JPH05219036A - Automatic switching system for communication line - Google Patents

Abstract

PURPOSE:To automate the constitution of a by-pass route in the case of a line break and shorten a telephone call failure time by providing each key station with a detector which can detects a break of a monitor signal and a switch. CONSTITUTION:When an in-use communication line 4 is normal, a speech from a controller 1 is sent to a high-order key station 14 through the switch 2 together with a line monitor signal generated by an oscillator 3, sent to a distributor 8, and then sent to a low-order key station through an amplifier 9 for transmission and the switch 2 again. If the in-use line 4 between some key stations is disconnected, the line monitor signal is cut off on the lower-order side than the disconnection position, so the line monitor signal detection of the switch 2 is put in operation, and a switching relay operates to switch the in-use line to the side of a stand-by communication line 5. Consequently, the higher-order key station uses the in-use communication line 4 and the lower- order key station uses the stand-by communication line 5 on the basis of the disconnection point as a border, so that the whole line between a commanding person and an on-vehicle station conductor is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of switching a communication line to a base station in mobile communication.

[0002]

2. Description of the Related Art As a conventional technique, there is a system shown in FIG. In mobile communication such as a train having a linear communication area, a signal passing through a communication line 4 that connects the control device 1 at the command station and each base station 14 is amplified by each base station and connected to the lower side with directionality. Has been done. Also, a separate line 5 is installed at the lowest station as a bypass route from the center, and the working line (4)
When an abnormality occurs in the circuit, the bypass line (5) can be used. The operation is as follows: When a part of the working line is cut off due to an accident, etc., the maintenance staff investigates the section where the line is cut off when contacted by the ordering staff for inability to call and disconnects the line if it can be specified. By switching the circuit changeover switches of all the base stations on the lower side of the section, the route of the central station-the lowest station-the base station of the line disconnection is constructed. At this time, the upper side of the broken line remains the current route. In this way, by switching the lower side of the line break to the backup route, it is possible to secure calls in all areas.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
It takes time to identify the broken line section, and it takes time to secure and move the workers to switch the line of the base station after the broken line section, which makes quick recovery difficult and makes train operation safe. There is a drawback that it causes trouble. It is an object of the present invention to eliminate these drawbacks, automate the detour route configuration due to line disconnection, and shorten the call unavailable time.

[0004]

In order to achieve the above object, the present invention automatically switches the line of a base station on the lower side when a signal added with a supervisory signal is sent to a communication line and a disconnection of the supervisory signal is detected. It was done.

[0005]

[Function] As a result, the connection line is cut off only during the switching time, but since the line can be secured almost continuously,
The cutoff time for command calls required for the safe operation of trains can be greatly reduced, and a small number of workers can be secured, which is economical.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a control device, 2 is a switcher, 3 is a line supervisory signal oscillator, 4 is a working communication line, 5 is a standby communication line, 6 is a line monitoring signal detector, 7 is a switching relay, 8 is a distributor for transmission, 9 Is a transmitting amplifier, 10 is a receiving synthesizer, 11 is a receiving amplifier, and 14 is a base station. Hereinafter, this operation will be described. Control device 1 when working communication line 4 is normal
Is transmitted to the upper base station 14 via the switch 2 together with the line supervisory signal generated by the oscillator 3, and then transmitted to the lower base station through the distributor 8 and the transmission amplifier 9 again to the lower base station. To be done. At this time, since the line supervisory signal detector 6 of the switch shown in FIG. 2 detects the signal, the switch relay 7 does not operate. Since the switching relay 7 is not operating in the lowest station, the contact t mounted only in the lowest station
_5, t ₆ is the signal of OFF next to the pre-contact line has been disconnected. On the other hand, the received signal passes through the reception combiner 10 of the base station 14, is amplified by the reception amplifier 11, and is sequentially sent to the upper station and input to the control device 1.

Here, when the working line 4 between certain base stations is disconnected, the line supervisory signal is cut off at the lower side of the disconnection point, so that the line supervisory signal detector 6 of the switching device 2 operates and the switching relay 7 operates. It operates and switches to the backup communication line side. By this,
With the disconnection as the boundary, the upper side base station uses the working communication line and the lower side base station uses the standby communication line, and the entire line between the dispatcher and the on-board crew is secured.
At this time, if individual signals are output from the switching device 2 and the base stations switched by the control device 1 are displayed, the disconnection section of the communication line can be easily designated.

[0008]

According to the present invention, when the communication line is not connected, the line is automatically switched to the standby line and the disconnection section can be specified. Therefore, the recovery time can be shortened and the maintenance staff can be easily secured to increase the reliability. ， Safer train operation is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of the present invention.

FIG. 2 is a block diagram of a line switching device of the present invention.

FIG. 3 is a block diagram of a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control device 2 Switching device 3 Line supervisory signal oscillator 4 Working communication line 5 Preliminary communication line 6 Line monitoring signal detector 7 Switching relay 12, 13 Line switching switch 14 Base station

Claims (1)

[Claims] 1. A command station and a plurality of base stations, a communication line is connected to two working and standby systems, and signals are distributed and combined at each base station and then amplified and sent to an adjacent base station. In the mobile communication system of the method described above, each base station is provided with means for detecting a disconnection of the supervisory signal and means for switching the line by its output, and a signal for monitoring the communication line is sent from the commanding station side and each base station is provided. When the disconnection of the above signal is detected in, the communication line automatic switching system is characterized in that the lower side of the detected base station is automatically switched to the backup communication line.