JPS63303524A - Train radio telephone system - Google Patents

Abstract

PURPOSE:To prevent the generation of a hit when a repeater is at fault by arranging a pair of antennas provided along the line of a train back to back and providing an auxiliary antenna to cover the dead zone of its own station of a radio repeater having a pair of radio transmitting receiving devices. CONSTITUTION:Along the line of a train, plural radio repeaters are provided. Respective repeaters make a pair of antennas C and D back to back and communicate with a moving station on a train with transmitting receiving devices A and B having a different frequency. An electromagnetic horn E to cover the dead zone of its own station to occur by the sharp directivity of the antennas C and D is provided toward the line. At the time of the normality, a radio zone is switched in the sequence of 1, 2, 3,.... For example, when a radio device A in charge of a zone 3 is troubled, the radio device of the zone 2 covers it, and at the dead zone, a hit is generated. The hit is prevented by a radio device B with an electromagnetic horn E. Thus, the generation of a hit due to the trouble of the radio device is prevented.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a train radio system, and in particular to a train radio system that uses frequencies above the microwave band to communicate between a mobile station in a train and a radio relay station along the train track. Regarding the system.

PRIOR ART A mobile communication system for trains that uses non-Ii1 frequencies above the microwave band has not been commercialized in Japan. f2°
A wireless device that transmits and receives (e.g. fl.

f2 is the frequency from the repeater to the mobile station, flo, f2° is the frequency in the opposite direction). Multiple radio repeaters are installed along the train tracks, each consisting of antennas placed back to back. There are train radio systems that relay between mobile stations (eg telephones) and local telephone exchanges. In such a wireless system, there is a dead zone of radio waves (an area where M waves cannot reach) when the wireless repeater is very close to the wireless repeater, so there is a drawback that communication will be cut off if the radio device of the wireless repeater breaks down. be.

This will be explained in detail using drawings. FIG. 5 is an example of a train radio system using a radio repeater in which a pair of antennas are arranged back to back. In Fig. 5, wireless repeaters a, b, c
,... is the installation hole III according to the frequency band used
(several 100 meters to several tens of meters), and one frequency f1 of the wireless repeater. fl.

and the other frequency f2. f2° covers the area between wireless repeaters to form a radio wave area. The mobile station onboard the train uses one frequency f1. Communication is possible by switching between f1° and the other frequency f2°f2° for each section.

However, as shown in Fig. 6, in the train radio system shown in Fig. 5, when a mobile station approaches a radio repeater, radio wave dead zones [)1, [)2, ...] exist. Therefore, when a wireless device malfunctions, an instantaneous interruption may occur during wireless zone switching ■→■→■... As a striking example of this, as shown in Figure 7, a wireless repeater with no I! Switching of wireless zones in the event of an illumination failure will be explained.

In Figure 7, during normal operation, the wireless zone is switched from ■→■
→■・・・・・・ is carried out. Here, for example, zone ■
There is no I that constitutes! If the iI device fails, even if zone (2) is continued to be used to rescue zone (2), IIi will occur in the vicinity of wireless repeater C, which is normally covered by the radio waves of zone (2).

Similarly, if a wireless device constituting zone (2) breaks down, an instantaneous power outage occurs near the wireless repeater (2).

Therefore, the present invention has been made to solve the problems of the prior art as described above, and its purpose is to:
To provide a train radio system which eliminates a dead zone of radio waves near a radio repeater and prevents instantaneous interruption near the radio repeater even when the radio equipment fails.

11 Summer 11 According to the present invention, a plurality of wireless relay stations each having a pair of wireless transmitters/receivers each having a pair of antennas placed back to back are installed along a train track, and the directivity of each of these antennas is set as the opposing direction. This train radio system relays between a mobile station and a fixed station in a train, and each of the relay stations covers a radio wave dead zone near the pair of antennas corresponding to its own relay station. A train radio system is obtained which is characterized in that it has respective auxiliary radio zones.

Example The present invention will be described in detail below using the drawings.

FIG. 1 is a system block diagram of one embodiment of the present invention. In the figure, multiple radio repeaters are installed along the train tracks, and each of these radio repeaters has a pair of radio transceivers A and B, respectively, with antennas C and D placed back to back. are doing. For example, a trumpet-shaped electromagnetic horn E is provided between the pair of antennas C and D, and this electromagnetic horn E allows the wireless transmission/reception 1ff
fA.

It is designed to compensate for the radio wave dead zone near B.

FIG. 2 shows an example of a pattern of 11 no-radio wave zones in each repeater in FIG. 1. The radio repeaters have different frequencies fl, f1' and f2 . f2° (for example, fl, f2 from the wireless repeater to the mobile station, fl in the opposite direction)
o, f2° are used, respectively) to create a wireless zone with so-called pencil beam-like directivity.
is formed.

On the other hand, the electromagnetic horn E forms an auxiliary radio zone 13 in order to compensate for the radio wave dead zone that exists near the radio repeater, thereby relieving the dead zone over the entire section. .

In such a configuration, switching of wireless zones during normal operation is performed in the following order: ■→■→■→■... However, in each area directly below the wireless repeater, the area is switched to an auxiliary wireless zone from each electromagnetic horn.

Here, if radio device A on one side of the repeater breaks down, zone ■ will be lost, but zone ■ can continue to be used as a relief for zone ■, and near the repeater, the zone ■ will be lost. Radio waves in zone ■ can be used. In addition, in the event of a failure of radio device B, zone ■ will be lost, but zone ■ will be used early to save this zone ■, and zone ■ from electromagnetic horn E can continue to be used near the repeater. .

FIG. 3 is a block diagram of another embodiment of the present invention, in which each wireless repeater has a horizontal omnidirectional antenna F instead of the electromagnetic horn E in FIG. This is an example in which a dead zone of radio waves near a repeater is attempted to be compensated for using a digital antenna F.

In this case, the zone switching is performed using one pair of antennas A of the repeater.
In addition to the zones of and B, a zone due to the third antenna F is added, so that ■→(a)→■→■→(b)→■
→ It is done as follows.

FIG. 4 shows an example of a pattern of radio wave zones in each repeater in the case of FIG. 3. The auxiliary zone, which is the radio wave zone 14 by antenna F, uses the third frequency pair f3° f3°.

In this case as well, the dead zone of radio waves near each repeater can be relieved by the same effect as in the embodiment of FIG. 1, so that instantaneous interruption of radio waves can be prevented even when a transmitter/receiver fails.

In the second embodiment, an omnidirectional antenna is used as the antenna F, but it is obvious that a directional antenna may be used to form the auxiliary radio wave zone.

Effects of the Invention As described above, according to the present invention, the dead zone of radio waves that occurs near the wireless repeater is covered, so that failure of the repeater can be avoided without using the radio frequency of the repeater to create a duplex configuration. This prevents momentary communication interruptions caused by This has the effect of making it possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the wireless zone configuration of the example in FIG. 1, FIG. 3 is a diagram showing another embodiment of the present invention, and FIG. Figures 5 to 7 are diagrams showing the wireless zone configuration of the example in Figure 3, and Figures 5 to 7 are column I! FIG. 1 is a diagram for explaining a wireless system. Description of symbols of main parts A, B... Transmitter/receiver C9D... Pair of antennas E... Electromagnetic horn F... Antenna

Claims (1)

[Claims] Multiple wireless relay stations each having a pair of wireless transmitters/receivers with a pair of antennas placed back to back are installed along the train tracks, and the directivity of each antenna is set in the direction of the opposite station, so that it is fixed to the mobile station inside the train. The train radio system is configured to perform relaying with stations, and each of the relay stations has an auxiliary radio zone that covers a dead zone of radio waves near the pair of antennas corresponding to the own relay station. A distinctive train radio system.