JPH0583011B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a transmission control method that interrupts a line in progress in wireless communication, and is particularly concerned with a transmission control method for interrupting a line in progress in a call in wireless communication, and in particular, in a transmission control method for interrupting a call in progress from multiple mobile stations on a single duplex radio line. This invention relates to a system that interrupts a base station.

[Conventional technology]

Wireless communication is advantageous when communicating with an unspecified number of parties scattered over a wide area, or when communicating while moving with each other. In particular, since mobile communications are communications with moving objects, various restrictions are imposed on them due to the propagation characteristics of radio waves. Base stations are capable of transmitting at high power, and antennas can also be strung up high. but,
Mobile stations are generally limited in transmission power, cannot afford to install antennas high, and can accommodate only a certain number of subscribers per wave, so there is a need for technology that makes effective use of frequencies. In consideration of these points, a small wireless zone system with low output power is adopted in mobile communications. This method has the advantage of being able to use the same frequency repeatedly, and is used in various fields including trains and automobiles.

Now, if the communication partner constructs a duplex single radio line with 1 base station and N mobile stations, the base station starts communication with one of the mobile stations and enters a busy state. Otherwise, other mobile stations had to wait until the call ended before starting communication with the base station.

[Problem that the invention seeks to solve]

In conventional duplex single radio circuits, when a base station is talking to a specific mobile station and another mobile station tries to call the base station to start communication, the base station Therefore, due to the interference that occurs when receiving radio waves at the same time,
The disadvantage is that the communication information transmitted from the mobile station interferes with the other station at each of the multiple stations.

[Means for solving problems]

The present invention provides a base station with a received electric field information transmitting device that detects the received electric field of radio waves transmitted from a mobile station communicating with the own station, modulates received electric field information indicating the strength into a transmitted radio wave, and transmits the received electric field information. In preparation, the received electric field of the radio waves currently being transmitted by the base station is compared with the received electric field based on the received electric field information sent out from the received electric field information transmitter of the base station, and as a result of the comparison, the received electric field of the radio waves currently transmitted by the base station is determined. The mobile station is equipped with an interrupt control device that allows transmission of radio waves when the received electric field at the base station for radio waves becomes larger than the received electric field at the base station for the transmitted radio waves from the mobile station currently communicating with the base station. It is prepared for.

[Effect]

It is possible to reliably interrupt a busy line.

〔Example〕

The present invention will be explained with reference to the drawings. FIG. 1 is a system configuration diagram of a transmission control method showing an embodiment of the present invention.

Reference numeral 1 denotes a base station, which is equipped with equipment for receiving radio waves of a predetermined frequency and transmitting radio waves of another predetermined frequency. 2 is a transmitting/receiving antenna of base station 1, 3
is connected to this antenna and transmits the received signal and the transmitted signal in one direction, and 4 is connected to the duplexer 3, which processes the received signal and extracts it as an audio signal, as well as transmits field strength information of the received signal. A receiver 5 is connected to the receiver 4 and is an electric field information modulator that modulates field strength information, and 6 is a transmitter whose output side is connected to the duplexer 3 and whose input side is connected to the modulator 5. Note that the speaker 7 is connected to the receiver, and the microphone 8 is connected to the transmitter 6. A mobile station 11 is equipped with equipment for transmitting radio waves of a predetermined frequency and receiving radio waves of another predetermined frequency. 12 is a transmitting/receiving antenna of the mobile station 11, 13 is a duplexer connected to this antenna and transmits the received signal and the transmitted signal in one direction, and 14 is connected to the duplexer 13 to process the received signal and extract it as an audio signal. At the same time, a receiver 15 is connected to the receiver 14 and inputs the field strength information to one input side. The electric field comparator 16 is a transmitter whose output side is connected to the duplexer 13 and whose input side is connected to the comparator 15. Note that the speaker 17 is connected to the receiver 14 via a duplexer 19, and the microphone 18 is connected to the transmitter 16. Duplexer 1
Reference numeral 9 is also connected to the other input side of the comparator 15, and sends the field strength information sent out by the base station 1, which is extracted by the receiver 14. Further, 20 is a press switch connected to the comparator 15. 21 indicates another mobile station, which is equipped with the same equipment as the mobile station 11;
Radio waves are transmitted and received using the antenna shown in .

Now, the operation of one embodiment of the present invention constructed as described above will be explained.

Radio waves of the frequency transmitted by the antenna 22 of the mobile station 21 are input to the antenna 2 of the base station 1 , and reach the receiver 4 through the duplexer 3 . Since the receiver 4 outputs the field strength information of this radio wave to the modulator 5, the field strength information is input to the transmitter 6 as a transmittable signal. Microphone 8 for transmitter 6
It is superimposed with the audio signal of , and is constantly transmitted from the antenna 2 via the duplexer 3. This radio wave is received not only by the mobile station 21 but also by the mobile station 11, and is received by the antenna 12.
The radio waves of frequency ' inputted to the receiver 14 reach the receiver 14 through the duplexer 13. Therefore, the receiver 14 outputs the received field strength information of the base station 1 to the comparator 15, and outputs the received field strength information of the mobile station 21 transmitted from the base station 1 to the demultiplexer 19. The audio signal is outputted, and received field strength information is outputted to the comparator 15 by the duplexer 19, and the audio signal is outputted to the speaker 17.
The comparator 15 compares the field strength information, and allows the transmitter 16 to transmit radio waves when the radio waves transmitted by the own station can definitely reach the base station 1 stronger than the radio waves transmitted by the mobile station 21. . Generally FM
In wireless communication, such as when a radio wave is sent from another mobile station that is somewhat stronger than the radio waves transmitted from the mobile station currently in use, the base station receives only the stronger radio waves without interference. becomes. Therefore, as described above, transmission control is performed based on the comparison result between the received electric field of the transmitted radio wave from the base station, that is, the received electric field of the own station at the base station, and the received electric field of the mobile station currently in communication at the base station. This makes it possible to interrupt reliably.

〔Effect of the invention〕

According to the present invention, the received electric field information obtained from the receiver of the base station is modulated into the transmission radio wave emitted from the base station and is constantly transmitted. The base station compares the received electric field information sent by the base station and allows the transmission of radio waves only when the radio waves are stronger than the currently active mobile station and reach the base station even if the radio waves are emitted from the own station. At the same time, radio waves are sent out in response to an interrupt request, making it possible to reliably interrupt an active line.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention. 1... base station, 2, 12, 22... antenna,
3, 13... duplexer, 4, 14... receiver, 5...
... Modulator, 6, 16 ... Transmitter, 7, 17 ... Speaker, 8, 18 ... Microphone, 11, 21 ... Mobile station, 19 ... Duplexer, 20 ... Press switch.

Claims (1)

[Claims] 1. In a duplex single radio line that communicates between a base station and one of multiple mobile stations, the base station receives the received electric field of the radio waves transmitted from the mobile station that is communicating with the base station. The mobile station is equipped with a received electric field information transmitting device that detects received electric field information indicating the strength of the received electric field and modulates it into a transmitted radio wave, and transmits the received electric field information indicating the strength of the received electric field. The received electric field based on the received electric field information transmitted from the received electric field information transmitting device of the station is compared with the received electric field based on the received electric field information transmitted from the received electric field information transmitter of A duplex device characterized in that it is equipped with an interrupt control device that allows the transmission of radio waves when the received electric field at the base station for the transmitted radio waves from the mobile station in the center is larger than the received electric field at the base station, and interrupts the line in progress. Transmission control method for a single radio line.