A method and device for network penetration of two subway lines

Abstract

The present application relates to a kind of two subway lines car ground wireless network through, include the following contents: for the same wireless receiver in vehicle configuration two sets of network identification name and key, each network identification name and key correspond to the wireless network configuration of one line;Setting the sequence of wireless receiver in vehicle access line;Setting switching condition, which includes: when the wireless base station signal strength of current access line is lower than the set value, switching is carried out.The present application does not need to manually carry out the work of frequent multiple upgrading and downgrading wireless base station as in the traditional subway through project;By configuring two sets of network identification name and key of wireless receiver in vehicle, automatically complete the automatic switching of wireless network.

Description

Technical Field

[0001] This invention relates to the field of rail transit communication, specifically to a device for connecting two subway lines via a vehicle-to-ground wireless network. Background Technology

[0002] In subway operation, the CBTC (Communication-Based Train Control) system's vehicle-to-ground wireless communication system is a key system for achieving reliable communication of train control information between the vehicle and the ground. This system enables bidirectional transmission of train control information between the vehicle and trackside signaling equipment based on communication. Currently, part of the vehicle-to-ground communication utilizes the Wi-Fi (Wireless Network) standard to connect the train to the wireless network, forming a transmission link between the vehicle and the ground.

[0003] In traditional WiFi systems, vehicle-mounted wireless receivers can only be configured with a single SSID (network identifier) ​​and key corresponding to their own network to achieve privatization and security of the vehicle-to-ground wireless network.

[0004] like Figure 1 As shown, under the WIFI standard, the train-to-ground wireless system of each subway line is a dedicated local area network (LAN). Wireless base stations are arranged along the rails and use a unique SSID and key agreed upon by the LAN. When a subway car enters the network, the onboard wireless receiver first scans the SSID of the trackside wireless base station. If it matches the pre-configured SSID, the key is verified. If the key verification is correct, network access is allowed.

[0005] If the SSID and key of the device need to be changed, the configuration of the trackside wireless base stations and the train-mounted wireless receivers of the entire line needs to be changed in a unified manner. However, the interval between wireless base station devices is generally between 250 and 350 meters. A subway line is generally more than 20 kilometers long, so the number of base stations on the line is huge, and it is difficult to configure them one by one.

[0006] When two subway lines need to be connected for operation, the networks of the two lines need to be integrated into a single system. During the initial debugging phase, a large amount of manual work is required to configure the trackside wireless base stations and train-mounted wireless receivers. Frequent upgrades and downgrades of software configuration can easily lead to configuration errors, which can affect the operation of the subway lines the following day.

[0007] When connecting trains to the ground via wireless networks, the SSIDs and keys of the wireless base stations on both lines need to be unified and configured as if they were a single line. This ensures that subway trains can identify and access the network from the trackside wireless base stations on both lines. However, connecting two subway lines inevitably involves a connection segment, so the wireless base stations on both lines cannot be pre-configured with the same SSIDs and keys for the connection. Otherwise, trains might access lines outside their current operating route, causing operational malfunctions.

[0008] With the improvement of modern subway operation efficiency, the demand for connecting two existing subway lines is gradually increasing.

[0009] When debugging the network, the efficiency of network connection becomes an issue.

[0010] Under the WIFI standard, if two existing subway lines need to be connected for operation, the trackside wireless base stations of the two lines need to have the same SSID and key so that the on-board wireless receivers can successfully access the network. This is a huge workload during the commissioning period. Usually, a large number of commissioning personnel are needed to upgrade hundreds of base stations on the line one by one and roll them back one by one after the commissioning is completed, resulting in huge labor costs.

[0011] During commissioning, if a fault occurs at the trackside base station during upgrades or downgrades, maintenance personnel will need to handle it on-site. Faults during upgrades will compress commissioning time and affect the commissioning progress, while faults during downgrades may affect operations the following morning. Either scenario represents a waste of project costs and social resources. Summary of the Invention

[0012] To address the aforementioned problems, this invention proposes a method for establishing a wireless network between two subway lines, comprising the following:

[0013] Configure two sets of network identifiers and keys for the same vehicle-mounted wireless receiver, with each network identifier and key corresponding to the wireless network configuration of one line;

[0014] The order in which the vehicle-mounted wireless receiver accesses the line is set, and the vehicle-mounted wireless receiver accesses the wireless network of the line through multiple wireless base stations set on the line.

[0015] Set switching conditions, which include: switching the wireless base station when the signal strength of the wireless base station currently connected to the vehicle wireless receiver is lower than a set value.

[0016] Furthermore, the wireless base station on the first line where the train runs is designated as the first base station group, and the wireless base station on the second line that crosses the line is designated as the second base station group. The onboard wireless receiver first connects to the first base station group.

[0017] Furthermore, the switching conditions specifically include:

[0018] When the train crosses from the first track to the second track, the onboard wireless receiver cannot connect to any of the wireless base stations in the first base station group, and switches to connect to all the wireless base stations in the second base station group.

[0019] Furthermore, when the train is running on the first track, if the signal strength of the wireless base station currently connected to the onboard wireless receiver is lower than the threshold, a pre-scan is initiated to add the accessible wireless base stations along the track to the base station list.

[0020] When the signal strength of the wireless base station currently connected to the vehicle wireless receiver is lower than the set value, the system will switch to the wireless base station ranked first in the base station list.

[0021] Furthermore, the accessible wireless base stations must meet the following conditions: the network identifier name and the key must be correctly matched; and the signal strength of the wireless base station must not be less than the set value.

[0022] Furthermore, the base station list satisfies the following: the first base station group has a higher priority than the second base station group; and in the first base station group, the wireless base station with higher signal strength has a higher priority, and in the second base station group, the wireless base station with higher signal strength has a higher priority.

[0023] Furthermore, when the switching operation is initiated but there is no available base station list, the currently connected wireless base station remains connected until an available wireless base station appears in the base station list.

[0024] Furthermore, prioritize connecting to wireless base stations with high signal strength from the base station list.

[0025] Furthermore, the threshold is greater than the set value.

[0026] Furthermore, the threshold is -60dB.

[0027] Furthermore, the set value is -70dB.

[0028] Furthermore, the train is equipped with onboard wireless receivers at both the front and rear of the train, and these receivers connect and switch with wireless base stations sequentially.

[0029] On the configuration page of the vehicle-mounted wireless receiver, there is a function button for switching between dual SSIDs and keys. When this function is enabled, the vehicle-mounted wireless receiver can perform the above-mentioned cross-line base station selection and implement cross-line functions. When this function is disabled, the vehicle-mounted wireless receiver can only perform base station selection on the first line operated by the vehicle.

[0030] During normal daytime operation, manually click the function button on the configuration page to disable the switching function of dual SSIDs and keys. The train will only connect to the current operating network and will not cause any other impact.

[0031] During nighttime commissioning, manually click the function button on the configuration page to enable the switching function of the two sets of SSIDs and keys. The train can then select cross-line base stations and implement cross-line functions.

[0032] This solves the problem of upgrading and downgrading a large number of base stations during the commissioning of the two lines, keeping the configuration of the trackside base stations on both lines unchanged; only the on-board wireless receiver is configured on the commissioning vehicle.

[0033] This invention also proposes a device for connecting two subway lines via a train-to-ground wireless network, comprising:

[0034] The vehicle-mounted wireless receiver is equipped with two sets of network identifiers and keys, with each network identifier and key corresponding to one line.

[0035] The first base station group and the second base station group are located on the first line and the second base station group is located on the second line that crosses the line. Each base station group is equipped with multiple wireless base stations.

[0036] The vehicle-mounted wireless receiver communicates with the wireless base station of the line via a network identifier and a key.

[0037] The present invention has the following beneficial effects:

[0038] 1. Unlike traditional subway construction projects, it does not require frequent manual upgrades and downgrades of wireless base stations;

[0039] 2. It can prevent sudden failures caused by multiple upgrades and downgrades of wireless base stations, so as to ensure the normal operation of the subway the next day;

[0040] 3. The vehicle-mounted wireless receiver can autonomously identify and authenticate the SSID and key of the two subway lines, and complete the automatic switching of the wireless network, saving a lot of debugging manpower. Attached Figure Description

[0041] Figures 1 to 4 This is a schematic diagram of the train running on the track;

[0042] Figure 5 A flowchart illustrating the wireless network connection between two subway lines;

[0043] Figure 6 A flowchart for switching connections to the vehicle-mounted wireless receiver;

[0044] Figure 7 This is a flowchart of a train crossing a railway line. Detailed Implementation

[0045] The following description, in conjunction with the accompanying drawings and specific embodiments, provides a more detailed explanation of the method and apparatus for establishing a wireless network connecting two subway lines.

[0046] like Figure 2-4As shown, the device for connecting two subway lines via a vehicle-to-ground wireless network proposed in this invention includes: an onboard wireless receiver configured with two sets of network identifiers (SSIDs) and keys for accessing the wireless network, each network identifier and key corresponding to the wireless network configuration of one line; a first base station group and a second base station group set up on the lines, the first base station group being set up on the first line and the second base station group being set up on the second line crossing over, each base station group having multiple wireless base stations set up along each corresponding line; the onboard wireless receiver communicates with the wireless base stations on each line through the network identifier and key. The onboard wireless receiver is equipped with a button for switching between the two sets of SSIDs and keys, requiring manual confirmation to enable or disable the function. This example uses subway lines L1 and L2 as examples, where line L1 is the first line and line L2 is the second line crossing over. The SSID of line L1 is DCS-L1, and the key is DCS123. The SSID of line L2 is DCS-L2, and the key is DCS321. Each line has a unique SSID and key. If a vehicle-mounted wireless receiver is connected to a line, it must verify the SSID and key of the wireless network on that line. Only after the SSID and key are verified can the receiver be connected to the line.

[0047] Please see Figure 5 and Figure 6 The present invention proposes a method for establishing a wireless network between two subway lines, comprising the following:

[0048] Without changing the configuration of the wireless base station on the track, two sets of SSIDs and keys for accessing the wireless network are configured for the same vehicle-mounted wireless receiver according to the wireless network configuration of the two lines. Each SSID and key corresponds to the wireless network of line L1 and line L2 respectively.

[0049] On the configuration page of the vehicle wireless receiver, set the following: the first choice is a set of SSID and key of the wireless base station of the first line L1, and the second choice is a set of SSID and key of the wireless base station of the cross line L2; the wireless base station of the first line is the first base station group, and the wireless base station of the cross line L2 is the second base station group. The vehicle wireless receiver first connects to the wireless network of the first line L1 where the first base station group is located.

[0050] Configure the first and second selection switching conditions for the vehicle-mounted wireless receiver. These conditions primarily include: switching the wireless base station when the signal strength of the wireless base station on the currently accessed line of the vehicle-mounted wireless receiver falls below a set value.

[0051] The specific switching conditions are as follows: the train's onboard wireless receiver will preferentially connect to the first base station group. When the train crosses from the first line to the second line, and all wireless base stations in the first base station group cannot be connected, the train will switch to and connect to the second base station group.

[0052] When the train is running on the first track, if the signal strength of the wireless base station connected to the onboard wireless receiver is lower than the threshold (optionally -60dB), a pre-scan will be initiated to add the accessible wireless base stations along the track to the base station list, as shown in Table 1 below.

[0053] Table 1. Base Station List

[0054] 1 First base station group -50dB 2 First base station group -60dB 3 Second base station group -68dB

[0055] The accessible wireless base stations must meet the following criteria: SSID and key verification is performed; correctly verified base stations must also have a signal strength no less than a set value, optionally -70dB. A list of available base stations is generated based on the priority order of the first base station group over the second. Furthermore, within the first base station group, wireless base stations with higher signal strength have higher priority, and similarly, within the second base station group, wireless base stations with higher signal strength have higher priority.

[0056] When the signal strength of the wireless base station currently connected to the vehicle-mounted wireless receiver is lower than the set value of -70dB, a handover is initiated. The receiver selects a base station from the available base station list, choosing the first-ranked base station in the list. According to the rules for generating the base station list, base stations in the first base station group have priority, and those with higher signal strength have even higher priority. Specifically, the first-ranked base station in the first base station group in Table 1 has priority over the second-ranked base station in the first base station group, and base stations from both first base station groups have priority over base stations from the second base station group.

[0057] In special circumstances, when there is no available base station list, keep the current wireless base station connected and continue scanning for trackside wireless base stations until an accessible wireless base station appears in the list.

[0058] On the configuration page of the vehicle wireless receiver, a button for switching between dual SSIDs and keys can be set up to allow manual confirmation to enable or disable this function.

[0059] After saving the above settings, there is no need to reconfigure them every time you debug. You only need to manually confirm the dual SSID and key switching function on and off on the configuration page of the vehicle wireless receiver.

[0060] When the function is off, the vehicle wireless receiver maintains a private local area network for each line and uses the unique SSID and key agreed upon by the local area network.

[0061] When the function is enabled, the onboard wireless receiver can select wireless base stations across lines, enabling the train to cross lines.

[0062] The method proposed in this invention uses trains equipped with onboard wireless receivers at both the front and rear to access the wireless networks of lines L1 and L2. The wireless receivers at the front and rear of the train sequentially connect and switch with the wireless base stations. Specifically, when lines L1 and L2 are connected, the process is as follows: Figure 7 As shown.

[0063] (1) First, the train runs on line L1, and the onboard wireless receivers at the front and rear of the train are connected to the line L1 wireless base station. Please refer to [link / reference]. Figure 2 ;

[0064] (2) When the train reaches the crossing point between lines L1 and L2, the front of the train first enters line L2 from line L1. At this time, the onboard wireless receiver at the front of the train selects a base station according to the configuration and switching rules, and switches to the wireless base station of line L2 as appropriate. The train begins to cross the lines. The onboard wireless receiver at the front of the train connects to the wireless network of line L2, and the onboard wireless receiver at the rear of the train connects to the wireless network of line L1. Please refer to [link to relevant documentation]. Figure 3 .

[0065] (3) The train continues its journey. At this point, the front of the train connects to the wireless base station on line L2, while the rear of the train selects a cross-line base station. Based on the configuration and switching rules of the onboard wireless receiver, the train switches to the wireless base station on line L2 as needed. The train then runs on line L2, and the onboard wireless receivers at both the front and rear of the train connect to the wireless network on line L2, completing the cross-line connection. Please refer to [link to relevant documentation]. Figure 4 .

[0066] The present invention has the following beneficial effects:

[0067] 1. Unlike traditional subway construction projects, it does not require frequent manual upgrades and downgrades of wireless base stations;

[0068] 2. It can prevent sudden failures caused by multiple upgrades and downgrades of wireless base stations, so as to ensure the normal operation of the subway the next day;

[0069] 3. The vehicle-mounted wireless receiver can autonomously identify and authenticate the SSID and key of the two subway lines, and complete the automatic switching of the wireless network, saving a lot of debugging manpower.

[0070] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for establishing a wireless network connecting two subway lines, characterized in that, Includes the following: Configure two sets of network identifiers and keys for the same vehicle-mounted wireless receiver, with each network identifier and key corresponding to the wireless network configuration of one line; The order in which the vehicle-mounted wireless receiver accesses the line is set, and the vehicle-mounted wireless receiver accesses the wireless network of the line through multiple wireless base stations set on the line. The accessible wireless base stations must meet the following criteria: the network identifier and key are correctly verified, and the signal strength is not less than a set value; a base station list is generated based on the order of the access lines and the signal strength. Among them, the wireless base station on the first line in which the train runs is the first base station group, the wireless base station on the second line into which the train crosses the line is the second base station group, and the on-board wireless receiver first connects to the first base station group. The base station list is prioritized according to the following rules: the first base station group has a higher priority than the second base station group, and within the same base station group, the wireless base station with the higher signal strength has a higher priority. Set switching conditions, which include: when the train is running on the first line, if the signal strength of the wireless base station currently connected to the onboard wireless receiver is lower than the threshold, start a pre-scan and add the accessible wireless base stations to the base station list. When the signal strength of the wireless base station currently connected to the vehicle wireless receiver is lower than the set value, the system will switch to the wireless base station ranked first in the base station list.

2. The method for establishing wireless network connectivity between two subway lines as described in claim 1, characterized in that, The switching conditions specifically include: When the train crosses from the first track to the second track, the onboard wireless receiver cannot connect to any of the wireless base stations in the first base station group, and switches to connect to the wireless base stations in the second base station group.

3. The method for establishing wireless network connectivity between two subway lines as described in claim 1, characterized in that, If no available base station list is found when switching is initiated, the currently connected wireless base station will remain connected until an available wireless base station appears in the base station list.

4. The method for establishing a wireless network between two subway lines as described in claim 1, characterized in that, The threshold is greater than the set value.

5. The method for establishing wireless network connectivity between two subway lines as described in claim 4, characterized in that, The threshold is -60dB.

6. The method for establishing wireless network connectivity between two subway lines as described in claim 4, characterized in that, The set value is -70dB.

7. The method for establishing a wireless network between two subway lines as described in claim 1, characterized in that, The train is equipped with onboard wireless receivers at both the front and rear of the train, and these receivers connect to and switch with wireless base stations in sequence.

8. A device for connecting two subway lines via a train-to-ground wireless network, used to implement the method described in any one of claims 1 to 7, characterized in that, Include: The vehicle-mounted wireless receiver is equipped with two sets of network identifiers and keys, with each network identifier and key corresponding to one line. The first base station group and the second base station group are located on the first line and the second base station group is located on the second line that crosses the line. Each base station group includes multiple wireless base stations. The vehicle-mounted wireless receiver communicates with the wireless base station of the line via a network identifier and a key.

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