JPS62154897A - Digital network equipment - Google Patents

Abstract

PURPOSE:To prevent the reduction of sound quality and to reduce a delay time by providing a selection control means for driving a branch means in case of judging by an identifying means that a destination station of a control signal is private branch exchange connected to a repeater, and in other cases, driving the repeating means. CONSTITUTION:A control part 410 is constituted of a microprocessor 411 for judging repeating and branching and a memory 412 storing the station number of a PBX. A destination dial number is recognized from a dial signal transmitted from a multiplexing circuit by a dial signal decomposing/composing circuit 211 and the number is transmitted to the microprocessor 411. The microprocessor 411 compares the number with own station number stored in the memory 412, and when both the values coincide with each other, outputs the same destination dial number to a dial signal decomposing/composing circuit 312 through an I/O port 311. When the destination dial number is different from own station number, idle channel 2n0 out of a multiplexing device interface part is selected to send the destination dial number to the succeeding multiplexing device through a control signal transmitter 8n2.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a digital network device using a multiplexing device and a private branch exchange for a digital transmission line, and in particular, to a digital network device using a multiplexing device and a private branch exchange for a digital transmission path, and in particular, a digital network device that uses a relay device between the multiplexing device and the private branch exchange. The present invention relates to a digital network device.

[Technical Background of the Invention 1 Conventionally, a digital network device in which a private branch exchange (PBX) is connected to a digital line uses a multiplexer and a digital line to connect the trunk lines of the PBX with a relay function to a point, as shown in Fig. 3.・It is structured to connect at two points.

In this digital network device, for example, when a call is made from the telephone terminal 11 (dial number @411-2341) to the telephone terminal 12 (dial number 111-1584), the PBX 21 connects the trunk line 31, the multiplexer 41, and the digital line. 51, the multiplexer 42, and the trunk line 32, the dial number is transmitted to the PBX 22.

Next, the dialed number is checked in the PBX 22, and if it is recognized that it is not the dialed number of the telephone terminal connected to the own station, the signal coming from the trunk line 32 is further multiplexed to the trunk line 33 using the relay switching function. device 42
, digital line 52, multiplexer 43, trunk line 3
4 and is transmitted to PBX23.

This call request is roughly transmitted to the PBX 24 by the PBX 23 under the same control as the PBX 22, and when the PBX 24 recognizes that the own number and the received destination number are the same, the call request is transmitted to the telephone terminal within the own office. Connected.

Through this series of operations, the connection operation from one telephone terminal to another is completed. When disconnected, the connection is canceled again under the control of the PBX using the same route.

[Problems with the Background Art] However, in such digital network devices, relay operations are performed via a PBX with a relay function, so that the audio signal of the PBX is processed by a multiplexer at, for example, 32 kbp.
s ADPCM code and when the multiplexer and PBX are connected via an analog signal interface, analog, digital (32 kbps
), analog conversion is required each time the signal is relayed between PBXs, and the problem often arises that the sound quality and transmission quality deteriorates when passing through multiple links.

Furthermore, when the compression method is a 16kbps APC method, there is a problem that a relatively large delay time is involved during encoding and decoding, and that repeating this encoding and decoding increases the total delay time. Ta.

[Object of the Invention] This invention was made in response to the above-mentioned circumstances, and it is an object of the present invention to provide a digital network device with less deterioration in sound quality and reduced delay time.

[Summary of the Invention] The present invention connects a plurality of multiplexing devices that digitally compress and multiplex voice signals and control signals from a private branch exchange via a digital transmission path, and transmits compressed digital signals and control signals. In the digital network device, a relay device is connected between the private branch exchange and the multiplexer, and a destination station number in a control signal sent from the multiplexer to the relay device is connected to the relay device. Identification means for identifying whether the office number is a private branch exchange; and branching means for transmitting a control signal to a private branch exchange connected to the relay device, decoding the compressed digital signal, and transmitting the compressed digital signal.
a relay means for relaying the control signal and the compressed digital signal to a multiplexer connected adjacently in the transmission direction; and a relay means for determining, by the identification means, that a destination station of the control signal is a station of a private branch exchange connected to the relay apparatus. By providing a selection control means for activating the branching means when the situation occurs, and activating the relay means for the other cases, deterioration in voice quality is prevented and delay time is reduced.

[Embodiments of the invention] Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a system diagram showing one embodiment of the present invention.

This digital network device includes PBXs 101 to 104 to which telephone terminals are connected, and PBXs 101 to 104 connected to telephone terminals.
11 to 114, and relay adapters 121 and 122 respectively provided between the multiplexer and the PBX.
, the digital line 131.132.133 that transmits digital signals between the multiplexing bag @, the connecting cables 141 to 144 that connect the multiplexing device and the relay adapter, and the multiplexing device, the relay adapter, and the PBX. It is composed of trunk lines 151 to 156.

Next, the operation of this digital network device will be described using as an example a case where a call is made from the telephone terminal 13 (dial number @411-2322) to the telephone terminal 14 (dial number 211-3303>).

First, when a call is made from the telephone terminal 13, a connection request is made to the PBX
104, the trunk line 156, the multiplexer 114, and the digital line 133 to the multiplexer 113, and then the connecting cable 144 to the relay adapter 122.

Next, the relay adapter 122 sends the destination dial number "211"
Since the call is different from the station number "311" of the directly connected PBX 103, the call is not connected to the PBX I03 and is returned to the other channel of the trunk line 143.

This returned connection request is transmitted to the relay adapter 121 via the multiplexer @ 113, the digital line 132, the multiplexer 112, and the connection cable 142. Since the destination dial number "'211" matches the office number of the directly connected PBX 102, this relay adapter accepts the call as
The PBX 102 selects the telephone terminal 14 and the connection is completed.

In the case of ending a call, for example, if the telephone terminal 13 disconnects, a disconnection instruction is sent from the PBX 104 to the trunk line 15.
6. The data is transmitted to the relay adapter 122 via the multiplexer 114, digital line 133, multiplexer 113, and connection cable 144.

Since this relay adapter 122 puts the channel in a relay state, this instruction is transmitted via the connection cable 143, multiplexer 113, digital line 132, multiplexer 112, and connection cable 142 while releasing the internal relay connection. and transmits it to the relay adapter.

The relay adapter 121 then branches that channel, but releases it and notifies the PBX 102 of the disconnection via the trunk line 153, and the PBX 102 disconnects (recovers) the telephone terminal 14, completing the series of operations. do.

In this embodiment, the audio signal is transmitted to the PBX 102 using PCM.
It is digitized and returned to -H analog on the trunk line 156, but after being converted into a digital compressed signal by the multiplexer 114, it is transmitted as the compressed digital signal until it is decoded by the relay adapter 121.

FIG. 3 is a block diagram of the structure of the relay adapter of this embodiment.

This relay adapter includes multiplexer interface sections 210 to 2nO that form an interface between a multiplexer and this relay adapter, PBX interface sections 310 to 3nO that form an interface between a PBX and this relay adapter, and each of these interfaces. a control section 410 for controlling the control section 410, a control bus 510 for transmitting control data from the control section 410, a relay exchange section 610 for relaying compressed data, and a time division multiplex bus 710 for exchanging this relay data. The main part is composed of:

Roughly speaking, the multiplexer interface units 210 to 2nO have dial signal decomposition and synthesis circuits 211 to 2n1 provided between the multiplexer and I10 ports 212 to 2n2 in which data for decomposition and synthesis are stored, and digital Branch relay control gates 213 to 2n3 that switch branching and relaying of signals
．． 214 to 2n4, and the dial signal decomposition and synthesis circuits 211 to 2n1 include control signal reception lines 811 to 8n1 that receive control signals from the multiplexer, and control signal transmission lines that transmit control signals to the multiplexer. 812-8n2 are connected, branch relay control gate 213-2n3.21
Compressed digital signal receiving lines 911 to 9n1 for receiving compressed digital signals from the multiplexer and compressed digital signal transmitting lines 912 to 9n2 for transmitting compressed digital signals to the multiplexer are connected to 4 to 2n4. .

Further, the control unit 410 includes a microprocessor 411 that determines whether to relay or branch, and a memory 412 that stores the station number of the PBX directly connected to this relay adapter.

Roughly speaking, the relay exchange unit 610 is composed of an I10 port 611 in which data from the control bus 510 is stored, and a time switch 612 for time division, and a time division multiplex bus 71.
A digital signal is relayed through 0.

The PBX interface units 310 to 3nO also have an I10 interface for transmitting and receiving control data to and from the control bus 510.
dial signal decomposition and synthesis circuits 312 to 3n in which dial signals are decomposed and combined between the ports 311 to 3n1 and the PBX;
2, and analog-to-digital conversion circuits 313 to 3n3 that convert compressed digital audio signals and analog audio signals, and dial signal decomposition and synthesis circuits 312 to 3n.
2 is a control signal connection line 1 for sending and receiving control signals with the PBX.
011~10n1.1012~10n2 are connected, and analog audio connection line 111 for transmitting and receiving analog audio signals with the PBX is connected to the analog digital conversion circuit 313~3n3.
1 to 11n1.1112 to 11n2 are connected.

Next, the operation of this relay adapter will be explained.

First, a dial signal transmitted from the multiplexing device via, for example, a control signal receiving line 811 is recognized as a destination dial number by a dial signal decomposition/synthesis circuit 211, and sent to a microprocessor 411 via an I10 port 212 and a control bus 510. transmitted to.

This microprocessor 411 compares the own station number in the memory 412 and if it matches, the I10 port 31
1, the same destination dial number is output to the dial signal decomposition/synthesis circuit 312, where it is roughly converted into an analog signal for the PBX, and transmitted to the PBX via the control signal connection line.

At the same time, the microprocessor 411
2, the branch relay control gates 213 and 214 are controlled so that the compressed digital signal transmitted from the multiplexer through the compressed digital signal receiving line 911 is transmitted to the analog-to-digital conversion circuit 313 of the PBX interface section. The signal decoded into an analog signal by this analog-to-digital conversion circuit 313 is transferred to the analog audio connection line 111.
1 to the PBX.

The analog signal from the PBX is transmitted from the analog audio connection line 1112 to the analog-to-digital conversion circuit 313, where it is encoded into a compressed digital signal and multiplexed via the branch relay control gate 214. information is sent to the conversion device.

If the destination dial number is different from the own number, the microprocessor 411 selects the free channel 2nO of the multiplexer interface unit in the relay direction, and connects the control bus 510 to the control bus 510 via the I10 port 2n2.
The received dial number is generated by the dial signal decomposition/synthesis circuit 2n1, and transmitted to the next multiplexer via the control signal transmission line 8n2.

At the same time, I1 of the PBX interface section 310.3nO
0 port 311.3 ml 1 outputs a signal (7), and the busy signal is transmitted to the PBX via the dial signal decomposition and synthesis circuit 312.3n2.

Rani microprocessor 411 has I10 port 21
Branch relay control gate 213 for each 2.2n2
．． 214.2n3.2n4 is instructed to switch to the relay side, and a compressed digital audio signal is output to the time division multiplex bus 710. The timings at which signals are output from the branch relay control gate 213 and the branch relay control gate 2n3 are different, and the output of the branch relay control gate 213 and the input of the branch relay control gate 214, and the output of the branch relay control gate 2n3 and the branch relay control gate The inputs of 2n4 are at the same timing.

Note that the time switch 612 is used in a normal exchange, and the microprocessor 411 is connected to the I10 port 61.
channel 210 between time division multiplexed buses 710 through 1
and instructs the exchange of signals on channel 2nO.

Through the above operations, the control signal is transmitted from the control signal receiving line 811 to the control signal transmitting line 8n2, and from the control signal receiving line 8n1 to the control signal transmitting line 812, and the compressed digital audio signal is transmitted from the compressed digital signal receiving line 911 to the compressed digital signal. The compressed digital signal can be transmitted from the compressed digital signal receiving line 9n1 to the compressed digital signal receiving line 912 to the receiving line 9n2.

On the other hand, when a disconnection signal is received from the control signal receiving line 811, for example, the microprocessor 411
This is recognized, and if branching is currently in progress, a disconnection instruction is issued to the I10 port 212 of the PBX interface unit 210, and a disconnection signal is sent to the PBX. Further, multiple other device interface section 210. PBX
Interface section 310. Then, the internal table in the memory of the control unit 410 for that vote is cleared.

Currently, for example, channel 210, channel 2nO
If relaying is in progress via , search I10 port 2n2 of relay channel 2n○ from the internal table of memory 412
A disconnection instruction is issued to the I10 port 2r12 and the disconnection signal is relayed, and then the multiplexer interface unit 210, 2no and the PBX interface unit 31
A reset of 0.3 nO and clearing of the time switch 612 and the table in the memory 412 are performed.

With the above steps, the process at the end of the call is completed.

Also, when a call is received from the PBX to which the relay adapter is connected, for example, via the control signal connection line 1012, the microprocessor 411 makes the call in the opposite direction from when there is a connection request from the control signal reception line 811. I10
Instruct ports 1 to 212 to connect, and branch relay control gate 2
13. PBX interface section 31 by controlling 214
0 is transmitted to the multiplexer interface section 210.

Note that when the multiplexer interface section 210 is being used as a relay, the busy state has already been transmitted from the control signal connection line 10]1 as described above, so a connection request is sent from the control signal connection line 1012. will never be done.

[Effects of the Invention] As explained above, the present invention provides a relay device between the multiplexing device and the local communication equipment, thereby eliminating the need to repeat digital-to-analog conversion, encoding, and decoding of voice and data signals. Therefore, communication with good transmission quality can be realized, and even if the delay time becomes significant due to complicated compression encoding, this delay time can be minimized.

By simply adding this relay device to a private branch exchange or multiplexing device that does not have a relay function, a large-scale digital network device with a relay function can be constructed.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a digital network device that is an embodiment of the present invention, Fig. 2 is a configuration block diagram of a relay adapter of the same embodiment, and Fig. 3 is a digital network using a conventional private branch exchange with a relay function. FIG. 2 is a system diagram of the device. 101-104...Private branch exchange (PBX)
>111-114...Multiplexer 121
．． 122......Relay adapter 131-13
3...Digital line 210~2nO...
...Multiplexer interface unit 310 to 3nO...PBX interface section 410...
...Control Department Applicant Toshiba Corporation Agent Patent Attorney Sasa Suyama - +11-1514 111-1274 211-3
750 311-4103 411-2341
1st mouth

Claims (1)

[Claims] (1) In a digital network device that connects a plurality of multiplexing devices that digitally compress and multiplex voice signals and control signals from a private branch exchange via a digital transmission path to transmit compressed digital signals and control signals, A relay device is connected between the exchange and the multiplexer, and whether the destination station number in the control signal sent from the multiplexer to this relay device is the station number of the private branch exchange connected to this relay device. an identification means for identifying the relay device, a branching means for transmitting a control signal to a private branch exchange connected to the relay device, decoding the compressed digital signal, and then transmitting the compressed digital signal; a relay means for relaying the signal and the compressed digital signal; and when the identification means determines that the destination station of the control signal is a station of a private branch exchange connected to the relay device, actuating the branching means;
A digital network device comprising: selection control means for operating the relay means when the relay means is not selected.