JPH0661935A - Digital cordless key telephone system - Google Patents

Abstract

PURPOSE:To prevent noises from being sent out to the opposite party of communication from a connector device when the carrier signal (talking) is cut between the connector device and a portable telephone set. CONSTITUTION:When a detecting circuit 14 detects the cut-off of the carrier signal sent to a connector device 10 from a portable telephone set 15 through a transmission/reception circuit 13 in a busy state between both portable telephone sets 15 and 16, the carrier signal is converted into a specific digital code and a digital code inserting circuit 12 inserts a channel B of a basic interface circuit 11 or an additional control bit into the digital code, then the digital code is informed to a main device 1. When the device 1 detects a specific digital code out of a basic interface circuit 7 through a detecting circuit 5, the device 1 inputs an idle signal showing no sound into the PCM signal path of the circuit 7 through an idle signal inserting circuit 3. In such a constitution, the noises are never sent to the telephone set 16 of the opposite party even if the transmission of the carrier signal is cut between the telephone set 15 and the device 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless button telephone device.

[0002]

2. Description of the Related Art A conventional digital cordless button telephone device has no means for notifying the presence or absence of a carrier signal from the connecting device to the control unit of the main device when the presence or absence of a carrier signal from a mobile phone is detected by the connecting device. When the disconnection of the carrier signal is detected, it is determined that the call between the mobile phone and the connection device is disconnected, and the connection device notifies the control unit of the main device using the call control channel, and the control unit of the main device notifies the other party. The call path with the mobile phone was disconnected.

[0003]

In the above-mentioned conventional digital cordless button telephone device, the control unit of the main device does not directly notify the disconnection of the carrier signal, and the call between the mobile telephone and the connection device is disconnected. If a mobile phone temporarily goes out of service area of the connected device, it will be notified until the connected device determines that the call is disconnected. There is a problem that noise is transmitted to the communication path until the main device is notified using the channel.

[0004]

A digital cordless button telephone device of the present invention includes a plurality of connecting devices for connecting to a plurality of mobile telephones via wireless lines, a plurality of telephone lines, and an ISDN line. A first device for accommodating the plurality of connection devices, wherein the connection device detects a presence / absence of a carrier signal from the mobile phones during a call;
And a detection signal from the first detection circuit to insert a predetermined digital code signal into the B channel or the additional control bit of the transmission frame structure at the S / T point of the ISDN line to the main device. A second basic interface circuit having a digital code insertion circuit and a first basic interface circuit having a basic interface for the ISDN line, and the main device having a second basic interface circuit having a basic interface for the ISDN line;
A second detection circuit for detecting the presence or absence of the digital code signal from the B channel or the additional control bit of the output of the second basic interface circuit; and a case where the second detection circuit detects the digital code signal. An idle signal insertion circuit for inserting an idle signal indicating silence in the PCM signal path of the second basic interface circuit, a line interface circuit including a codec circuit for interfacing with the plurality of telephone lines, and the line interface circuit and And a speech path switch forming a digital speech path for the second basic interface circuit, wherein the digital code insertion circuit is for the main unit.
The predetermined digital code signal is inserted into a specific bit corresponding to the B channel speech channel of the transmission frame structure at the S / T point of the SDN line, or the digital code inserting circuit is used by the digital code inserting circuit for the main unit. The predetermined digital code signal is inserted into the multi-frame bit of the transmission frame structure at the S / T point, or the digital code insertion circuit is a spare of the transmission frame structure at the S / T point of the ISDN line to the main unit. The predetermined digital code signal is inserted into the bit.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a digital cordless button telephone device according to an embodiment of the present invention.

In FIG. 1, a digital cordless button telephone device of the present embodiment is a mobile telephone 15, 16 and a connection device 1 for accommodating the mobile telephone 15, 16 via a wireless line.
0 and the main device 1 that accommodates the telephone line 17 and the connection device 10.

The connection device 10 transmits / receives a carrier wave signal for a call with the mobile phones 15 and 16, a detection circuit 14 for detecting the presence / absence of a carrier wave signal during a call, and a carrier wave signal during a call. If not, a digital code insertion circuit 12 for inserting a predetermined digital code signal into the B channel or additional control bit of the frame structure at the S / T point of ISDN, and the IS connected to the main unit 1.
It has a basic interface circuit 11 for interfacing with the DN line 9.

The main unit 1 has a basic interface circuit 7 for interfacing with the ISDN line 9 and a detection circuit 5 for detecting a predetermined digital code signal from the B channel or the additional control bit in the received frame from the connection unit 10. The idle signal insertion circuit 3 for inserting an idle signal indicating silence when a predetermined digital signal is detected by the detection circuit 5 into the PCM signal path, the digital speech path switch 8, the telephone line 7 and the speech path switch 8. A line interface circuit 2 for interfacing and a control circuit 6 for controlling the main device 1 as a whole are included.

Next, the operation of this embodiment will be described.
When a key operation for making a call from the mobile phone 15 to the mobile phone 16 is performed, the mobile phone 15 transmits a call signal using a wireless control channel. At this time, the connection device 10 waits for and receives the carrier signal from the mobile phones 15 and 16. When the transmission / reception circuit 13 and the detection circuit 14 of the connection device 10 receive the carrier signal of the calling signal of the mobile phone 15, the transmission / reception circuit 13 sends a response signal to the mobile phone 15 and secures the call channel. At the same time, the connection information of the calling signal is sent to the basic interface 7 and the control circuit 6 of the main device 1 through the digital code insertion circuit 12, the basic interface circuit 11, and the D channel (control channel) of the ISDN line 9.

Based on the connection information, the control circuit 6 sends an incoming call signal to the portable telephone 16 to the transmission / reception circuit 13 of the connection device 10 through the D channel of the basic interface by a route opposite to that at the time of calling. . The transmission / reception circuit 13 sends an incoming call signal using a wireless control channel. Mobile phone 16
Is in a standby state for receiving an incoming call signal, receives the incoming call signal, and responds by key operation. In response to the response operation, the mobile phone 16 sends a response signal to the wireless control channel. The transmission / reception circuit 13 of the connection adapter 10 that has received the response signal secures the communication channel and sends the response signal to the control circuit 6 of the main device 1. The control circuit 6 controls the call path switch 8 to connect the call channels of the mobile phone 15 and the mobile phone 16 to enable a call.

At this time, if the mobile phone 15 goes out of the service area of the connection device 10, the transmission / reception circuit 13 and the detection circuit 14 of the connection device 10 detect disconnection of the carrier signal of the call from the mobile phone 15, The connection device 10 notifies the main device 1 of the disconnection of the carrier signal by any of the methods (1) to (4).

(1) P of the communication channel of the transmission / reception circuit 13
The B channel of the basic interface circuit 11 and the ISD in which the specific digital code for disconnection of the call predetermined by the digital code insertion circuit 12 in the CM signal path is set as no carrier signal.
Basic interface circuit 7 of main device 1 via N line 9
Send to.

(2) P of the communication channel of the transmission / reception circuit 13
A digital code insertion circuit 12 in the CM signal path uses one of the communication channels as a control channel, and a bit corresponding to the channel number is a digital code without a carrier signal in the B channel of the basic interface circuit 11 and the ISDN line 9
To the basic interface circuit 7 of the main device 1 via.

(3) The digital code inserting circuit 12 inserts a digital code without a carrier signal by inserting it into the multi-frame bit (M bit) at the S / T point of the ISDN of the basic interface circuit 11 via the ISDN line 9. 1 to the basic interface circuit 7.

(4) The digital code inserting circuit 12 inserts a digital code without a carrier signal by inserting it into the spare bit (S bit) at the S / T point of the ISDN of the basic interface circuit 11 via the ISDN line 9 to the main unit 1. To the basic interface circuit 7.

Next, with respect to the signal without a carrier wave received through the basic interface circuit 7 of the main unit 1, the detection circuit 5 performs detection and detection corresponding to the above-mentioned methods (1) to (4). Take the idle signal (silent signal) transmission procedure.

(1) When a predetermined specific digital code is detected from the B channel of the basic interface circuit 7, an idle signal indicating silence is detected from the idle signal insertion circuit 3 while the specific digital code is detected. It is sent to the switch 17.

(2) The idle signal (silent signal) is inserted into the idle signal insertion circuit 3 while the digital code without the carrier signal is detected in the bit corresponding to the channel number from the B channel used as the control channel of the basic interface circuit 7. From the communication path switch 8.

(3), (4) Basic interface circuit 7
While a digital code without a carrier signal is detected from the additional control bits (M bits, S bits) of 1, the idle signal (silence signal) is sent from the idle signal insertion circuit 3 to the speech path switch 8.

Next, the speech path switch 8 inserts the transmitted idle signal into the speech channel used by the mobile phone 16. This prevents noise from being sent to the mobile phone 16 even if the carrier wave is cut off during a call.

[0022]

As described above, according to the present invention, when the disconnection of the carrier signal from the portable telephone is detected by the connecting device,
Connection of the mobile phone during a call is made by converting the disconnection of the carrier signal from the connection device into a digital code, inserting it into the B channel or additional control bits (M bits, S bits) of the basic interface of ISDN, and sending it to the main device. When the device goes out of the service area, or because the main device can recognize a momentary interruption in real time, the load on the control channel is reduced, and the noise that occurs until it is recognized as a call disconnection can be erased. Have an effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing a digital cordless button telephone device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 main device 2 line interface circuit 3 idle signal insertion circuit 5 detection circuit 6 control circuit 7 basic interface circuit 8 speech path switch 9 ISDN line 10 connection device 11 basic interface circuit 12 digital code insertion circuit 13 transmission / reception circuit 14 detection circuit 15 mobile phone 16 mobile phones 17 telephone lines

Claims (4)

[Claims] 1. A plurality of connection devices for connecting to a plurality of mobile telephones via a wireless line, and a main device for accommodating a plurality of telephone lines and accommodating the plurality of connection devices via an ISDN line, The connection device includes a transmission / reception circuit that performs wireless transmission / reception with the plurality of mobile phones, a first detection circuit that detects the presence or absence of a carrier signal from the mobile phone during a call, and a detection from the first detection circuit. A digital code insertion circuit for inserting a predetermined digital code signal into a B channel or an additional control bit of a transmission frame structure at the S / T point of the ISDN line to the main unit by a signal; and a basic interface to the ISDN line. A first basic interface circuit, wherein the main device has a second basic interface having a basic interface to the ISDN line. This interface circuit and this second
A second detection circuit for detecting the presence or absence of the digital code signal from the B channel or the additional control bit of the output of the basic interface circuit of, and the second detection circuit when the second detection circuit detects the digital code signal. 2, an idle signal insertion circuit for inserting an idle signal indicating silence in the PCM signal path of the basic interface circuit, a line interface circuit including a codec circuit for interfacing with the plurality of telephone lines, the line interface circuit and the second And a voice communication path switch that constitutes a digital communication path to the basic interface circuit of 1. 2. The digital code inserting circuit inserts the predetermined digital code signal into a specific bit corresponding to a B channel speech channel of a transmission frame structure at the S / T point of the ISDN line for the main unit. The digital cordless button telephone device according to claim 1, wherein: 3. The digital code inserting circuit inserts the predetermined digital code signal into a multi-frame bit of a transmission frame structure at an S / T point of the ISDN line for the main unit. 1
The described digital cordless button telephone device. 4. The digital code inserting circuit inserts the predetermined digital code signal into a spare bit of a transmission frame structure at an S / T point of the ISDN line for the main unit. The described digital cordless button telephone device.