JP2004096142A - Area polling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a risk of collision of radio data from a plurality of mobile stations in a radio data transmission system including the plurality of mobile stations each provided with a radio device for transmitting the vehicle number information of its own station and positional movement information, and a base station for receiving and processing the information from each of the mobile stations. <P>SOLUTION: For an area polling signal from the base station, center point information within a predetermined range is added in addition to latitude/longitude information within a predetermined range, the distance between the base station and the position of the own vehicle is calculated from the center point information in a mobile station, and a timing for transmitting the movement/position information in radio data is controlled, thereby reducing collision on the radio data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a local area polling method in a wireless data transmission system including a plurality of mobile stations and base stations, such as a taxi dispatch system.
[0002]
[Prior art]
In the conventional district area polling method, when the base station performs district area polling for collecting data of mobile stations within a certain range from the base station in order to obtain the latest dynamic / position information of the mobile station, , Latitude / longitude range information was set and transmitted to all mobile stations as fixed range area information.
[0003]
The mobile station that has received the information compares the latitude / longitude information of the current position of the own station with the current position and determines whether or not the own station is located within the certain area. If it is determined that the mobile station is located within the base station, the dynamic / position information of the own station is transmitted to the base station at random timing.
[0004]
The base station receives the dynamic / positional information transmitted from the mobile station within the predetermined range area, and performs processing such as displaying a map screen.
[0005]
[Problems to be solved by the invention]
According to the conventional technology, when a large number of mobile stations exist within a certain area required by the base station, there is a high possibility that radio data of dynamic / positional information transmitted by the mobile stations will collide, and When a lot of occurrences occur, there is a problem that information on the mobile station cannot be obtained accurately.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to reduce the collision of wireless data and accurately receive information from a mobile station when performing area area polling.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention adds a certain range of center point information in addition to a certain range of latitude / longitude information from the base station, and allows the mobile station to determine the vehicle position from the center point information. By calculating the distance to and controlling the timing of transmitting dynamic / position information in wireless data, collisions on wireless data can be reduced and mobile station information at the base station can be displayed more accurately. It was done.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the mobile station includes a position detecting device 1, a processing device 2, and a wireless device 3, and the base station includes a wireless device 4, a signal processing device 5, and a display device 6.
[0009]
Hereinafter, the operation of the embodiment of the present invention will be described. The base station sets the required fixed range 13 where the mobile station is located on the map screen 11 being displayed, as shown in FIG. Next, the signal processing device 5 converts the data into latitude / longitude range data, and then transmits the local area polling data 9 of FIG.
[0010]
After receiving the local area polling data 9 received from the base station, the mobile station compares the vehicle location data obtained by the position detection device 1 with the processing device 2 in advance, and locates the mobile station within the corresponding range. If it has, a return signal 10 is transmitted to the base station via the wireless device 3. In the base station, the wireless device 4 and the signal processing device 5 receive and process the return signal 10 from the mobile station and display it on the display device 6.
[0011]
Next, with reference to FIG. 2, the transmission timing of the area polling signal transmitted from the base station and the return signal returned from the mobile station will be described. When there are a large number of mobile stations within the range specified by the base station, the return signal transmission timing of the mobile station is divided into slots so that the return signals transmitted by the mobile stations do not collide with each other, and are randomly selected according to the slots. Send. In the example of FIG. 2, by dividing into 15 slots and transmitting the corresponding mobile station at any timing of A1 to A15, it is possible to reduce the collision of the return signal.
[0012]
In the embodiment of the present invention, when the base station transmits the latitude / longitude data of the fixed range 14 to the mobile station, as shown in FIG. 3, the latitude / longitude data of the center point 15 is also transmitted at the same time.
[0013]
The mobile station calculates the distance from the center point to the own vehicle position in addition to the condition that exists in a certain range. This distance condition is added to the timing for transmitting the return signal. For example, vehicles near the center point are randomized in slots A1 to A5, vehicles located at a middle distance from the center point are randomized in slots A6 to A10, and slots A11 to A5 are located far from the center point. By performing randomization of the transmission timing in a plurality of steps such as randomization in A15, it is possible to reduce the collision of the return signals of the mobile stations with each other.
[0014]
【The invention's effect】
In the conventional method, when there are many mobile stations within a certain area specified by the base station, collision of the return signal of the mobile station occurs, and the dynamics and position of the mobile station can be accurately grasped. Did not.
[0015]
In addition, in the conventional method, a collision of a return signal occurs irrespective of a vehicle closer to the center point and a vehicle farther in a certain range, and the vehicle closest to the center point most needed by the base station can be correctly displayed. could not.
[0016]
ADVANTAGE OF THE INVENTION According to this invention, even when many mobile stations exist in the area | region of a fixed range, while being able to reduce the collision of the return signal of a mobile station, the effect which can also display the vehicle near a center point has the effect. Have.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a system configuration according to an embodiment of the present invention.
FIG. 2 is a timing chart showing one embodiment of the present invention.
FIG. 3 is a diagram showing a display on a display device of a base station according to an embodiment of the present invention.
[Explanation of symbols]
1: position detection device, 2: processing device, 3: wireless device, 4: wireless device,
5: signal processing device, 6: display device, 7: base station transmission timing,
8: mobile station transmission timing, 9: district area polling signal, 10: return transmission signal, 11: display device screen, 12: display device screen, 13: fixed range area,
14: fixed area, 15: center point.

Claims (1)

In a wireless data transmission system including a plurality of mobile stations including a wireless device that transmits the vehicle number information and position dynamic information of the own station, and a base station that receives and processes information from the mobile station,
A district area polling method configured to reduce collision of wireless data from the plurality of mobile stations.

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