JPH05199170A - Radio communication system - Google Patents

Abstract

PURPOSE:To communicate with the base station having radio line of high quality by adding a function detecting the electric field intensity during the reception of calling data from a mobile station and transmitting the electric field intensity information together with a selection signal for selecting a central station or base station at the time of transmitting the selection signal. CONSTITUTION:An electric field intensity discrimination section 9 discriminates whether or not a signal comes from plural base stations and whether or not incoming time difference T is within a prescribed time in the case incoming calls come from plural stations. When a call comes from one base station, a line changeover section 8 switches lines and controls so as to send a changeover and signal to a base station A. When calls come from plural base stations and the incoming time difference T is within the prescribed time, the calls are judged to be the one from one mobile station ab, repeater stations with higher electric field intensity is selected in decided order, sending a changeover end signal and a connection unable signal to each base station. In the case calls come from plural base stations and the incoming time difference T exceeds the prescribed time, the call is judged to be the one from plural mobile stations, sending a changeover end signal to the base station receiving calls earlier and a connection unable signal to the other base station.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention secures a wide service area by installing a plurality of base stations in a self-employed wireless communication system, and a mobile station passes through an optimum base station in this area. The present invention relates to improvement of a wireless communication system for communication.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a conventional wireless communication system. 1 is a central station, 2 is a base station A, 3 is a base station B, 4 is a base station N, 5 is a mobile station a, 6 is a mobile station n, and a wired line or carrier is provided between the central station and each base station. The line is connected, and the base station and the mobile station are connected by a wireless line. In the case of this method, the communication traffic between the base station and the mobile station is small, but when the area to be served is along the railway,
Since it is wide, it is composed of one radio frequency.

When the mobile station a is selected from the central station 1 for communication, the line switching unit 8 selects the line of the base station A to which the mobile station a belongs and the transmission / reception control unit 7 sends call data. When the transmission / reception control unit 10 of the base station A receives the calling data, it converts the calling data into data for the mobile station, and then sends the calling data from the transmitting / receiving unit 11 to the mobile station a. The mobile station a transmits the signal obtained from the transmission / reception unit 14 to the transmission / reception control unit 1
When it is received at 5 and it is determined that the call is to the own station, the communication mode is entered. When the central station 1 is selected from the mobile station a for communication, the call data created by the transmission / reception control unit 15 is transmitted via the transmission / reception unit 14. The base station A once stores the signal obtained from the transmitting / receiving unit 11 in the data storage unit 12, and when it judges that the call is to the central station, it sends out a central station selection signal composed of a tone or the like.

When the line switching unit 8 receives this signal, it performs a corresponding line switching and sends a switching completion signal to the base station A. When the transmission / reception control unit 10 receives this, the data stored in the data storage unit 12 is converted into data for the central office and then transmitted. When the central station receives this by the transmission / reception control unit 7 and determines that it is a call to the own station, it enters the communication mode. Mobile station a
In the case of selecting the mobile station n for communication from the base station A, if the base station A determines that the call is via the base station N, the base station N selection signal composed of a tone or the like is sent to the line switching unit 8 of the central station 1. However, the subsequent operations are performed in the same manner as the operations in the above two cases.

As shown in (ab) of FIG. 1, the mobile station a is located at a point where the service areas of the base station A and the base station B overlap, and the central station 1 or the mobile station n is selected for communication as described above. In this case, both the base station A and the base station B send a selection signal composed of a tone or the like to the line switching unit 8 of the central station 1, so that the line switching unit 8 can be used in accordance with a predetermined priority order. Send a switching completion signal to the base station,
A line is configured to enable communication by returning a connection disable signal to the other base station.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
A drawback is that when the radio waves of one mobile station are simultaneously received by multiple base stations and each base station requests connection to the central line switching unit, one base station is selected in a predetermined priority order. is there. An object of the present invention is to eliminate this defect and select a better base station to obtain a good communication line.

[0007]

In order to achieve the above object, the present invention adds a function for verifying the electric field strength during reception of call data from a mobile station and sends a signal for selecting a central station or a base station. In addition, the electric field strength information is also transmitted so that the electric field judgment unit provided in the central station makes a judgment and selects a base station having a stronger electric field strength.
The electric field strength level to be verified by the base station is sufficient for this purpose with about two levels that can judge the quality of the wireless line. If the electric field strength is at the same level, one base station is selected according to a predetermined priority order. .

[0008]

As a result, even if there is a mobile station at a point where the service areas of a plurality of base stations overlap, it is possible to capture and communicate with a base station having a stronger electric field strength and a better radio channel quality.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. 1 is a central station, 2 is a base station A, 3 is a base station B, 4 is a base station N, 5 is a mobile station a, 6 is a mobile station n, and a wired line or carrier is provided between the central station and each base station. The line is connected, and the base station and the mobile station are connected by a wireless line. In this method, the communication traffic between the base station and the mobile station is small, but the area to be serviced is wide, such as along the railway.

When the mobile station a is selected from the central station 1 for communication, the line switching unit 8 selects the line of the base station A to which the mobile station a belongs and the transmission / reception control unit 7 sends out the calling data. When the transmission / reception control unit 10 of the base station A receives the calling data, it converts the calling data into data for the mobile station, and then sends the calling data from the transmitting / receiving unit 11 to the mobile station a. The mobile station a transmits the signal obtained from the transmission / reception unit 14 to the transmission / reception control unit 1
When it is received at 5 and it is determined that the call is to the own station, the communication mode is entered.

When the central station 1 is selected from the mobile station a for communication, the call data created by the transmission / reception control section 15 is sent out via the transmission / reception section 14. The base station A stores the signal obtained from the transmitting / receiving unit 11 once in the data storage unit 12, determines the received electric field strength during this time by the electric field verification unit 13, and when it determines that the call is to the central station, it selects a central station composed of tones or the like. The signal and the electric field strength judgment signal are transmitted. Electric field determination unit 9
Determines whether the corresponding signal is received from a plurality of base stations and, if received from a plurality of stations, whether the difference T in the arrival time is within a predetermined time. When an incoming call is received from one base station, the line switching unit 8 controls the line to be switched and sends a switching completion signal to the base station A, and the incoming call is received from a plurality of base stations. If is within the specified time,
Judging that the incoming call is from one mobile station (ab), select a relay station with a strong electric field strength in a predetermined order,
The switching completion signal and the connection disable signal are sent to the respective base stations. When the call arrives from a plurality of base stations and the difference T in the arrival time is equal to or longer than a predetermined time, it is determined that the call arrives from a plurality of mobile stations, and a switching completion signal is sent to the base station that received the call earlier, and a connection is made to another base station. Send a disable signal.

When the transmission / reception control unit 10 receives the switching completion signal, the data stored in the data storage unit 2 is converted into central data and then transmitted. When the central station receives this by the transmission / reception control unit 7 and determines that it is a call to the own station, it enters the communication mode. When the mobile station a is selected from the mobile stations a to communicate with each other, if the base station A determines that the call is via the base station N, the base station N configured by a tone or the like is provided to the line switching unit 8 of the central station 1.
The operation after transmitting the selection signal is the same as the operation in the above two cases.

[0013]

According to the present invention, in a system in which a single radio frequency is used in a self-employed wireless communication system and a plurality of base stations have a wide service area, when a mobile station exists at a point where the areas overlap. Optimal base station selection can be realized by a simple means.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a system related to the present invention.

FIG. 2 is a block diagram showing the configuration of the present invention.

FIG. 3 is a block diagram showing a conventional configuration.

[Explanation of symbols]

 1 Central Station 2 Base Station A 3 Base Station B 4 Base Station N 5 Mobile Station a 6 Mobile Station n 7 Transmission / Reception Control Section (Central Station) 8 Line Switching Section 9 Electric Field Judgment Section 10 Transmission / Reception Control Section (Base Station) 11 Transmission / Reception Section (Base station) 12 Data storage unit 13 Electric field verification unit 14 Transmission / reception unit (mobile station) 15 Transmission / reception control unit (mobile station)

Claims (1)

[Claims] 1. A wireless communication system comprising a central station and a plurality of base stations / mobile stations, wherein the base station is provided with an electric field verification section, a data storage section, and a transmission / reception control section, and the central station is provided with an electric field determination section and line switching. Section and transmission / reception control section are provided, and when call data is received from the mobile station to the base station, it is stored in the data storage section and the electric field verification section verifies the electric field, and the verification result is sent to the line switching section of the central station together with the connection request. At the same time, when a request is issued from multiple base stations, the electric field determination section determines whether the mobile station is the same mobile station or different mobile stations based on the arrival time difference of the verification result and selects the optimum base station based on the electric field strength level. Alternatively, the connection-disabled signal is returned to each base station, and only one connected base station sends the call data of the data storage unit, and the transmission / reception control unit of the central station or another base station receives it to enter the communication mode. A wireless communication system characterized by the following.