JPH05314395A - Communication equipment between car and roadside equipment - Google Patents

Abstract

PURPOSE:To eliminate the interference waves of communication by providing a radio equipment for transmitting/receiving radio waves between base stations on a road and an obstacle detector for detecting upper obstacles. CONSTITUTION:When an obstacle detector 6 detects the presence of the road up in a mobile station traveling direction, a radio equipment 5 does not transmit the radio waves until it is out of the communication zone of the base station on the road under reception. Then, the base station on the road under reception repeats the similar procedure every time the radio waves from the base station on the road are received. Thus, in multi-level crossing roads, moving cars traveling the lower road can be prevented from applying the interference waves to the communication between the base stations on the road up in the mobile station traveling direction and the mobile station.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road-to-vehicle communication device used for wireless communication between a road base station and a mobile station existing in a communication zone of the road base station.

[0002]

2. Description of the Related Art FIG. Four
It is explanatory drawing which shows the individual communication image between the roadside base station and mobile station of the road-to-vehicle information system shown in No. 3, No. 58, page 58-64 (1989). In the figure, 1
a is a mobile station, 2a and 2b are road base stations (hereinafter referred to as beacons) that are intermittently installed along the road to form a narrow spot-like communication zone, and 3 is moved via the beacons 2a and 2b. It is a system center for performing data communication with the station 1a. FIG. 4 is a block diagram showing a configuration of a conventional mobile station 1a, in which 4 is an antenna and 5 is a wireless device.

A mobile station 1a running on a road transmits and receives data at high speed to and from the roadside base stations 2a and 2b while running in a communication zone of the roadside base stations 2a and 2b, which are installed intermittently along the road. Then, various information is collected and provided with the system center-3. The mobile station 1a configured as shown in FIG. 4 is configured to transmit a radio wave by the wireless device 5 when it enters the communication zone of the roadside base stations 2a and 2b. Now, on the road crossing over as shown in FIG. 5, the on-road base station 2a is installed on the upper road, and the mobile station 1b traveling on the lower road enters the communication zone of the on-road base station 2a. Suppose At this time, the mobile station 1b transmits a radio wave to the roadside base station 2a on the upper road which is not the object of communication. This radio wave arrives directly or by diffraction or the like and becomes an interference wave for communication between the roadside base station 2a and the mobile station 1a. As a result, the communication quality of the on-road base station 2a and the mobile station 1a deteriorates.

[0004]

In the conventional road-to-vehicle communication device as described above, the road base station 2a on the upper road is generated by the radio wave transmitted from the mobile station 1b traveling on the lower road on the road crossing over the road. There is a problem that the communication quality of the mobile station 1a deteriorates.

The present invention has been made to solve the above problems, and a mobile station running on a road below a road crossing overpasses an interference wave in communication between an on-road base station and a mobile station on an upper road. The object is to obtain a road-to-vehicle communication device that does not give

[0006]

A road-to-vehicle communication device according to the present invention is provided with a radio device for transmitting and receiving radio waves to and from a road base station, and an obstacle detector for detecting an obstacle above. It is a thing.

[0007]

In the road-to-vehicle communication device configured as described above,
Since the obstacle detector can detect the presence of the road above the mobile station and control the radio, the mobile station running on the road below the road crossing the overpass is a base station of the road above-the mobile station. Interference will not be given to the communication between them.

[0008]

【Example】

Example 1. FIG. 1 is a block diagram showing a road-vehicle communication device according to an embodiment of the present invention. The road-to-vehicle communication device is installed in each of the mobile stations 1a and 1b. In the figure, the same symbols as those in FIG. 4 indicate the same or corresponding portions. In FIG. 1, 6
Is an obstacle detector that detects whether there is an obstacle above by using radio waves, light, ultrasonic waves, image recognition, or the like. FIG. 2 is a flow chart showing the processing procedure according to this embodiment.

As in the conventional case, it is assumed that the mobile station 1b traveling on the lower road enters the communication zone of the roadside base station 2a.
At this time, the obstacle detector 6 of the road-vehicle communication device mounted on the mobile station 1b detects the road above the mobile station (step 7). The obstacle detector 6 detects an obstacle above the moving direction of the mobile station by reflection of a medium such as radio waves, light, and ultrasonic waves, or image recognition, and determines whether the obstacle is a road based on its distance and size. Identify. When the wireless device 5 receives the radio wave from the roadside base station 2a and the obstacle detector 6 does not detect the presence of the road above the moving direction of the mobile station in the determination in step 7, the wireless device 5 transmits the radio wave. Then, the communication with the on-road base station 2a is started, and the communication is performed bidirectionally (step 8).

However, even if the wireless device 5 receives the radio wave from the roadside base station 2a, if the obstacle detector 6 detects the presence of a road above the traveling direction of the mobile station, the wireless device 5 transmits the radio wave. No transmission is performed (step 9). In step 10, it is determined whether or not the radio wave is being received from the roadside base station 2a. If it is being received, the process returns to step 9 and the radio wave is not transmitted. In the determination in step 10, when the radio wave from the roadside base station 2a is no longer being received, the radio device 5 of the mobile station 1b can transmit and receive the radio wave. That is, when the obstacle detector 6 detects the presence of the road above the traveling direction of the mobile station, the radio device 5 does not transmit the radio wave until it leaves the communication zone of the on-road base station being received. Every time a radio wave from the roadside base station is received, the roadside base station that is receiving the signal repeats the same procedure. As a result, it is possible to prevent the mobile station 1b traveling on the lower road from giving an interference wave to the communication between the on-road base station 2a and the mobile station 1b on the upper road in the traveling direction of the mobile station.

It should be noted that the obstacle detector 6 is not limited to the above-mentioned embodiment, but any detector capable of detecting an obstacle above may be used.

[0012]

As described above, according to the present invention, since the radio device for exchanging radio waves with the roadside base station and the obstacle detector for detecting the obstacle above are provided, There is an effect of providing a road-to-vehicle communication device capable of preventing a mobile station traveling on a road below an intersecting road from giving an interference wave to communication between a road base station and a mobile station on an upper road.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a road-vehicle communication device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of the road-to-vehicle communication device according to the first embodiment.

FIG. 3 is an explanatory diagram showing an example of communication between a roadside base station and a mobile station in a road-to-vehicle information system.

FIG. 4 is a configuration diagram showing a conventional road-vehicle communication device.

FIG. 5 is an explanatory diagram showing an example of communication between a roadside base station and a mobile station in a road-to-vehicle information system.

[Explanation of symbols]

 1a Mobile station 1b Mobile station 2a Road base station 2b Road base station 5 Radio equipment 6 Obstacle detector

Claims (1)

[Claims] 1. A road-to-vehicle communication device comprising: a wireless device for transmitting and receiving radio waves to and from a roadside base station; and an obstacle detector for detecting an obstacle above.