JP5084635B2 - Wireless communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a train wireless communication system for preventing frequencies from erroneously switched even when an on-vehicle station on a train receives both inappropriate advance notice line section data and established line section data. <P>SOLUTION: The wireless communication system performs wireless communication with an on-vehicle station 6a on a train 1a, an advance notice base station 2 on the ground, and an established base station 3. The on-vehicle station 6a switches frequencies of wireless communication on the basis of the advance notice line section data B when the advance notice line section data B and the established line section data B are successively received. The on-vehicle station 6a updates an advance notice signal to be a basis for switching frequencies from advance notice line section data B to the advance notice line section data A when the station successively receives the advance notice line section data B and the advance notice line section data A before it receives the established line section data B. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a wireless communication system, and more particularly to a wireless communication system that performs wireless communication between an on-board station and a base station.

  In the train radio communication system, radio communication is performed between an on-board station on a train and a base station. In the conventional train radio system, the base station installed near the line section boundary is the line section data including the frequency data of wireless communication for the on-board station on the train that crosses the line section boundary. Send. The onboard station automatically switches the frequency of wireless communication based on the line data. Thus, in a conventional train radio communication system, when a train crosses a line, even if a person forgets to switch the frequency, the frequency is automatically switched.

  In the train radio communication system described above, no problem occurs when all trains cross the same line section. However, for example, when the B route section branches from the A line section in the travel route of the train, one train crosses the line section B while another train does not cross the line section A. It may remain a line zone. Therefore, when the base station transmits only a single type of line segment data, some on-board stations may not be able to switch to the destination frequency.

  Therefore, a train radio communication system has been proposed that transmits line segment data corresponding to the destination of each train to each on-board station so that all on-board stations can be switched to an appropriate frequency. Patent Document 1 describes a train radio communication system in which the system is further improved. In this train radio communication system, the first base station (hereinafter referred to as advance notice base station) transmits line data (hereinafter referred to as advance notice line area data), and the second base station (hereinafter referred to as confirmed base station) Line data (hereinafter referred to as fixed line data) is transmitted.

  When the onboard station receives the warning line data once, it enters a state of waiting for reception of the corresponding fixed line data for a certain period of time and cannot receive the warning line data. When the onboard station in this state receives the corresponding confirmed line data, it switches the frequency of the wireless communication based on the notice line data. As a result, even if the onboard station of one train receives the notice line data that should be received only by the onboard station of another train, it does not receive the confirmed line area data corresponding to the notice line data. In this case, erroneous switching of the frequency is prevented.

JP 2003-224506 A

  However, in wireless communication using an antenna (antenna), the range (area) in which radio waves from the base station can reach varies depending on the environment, so the area may be expanded. In addition, there are cases where the preceding train and the following train that cross the line to different line sections approach each other, and there are cases where the trains that cross the different line sections run in parallel even after passing through the branch point. Therefore, even if the onboard station receives the notice line data and the confirmed line area data in stages, the notice line that the onboard station of one train should receive only at the onboard station of another train There are cases where both ward data and confirmed line data are received. In this case, there is a problem that an on-board station of a certain train erroneously switches the frequency of wireless communication based on inappropriate notice line data.

  The present invention has been made to solve the above-described problems. Even when the on-board station of a train receives both inappropriate notice line data and fixed line data, the frequency error is caused. An object of the present invention is to provide a train radio communication system capable of preventing switching.

  A wireless communication system according to the present invention is a wireless communication system that performs wireless communication between a first station on a mobile body and a second station on the ground, and the first station transmits a warning signal and a confirmation signal. When sequentially received, the radio communication frequency is switched based on the notice signal. When the first station receives the first warning signal and the second warning signal in sequence before receiving the confirmation signal, a warning signal as a basis for switching the frequency is obtained. The first notice signal is updated to the second notice signal.

  According to the wireless communication system of the present invention, when the first station on the mobile body receives the first warning signal and the second warning signal in sequence, the warning signal as a basis for switching the frequency of the wireless communication. Is updated from the first notice signal to the second notice signal. Therefore, even when the first station receives an unacceptable confirmation signal after receiving an inappropriate notice signal as the first notice signal, the first station receives an appropriate notice signal as the second notice signal during reception. Thus, it is possible to prevent erroneous frequency switching.

<Embodiment 1>
The radio communication system according to the present embodiment is a train radio communication system that performs radio communication between a first station on a train, which is a moving body, and a second station on the ground. In the following description, the first station is an on-board station, and the second station is a notice base station and a confirmed base station. Before describing the train radio communication system according to the present embodiment, the train radio communication system as a premise will be described.

  As shown in FIG. 3, the premise train radio communication system includes a subsequent train 1 a, a preceding train 1 b, a notice base station 2, a confirmed base station 3, and a switching unit 4. Hereinafter, when the subsequent train 1a and the preceding train 1b are not distinguished, they may be referred to as the train 1. The A line section 5 is provided up to the switching section 4 and the switching section 4 branches into an A line section 5a and a B line section 5b starting from the switching section 4. The switching unit 4 includes, for example, points and traffic lights. The switching unit 4 switches the destination of the train 1 to either the A line section 5a or the B line section 5b.

  The train 1 moves from the position indicated by the solid line in FIG. 3 to the position indicated by the dotted line in FIG. 3 after a predetermined time has elapsed. As shown in the figure, the preceding train 1b travels on the B line section 5b after passing through the switching section 4, whereas the subsequent train 1a travels on the A line section 5a after passing through the switching section 4. On-board stations 6a and 6b are provided on the succeeding train 1a and the preceding train 1b. Hereinafter, when the onboard station 6a and the onboard station 6b are not distinguished, they may be referred to as the onboard station 6. The on-board station 6 has a wireless device, and performs wireless communication between the notice base station 2 and the confirmed base station 3 using the wireless device.

  The switching unit 4 described above transmits a switching signal 7. This switching signal is a signal indicating whether the destination of the train 1 is the A line section 5a or the B line section 5b, and corresponds to, for example, a signal indicating a point switching direction. The notification base station 2 is provided in the vicinity of the switching unit 4 and transmits the notification line segment data when receiving the switching signal 7 from the switching unit 4. This notice line section data includes notice line section data B for switching from the frequency of the A line section 5 to the frequency of the B line section 5b. In FIG. 3, the area in which the notice line section data from the notice base station 2 reaches is shown as area 8. The confirmed base station 3 is provided behind the switching unit 4 in the traveling direction of the train 1 and transmits confirmed line section data. The determined base station 3 according to FIG. 3 transmits the determined line segment data B for switching from the frequency of the A line segment 5 to the frequency of the B line segment 5b. In FIG. 3, a range in which the confirmed line segment data B from the confirmed base station 3 reaches is indicated as an area 9.

  When the onboard station 6 receives the notice line data once, it enters the reception waiting state for the fixed line data for a certain period of time and cannot receive the notice line data. The on-board station 6 in this state receives the confirmed line segment data and switches the radio communication frequency based on the received notice segment data when the predetermined condition is satisfied. The predetermined condition corresponds to, for example, a condition that the contents match each other in the received notice line segment data and confirmed line segment data, or a condition that the contents are received according to a determined rule. On the other hand, when the above-mentioned predetermined condition is not satisfied within the above-mentioned fixed time, the onboard station 6 determines that a time-out has occurred, and cancels the received notice line segment data.

  In the train radio communication system according to FIG. 3, when the onboard station 6 receives the notice line section data B, the onboard station 6 enters a waiting state for the confirmed line section data B corresponding to the notice line section data B for a certain time. When the onboard station 6 sequentially receives the notice line segment data B and the confirmed line segment data B, the on-board station 6 assumes that the above-mentioned predetermined condition is satisfied. Shall be switched.

  The operation of the onboard station 6 will be described by taking the onboard station 6b as an example. The notice base station 2 according to FIG. 3 transmits notice line section data B for switching to the frequency of the B line section 4a, which is the destination of the onboard station 6b. As indicated by the solid line, when the preceding train 1b travels in the area 8, the onboard station 6b receives the notice line section data B from the notice base station 2. Hereinafter, in order to simplify the description, the fact that the onboard station 6 has received the warning line section data B is described as “(B)” below the onboard station 6.

  As shown by the dotted line in FIG. 3, when the preceding train 1b passes through the switching unit 4 and enters the B line section 5b and travels in the area 9, the onboard station 6b of the preceding train 1b The fixed line data B transmitted from the station 3 is received. Thus, the onboard station 6b sequentially receives the notice line segment data B and the confirmed line segment data B, and the onboard station 6b determines the frequency of the wireless communication based on the received notice line segment data B. Switch automatically. The onboard station 6a performs the same operation as the onboard station 6b because it is necessary to automatically switch the frequency at a branch point other than the branch point shown in FIG.

  As described above, each of the onboard stations 6a and 6b related to the train radio communication system as a premise receives the notice line data B and the confirmed line data B sequentially, and performs wireless communication based on the notice line data B. Is switched to the frequency of line B 5b. Here, it is assumed that the on-board station 6a of the succeeding train 1a has the notice-line data B that should be received only by the on-board station 6b of the preceding train 1b, that is, the notice-line data B that is not appropriate for the on-board station 6a. Assume that the signal is received in area 8. Even in such a case, in the state shown in FIG. 3, since the onboard station 6a does not receive the determined line segment data B that is not appropriate within the area 9, the onboard station 6a determines that a timeout has occurred. Cancel the notice line data B.

  As described above, according to the premise train radio communication system, even if the onboard station 6a receives the inappropriate notice line data B, it is possible to prevent erroneous frequency switching. In the above, the case where the following train 1a does not cross the line and the preceding train 1b crosses the line has been described, but the preceding train 1b does not cross the line and the following train 1a crosses the line. But it is the same. However, even in such a train radio communication system, there has been a problem that erroneous frequency switching may occur. The problem will be described with reference to FIG.

  In wireless communication using an antenna, the areas 8 and 9 of the advance notice base station 2 and the confirmed base station 3 may vary depending on the radio wave propagation environment and may be enlarged. FIG. 4 shows areas 8 and 9 enlarged from FIG. Moreover, these intervals may become narrow depending on the traveling state of the succeeding train 1a and the preceding train 1b. FIG. 4 shows a case where the interval between the succeeding train 1a and the preceding train 1b is narrowed. The train 1 moves from the time point indicated by the solid line to the position indicated by the dotted line after a predetermined time has elapsed.

  At the time indicated by the solid line, both the preceding train 1b and the following train 1a reach the area 8, and the onboard station 6a of the following train 1a should be received only by the onboard station 6b of the preceding train 1b. The ward data B is received. In FIG. 4, as in FIG. 3, these received states are indicated as “(B)” on the lower side of the onboard station 6a and on the lower side of the onboard station 6b. In this case, both the onboard stations 6a and 6b are in a waiting state for receiving the confirmed line segment data B corresponding to the notice line segment data B for a certain period of time.

  When the area 9 of the confirmed line segment data B is not expanded, the onboard station 6a does not receive the inappropriate confirmed line segment data B in the area 9 as described above, and thus the inappropriate notice line segment data is not received. Even if B is received, the frequency is not erroneously switched. However, as shown in FIG. 4, when the area 9 is enlarged, the onboard station 6a of the subsequent train 1a also receives the determined line segment data B that is not appropriate, and thus a frequency switching occurs. was there. Moreover, although not shown in figure, when the succeeding train 1a and the preceding train 1b run in parallel after passing through the switching unit 4, erroneous frequency switching has occurred.

  A train radio communication system according to the present embodiment that solves this problem will be described below with reference to FIG. Note that, in the configuration of the train radio communication system according to the present embodiment, the same configuration as the premise train radio communication system is denoted by the same reference numeral, and the configuration not newly described is the same as described above. It shall be. The train radio communication system according to the present embodiment includes a subsequent train 1a, a preceding train 1b, a notice base station 2, a confirmed base station 3, and a switching unit 4, as in the above-described train radio communication system.

  When the on-board station 6 as the first station according to the present embodiment sequentially receives the warning line data that is the warning signal and the fixed line data that is the final signal, the on-board station 6 performs wireless communication based on the warning line data. Switch the communication frequency. That is, the onboard station 6 according to the present embodiment, based on the forewarning line data B, when receiving the forewarning line data B and the confirmed line area data B sequentially, like the above-mentioned onboard station. It is assumed that the frequency of wireless communication is switched.

  The onboard station 6 according to the present embodiment, unlike the above-described onboard station 6, sequentially receives the first forewarning line data and the second forewarning line data before receiving the confirmed line area data. In this case, the notice line segment data used as the basis for frequency switching is updated by overwriting the second notice line segment data received later from the first notice line segment data received earlier. In the present embodiment, the first notice line section data is the above-described notice line section data B, and the second notice line section data is for switching from the frequency of the B line section 5b to the frequency of the A line section 5a. It is assumed that it is the notice line section data A.

  The operation of the train radio communication system having the above configuration will be described using the onboard station 6a as an example. As a premise, it is assumed that the onboard station 6a of the following train 1a has received the notice line data B that should be received only by the onboard station 6b of the preceding train 1b in the area 8, as in FIG. Thereafter, the train 1 according to the present embodiment moves to the position indicated by the solid line in FIG. 1 when a little time has passed since the position indicated by the solid line in FIG. 4. At this time, the preceding train 1b travels in the B line section 5b, but the subsequent train 1a travels in the A line section 5.

  At this time, the notice base station 2 transmits notice line section data A. Then, the on-board station 6b according to the present embodiment sequentially receives the warning line data B and the warning line data A before receiving the confirmed line data B, and therefore the basis of frequency switching. The warning line data is updated from the warning line data B to the warning line data A. In FIG. 1, the fact that the onboard station 6a has updated the notice line data as the basis for switching the frequency from the notice line data B to the notice line data A is indicated on the lower side of the onboard station 6a as “( B → A) ”. As a result, the on-board station 6a is in a waiting state for receiving the fixed line data A for a certain period of time.

  The train 1 moves to a position indicated by a dotted line in FIG. 1 after a lapse of time from the time indicated by the solid line in FIG. At this time, the onboard station 6a of the following train 1a travels in the area 9, and therefore receives the determined line segment data B that is not appropriate. However, since the onboard station 6a is in a waiting state for receiving the confirmed line section data A, even if the confirmed line section data B is received, the onboard station 6a is based on the notice line section data B that is not appropriate for the onboard station 6a. Does not switch radio communication frequency.

  According to the train radio communication system according to the present embodiment as described above, even when the onboard station 6b receives the inappropriate line segment data B after receiving the inappropriate line segment data B, they are not. By receiving the appropriate notice line segment data A during the reception, it is possible to prevent erroneous frequency switching. In the present embodiment, the train radio communication system has been described. However, the wireless communication system according to the present invention is not limited to this, and the same effect as described above can be obtained as long as the frequency is automatically switched.

<Embodiment 2>
In the first embodiment, the on-board station 6 receives the notice line data B and the notice line data A in order before receiving the confirmed line data, so that the notice line as a basis for frequency switching is received. The ward data is updated by overwriting the sight line data A from the sight line data B. On the other hand, in the present embodiment, the onboard station 6 receives an invalid signal, which is a predetermined signal, between receiving the notice line data and receiving the confirmed line data. The notice line data received before the invalid signal is invalidated.

  The operation of the train radio communication system according to this embodiment will be described with reference to FIG. Of the configurations of the train radio communication system according to the present embodiment, the same configurations as those of the train radio communication system according to the first embodiment are denoted by the same reference numerals, and configurations not newly described are implemented. It is assumed that the configuration is the same as that of the first embodiment.

  The operation of the train radio communication system having the above configuration will be described using the onboard station 6a as an example. As a premise, it is assumed that the onboard station 6a of the following train 1a has received the notice line data B that should be received only by the onboard station 6b of the preceding train 1b in the area 8, as in FIG. Thereafter, the train 1 according to the present embodiment moves to the position indicated by the solid line in FIG. 2 when a little time elapses from the time indicated by the solid line in FIG. 4.

  At this time, the advance notice base station 2 transmits an invalid signal. Then, since the onboard station 6b according to the present embodiment receives the invalid signal from the reception of the notice line segment data B to the reception of the confirmed line segment data, the notice received prior to the invalid signal is received. Invalidate the line data B. In FIG. 2, “(B → ×)” is written below the onboard station 6 a that the onboard station 6 a invalidates the previously received notice line data B. As a result, the onboard station 6b returns to the state before the notice line segment data B is received. This is described as “(×)” below the upper station 6a.

  The train 1 moves to the position indicated by the dotted line in FIG. 2 when a little time has elapsed from the time indicated by the solid line in FIG. At this time, the onboard station 6a of the following train 1a travels in the area 9, and therefore receives the determined line segment data B that is not appropriate. However, since the onboard station 6a is not in a waiting state for receiving the confirmed line section data B, even if the confirmed line section data B is received, Does not switch radio communication frequency.

  According to the train radio communication system according to the present embodiment as described above, even when the onboard station 6b receives the inappropriate line segment data B after receiving the inappropriate line segment data B, they are not. By receiving the invalid signal during the reception of the frequency, it is possible to prevent erroneous frequency switching. In this embodiment, the onboard station 6 invalidates the previously received one notice line section data B when it receives the invalid signal after receiving the one notice line section data B. It was. However, the present invention is not limited to this. When the onboard station 6 receives the invalid signal after receiving the plurality of warning line data, it invalidates all of the plurality of previously received warning line data. It may be a thing.

It is a figure which shows the structure and operation | movement of the train wireless communication system which concerns on Embodiment 1. FIG. It is a figure which shows the structure and operation | movement of the train radio | wireless communications system which concerns on Embodiment 2. FIG. It is a figure which shows the structure and operation | movement of the train radio | wireless communications system used as a premise. It is a figure which shows the problem of the train radio | wireless communications system used as a premise.

Explanation of symbols

  1 train, 1a following train, 1b preceding train, 2 notice base station, 3 confirmed base station, 4 switching unit, 5, 5a A line section, 5b B line section, 6, 6a, 6b on-board station, 7 switching signal, 8,9 area.

Claims (2)

A wireless communication system for performing wireless communication between a first station on a mobile body and a second station on the ground,
The first station is
When the notice signal and the confirmation signal are received sequentially, the frequency of the wireless communication is switched based on the notice signal,
When the first notice signal and the second notice signal are sequentially received before the confirmation signal is received, the notice signal based on the switching of the frequency is changed from the first notice signal to the first notice signal. Update to the second warning signal,
Wireless communication system. A wireless communication system for performing wireless communication between a first station on a mobile body and a second station on the ground,
The first station is
When the notice signal and the confirmation signal are received sequentially, the frequency of the wireless communication is switched based on the notice signal,
When the predetermined signal is received between the reception of the notification signal and the reception of the confirmation signal, the notification signal received prior to the predetermined signal is invalidated.
Wireless communication system.

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