JPH05199551A - Isdn digital telephone system - Google Patents

Abstract

PURPOSE:To require no calling charge to a one-way extension call and also to evade the busy state of a B channel. CONSTITUTION:When the contents of the information element added to a call setting message received by a connecting device 2 from a calling telephone set 4a show the one-way extension call request information, the device 2 does not send the received message to an ISDN network and sends the message back to a telephone set 4a with designation given through a call channel B1 for example. At the same time, a call setting message which defines the contents of am incoming address information element, etc., of the message as an extension number is produced and sent to an incoming call telephone set 4b. At the same time, the call channel of the set 4b is set at B1. Under such conditions, the side tone of the set 4a is controlled at a proper level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection device connected to an ISDN network and a plurality of ISDs connected to this connection device.
The present invention relates to an ISDN digital telephone device composed of N telephones.

[0002]

2. Description of the Related Art Generally, one ISDN line has a DSU
Up to eight ISDN telephones can be connected in a bus format via a (line terminating device), and the ISDN telephones accommodated in this one ISDN telephone line make an extension call, that is, one person to another person. When making a one-way extension call indicating a typical transmission, a dial key is operated to input a dial number corresponding to this ISDN line, and then a subaddress is input to make a call to the ISDN network. Then, the ISDN line is accommodated and an incoming call arrives at the ISDN telephone corresponding to the above subaddress, and the corresponding IS
The above-mentioned one-way extension call is carried out by the response of the DN telephone.

[0003]

However, when one-way extension telephone call is made between telephones accommodated in one ISDN line, if the ISDN telephone on the calling side is set to, for example, the B1 channel, the called party is called. Since the B2 channel is set in the ISDN telephone on the side, the two signal channels for communication are blocked. Therefore, other IS
During this period, the DN telephone has a problem that it cannot make an outside call or a one-way extension call. Therefore, it is an object of the present invention to allow another telephone to make an outside line call or a one-way extension call even during a one-way extension call.

[0004]

In order to solve such a problem, the present invention provides an ISDN telephone apparatus comprising a connection device connected to an ISDN network and a plurality of ISDN telephones connected to the connection device. In the case of making a one-way extension call between a plurality of ISDN telephones, the ISDN of the calling side
The connection device is provided with a means for setting the same call signal channel in the telephone and the ISDN telephone on the called side. In addition, the ISDN telephone is provided with a side tone adjusting means for making a one-way extension call.

[0005]

For example, during a one-way extension call such as one-way transmission, the same call signal channel is set to the calling side telephone and the called side telephone. Further, the side tone of the calling side telephone set with the same call channel as that of the called side telephone is adjusted to an appropriate value.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 4 is a connection configuration diagram of the ISDN telephone device according to the present invention, and shows an example in which the connection device 2 is arranged between the DSU 1 terminating one ISDN line and a plurality of ISDN telephones 4a to 4n. Further, FIG. 5 shows that a plurality of ISs are added to the DSU 3 in which the function of the connection device 2 is added to the function of the DSU 1.
An example is shown in which DN telephones 4a to 4n are connected. FIG. 1 is a block diagram showing an embodiment of the ISDN telephone device of the present invention, which shows a configuration corresponding to the connection device 2 described above. Further, FIG. 2 is a block diagram of the DSU 3 having the function of the DSU 1 and the function of the connection device 2. Note that FIG. 3 is a block diagram of the ISDN telephone 4.

First, the connection device 2 shown in FIG.
0, ROM 21, RAM 22, transformers 23, 29, driver / receivers 24, 28, I interface circuits 25, 27, B channel exchange unit 26, connection detection unit 30,
It is composed of the connection circuit 31 at the time of power failure, the DC / DC converter 32, the switch 33, the AC power receiving section 34, the AC adapter 35 and various clock signals a to c, and the portion surrounded by the dotted line in the figure is the T point. It is the / S point control unit 10. It should be noted that the DSU 1 is connected to the T point side indicated by the X mark, and the ISDN telephone 4 is connected to the S point side. Further, B1 and B2 indicate a B channel which is a signal channel for communication, and D is a data bus for the CPU 20 to perform D channel control and other controls.

Note that the B1 and B2 channels are replaced by the CPU
It is performed by the B channel switching unit 26 based on the instruction of 20. For example, as shown in FIG. 8, the setting of the B channel when performing a one-way extension call between ISDN telephones receives a call setting message from the calling telephone 4a and transmits a call setting acceptance message to the calling telephone 4a. If, for example, the B1 channel is set for the calling telephone 4a, the same B1 channel as the above is set for the called telephone 4b when a call setup message is transmitted to the called telephone 4b.

Further, as shown in FIG. 2, the DSU 1
3 is a block diagram of a DSU 3 equipped with the functions of the connection device 2 and the DSU 3 described above.
0, interface circuit section 11, line termination circuit section 1
3, a driver 14, a transformer 15, and a power supply circuit 16, and the ISDN lines L1 and L2 are connected to the transformer 15.

Further, FIG. 3 shows the ISDN as described above.
FIG. 3 is a block diagram of the telephone 4, which is used for inputting a control unit 40, a setting unit 41, an extension key 42 used for a one-way extension call, a display unit 43 for performing various displays, a dial key and an extension number. Operation unit 44 including sub-address keys and call keys, a line I / F unit 45 that interfaces with an ISDN line, an analog signal control unit 46 that generates various tone signals, and analog-digital conversion of voice signals. A codec 47 for performing the side tone adjustment circuit 4 for adjusting the side tone of the telephone during a one-way extension call
8, handset 49, AC power supply 50, AC adapter 5
1, a power supply switching unit 52, and a power supply unit 53 that supplies power to each unit of the telephone, and is connected to the connection device 2 or the DSU 3 via the line I / F unit 45.

Next, FIG. 6 is a block diagram showing a main part of the sidetone adjusting circuit 48 in the ISDN telephone 4. The sidetone adjusting circuit 48 includes a sidetone adjusting section 60, amplifiers 61, 62, and
And a sidetone addition circuit 63. The sidetone adjustment circuit 48 operates under the control of the control unit 40 only during a one-way extension call, and can provide an optimum sidetone in terms of call quality. Generally, the transmission signal from the transmitter T in the handset 49 is transmitted to the other party and, at the same time, is heard as a reception signal from the receiver R. However, during a one-way extension call, as described above, since the same B channel is used by the calling side telephone and the called side telephone, the transmission signal heard from the receiver R, that is, the side tone is abnormally large. It is not good for call quality. For this reason, the side tone adjusting circuit 48 is provided so that the side tone adjusting circuit 48 is activated only during a one-way extension call.

FIG. 7 is a timing chart showing the operation of such a side tone adjusting circuit 48. The waveform shown in (a) of FIG. 7 is a transmission signal from the transmitter T, and a indicates a transmission level. Here, when a call is made using the same B channel and the sidetone adjusting circuit 48 is not provided, the waveform of the reception signal heard from the receiver R becomes a waveform as shown in (b), and (a) The waveform of the transmission signal is received with almost no attenuation. Therefore, by providing the side tone adjusting circuit 48 and operating the side tone adjusting circuit 48,
The level of the transmission signal of (a) is appropriately reduced (a / n) from the reception signal of (b) and subtracted [that is, the opposite phase signal of the transmission signal whose level is reduced as shown in (c)]. Is generated and adjusted by adding it to the received signal of (b)], and the optimum sidetone signal level [a
(N-1) / n] is obtained. In this embodiment, the analog signal is processed to obtain the optimum received signal, but the same result can be obtained by processing the digital signal itself using a DSP or the like. The handset may be muted without providing the sidetone adjustment circuit 48.

Next, in FIG. 8, the connection device 2 (or DSU 3) is provided between the ISDN network and the ISDN telephone 4, and I
FIG. 9 is a sequence diagram showing an operation in a case where a one-way extension call can be made without going through the SDN network. this is,
In the ISDN telephone 4a, a one-way extension call request information is set in the user / user information element, and a call setup message to which the user / user information element is added is transmitted to make an one-way extension call with the ISDN telephone 4b. An example is shown. The extension call in this case is ISD
Since it does not go through the N network, it is a free call. That is, ISD
When the extension key 42 is pressed on the N telephone 4a, the one-way extension call request information is set in the user / user information element, and the dial key for calling the ISDN telephone 4b is operated by operating the dial keys or the like in the operation unit 44. When the input or subaddress is input, these input data are set in the destination address information element or the destination subaddress information element. Then, when the transmission key in the operation unit 44 is pressed, a call setting message to which the above-mentioned information elements are added is created and transmitted to the connection adapter 2.

When the connection device 2 receives the call setup message from the telephone 4a and determines that the content of the user-user information element added to this message is the one-way extension call request information, it receives it. Without sending the call setup message to the ISDN network, the call setup acceptance message is specified and returned to the calling side telephone 4a by, for example, the call channel B1, and the called address information element and the called subaddress information element of the call setup message are sent. A call setup message with the contents as an extension number is created and transmitted to the ISDN telephone 4b. Then, at this time, the B1 channel is set as the communication channel for the telephone 4b.

When an extension call is made to the telephone set 4b in this manner, and then a calling message is sent from the called telephone set 4b, the connection device 2 causes the calling side telephone set 4 to make a call.
Send a paging message to a. Then, when the telephone 4b answers the call, the connection device 2 causes the telephone 4a,
Various messages are transmitted to and received from the telephone 4b, and a one-way extension telephone call state, which is a one-way transmission from the telephone 4a to the telephone 4b, is performed. In this way, the control of the connection device 2 enables a free one-way extension call that does not pass through the ISDN network. In addition, since the same call channel is set by the control of the connection device 2 during such a one-way extension call, other call channels (for example, B2 channel) are in an unused state, and this unused channel is used. Other I
The SDN telephone can make an outside line call or a one-way extension line call.

Next, FIGS. 9A and 9B show ISDN.
A control unit 40 that controls the sidetone adjustment circuit 48 in the telephone 4.
3 is a flowchart showing the operation of FIG. First, (a) of FIG. 9 will be described. As described above, since the same B channel is used during a one-way extension call, the side tone of the telephone becomes loud. Therefore, after the off-hook is detected in the ISDN telephone 4, it is determined in step 100 that the extension key 42 for performing a one-way extension call is pressed,
When the press of the extension key 42 is detected and it is determined to be "Y", one-way extension transmission is performed, so that the side tone adjustment unit 60 is activated in step 101. afterwards,
The various messages as described above are transmitted to and received from the connection device 2, and at step 102, the one-way extension telephone call state is entered. When such an extension call state is established, next, in step 103, on-hook is judged. Then, when the on-hook for ending the one-way extension call is performed, the side tone adjusting unit 60 is made inoperative in step 104.

As described above, in the calling side telephone,
When the extension key 42 is pressed, the sidetone adjusting unit 60 is activated to obtain the optimal sidetone in a one-way extension call. In the case of the called ISDN telephone, specific information from the connection device 2 is obtained when the one-way extension call is formed and the analog signal control unit 46 is set to the operating state and the speaker receiving state is set, or the connection is established. Based on the contents of the destination address / destination sub-address information element added to the call setup message from the device 2, the analog signal control unit 4
It is also possible to set 6 as the operating state and the speaker receiving state.

If the pressing of the extension key 42 is not detected and "N" is determined in step 100, it means that the outside line is transmitted, and the side tone adjusting section 60 is controlled in the inoperative state in step 105. After that, dial operation is performed and various messages are transmitted and received, and then step 10 is performed.
At 6 the call goes to the outside line. When the on-hook for ending the call is detected and it is determined to be "Y" in step 107, the process ends.

Next, FIG. 9B shows a side tone adjusting circuit 48.
8 is a flowchart showing the operation of another embodiment of the control unit 40 that controls the above. That is, when the ISDN telephone 4 is off-hooked and the dial operation is performed in step 150, the dial number is checked and step 151
Then, it is judged whether or not this dial number is an extension number. And this dial number is this ISDN telephone 4
If the dial number is the same as that of the ISDN line connected to, and it is determined to be "Y" in step 151, the side tone adjusting section 60 is controlled in steps 152 to 155. These processing controls are shown in FIG. 9 (a) described above.
Since it is the same as the processing control in steps 101 to 104, the description thereof will be omitted. Further, when the operated dial number does not correspond to the extension number and it is determined to be “N” in step 151, the processing control for disabling the side tone control unit 60 shown in step 156 and thereafter is executed.

[0020]

As described above, according to the present invention, the same call signal channel is set for both the calling and called telephones during a one-way extension call.
Even if the other telephone is in the one-way extension call, the other call channel is vacant. In this case, there is an effect that the vacant channel can be used for the outside call and the one-way extension call. Further, since the side tone can be adjusted to an appropriate value when a one-way extension call is made using the same call signal channel, good call characteristics can be obtained.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing another embodiment of the ISDN digital telephone device.

FIG. 3 is a view showing I constituting the above ISDN digital telephone device.
It is a block diagram of an SDN telephone.

FIG. 4 is a connection configuration diagram of the ISDN digital telephone device.

FIG. 5 is a connection configuration diagram of the ISDN digital telephone device.

FIG. 6 is a block diagram of a side tone adjusting circuit in the ISDN telephone.

FIG. 7 is a timing chart of the side tone adjustment circuit.

FIG. 8 is a sequence diagram showing an operation of the ISDN digital telephone device.

FIG. 9 is a flowchart showing the operation of the ISDN telephone.

[Explanation of symbols]

 1, 3 DSU 2 connection device 4 ISDN telephone 10 T point / S point control unit 11 interface circuit unit 12 line termination circuit unit 13 transmission line termination circuit unit 20 CPU 25, 27 I interface circuit 26 B channel switching unit 40 control unit 42 Extension key 44 Operation unit 45 Line I / F unit 46 Analog signal control unit 47 Codec 48 Sidetone adjustment circuit 49 Handset 60 Sidetone adjustment unit 61, 62 Amplifier 63 Sidetone addition circuit T transmitter R receiver

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04Q 5/00 8627-5K

Claims (2)

[Claims] 1. An ISDN digital telephone device comprising a connection device connected to an ISDN network and a plurality of ISDN telephones connected to the connection device, wherein a one-way extension call is made between the plurality of ISDN telephones. An ISDN digital telephone device, characterized in that the connection device is provided with means for setting the same call signal channel in both ISDN telephones. 2. The ISDN digital telephone apparatus according to claim 1, wherein the ISDN telephone is provided with a side tone adjusting means for adjusting a side tone of the ISDN telephone when a one-way extension call is made. Digital telephone device.