Train radio system

Abstract

To obtain a train radio system capable of quickly starting an actual call.SOLUTION: At startup (A) of a central device 30, for example, initial operation is performed (S101) by operation of a power source switch and a reset switch in the central device 30. This operation can be performed once, for example, before a start of a train. Thereafter, a line control unit recognizes this initialization operation as a trigger, and establishes and connects (S102) a line among a command console 40, the central device 30, and all the base stations 20. Each line enters a standby state for transmitting a voice signal. Operation (B) when a call is made from the command console 40 to a mobile station 10 side and operation (C) when a call is made from the mobile station 10 to the command console 40 side are both performed after the above-described operation. Therefore, after transmission (S103, S106) of a control signal (call start telegram) for starting a call, transmission (S104, S107) of the voice signal can be promptly performed.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a train radio system in which radio communication is performed between a mobile station mounted on a train and a command console via a base station. [Background technology]

[0002] In a train radio system that performs radio communication between a mobile station (on-board station) mounted on a moving train and a command console fixed at one point on the ground, base stations are installed at multiple points on the ground, and communication between the command console and the mobile stations is performed via one base station corresponding to the position of the train. The content of this communication includes, for example, a communication from the command console to give common instructions to all trains (mobile stations), and individual communication from each train (mobile station) to the command console.

[0003] Patent Document 1 describes the configuration of such a train radio system. Here, a line control station (central device) is provided that appropriately controls the communication lines between the command console, the base station, and the mobile station. When the command console transmits a voice message to the mobile station, the command console first transmits a call setup message, which is a signal indicating that a voice message is about to be transmitted, to the line control station as pre-transmission call control, and the line control station transmits this call setup message to the base station. The base station then transmits a corresponding call signal to the mobile station, which causes the mobile station to recognize that there is a call request from the command console and transmits an acknowledgment response to this, which is then transmitted to the base station, which in turn transmits this information to the line control station, which in turn transmits this information to the command console.

[0004] This allows the command console, the line control station, the base station, and the mobile station to all recognize that a call is about to be made from the command console to the mobile station. Therefore, the line control station establishes a call channel (line) to be used for this call, and then starts the call from the command console. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-289646 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0006] In the above operation, a certain amount of time is required for call control before the actual call is started. On the other hand, in train radio systems, for example, calls from the command console to a mobile station and calls from a mobile station to the command console are often highly urgent. For this reason, there is a demand for a train radio system that can quickly start an actual call.

[0007] The present invention has been made in view of the above circumstances, and has an object to solve the above problems. [Means for solving the problem]

[0008] The present invention is a train radio system comprising a mobile station mounted on a train, a plurality of base stations installed at different points on the ground and connected to the mobile station via wireless communication, a central device connected to each of the base stations via a network, and a command console connected to the central device and issuing instructions to the mobile stations, in which voice signals are transmitted and received between the command console and the mobile stations, and before the start of transmission of the voice signal, a control signal to start transmission of the voice signal is issued from the command console, which is the side that starts the transmission, or one of the plurality of mobile stations to the central device before the transmission of the voice signal, and a plurality of lines for transmitting the voice signal between the command console and each of the base stations via the central device are simultaneously connected by a trigger issued from any of the central device, the command console, or the base station before the control signal to start transmission of the voice signal is issued. The trigger may be issued by the central device upon start-up of the central device. The trigger may be issued by the command console or one of the base stations. Any one of the command console, the base station, and the mobile station may repeatedly issue a control signal to start the transmission after starting the transmission of the voice signal. Effect of the Invention

[0009] It is possible to obtain a train radio system that can quickly start an actual call. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing an overall configuration of a train radio system according to an embodiment; [Diagram 2] 2 is a diagram showing connections between a central device, a command console, and a base station in a train radio system according to an embodiment of the present invention. FIG. [Diagram 3] 1 is a diagram showing an example of the flow of a control signal until an actual call is started in a conventional train radio system. [Figure 4] 5 is an example of an operation until a call is started in the first example of the train radio system according to the embodiment. [Diagram 5] FIG. 4 is a diagram showing an operation of simultaneously connecting lines in a central device in the first example of the train radio system according to the embodiment. [Figure 6] FIG. 2 is a diagram showing operations when a control signal to start a call is received (a) and when a call is subsequently being made (b) in a first example of a train radio system according to an embodiment. [Figure 7] 10 is an example of an operation until a call is started in the second example of the train radio system according to the embodiment. [Figure 8] 13 is an example of an operation before a call is started and during a call in the third example of the train radio system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present invention will be specifically described. Fig. 1 is a diagram showing the overall configuration of this train radio system 1. A mobile station 10 is mounted on a moving train T. Base stations 20 are fixed on the ground and installed in multiple locations. As the mobile station 10 moves, it is capable of wireless communication with any of the base stations 20. As shown in the figure, a plurality of trains T (mobile stations 10) are provided, and each of them performs wireless communication with any of the base stations 20.

[0012] All the base stations 20 are connected to a central device 30 via a network N, and a command console 40 is connected to the central device 30. The central device 30 is a computer having a configuration as described below, and the command console 40 is a computer capable of inputting and outputting voice. The manager can use the command console 40 to make calls with each mobile station 10, or with the driver of the train T via the mobile station 10. Similarly, the driver of the train T can use the mobile station 10 to make calls with the manager via the command console 40. Although there is only one command console 40 in FIG. 1, multiple command consoles may be provided.

[0013] Fig. 2 is a diagram showing the configuration of the command console 40 and the central unit 30 and the signal flow therebetween. As described above, both the command console 40 and the central unit 30 are composed of computers, but below, only the configuration related to voice communication in the command console 40 and the central unit 30 will be mainly described. That is, in addition to the components described below, they also have components that are included in a normal computer. Also, while only one base station 20 is shown in Fig. 2, in reality, multiple base stations 20 are connected to the central unit 30 via a network N as shown in Fig. 1.

[0014] In Fig. 2, signals flowing between the command console 40, the central unit 30, and the base station 20 include control signals used for call control and voice signals for calls, and these signals follow different paths. In Fig. 2, the flow of control signals is indicated by dotted lines, and the flow of voice signals is indicated by solid lines. The command console 40 is provided with a control signal input / output unit 41 that issues control signals related to call control from itself or receives them from the central unit 30. In addition, the command console 40 is provided with a control signal interface (IF) unit (command console side control signal interface (IF) unit) 42 that exchanges control signals related to call control with the central unit 30.

[0015] The command console 40 is also provided with an audio input / output unit 43 including a microphone and speaker used when the manager makes a call. When the command console 40 transmits a voice, the audio input / output unit 43 generates an audio signal from the voice input to the microphone, and when the command console 40 receives a voice, the received audio signal is output from the speaker. The command console 40 is also provided with an audio signal interface (IF) unit (command console side audio signal interface (IF) unit) 44 that exchanges this audio signal with the central device 30.

[0016] The central unit 30 is also provided with a control signal IF unit (central unit side control signal IF unit) 31 and a voice signal IF unit (central unit side voice signal IF unit) 32, which exchange control signals and voice signals with the command console 40 side, corresponding to the control signal IF unit 42 and voice signal IF unit 44. The control signals and voice signals input to the central unit 30 side are both input to a line control unit 33, and from there input to a base station interface (IF) unit 34, which exchanges these signals with the base station 20 side. Here, voice signals are exchanged via a line (communication channel) formed between the command console 40 and the base station 20 via the central unit 30.

[0017] When a call is transmitted from the base station 20 (mobile station 10), a control signal and a voice signal from the base station 20 are input to the line control unit 33 via the base station IF unit 34, and are then transmitted to the command console 40 via the control signal IF unit 31 and the voice signal IF unit, respectively. At this time, the central device 30 is provided with a call control unit 35 which controls the line control unit 34 in response to the control signal and determines the line (communication channel).

[0018] In the train radio system according to the present embodiment, the operations of the line control unit 33 and the call control unit 35 are particularly different from those of the conventional system. First, the conventional operations of the line control unit 33 and the call control unit 35 will be described.

[0019] 1 and 2, the number of mobile stations 10 (or base stations 20) that can simultaneously communicate with the command console 40 is determined by the number of communication channels (lines) used for transmitting voice signals. For this reason, generally, for example, when a call is being made between the command console 40 and one base station 20 (mobile station 10), if another base station 20 (mobile station 10) newly communicates with the command console 40, another line is set up for this new call. The line control unit 33 sets up such lines. In the conventional technology, this setting (establishment of a line) is performed based on a control signal issued from the command console 40 or base station 20 side.

[0020] FIG. 3 shows the flow of signals in the conventional technology until a call is started from the command console 40 to a certain mobile station 10, and this is the content described in FIG. 3 of Patent Document 1. Here, too, the flow of the control signal in FIG. 2 is shown by dotted lines, and the flow of the voice signal is shown by solid lines. Here, by the operation of the administrator (for example, by operating a key), the control signal input / output unit 41 of the command console 40 issues a control signal (call setting message) to the central device 30 to call the mobile station 10 for a call. The line control unit 33 of the central device 30 receives this control signal and transmits this control signal (call setting message) to the base station 20 corresponding to the mobile station 10. If a call is not being made between the base station 20 and the mobile station 10 at this time, the base station 20 transmits an idle line signal to the mobile station 10, but when the base station 20 receives this control signal, it switches the idle line signal to a call signal. This allows the mobile station 10 to recognize that a call request has been made from the command console 40.

[0021] Thereafter, the mobile station 10 transmits a control signal (synchronization burst signal) to the base station 20 to the effect that it has recognized this request. In response, the base station 20 transmits a control signal (transmission right confirmation message) to the central unit 30. When the central unit 30 receives this, the line control unit 33 determines whether or not there is a currently available call channel (line), and if there is a line, transmits a control signal (transmission right acceptance message) to the base station 20 as a response. That is, at this stage, the line to be used between the command console 40, the central unit 30, and the base station 20 in the call between the command console 40 and the mobile station 20 is set.

[0022] The operation of setting up a line between the command console 40 and the base station 20 in this manner is performed by controlling the line control unit 33 when the call control unit 35 receives the above control signal in Fig. 2. In this case, one line is set up for use in a call between the command console 40 and one base station 20.

[0023] The base station 20, which has received the control signal (transmission right acceptance message), transmits a new control signal (burst acceptance signal) as a response to the mobile station 10. This causes the mobile station 10 to recognize that it is ready to respond to the call from the command console 40, and further transmits a new control signal (call response signal) to the base station 20. The base station 20, which has received this, transmits a new control signal (transmission right acquisition message, call setup acceptance signal, response signal) to the central unit 30. This allows the central unit 30, base station 20, and mobile station 10 to share the recognition that a call from the command console 40 to the mobile station 10 is about to be made, and the fact that the line to be used for that call is ready.

[0024] Thereafter, the central unit 30 transmits a control signal (response confirmation signal) to the mobile station 10 via the base station 20, and transmits a control signal (line information display (in-call) signal) indicating the set line information to the command console 40. This causes a voice signal to be transmitted from the command console 40, and an actual call is started. In the above operation, after control signals are exchanged multiple times between the command console 40, the central unit 30, the base station 30, and the mobile station 10, a line (call channel) for transmitting a voice signal is established, and then the actual call is started.

[0025] In Figure 3, area S1 corresponds to the operation of exchanging control signals until the line is established, area S2 corresponds to the operation of establishing the line for this call, area S3 corresponds to the operation of exchanging control signals from the establishment of the line until the actual call starts, and area S4 corresponds to the operation of actually making the call (sending and receiving voice signals).

[0026] On the other hand, in recent train radio systems, the types of calls required are becoming more diverse, such as simultaneous calls from the control console 40 and warnings of danger, due to the need to ensure safety during operation and the congestion of train schedules. This has resulted in an increase in the number of lines required for transmitting the above-mentioned voice signals, and has increased the load on the central unit 30 in particular. Furthermore, there has been a demand to shorten the time required from the time a call is requested until the call is actually made (until transmission starts).

[0027] Therefore, in the train radio system 1 according to the embodiment of the present invention, lines are established in advance between the command console 40, the central unit 30, and all the base stations 20, regardless of whether a control signal indicating that a call is about to be started is issued from the call origin (the command console 40 or the mobile station 10). At this time, various control signals are used as in the case of FIG. 3, but all the lines are prepared in advance. In this case, the area S2 in FIG. 3 is not required when starting an individual call, and at least the operation of the area S1 as the preparation stage prior to that can be greatly simplified. Therefore, an actual call can be started in a short time. The operation of simultaneously establishing all the lines in this way is performed when the central unit 30 receives a trigger. This trigger is issued from either the central unit 30 itself, the command console 40, or the base station 20.

[0028] For this reason, in this train radio system 1, the line control unit 33 and the call control unit 35 operate so as to perform such operations. Fig. 4 is a sequence diagram showing the operations in the case where all lines are thus established when the central unit 30 is started up (first example). From the top, the following operations are described: A: operations when the central unit 30 is started up, B: operations when a call is made from the command console 40 to the mobile station 10, and C: operations when a call is made from the mobile station 10 to the command console 40.

[0029] First, when the central unit 30 is started (A), an initialization operation is performed, for example, by operating a power switch or a reset switch in the central unit 30 (S101). This operation can be performed once, for example, before the departure of a train. After that, the line control unit 33 recognizes this initialization operation as a trigger, and establishes and connects lines between the command console 40, the central unit 30, and all base stations 20 (S102), and each line goes into a standby state for transmitting audio signals.

[0030] Fig. 5 is a diagram showing the operation of the central device 30 at this time. Here, lines between components through which no signal flows during operation in Fig. 2 are omitted. As described above, in the conventional technology, the line control unit 33 connects a line between the command console 40 and one base station 20 under the control of the call control unit 35, whereas here, in particular, the lines between the command console 40 and all base stations 20 are simultaneously connected.

[0031] 4, the operation (B) when making a call from the command console 40 to the mobile station 10 and the operation (C) when making a call from the mobile station 10 to the command console 40 are both performed after the above operations. Therefore, in these cases, after sending a control signal (call start message) to start the call (S103, S106), it is possible to send a voice signal (S104, S107) quickly. After that, the call is ended by sending a control signal to end the call from the call origin (S105, S108).

[0032] 6 is a diagram showing the operation of the central unit 30 in transmitting a control signal to start a call (S103) (a) and transmitting a voice signal (b) in the operation when a call is made from the command console 40 to the mobile station 10. In Fig. 6(a), a control signal to start a call (call start message) is generated by off-hooking or operating an operation key in the control signal input / output unit 41 in the command console 40 in Fig. 2. This control signal reaches the mobile station 30 via the central unit 30 and the base station 20.

[0033] In Fig. 6(b), an audio signal is generated from a microphone in the audio input / output unit 43 in the command console 40 in Fig. 2. This audio signal is transmitted to the base station 20 via the line formed at this point, and then reaches the mobile station 10, and is output from the speaker on the mobile station 30 side.

[0034] FIG. 6 shows the operation when a call is made from the command console 40 side, but the operation is similar when a call is made from the mobile station 10 (base station 20) side, except that the flow of each signal is reversed.

[0035] Next, an operation (second example) will be described when a line is connected on the central unit 30 side by a trigger (control signal) issued from the command console 40 side. Fig. 7 is a sequence diagram showing the operation in this case, and corresponds to Fig. 4, and shows the operations from top to bottom: D: when the central unit 30 is started up, E: when the command console issues an instruction to connect the line to the central unit, and F: when a call is made from the command console 40 to the mobile station 10 side.

[0036] Here, at the start-up of the central device 30 (D), unlike the operation of FIG. 4, only the device (computer) is started (S111), and no line is connected. Instead, this operation is instructed by issuing a control signal for this purpose from the command console 40 (S112) at E, and as a result, the central device 30 establishes and connects lines with all the base stations 20 (S113), resulting in a state similar to the end of A in FIG. 4. Therefore, when making a call thereafter (F), as in C in FIG. 4, after transmitting a control signal to start the call (S114), it is possible to transmit a voice signal (S115) promptly. Here, the case where the call is made from the command console 40 side is shown, but the same applies to the case where the call is made from the mobile station 10 side. Also, although the command to connect the line is issued from the command console 40 side in E in FIG. 7, this command may be issued from one of the base stations 20.

[0037] The instruction to connect the line (S112) in E of Fig. 7 may be automatically issued when a control signal for starting a call is first transmitted from the command console 40 (S114) in a state where the line is not yet connected. In this case, the time required to start the first call will be longer, but the time required to start calls thereafter will be shorter. Similarly, this instruction may be issued by the base station 20 that first receives a control signal for starting a call from the mobile station 10 among the multiple base stations 20.

[0038] In the above-described train radio system 1, the line to be used is set in advance before a control signal to actually start a call is issued, so that calls can be made quickly from the control console 40 side or the mobile station 10 side.

[0039] Furthermore, the operation of establishing and connecting a line in the line control unit 33 is no different from that of a central unit in a conventional train radio system, and only the timing at which this operation is performed is different. Therefore, this central unit 30 (train radio system 1) can be obtained at low cost by, for example, changing the firmware in a conventional central unit.

[0040] Here, for example, if a fault occurs in the central unit 30 while a call is being made at B in Fig. 4 (S104), the call is interrupted. In this case, it may be necessary to restart the central unit 30 in order to recover from the fault. In this case, as shown at A in Fig. 4, the line is automatically set up again after the restart (S102).

[0041] However, in this case, when the line is reconnected, the central unit 30 has not received the call start message (S103), which is a prerequisite for making an actual call (S104). Therefore, even if the line is reconnected, unless the central unit 30 receives a call start message from the command console 40, it cannot recognize that a call is currently in progress, and it cannot immediately resume the call.

[0042] Fig. 8 shows an example (third example) that takes such a case into consideration, in which the operation during a call from the command console 40 side is shown in correspondence with B in Fig. 4. Here, likewise, a control signal (call start message) indicating that the call is to be started is transmitted before the call is actually started (S103), and then an audio signal is transmitted (S104).

[0043] However, in the operation of B in Fig. 4, the transmission of the call start message (S103) is performed only once before the transmission of the voice signal, whereas in the operation of Fig. 8, the transmission of the call start message (S121) is performed repeatedly even after the transmission of the voice signal (S104). This operation is performed in parallel with the transmission of the voice signal (S104), and is repeated periodically at a fixed time interval until a control signal to end the call is transmitted (S105).

[0044] As a result, while the voice signal continues to be transmitted (S104), the central unit 30 (call control unit 35) after rebooting can immediately receive a call start message and resume the call thereafter. That is, the call can be resumed promptly after the central unit 10 is rebooted. Note that the transmission of the call start message (S121) only needs to be performed multiple times, and does not necessarily need to be repeated periodically.

[0045] 8 shows a call from the command console 40, the same applies to a call from the mobile station 10 (base station 20). That is, the mobile station 10 or the base station 20 can repeatedly transmit the call start message (S106) in C in FIG. 4 from the start of the transmission of the voice signal (S107).

[0046] In this operation, the operation of issuing a control signal (call start message) to start a call is no different from the operation of the command console, base station, or mobile station, which is the source of the call in a conventional wireless communication system, and the only difference is that this operation is performed repeatedly during the call. Therefore, as in the first and second examples, the command console 40, base station 20, or mobile station 10 (train radio system 1) that performs this operation can be obtained at low cost. In addition to simultaneously connecting the lines by a trigger as described above, by performing this operation, it is possible to quickly restore the system if a failure occurs during a call.

[0047] The present invention has been described above based on the embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components, and that such modifications are also within the scope of the present invention. [Explanation of symbols]

[0048] 1 Train radio system 10 Mobile Station 20 base station 30 Central unit 31 Control signal IF section (Central equipment side control signal IF section) 32 Audio signal IF section (Central equipment side audio signal IF section) 33 Line Control Unit 34 Base station IF section 35 Call Control Unit 40 Command console 41 Control signal input / output section 42 Control signal IF section (control signal IF section on the command console side) 43 Audio input / output section 44 Audio signal IF section (command console side audio signal IF section) N Network T train

Claims

1. A train radio system comprising: a mobile station mounted on a train; a plurality of base stations each installed at a different point on the ground and connected to the mobile station by wireless communication; a central device connected to each of the base stations via a network; and a command console connected to the central device for issuing commands to the mobile station, wherein voice signals are transmitted and received between the command console and the mobile station, Before the start of transmission of the voice signal, a control signal to start the transmission of the voice signal is issued from the command console, which is a side that starts the transmission, or one of the plurality of mobile stations, to the central device before the transmission of the voice signal; A train radio system characterized in that a plurality of lines transmitting the voice signals between the command console and each of the base stations via the central device are simultaneously connected by a trigger issued from either the central device, the command console, or the base station before a control signal to start transmitting the voice signal is issued.

2. 2. The train radio system according to claim 1, wherein the trigger is issued by the central device when the central device is started up.

3. 2. The train radio system according to claim 1, wherein the trigger is issued by the command console or one of the plurality of base stations.

4. A train radio system as described in any one of claims 1 to 3, characterized in that any one of the command console, the base station, and the mobile station repeatedly issues a control signal to start the transmission after starting the transmission of the voice signal.

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