JPS6230443A - Train radio communication system - Google Patents

Abstract

PURPOSE:To access a packet channel simply and without collision of transmission similarly with a private line by dividing time base to several slots, combining them with radio channels and specifying and allotting them to all trains. CONSTITUTION:Two slots are allotted on time axis, and four slots are allotted on a frequency axis. These are combined to provide eight slots in total, and these are allotted to eight trains on the line fixedly. Slot number S1-S4 are designated by time reference pulse 1 from a fixed form data circuit, and a ground station is accessed by a mobile station through radio channels f1-f4 of general purpose data circuit. Data transmission from a ground station to a mobile station is made through radio channels fa-fd respectively. Similarly, designation of slots S5-S8 is made by time reference pulse 2 through the fixed form data circuit, and packet transmission is made through a general purpose data circuit and through channels f1-f4 and corresponding channels fa-fd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a train radio communication system, and in particular, the radio direction from a ground station to a mobile station of each train is transmitted in a broadcast mode with an address added to a train within a specific area. The radio direction from the mobile station to the ground station accessing the train is related to a system that accesses the radio channel and performs packet transmission in a contention mode.

[Prior Art] Conventionally, as a packet data transmission system using train radio, for example, "Electronic Control Communication System for Shinkansen" published by the Institute of Electronics and Communication Engineers on December 10, 1980
Chapter 4 (Train Communication System, pp. 133-142)
As shown in Figure 2, after discussing the start of data communication over a contact phone and setting up the wireless line to be accessed by polling via the fixed data line, which is the connection control line, the Tomawaba station transfers the packet data. There was a seven-person channel system with switching.

Normally, data communication lines in train radio are divided into two types, depending on their purpose: fixed data lines that periodically collect short fixed data, and general-purpose data lines that transmit relatively long data that occurs randomly. Communication connection control for fixed data systems is performed by polling mobile stations, and connection control for general data systems is performed via fixed data lines.

FIGS. 4 and 5 are shown in the above-mentioned document, and respectively show the configuration of a general-purpose data system and an example of a terminal device transmission control sequence in a conventional train radio communication system.

In FIG. 4, the data terminal device can be connected to a central station 1, a control station 2, and a mobile station 4, respectively, and a total of four radio channels can be assigned, including channels eh17 and ch18 shown in the figure. There is. Central station 1
One station is placed in the entire system, and a control station 2 that supervises about 10 base stations 3 is placed along the route and controlled by a central station 1. The central station 1, the control station 2, and the base station 3 are connected by fixed dedicated data line #i (wired), and the base station 3 and mobile station 4 are connected by 1, CX ( Fire
; leaky coaxial) connected by a wireless line. The central station 1, control station 2, and base station 3 constitute a terrestrial (fixed) station, and the mobile station 4 is also called an on-vehicle station.

What is shown in the central station 1 and the control station Z are grid-shaped line switches as data transmission racks 1m and 2a, respectively, and the designated central The central station terminal rlTg of station 1 or the ground terminal rlt (not shown) of control station 2 corresponds to radio channels c1117 and c I+ 18 used by the mobile station terminal device (not shown) with which it communicates. It connects to the terrestrial line.

Next, using the general-purpose data system shown in Figure 4 as an example, f55
The transmission control sequence of the vehicle monitor, that is, the mobile station terminal device that displays the operating status of the train and the operating status of each vehicle's equipment on the display of the train platform and supports the driver's judgment and treatment will be explained with reference to the figure. During transmission, the vehicle driver monitors the vehicle while communicating with the train dispatcher by telephone.
In other words, a "transmission request" signal is sent to the data transmission rack 4a of the mobile station 4 by key operation (pressing the CTC key) on the mobile station side terminal device.・The data transmission rack 4a of the mobile station 4 sends a polling request for fixed data type. 1-close request in response to “
Outputs a signal (the thick arrow pointing to this signal represents a regular data line, the other arrows represent a general purpose data channel). Upon receiving this, the data transmission rack 1a of the central station 1 outputs a ``reception request 1 signal'' to the terminal device Tg on the central station 1 side, such as a command display, and thereafter, the terminal device f!
After confirming the input of the "receive 0" signal from Tg, a "connection OK" signal with an address is sent to the mobile stations 4 all at once via the standard data line again. Upon receiving this, the data transmission rack 4a of the mobile station 4 at the address sends a "sendable" signal to the mobile station terminal device.

The above sequence completes the line setup between the mobile station terminal equipment and the central office terminal equipment ffiTg, and from now on, the End (o-End"c- screen data and "8 CK (acknowledgement)" signal) are mutually transferred as shown.

When the necessary data transfer between both terminal devices is completed, the next line release sequence begins. The sequence for releasing the line is the same as for the line IQ setting described above, and pressing the clear key on the mobile station terminal equipment allows EOT (end of text).
The signal is sent to the mobile station 4, and the data transmission rack 4a of the mobile station 4 outputs a "release request" signal to the central station 1 as a response to the polling request for the fixed data line. In 1a, the line release sequence is completed by emitting the fixed data line again and notifying the "release 1 signal" with an address all at once.

This completes the data transmission between the terminal devices, that is, between the vehicle monitor and the command display.6 [Problem to be solved by the invention 1] Since the Jumei system is configured as described above, data is collected periodically. There is no problem when transmitting long data between the same terminal devices, but when transmitting and receiving small amounts of data that occur randomly in time, such as communication between multiple data terminal devices of a mobile station and a ground station, In order to make it suitable for a so-called packet transmission system, there were problems such as (1) the inability to switch radio channels frequently, and (2) the inability to control high-speed contention for the right to transmit the radio channel.

The present invention has been made in order to solve the above-mentioned problems, and provides a packet transmission path access system that can control transmission rights transfer of radio channels in train radio at high speed and switch frequently. The purpose is to

[Means for Solving the Problems 1] In order to achieve the above object, the train wireless communication system according to the present invention uses a connection control line as a packet transmission line access method in the direction from the on-board mobile station to the ground station. The fixed data line is separated from the multilayer data line which is the data line, the transmission timing is divided into a plurality of slots with a fixed time width, and the polling cycle is set, and the transmission slot is set by combining the desired number of wireless channels in the same polling cycle. is provided as an integer multiple of the radio channel, and this slot is prefixed with a fixing agent to each train through the fixed data circuit #a, and each train Ill accesses the specified slot to perform packet transmission.

[Operation] The transmission right contention control in the direction from the mobile station to the ground station in the train radio positioning system of the present invention combines slots on the time axis and slots on the frequency line and logically calculates the product of their numbers. Corresponding transmission slots are set so that the number of slots is greater than or equal to the number of trains on the line, and transmission slots for each train calculation are allocated so that each train can access the channel without transmission Hj collision.

[Embodiment 1] An embodiment of the train wireless communication system according to the present invention will be described below with reference to the accompanying drawings.

Fig. 1 shows a time chart for explaining the train M line communication system of the present invention, in which two slots are allocated on the time axis, four slots are allocated to the frequency wheel load, and these are combined to make a total of eight slots. This is installed on the line 8
An example of fixed assignment to trains is shown. In other words, radio channels are time- and frequency-divided in both directions, from the on-board mobile station to the ground station (consisting of the central station 1, control station 2, and base RI 3) and from the ground station to the on-board mobile station. Compatible with train mobile stations.

Figure 1 (,) shows time reference information synchronized with the polling cycle and slot designation information corresponding to each polling cycle being repeated in broadcast mode from the ground station to the mobile station via a fixed data line that is a connection control line. −・Indicates a state where simultaneous notification is being performed.

Figures 1 (b) and (c) illustrate eight slots each in the direction from the upper station and ground station to the on-vehicle mobile station in the travel range of the JrL mobile station assigned to the general data line, which is the data line. They each form a communication signal pair between a mobile station and a ground station.

As can be seen from FIG. 1, each slot is synchronized with a time reference pulse notified all at once from the fixed data line, and two slots (for example, Sl and S5) occur alternately on the rJl pongee. In addition, in the case of this embodiment, there are four radio channels on the same time axis, namely, channels f1 to r4 from the on-board mobile station to the ground station, and channels fa-rd from the ground station to the on-board mobile station. Provided. Therefore,
Logically, a total of eight slots are prepared.

If these 8 slots are assigned to which trains, they are repeatedly notified all at once over a fixed data line, equivalently a radio channel dedicated to each train exists, and each train can transmit radio signals without transmission collisions. For example, slot numbers 51 to S4 are specified in the time reference pulse ■ from the regular data line in FIG.
The ground station is accessed via the ground station, and data transmission from the ground station to the mobile station takes place via radio channels fa-fa, respectively. Similarly, the designation of slots) S5 to S8 is carried out via a fixed data line using a time reference pulse ■, and the designation of slots S5 to S8 is performed via a general-purpose data line to radio channels f1 to
f4 and their corresponding wireless channels fa-
Packet transmission is performed via fd.

Since the radio channel allocation in the above case is semi-fixed and the radio channel switching is periodic, the radio channel access procedure is simple.

In the above embodiment, the case where two slots are allocated on the time axis has been explained, but the same effect can be obtained when three or more slots are allocated. Furthermore, although slot designation is performed using a fixed data line, a dedicated slot for slot designation, which is different from the data slot, may be allocated on a general-purpose data line in the direction from the on-vehicle mobile station to the ground station.

Effect of the invention 1 As described above, according to the present invention, the time axis is divided into several slots F, and these are combined with a desired number of unused channels, so that the logical number of channels can be reduced. Since it is possible to increase the number of radio channels to an integral multiple of the number of radio channels and to specifically allocate these channels to all trains on the line, mobile stations on each train can easily access them as if they were accessing a dedicated line. , and has the advantage of being able to access the packet channel without transmission collisions.

[Brief explanation of drawings]

FIG. 1 is a time chart diagram for explaining one embodiment of the train wireless communication system according to the present invention, and FIG. 12 is a configuration diagram of a general-purpose data system in a conventional train wireless communication system.
FIG. ttS3 is a diagram illustrating a transmission control sequence in a conventional train radio communication system. 1: Central station, 2: Control station, 3: Base station, 4: Mobile station, T
g: Terminal device In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) The first radio direction from the ground station to the mobile station of each train is accessed in broadcast mode with an added address, and the second radio direction from the mobile station to the ground station is accessed in the radio channel in transmission right contention mode. In the train wireless communication system to be accessed, wireless slot designation information is transmitted and allocated corresponding to each train in the first wireless direction via a fixed data line every polling cycle, and the wireless slot designation information corresponding to each allocated wireless slot is A train radio communication system characterized in that packet transmission is performed from a mobile station in the second radio direction via a radio channel of a general-purpose data line separated from the fixed data line. (2) The train wireless communication system according to claim 1, wherein the wireless slot is divided on both the time axis and the frequency axis. (3) The train wireless communication system according to claim 1 or 2, wherein the ground station includes a central station, a control station, and a base station.