and receiving data through a network to be tested, stamping a timestamp on an application layer, and transmitting the data to a PC (Personal Computer) end for calculation, so as to obtain the time delay and fluctuation of the network. The system simplifies the arrangement of a network system, achieves the real-time monitoring and feedback of the internal and external environments of the train, and meets the requirements of the high-speed train 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 sensing network system and a testing method thereof. Background Art

[0002] With the rapid development of high-speed train technology, the CR400 intelligent EMU, as one of the important representatives of modern railway transportation, is equipped with advanced power systems, on-board control systems and network communication capabilities. In traditional train networks based on wired connections, there is often a risk of network failure caused by abnormal terminal equipment. For example, if a terminal device in the Ethernet fails and sends a large number of broadcast packets, these broadcast data will occupy a large amount of network bandwidth, resulting in the inability to process normal control data in a timely manner, thereby increasing the possibility of network interruption. In addition, the fixed wiring structure of wired connections also limits the flexibility and adaptability of the network, especially in the face of special environmental factors such as vibration and electromagnetic interference during train operation. Wired connections are susceptible to problems such as loose connectors and aging of shielding layers, further reducing the reliability and stability of network communications. Such problems not only increase the complexity and cost of network operation and maintenance, but also limit the network's ability to respond to dynamic environmental changes and quickly deploy new technologies.

[0003] Therefore, in order to address the above-mentioned problems and to provide further development space in the future, the CR400 intelligent EMU urgently needs a more flexible, intelligent, more perceptual and 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 solution:

[0006] In a first aspect, the present invention provides 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;

[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 adopts the marshaling Ethernet bus ECN. Two marshaling network switches ECNN are set in each carriage, one of which is used as the main switch and the other as the slave switch. When the main switch fails, it automatically switches to the slave switch for communication. The two marshaling network switches ECNN in each carriage are connected to the marshaling Ethernet bus ECN.

[0009] Each device in the carriage is point-to-point connected to the corresponding marshaling network switch using a star topology, and the two switch machines in the same carriage share the 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 of 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 NDT are connected to the marshaling network switches ECNN at both ends of the system to be tested through Ethernet cables. One of the two Ethernet testers NDT is used as the master NDT and the other as the slave NDT. The master NDT includes local ports and remote ports, and the slave NDT only writes local ports. The remote port number is obtained after the master NDT initiates communication with the slave NDT. The master NDT receives information from all IPs, and 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] Use the master NDT to process the slave NDT’s polling information delay as the NDT internal processing delay;

[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 data requests to the master NDT. When the master NDT receives the data request, it records the timestamp T of the application layer. app2 , send a reply message and record the application layer timestamp T app3 ;

[0019] 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.

[0020] Furthermore, in the test method, two PCs are connected to the marshaling network switch ECNN of the system to be tested via Ethernet, one as a host and the other as a slave.

[0021] Furthermore, two PCs are used to perform flow tests on the system under test, including:

[0022] 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;

[0023] To ensure that the bandwidth to be tested is fully utilized, multiple data streams with the same direction are copied for testing;

[0024] If you need to test the bidirectional throughput, you need to establish another reverse data flow and replicate it;

[0025] If there is bidirectional data flow, the data flow is grouped according to direction;

[0026] Set the test stop time to the moment when any data stream completes transmission;

[0027] 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, the throughput fluctuation R and bandwidth efficiency E are calculated based on the above data.

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

[0029] R=T max -T min

[0030] The bandwidth efficiency E calculation formula 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; transactions is the number of times it is sent, indicating how much data of file_size is contained in each record; number_of_records indicates the number of records finally generated.

[0035] Furthermore, the calculation formula for the 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] Further, 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 includes 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] The present invention aims at the problem that the wired connection of the CR400 high-speed train group is susceptible to loose connectors, aging of the shielding layer and other problems under the interference of special environmental factors such as vibration and electromagnetic interference during operation. A high-speed train wireless communication perception network is invented, which uses wireless technology to replace traditional wired connections, simplifies the system layout and maintenance process, and uses various sensors to monitor and feedback the internal and external environment of the train in real time; through bridges, open WiFi APs and LoRa communication nodes, network expansion is easier, space is reserved for future development, and new modules can be deployed more quickly. At the same time, a variety of sensors such as LoRa and WiFi are introduced into the network. These sensors can monitor the status of the inside and outside of the train in real time, such as environmental factors such as temperature, vibration, and air pressure, help the network better adapt to changes in the external dynamic environment, improve the network's perception of dynamic environmental changes, and enhance the flexibility and adaptability of the network.

[0045] In addition, the present invention also proposes a testing method to comprehensively test the latency, jitter and other performance of the constructed perception network, and further collect throughput data, calculate data such as throughput fluctuation and bandwidth efficiency, thereby ensuring the stability and reliability of network communications and meeting the needs of modern high-speed trains for stable and efficient communications. At the same time, it provides 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

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

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

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

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

[0051] Take the CR400 intelligent EMU as an example. It consists of eight carriages, of which four carriages form a traction unit, including one traction carriage and three ordinary carriages. The eight carriages are evenly divided into two groups. The two EMUs can be reconnected and run together. 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.

[0052] The vehicle-level bus adopts the marshaling Ethernet bus ECN. Two marshaling network switches ECNN are set in each carriage, one of which is the main switch and the other is the slave switch. The two switches in the same carriage share the virtual MAC address and IP address. When the main switch fails, it automatically switches to the slave switch for communication. The two 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 equipment in the carriage includes: 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 to realize wireless communication between the backbone network switches ETBN between carriages between 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 to realize 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, the security and reliability of the network are effectively improved.

[0056] In addition, the perception network of the present invention also includes a LoRa communication gateway, which is used for information exchange between different train groups, collision warning, and node data forwarding of narrowband, low-power, long-distance wireless node networking communication. The LoRa sensor perception network includes: wireless infrared axle temperature sensors, wireless vibration sensors, wireless temperature and humidity sensors, wireless air pressure and altitude sensors, etc. installed on the track.

[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 delay and fluctuation of the network. The above-mentioned embedded Ethernet channel delay and jitter tester NDT uses the Modbus-UDP protocol for communication, the main 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 working modes and transmission rates to communicate with network devices of different rates. Use a micro-USB interface for power supply and data transmission. Specifically include the following steps:

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

[0061] Two Ethernet testers NDT are connected to the marshaling network switch ECNN at both ends of the system to be tested through Ethernet cables. One of the two Ethernet testers NDT is used as the master NDT and the other is used as the slave NDT. The two NDTs communicate through the Modbus-UDP protocol; and the NDT is connected to the PC through Micro-USB. The serial port debugging assistant is run on the PC to read the information transmitted by the NDT serial port.

[0062] The purpose and use of the present invention to set up two PCs is mainly to achieve two-way testing and monitoring of the network to be tested, ensuring accurate and comprehensive network performance data. The configuration of the master PC and the slave PC is used to establish end-to-end data communication in order to test performance such as throughput, latency, and fluctuation. This setting can achieve two-way data stream transmission.

[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 connected. The PC connected to the master NDT is the master PC, which serves as the console end in the flow test, and 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, etc., analyze and report performance results. The endpoint is the device or process responsible for sending and receiving test traffic. These endpoints can be deployed at locations in the network where performance testing is required.

[0065] 2) Define the port numbers at both ends, where the master NDT includes the local port and the remote port, the slave NDT only writes the local port, and the remote port number is obtained after the master NDT initiates communication with the slave NDT; the master NDT receives information from all IPs, and 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, the buffer space is released; and when sending the data request, the timestamp T of the MAC layer and the application layer is recorded 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 the 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 NDT will not fluctuate greatly; and the two NDTs have the same configuration and basically the same internal processing delay, so the polling information delay of the master NDT is used as the internal processing delay of 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 data from NDT app4 The time difference T app4 -T app1 , the 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 calculation formula for 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 also installs traffic testing software on the PC to perform traffic testing on the system to be tested, and collects throughput data to calculate 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 for 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; transactions is the number of times it is sent, indicating how much data of file_size is contained in each record; number_of_records indicates the number of records finally 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 the bidirectional throughput, you need to establish another 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, the throughput fluctuation R and bandwidth efficiency E are calculated based on the above data.

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

[0088] R=T max -T min

[0089] The bandwidth efficiency E calculation formula is:

[0090]

[0091] The test method of the present invention is based on the STM32H7 single-chip microcomputer, communicates through the Modbus-UDP protocol, has a high-precision timestamp recording function, and supports microsecond accuracy. Compared with traditional operating system software testing, this method reduces the delay caused by the operating system, and provides a comprehensive network performance testing method by combining an embedded tester with flow testing software to achieve 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; and supports POE and Micro USB power supply, Micro USB serial port data printing, long-distance communication with other devices, and microsecond-level precise timing and other functions.

[0093] The Ethernet interface module includes 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 MicroUSB serial port printing data.

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

[0097] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0098] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather 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 adopts the marshaling Ethernet bus ECN. Two marshaling network switches ECNN are set in each carriage, one of which is used as the main switch and the other as the slave switch. When the main switch fails, it automatically switches to the slave switch for communication. The two marshaling network switches ECNN in each carriage are connected to the marshaling Ethernet bus ECN. Each device in the carriage is point-to-point connected to the corresponding marshaling network switch using a star topology, and the two switch machines in the same carriage share the 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 is 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 test method for a high-speed train wireless communication perception network system, characterized in that: include: Two Ethernet testers NDT are connected to the marshaling network switches ECNN at both ends of the system to be tested through Ethernet cables. One of the two Ethernet testers NDT is used as the master NDT and the other as the slave NDT. The master NDT includes local ports and remote ports, and the slave NDT only writes local ports. The remote port number is obtained after the master NDT initiates communication with the slave NDT. The master NDT receives information from all IPs, and 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 to process the slave NDT’s polling information delay as the NDT 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 timestamp T of the application layer. 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 the 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 through Ethernet, one as the host and the other as the slave.

6. The method for testing the high-speed train wireless communication perception network system according to claim 4, characterized in that: The flow test of the system under test is carried out through 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 the bidirectional throughput, you need to establish another 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 the average throughput Actual data transmission volume D, theoretical maximum bandwidth B max and transmission time t, the throughput fluctuation R and bandwidth efficiency E are calculated based on the above data.

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

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

9. The method for testing the 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, It is the average one-way transmission delay of this test.

10. The method for testing the 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 includes 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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