JP3102733B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system, and more particularly to a radio communication system excellent in operability.

[0002]

2. Description of the Related Art In a radio communication system for communicating with each other via a radio line with relatively low power, a specific low power receiver, a specific low power repeater, and a specific low power receiver as a calling station, a relay station, and a response station. A specific low power device such as a power transceiver is provided, and various signals from the calling station and the answering station, such as a calling signal from the calling station and a response signal from the answering station, are transmitted via the relay station. The communication is established only when a response from the responding station exists. At this time, the specific low-power devices such as the calling station, the relay station, and the answering station use ATIS (Automatic Transmit Identifi- cation) as a call name defined by the Radio Law.
communication system), and detects that each specified low-power device has received a signal at the same frequency as the radio wave to be emitted and having a level higher than a predetermined threshold,
It has a carrier sense function to prevent emission of radio waves when the signal is received.

FIG. 7 shows an operation procedure of the conventional wireless communication system.
First, when performing communication at a calling station, an operator turns on a PTT (Push to Talk) switch, transmits once, and then sets the PTT switch to OF.
The transmission from the relay station is set to F, the PTT switch is turned on again, and communication via the relay station starts for the first time. In FIG. 7, C / S means execution of the carrier sense function, and ATIS means execution of the transmission function of ATIS. Also, on the response station side, after the transmission of the relay station is completed, the operator of the response station turns on the PTT switch to transmit once, then turns off the PTT switch, receives the transmission from the relay station, and again transmits the PTT switch. Is turned ON, a response via the relay station is possible for the first time.

[0004]

As described above, in the conventional wireless communication system using specific low-power devices, it is necessary to execute a carrier sense operation defined by the Radio Law, so that the caller and In each specific low-power device as a response station or the like, the PTT switch needs to be turned on and off, and the operation is complicated.

[0005] In addition, since the communication is started after waiting for a response from the answering station to the call from the calling station, there is no immediate response from the answering station after the calling from the calling station is completed. Cannot confirm the presence of the answering station, and it is possible to confirm that the answering station is absent for the first time when no response signal is received even after repeating the calling process several times. Therefore, after the call from the calling station is completed, it takes time to confirm the presence or absence of the answering station.Also, even though the answering station is absent, for example, whether the radio wave reaches the partner station with which communication is desired. If you talk to the microphone in a state where you do not have it, you will communicate.

[0006] Therefore, an object of the present invention is to solve the above problems and to provide a radio communication system with improved operability.

[0007]

In order to solve the above-mentioned problems, a radio communication system according to the present invention provides a calling station which executes a predetermined process including a carrier sense function and an ATIS transmission function as a call name. In a wireless communication system comprising a relay station and a responding station, in which communication between the calling station and the responding station is performed via the relay station, the wireless communication system responds to an ON operation of a PTT switch for instructing a call start from the calling station. The calling station performs the predetermined processing, the relay station detects a match of the tone signal from the transmission signal from the calling station, and then executes the predetermined processing. After performing the predetermined process after detecting the match of the tone signal from the received signal from the, the calling station detects the rise of the transmission from the relay station in response to the fall of the transmission signal from the responding station Configured to initiate the communication.

[0008]

According to the present invention, the OTT of the PTT switch from the calling station is determined.
In response to the N operation, a predetermined process including a carrier sense function and an ATIS transmission function of the calling station are automatically performed, and a predetermined process is performed after detecting a match of a tone signal from a transmission signal from the calling station of the relay station. Detects a rising edge of the transmission from the relay station in response to the fall of the transmission signal from the answering station of the calling station by executing a predetermined process after detecting the matching of the tone signal from the reception signal from the relay station of the answering station. Start communication later.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration block diagram of a relay station (specific low power repeater) showing one embodiment of a wireless communication system according to the present invention. The reception signal received by the antenna 1 is subjected to predetermined reception processing in the front end 2 and
The signal is converted by the F circuit 3 into an IF signal. The IF signal is FM-detected by the detection circuit 4 and then amplified by the low-frequency amplification circuit 5 and supplied to an output unit such as a speaker.

The carrier detection circuit 6 detects a carrier signal from the IF signal obtained by the IF circuit 3 and sends the detection signal to the control circuit 8. The tone decoder 7 includes a detection circuit 4
Based on the FM detected audio signal from the CTCSS (Continuous Tone) defined by the well-known EIA standard.
The tone signal of the Coded Squelch System is decoded, and the decoding result is sent to the control circuit 8.

The control circuit 8 receives the carrier signal from the carrier detection circuit 6, executes the above-described carrier sensing function, activates the ATIS transmission circuit 9 and the transmission circuit 12 when it is determined that the emission of the radio wave is OK, and operates the ATIS information. Is supplied to the modulation circuit 11. The control circuit 8 also determines whether the tone signals decoded by the tone decoder 7 match, and when they match, operates the tone encoder 10 to supply the tone signal to the modulation circuit 11. Control unit 8
Performs transmission / reception control and various types of control of specific low-power devices in addition to the above-described operation control.

The modulation circuit 11 modulates the FM detection signal from the detection circuit 4, the ATIS signal from the ATIS transmission circuit 9, and the tone signal from the tone encoder 10, and transmits the modulated signal to the antenna 13 via the transmission circuit 12. .

Although FIG. 1 shows an example of a relay station, a calling station and a responding station are also basically configured in the same way. ,
The only difference is that an audio signal from an audio input means such as a microphone is input after being amplified at a low frequency.

FIG. 2 is a timing chart showing the operation of this embodiment, and shows a calling station (specific low power transceiver).
When the PTT switch is turned ON, the above carrier sense function is executed to determine whether or not transmission is possible. When transmission is possible, ATIS and tone signal transmission (superimposed on the transmission signal) is performed.

This transmission is performed, for example, for 300 msec, and thereafter returns to the receiving state regardless of ON / OFF of the PTT. The relay station receives the transmission, detects a tone match, executes carrier sense, and then automatically sends ATIS and tone signals for, for example, 600 msec. The answering station receives the transmission signal from the relay station,
After the tone coincidence is detected, after the carrier sense is performed as in the case of the calling station, the transmission of the ATIS and the tone signal is performed, for example, by 600
msec automatically and return to the receiving state.

The relay station that has detected the fall of the transmission of the responding station starts transmission. The calling station that has detected the rising edge of the transmission of the relay station starts transmission, and communication is established and started only here.

The above series of operations is performed by the operator once
Just by turning on the switch, the control unit (configured with a microprocessor) executes the communication, so that the communication is automatically started.

Also, after the PTT switch is turned on, a beep sound is generated until the communication starts, so that the start of the communication can be known. If a return signal cannot be detected, an error beep sounds. You can also

The operation procedure of the calling station, the relay station and the answering station in the above embodiment is shown in the flowcharts of FIGS. 3, 4 and 5. The operation procedure of the calling station will be described with reference to FIG. 3. First, it is determined whether or not the PTT switch is ON (step S101). If it is ON, a beep sound is started (step S102). Then, the carrier sense function is executed, and transmission OK (permission / non-permission) is determined (step S103). Here, if it is determined that the transmission is OK, the transmission is started (step S104), the ATIS is transmitted (step S105), and after the transmission of, for example, 300 msec is completed (step S106), it is determined whether or not there is a response (step S106). Step S107).

In step S107, if there is a response, the beep sound is terminated (step S108), communication is started (step S109), and the PTT switch is turned off.
Wait for the FF state (step S110). PTT
When the switch is turned off, the transmission ends and the operation returns to the operation start state.

In steps S103 and S107,
As a result of the carrier sense, if the transmission is not OK or there is no response, after performing an access failure process (steps S112 and S113) described later, the process returns to the operation start state.

In the access failure processing in steps S112 and S113, first, an error beep sound is started (step 114), and after the PTT switch is turned off (step S115), the error beep sound is terminated (step S115). Step S116).

As shown in FIG. 4, the relay station determines whether or not a signal has been received after the start of the operation (step S2).
01), if the tone is received, the tone matching is determined (step S202). If the tone is matched, the carrier sense function is executed to determine whether the transmission is OK (step S203). If the transmission is OK, the transmission is started (step S204), and the ATIS is transmitted (step S2).
05) Then, the transmission is terminated (step S206), and it is determined whether or not there is a response from the responding station (step S207).

At step S207, when there is a response from the responding station, the transmission is started (step S209) after waiting for the fall of the transmission (step S208).
Wait for the calling station to stop transmitting (step S210). After the transmission of the calling station is terminated, the transmission is terminated (step S211),
Return to the operation start state.

If it is determined in steps S201, S202, S203 and S207 that there is no signal reception, tone mismatch, carrier sense, transmission is impossible, and there is no response from the responding station, the operation returns to the operation start state.

As shown in FIG. 5, after starting the operation, the responding station determines whether or not a signal has been received (step S301). If the signal has been received, it determines whether the tone matches (step S30).
2). If the tones match, the carrier sense function is executed (step S303). If the transmission is OK, the transmission is started (step S304), the ATIS is transmitted (step S305), and the transmission is terminated. (Step S306), the operation returns to the operation start state.

Referring to FIG. 6, in the relay station, the transmission of the tone is interrupted at the end of the transmission, and then the transmission ends. As a result, in the calling station or the answering station, the tone squelch circuit is closed first, so that comfortable communication can be performed without hearing a so-called squelch tail (squeak).

[0028]

As described above, according to the radio communication system according to the present invention, a communication system with significantly improved operability can be constructed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a relay station (specific low power repeater) showing one embodiment of a wireless communication system according to the present invention.

FIG. 2 is a timing chart showing the operation of the present embodiment.

FIG. 3 is a flowchart showing a calling station operation processing procedure in the embodiment.

FIG. 4 is a flowchart illustrating an operation processing procedure of a relay station in the present embodiment.

FIG. 5 is a flowchart illustrating an operation processing procedure of a response station according to the embodiment.

FIG. 6 is a timing chart for explaining the operation of this embodiment.

FIG. 7 is a timing chart illustrating an operation of a conventional wireless communication system.

[Explanation of symbols]

Reference Signs List 1, 13 antenna 2 front end 3 IF circuit 4 detection circuit 5 low frequency amplification circuit 6 carrier detection circuit 7 tone decoder 8 control circuit 9 ATIS transmission circuit 10 tone encoder 11 modulation circuit 12 transmission circuit

Claims (1)

(57) [Claims] 1. A calling station, a relay station, and a response station, each of which performs a predetermined process including a carrier sense function and a transmission function of ATIS as a call name, and includes a calling station and a response station via the relay station. In the wireless communication system in which the communication is performed, the calling station executes the predetermined process in response to an ON operation of a PTT switch for instructing a call start from the calling station, and the relay station executes the calling process. After detecting the match of the tone signal from the transmission signal from the calling station, execute the predetermined processing,
The responding station executes the predetermined process after detecting a match of the tone signal from the received signal from the relay station, and the calling station responds to the fall of the transmission signal from the responding station from the relay station. A wireless communication system characterized in that communication is started by detecting a rising edge of transmission.