JP2000341737A - Base station selection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station selection system capable of always selecting a base station closests to a mobile station and high in receiving input level. SOLUTION: Each of a portable set and a base station is provided with a device, e.g. a GPS receiver 5, for automatically recognizing the position of its own station, a relative distance between the base station and the portable set is calculated, response order is automatically decided from a relative distance between the portable set and an adjacent another base station, and the portable set is allowed to communicate with the base station having the nearer relative distance. The base station monitors also a received receiving input level, and when there is no lowermost receiving input level, negates data, so that the reliability of data is improved and the optimum base station is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a mobile station (portable device).
In a mobile radio communication system including a plurality of base stations and a plurality of base stations, the present invention relates to a method of selecting one base station to be a communication partner of the mobile station among the plurality of base stations.

[0002]

2. Description of the Related Art Conventionally, when a line connection request signal is transmitted from a mobile station (hereinafter referred to as a portable device), the base station receiving the signal returns a response signal to the portable device. However, the above operation is a case where the electric field is sufficiently secured and only one opposition is provided. In practice, in a system with multiple base stations,
The portable device transmits a line connection request signal. Conventionally, in order to prevent multiple base stations receiving the request signal from responding at the same time and causing a data collision, priorities are assigned in advance to multiple base stations in the system, and a response is made from a base station with a higher priority. I was letting it. That is, if there is no response from the highest priority base station for a certain period of time, the next higher priority base station responds to the portable device.

Also, since the propagation loss from the portable unit to the base station and from the base station to the portable unit are basically the same, in order to improve the reliability, the base station needs to be higher than the minimum reception input level of the line design. The data was set invalid except for the data of. For this reason, conventionally, even if there is a base station where the relative distance between the portable device and the base station is short and the reception input level is sufficient,
In accordance with the fixed priority determined in advance, there is a problem that, despite the lowest reception input level, it responds to the line connection request signal from the portable device and causes a communication error due to the influence of a shield or the like. Was.

[0004]

In the above-mentioned prior art,
Since the base station that has received the line connection request signal from the portable device responds according to a fixed priority determined in advance, there is a problem that communication cannot be performed even if there is another base station with good line conditions. . That is, there has been a problem that communication may not be possible with a base station which is closest to the mobile station and has a high reception input level. An object of the present invention is to provide a base station selection method that eliminates such a problem and can always select a base station that is closest to a mobile station and has a high reception input level.

[0005]

According to the present invention, in order to achieve the above-mentioned object, a mobile station automatically transmits position information using a device capable of automatically recognizing its own position, such as a GPS receiver. It is configured so that the relative distance is calculated on the receiving side by transmitting the location information added to the data to be transmitted and transmitted, thereby selecting the closest base station and returning a response. is there.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, as shown in FIG. 2, the mobile radio communication system includes a mobile station (portable device) 20, a plurality of base stations 14 to 17, an exchange 18, and a central station 19. First, the configuration of each base station and portable device in the present embodiment will be described with reference to FIG. In the present embodiment, a case where the wireless device of each base station and the portable device have the same configuration will be described below as an example.

[0007] As shown in FIG. 1, the portable device converts a signal received by the GPS antenna 4 into position information data by the GPS receiver 5, and transmits it to the logic control unit 6 periodically. The logic control unit 6 periodically updates the transmitted information, adds position information when there is a request signal operation from the operation unit 9, and transmits the information from the radio antenna 1 via the transceiver unit 2. I do. Similarly, the radio device of each base station has a GPS antenna 4
Is converted into position information data by the GPS receiver 5 and transmitted to the logic controller 6 periodically. Since each base station basically does not move, the GP in the configuration of FIG.
Instead of having the S antenna 4 and the GPS receiver 5, the location information of the own station may be simply stored in the memory. Next, the logic control unit 6 receives the radio wave transmitted from the portable device from the transceiver unit 2 via the radio antenna 1. The transceiver unit 2 sends a signal indicating the received reception input level to the reception input determination circuit, and transmits data transmitted from the portable device to the logic control unit 6.

[0008] Here, the logical control unit 6 calculates a relative distance from the position information of the portable device and the position information of the own station, and confirms that a sufficient level from the reception input level determination unit 3 is secured. Judging from the adjacent base station, if the own station is closest, it immediately returns a response to the portable device. At the same time as returning a response, the base station outputs a line connection request signal from the portable unit from the logic control unit 6 to the data input / output terminal 8 via the data transmission unit 7 and the central terminal 19 of the central office via the exchange 18. Transmit to

Next, the priority of each base station will be described with reference to FIG. In FIG. 2, zone A10 is a base station A14, zone B11 is a base station B15, zone C12.
Indicates a service area of the base station C16, and a zone D13 indicates a service area of the base station D17. When the portable device 20 transmits data between the base station A14 and the base station B15, the zone A1
0, received between zones B11. Suppose zone A10,
If you are at the intersection of zone B11, base station A14,
The base station B15 calculates the relative distance between the portable device and the adjacent base station and the relative distance between the portable device and the base station B15 based on the calculation result.
Is closer, the top priority is base station B15 and then base station A14. The transmission timing of the base station A14 having a lower priority may be performed in the same manner as in the conventional monitoring for a fixed time. In this way, after the base station B15 closest to the portable device 20 is selected, the base station 15 that has responded is selected.
Transmits the line connection request data from the portable device 20 to the exchange 1
8 to the center terminal 19 of the central office. The center terminal 19 processes received data and transmits the data to the portable device 20 via the exchange 18 and the base station B15. Also, even if the signal reaches the zone D13 due to overreach of the base station or the like, the priority of the response is the last because the relative distance is the longest. Therefore, it is possible to prevent the base station having the lowest reception input level from responding to the portable device with a fixed priority order as in the related art, thereby preventing the occurrence of communication abnormality.

[0010]

According to the present invention, even when a portable unit transmits data between a plurality of adjacent base station zones, an optimum base station (a base station having the closest relative distance) is obtained based on each relative distance.
Can be selected, and the reliability of data transmission is improved. Also, interference due to data collision between base stations can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a mobile communication system.

[Explanation of symbols]

1: wireless antenna, 2: transceiver,
3: reception input level determination circuit 4: GPS antenna, 5: GPS receiver, 6: logic control unit, 7: data transmission unit, 8: data input / output terminal, 9: operation unit, 1
0: Zone A, 11: Zone B, 1
2: Zone C, 13: Zone D, 1
4: base station A, 15: base station B, 1
6: base station C, 17: base station D, 1
8: exchange, 19: center terminal, 2
0: Portable device.

Claims (1)

[Claims] In a base station selection method for a mobile communication system including a mobile station and a plurality of base stations, a position detecting means for automatically detecting a position of the own station is provided to the mobile station; Control means for adding information on the station position to the data transmitted to the base station, wherein each of the plurality of base stations receives and detects position information from the mobile station and determines the relative distance between the mobile station and the own station. A base station selection method, comprising: a control unit for automatically calculating the base station; and selecting a closest base station among relative distances between each of the plurality of base stations and the mobile station.