JPH0337777B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a wireless telephone device connected to a subscriber line,
In particular, the present invention relates to a wireless telephone device that performs connection control operations using digital signals.

[Prior art]

Up until now, connection control of wireless telephone devices has mainly been based on tone signals, and there are two types of tone signals, one within the voice band and one outside the voice band. However, in recent years, with the advancement of digital technology, connection control has come to be performed using digital signals. In systems using digital signals, signal speeds are becoming faster due to shorter connection operations and the like.

In general, for data speeds such as 600bps or 1200bps, the spectrum of the signal itself extends into the voice band, so when call termination is activated, the data signal sent from the terminating party can be heard by the other party's handset and the conversation is interrupted. It remains as an unpleasant sound after.

[Purpose of the invention]

The present invention provides a device that eliminates the above-mentioned discomfort after a conversation by using a low-speed digital signal that does not have a voice band spectrum when performing a call-end operation.

[Structure of the invention]

In order to achieve the above object, a radio telephone device according to the present invention is a radio telephone device that is connected to a subscriber line and performs a connection operation using a digital signal, and includes a first digital signal sending means, a second the first digital signal sending means outputs a digital signal having a signal spectrum including a voice band as a control signal during a connection control operation other than a call termination operation. The second digital signal transmitting means transmits a digital signal having a signal spectrum other than the voice band, which is blocked by a bandpass filter of an audio circuit provided in the receiving station, as a call termination signal during a call termination operation. The switching means switches the output from the first digital signal sending means to the output from the second digital signal sending means at the time of call termination operation.

[Effect]

In the present invention, a first digital signal having a signal spectrum including the voice band is used as a control signal for connection control operations other than the call termination operation. This is to switch to a second digital signal having a spectrum. It is desirable to shorten the connection time before starting a call as much as possible. If the connection time is long before a call can be started, there will be a time delay between picking up the handset and hearing the dial tone, which is inconvenient for use. However, when the call ends, conversation is no longer necessary, so there is no problem even if it takes some time to disconnect.

In the present invention, a low-speed digital signal that does not have a voice band spectrum is used in practice, but in theory, a signal that has a signal spectrum that is higher than the voice band may be used as the second digital signal.

Audio band frequency is 0.3-3.1kHz (or 3.4kHz)
It is. Therefore, the second digital signal with a signal spectrum outside the audio band is specifically a signal whose frequency is below 0.3kHz, or vice versa.
It is a signal with a frequency of 3.1kHz (or 3.4kHz).

However, signals with frequencies higher than 3.1kHz (3.4kHz) are not used for single radio communications.
In this sense, it can be said that it is practical to use an out-of-audio band signal smaller than 0.3 kHz as the second digital signal.

〔Example〕

The present invention will be described in detail below with reference to the drawings.
Before describing embodiments of the present invention, an example of a conventional radio telephone device will be described with reference to FIG. In Fig. 1, 1 is a subscriber line terminal, 2 is a 2-wire/4-wire conversion circuit, 3, 4, 25, 26 are bandpass filters, 5, 27
is a control section, 6 and 23 are transmitting sections, and 7 and 24 are receiving sections. Further, 8 and 22 are duplexers, 9 and 21 are antennas, 10 and 29 are data transmitters, and 11 and 30 are
28 is a data detector, 28 is a transmitting/receiving unit, 100 is a base station, and 101 is a mobile device.

It is now assumed that the base station 100 and the mobile device 101 are in a communication state. When the mobile device 101 ends the call, a signal indicating that the call is to be ended is input from the transmitter/receiver section 28 to the control section 27 . The control unit 27 is the data transmitter 2
9 to send a call end signal, and the transmitter/receiver unit 2
Stop the operation of the microphone and register bar in step 8. The end-of-call signal from the data transmitter 29 is modulated and amplified by the transmitter 23, and transmitted to the base station 100 through the duplexer 22 and antenna 21.

At the base station 100, the end-of-call signal sent from the mobile device 101 passes through the antenna 9, the duplexer 8,
The receiving section 7 demodulates the signal. The demodulated end-of-call signal is confirmed by the data detector 11 to be a end-of-call signal. When the end of call signal is confirmed, the data detector 11
is the control unit 5 which sends a confirmation signal for the end of call signal to the control unit 5.
When receiving the confirmation signal of the paper talk signal from the data detector 11, the audio circuit of the 2-wire/4-wire converter 2 is disconnected, the connection with the subscriber line is canceled, and the transmitter 6 is sent to the data transmitter 10. command to cut off the output. When the transmission output of the base station 100 is cut off, the reception section 24 of the mobile device 101 cuts off the reception.
A reception disconnection signal is sent to the control unit 27 via the data detector 30. When the control section 27 receives the reception disconnection signal, the control section 27 disconnects the transmission section 23 via the data transmitter 29.

The call termination operation is completed by the procedure described above, but the conventional call termination signal demodulated by the receiving unit 7 of the base station 100 has a spectrum of the termination signal that is 3rd.
It has a spectrum component within the passband of the bandpass filter 4, as shown by a in the figure. Therefore, until the call termination signal is detected and confirmed by the data detector 11 and the connection with the subscriber line is canceled by the audio circuit disconnection signal of the 2-wire/4-wire converter 2 from the control unit 5, The signal passes through the bandpass filter 4, passes through the 2-wire/4-wire converter 2, and is sent to the subscriber line terminal 1, and part of the end-of-call signal is heard by the telephone of the other party.

In the above-mentioned conventional example, a part of the end-of-talk data signal is always heard after the end of the conversation, and remains as an unpleasant sensation after an otherwise pleasant conversation.

FIG. 2 is a block diagram of an example of a specific embodiment of the present invention. In FIG. 2, 1 is a subscriber line terminal, 2 is a 2-wire/4-wire converter, 3, 4, 25, 26 is a bandpass filter, 5, 27 is a control unit, 6, 23 is a transmitter,
7, 24 are receivers, 8, 22 are duplexers, 9, 21
is an antenna. Further, 10 and 29 are first data transmitters having a signal spectrum including a voice band. 11 and 30 are first data detectors.
12 and 31 are second data transmitters having a signal spectrum outside the voice band. 13 and 32 are second data detectors, 28 is a transmitting/receiving unit, 100 is a base station, and 101 is a mobile device.

When the base station 100 and the mobile device 101 are in a conversation state and the mobile device 101 performs a call termination operation, the transmitter/receiver unit 28
A signal indicating that the call is to be terminated is input to the control unit 27. The control unit 27 causes the second data transmitter 31 to transmit a call end signal, and also stops the operation of the microphone and receiver of the transmitting/receiving unit 28. The end-of-call signal from the second data transmitter 31 is modulated and amplified by the transmitting/receiving section 23, and transmitted to the base station 100 through the duplexer 22 and the antenna 21.

At the base station 100, the end-of-call signal sent from the mobile device 101 passes through the antenna 9 and the duplexer 8, and is demodulated by the receiving section 7. The demodulated end-of-call signal is the second
The second data detector 13 confirms that the signal is a call end signal, and upon confirmation, the second data detector 13 sends a call end confirmation signal to the control unit 5. When the control unit 5 receives the end-of-call confirmation signal, it disconnects the audio circuit of the 2-wire/4-wire converter 2, releases the connection with the subscriber line, and sends the first data transmitter 10 to the transmitter 6. Commands to turn off transmission output.

When the transmission output of the base station 100 is cut off, the reception section 24 of the mobile device 101 becomes cut off, and sends a reception cut off signal to the control section 27 via the first data detector 30. When the control section 27 receives the reception disconnection signal, the control section 27 disconnects the transmission section 23 via the first data transmitter 29.

The end-of-call operation is completed by the procedure described above, but in the present invention, the spectrum of the end-of-call signal sent from the second data transmitter 31 is filtered by the bandpass filter 4 as shown by b in FIG. It has no spectral components within the passband. Therefore, the end-of-call signal demodulated by the receiver 7 is blocked by the bandpass filter 4 and is not sent to the subscriber line terminal 2, so that the other party does not hear it as an unpleasant sound.

Generally the audio band is 0.3-3.1kHz (or 3.4kHz)
It is. Therefore, the spectrum of the first digital signal extends to the pass band as shown in a of FIG. For example, a 1200 baud Manchiesta code digital signal corresponds to this, and the pulse width is generally 50% duty, and by passing only the main lobe through a filter, the digital signal has a spectrum as shown in Figure 3a. It uses signals.
On the other hand, the second digital signal generally has a pulse width of 50% duty like the first digital signal, and is filtered to pass only the main lobe to produce a signal having a spectrum as shown in Figure 3b. An example of this is a 200 baud Manchester code digital signal.

In addition, in the present invention, in order to shorten the connection time in the case of a calling operation and an incoming call operation, the first data transmitter 10, 29 sends out a signal having a spectrum within the voice band as in the conventional example. data detector 11,
Detected at 30.

Also, in the block diagram of the specific example of the present invention, the base station 1
A second data transmitter in 00 and a second data detector in mobile device 101 are described, but in the case where a disconnection signal is sent from the exchange through the subscriber line, 2 If the line/four-line conversion circuit 2 detects the disconnection signal, and the controller 5 operates the second data transmitter 12 to send out the disconnection signal having the spectrum shown in b in FIG. Similar to the above explanation, the disconnection signal demodulated by the receiving section 24 is blocked by the bandpass filter 26 and cannot be heard by the transmitting/receiving section 28, which is effective.

〔Effect of the invention〕

As explained above, the present invention switches to a signal having a spectrum outside the voice band and uses this signal to terminate the call, so that the other party cannot hear the call termination signal, and therefore the call ends when the conversation ends. This has the effect of not causing discomfort to the other party.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional radio telephone device, FIG. 2 is a block diagram of a radio telephone device according to the present invention, and FIG. 3 is a diagram showing the spectrum and passband of a digital signal. 1...Subscriber line terminal, 2...2-wire/4-wire converter, 3, 4, 25, 26...Band filter, 5, 2
7...control section, 6,23...transmission section, 7,24...
...Receiving unit, 8, 22... Dual unit, 9, 21... Antenna, 10, 29... First data transmitter, 1
1, 30...first data detector, 12, 31...
...Second data transmitter, 13, 32...Second data detector, 28...Transceiver unit, 100...Base station, 101...Mobile device.

Claims (1)

[Scope of Claims] 1. A wireless telephone device connected to a subscriber line and performing a connection operation using digital signals, which comprises a first digital signal sending means, a second digital signal sending means, and a switching means. The first digital signal sending means outputs a digital signal having a signal spectrum including a voice band as a control signal during a connection control operation other than a call termination operation, and the first digital signal sending means outputs a digital signal having a signal spectrum including a voice band. The transmitting means outputs a digital signal having a signal spectrum outside the voice band that is blocked by a bandpass filter of the voice circuit provided in the receiving station as a call termination signal during a call termination operation, and the switching means . A wireless telephone device, characterized in that the output from the first digital signal sending means is switched to the output from the second digital signal sending means during a call termination operation.