JPH0217733A - Radio equipment with function to prevent external output of clear-down signal - Google Patents

Abstract

PURPOSE:To obtain sharp sound quality with a few noise by detecting a system tone at a speech channel(Sch), and performing a squelch operation when the tone is not received for a constant time. CONSTITUTION:First of all, channel designation is received by issuing a call in a Cch(control channel), and when it is a designation signal addressed to its own station, the Sch is set, then, a counter is cleared to 0. And since no system tone is overlapped at the time of issuing a simultaneous command, a tone is outputted from a speaker. When it is not the simultaneous command, the state of a PT is checked, and the qualification of a reception state is performed when it is set at an OFF state. When the PT is set at an ON state, a transmission processing is performed. When a timer overflows, the tone and a carrier are judged. Next, when no clear-down signal is received, the counter is counted up by one. When the counter counts exceeding N, squelch control is performed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is a mobile station (mounted in a vehicle) used in an MOA system.
Alternatively, the present invention relates to a wireless device that prevents a command station from outputting a call end signal to the outside.

[Conventional technology]

The wireless equipment used in the conventional MOA system transmits calls, codes, and
Transmits data, etc. The condition for terminating the call with Bah is when the control station cannot receive the system tone for a certain period of time. In this case, if the control station determines that the call is over,
The transmission of the 8ch carrier wave was stopped.

In the mobile station, when there is no Sch carrier,
It determines that the call is over and returns to the control channel (hereinafter referred to as Cch). At this time, I activated the squelch to prevent noise from coming out of the radio's speaker.

[Problem to be solved by the invention]

Since conventional wireless equipment was configured as described above, M
In CA's new system (Narrow), a call end signal is transmitted at the end of a call, so there was a problem that the sound came out from the speaker of the m-line device.

This invention was made to solve the above-mentioned problems, and its purpose is to obtain clear sound quality with less noise, which is one of the characteristics of the MCA system.

[Means to solve the problem]

The current system (wide) has 6 control stations for the MCA system.
2 seconds for IFr systems (narrow).
If the tone cannot be received, it is determined that the call is over and a call end signal is sent. Therefore, the mobile station including the command station related to this FIAK is designed to detect the system tone during Sch, and to operate squelch if the tone cannot be received for a certain period of time (within 2 seconds).

[Effect]

The wireless device according to the present invention operates a squelch when there is no system tone continuously for a certain period of time in Sch, and receives data (including audio) from the speaker of the wireless device.
I don't give out.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. The figure is a flowchart of a squelch control method for a mobile station (including a command vehicle) during Sch.

First, a call is made on Cch, the channel is specified in step ST1, and it is checked in step ST2 whether or not the own channel has been specified. If the designated signal corresponds to the own station, 8oh is set in step ST3, and the counter is set to O. If it is not the own station, ach processing is performed in step 5T14. After setting channel 8, it is determined whether the channel command is based on the -sai command (step 5T).
4) Since the system Φ tone is not superimposed when the -simultaneous command is issued, at this time the squelch is opened in step 8T15 and the sound is output from the speaker (-simultaneous command processing). -If it is not a simultaneous command, check the PT status control in step 8T5 OFF'
If so, the reception state is set in step ST6.

If PT is ON, transmission processing is performed in step 5T16. A timer is set in step ST6. this is,
For example, assume that the tone detection interval is loomg, and if 1.58 tones cannot be received continuously, squelch control is performed. At this time, the timer setting in step ST6 is set to loomg, and N in step 5T12 is set to 15.

At step S'l'7, the timer overflows L7'
c, tone (Step 8T8), Φ Yaria (Step 8T9) is determined. Next, if a call termination signal is not received (Step S'I'lO), the counter is incremented by 1 in Step 5T11. When the 0 counter becomes larger than N (here, 15), squelch is controlled. This is K
Therefore, if the system cannot detect a mocking tone for a certain period of time, the squelch is controlled and the received data is not emitted from the speaker. Also, in the reception state processing, the squelch is turned off and audio is output from the speaker.

(Effects of the Invention) As described above, according to the present invention, when a system tone is detected and the tone cannot be received for a certain period of time, the squelch is controlled.
You can feel the effect of making a very fresh and manly sound.

[Brief explanation of the drawing]

The figure is a flowchart showing a squelch control method for preventing the output of a call termination signal in a wireless device according to an embodiment of the present invention.

Claims (1)

[Claims] In wireless equipment that transmits and receives voice, code, data, etc. using the MOA system, if a system tone is detected during a call channel and the tone cannot be received for a certain period of time, the squelch is activated and the end-of-call signal is not emitted as sound from the speaker. A wireless device with external output prevention for end-of-call signal, characterized by: