JP3469123B2 - Audio transmission apparatus and method and audio band signal transmission system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided between a switchboard and a transmission line, and converts voice band signals into ATM (asynchronous transfer mode) cells and outputs them to the transmission line, or an ATM cell received from the transmission line. The present invention relates to a voice transmission device and method for returning a voice band signal and outputting the voice band signal to an exchange, and a voice band signal transmission system using the same.

[0002]

2. Description of the Related Art When a large-scale network is constructed,
The voice band signal passes through the relay point and is transmitted to the other party. Since it is the exchange that performs voice circuit switching at the relay site, the voice transmission device must decode the cellized voice based on the original and deliver it to the exchange.

However, when the compression encoding / decoding of voice is repeated a plurality of times, the voice quality is deteriorated depending on the number of times,
In addition, there is a disadvantage in that the delay time increases due to processing delay associated with compression encoding / decoding, cell formation, cell disassembly processing delay, and the like.

In order to solve this, for example, an identification signal inserting section for inserting a predetermined identification signal into a voice band signal obtained by cell decomposition and compression decoding and outputting the voice band signal to a switch, and a voice band signal from the switch. An identification signal detection unit that detects that a predetermined identification signal is included, a changeover switch, a cell relay signal generation unit that inserts a cell in the signal band to be output to the exchange, and a cell from the signal received from the exchange. By providing a cell extractor for extracting, by performing cell relay transmission in which cells are transferred in the form of cells without performing compression encoding and decoding of voice in the relay section, no matter how many stages of relay exchange are performed. The compression encoding / decoding is performed only once to prevent deterioration of voice quality and increase of delay time.

[0005]

However, in a network composed of a plurality of voice transmission devices, when the voice transmission device on the transmission side and the voice transmission device on the reception side do not implement the same voice encoding algorithm, The intermediate voice transmission device does not perform compression encoding / decoding of voice as described above, and inserts a cell in the signal band to be output to the exchange,
When the cell is extracted, it is compression-encoded by the voice-transmission device on the transmission side, and the cell that has been made into a cell reaches the voice-transmission device on the reception side as it is, and is compression-decoded by an algorithm different from that used for compression-encoding. Therefore, there is an inconvenience that the sound cannot be reproduced properly.

For this reason, cell relay transmission cannot be used in a network in which voice transmission devices in which different voice compression encoding algorithms are implemented coexist, and the facsimile (FA
Even in a network in which a voice transmission device that demodulates a signal X) into a cell and a voice transmission device that transmits a waveform without demodulating a FAX signal coexist, cell relay transmission cannot be used.

The present invention has been made in order to solve such a conventional problem, and even in a network in which different voice compression coding algorithms and voice transmission devices implementing a FAX transmission system are mixed, voice quality is improved. It is an object of the present invention to provide a voice transmission device and method, and a voice band signal transmission system capable of preventing the deterioration of the signal and the increase of the delay time.

[0008]

In the voice transmission apparatus of the present invention, cell disassembling / decoding means for decomposing a cell received from a transmission path, compressing and decoding the cell and returning it to a voice band signal, and the output signal are predetermined. Identification signal insertion means for inserting a plurality of types of identification signals and outputting to the exchange, cell relay signal generation means for generating a signal in which cells are inserted in the signal band to be output to the exchange, and voice band signals from the exchange. Identification signal detecting means for detecting that a plurality of types of identification signals are included, switching means for switching when the identification signal detecting means detects the same identification signal inserted by the identification signal inserting means, and an exchange. The coding / cell assembling means for compressing and coding the voice band signal obtained from the above into a cell and transmitting it to the transmission line, and the cell extracting means for extracting the cell inserted in the signal band from the exchange. Receiving from the transmission line by switching the identification signal to be inserted by the identification signal inserting means according to the type of the voice transmission device connected via the transmission line and the voice transmission device connected via the exchange. The selected cell is switched between compression and decoding to restore the voice band signal to the voice band signal or transmission of the relay section as a cell without compression and decoding to the voice band signal.

According to the present invention, it is possible to prevent the deterioration of the voice quality and the increase of the delay time even in the network in which the voice transmission devices having the different voice compression encoding algorithms and the FAX transmission system are mixed. A voice transmission device capable of being obtained is obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A voice transmitting apparatus according to claim 1 of the present invention is a cell disassembling / decoding means for disassembling a cell received from a transmission path, compressing and decoding it, and returning it to a voice band signal, and an output signal thereof. Identification signal inserting means for inserting a plurality of types of predetermined identification signals into the switch and outputting to the exchange, cell relay signal generating means for generating a signal in which cells are inserted in the signal band to be output to the switch, and voice band signal from the switch And a switching means for switching when the identification signal detecting means detects the same identification signal inserted by the identification signal inserting means. And a coding / cell assembling means for compressing and coding the voice band signal obtained from the exchange into a cell and assembling it into a transmission line, and a cell extracting means for extracting the cell inserted in the signal band from the exchange. Receiving from the transmission line by switching the identification signal to be inserted by the identification signal inserting means according to the type of the voice transmission device connected via the transmission line and the voice transmission device connected via the exchange. The selected cell is switched between compression and decoding to restore the voice band signal to the voice band signal or transmission of the relay section as a cell without compression and decoding to the voice band signal.

According to the present invention, when the voice transmission devices are connected to each other by the exchange, the identification signal detecting means detects that the signal from the voice transmission device of the relay connection partner includes a predetermined identification signal. If the detected identification signal is the same as the identification signal inserted by the identification signal inserting means, the cell relay signal generating means and the cell extracting means are switched to start the cell relay transmission operation. When a voice transmission device is connected to a telephone, a fax machine, a modem, etc. by an exchange, an identification signal is not detected, and therefore the cell disassembling means and the encoding / cell assembling means are switched to compress and encode the voice.
Decoding, cell assembly, and cell disassembly are performed.

According to a second aspect of the present invention, in the first aspect of the invention, when the voice band signal obtained from the exchange is made into cells without compression encoding and is transparently transmitted, cell relay signal generation is performed. The least significant bit of the band signal is bit stealed by the means to set the control information, and the identification signal inserting means inserts the identification signal to transmit the relay section as a cell.

According to the present invention, the method of inserting a cell is changed according to the voice compression method of the cell to be relayed, and control information indicating the cell insertion position and the compression method is included in the position of the least significant bit (LSB).

In the voice transmission method according to the third aspect, the cell received from the transmission line is decomposed by the cell disassembling means, compression-decoded to restore the voice-band signal, and the voice-band signal obtained by compression-decoding is predetermined. A plurality of types of identification signals are inserted by the identification signal insertion means and output to the exchange, and a signal in which control information indicating cells and cell insertion positions and compression methods is inserted in the signal band to be output to the exchange is generated by the cell relay signal generation means. Generate,
The identification signal detecting means detects that the voice band signal from the exchange contains a plurality of predetermined identification signals,
When the voice band signal obtained from the exchange is compression-encoded, it is assembled into cells by the cell assembling means and transmitted to the transmission line, and when the identification signal detecting means detects the same identification signal as inserted by the identification signal inserting means, the switching means is switched. A cell that is switched and inserted in the signal band from the exchange is extracted by the cell extraction means, and an identification signal is output according to the type of the voice transmission device connected via the transmission line and the voice transmission device connected via the exchange. By switching the identification signal to be inserted by the inserting means, it is determined whether the cell received from the transmission path is compressed and decoded to return to the voice band signal or whether the relay section is transmitted as the cell without compression and decoding to the voice band signal. It is to switch.

According to the present invention, when the voice transmission devices are connected by the exchange, the identification signal detecting means detects that the signal from the voice transmission device of the relay connection partner includes a predetermined identification signal. If the detected identification signal is the same as the identification signal inserted by the identification signal inserting means, the cell relay signal generating means and the cell extracting means are switched to start the cell relay transmission operation. When a voice transmission device is connected to a telephone, a fax machine, a modem, etc. by an exchange, an identification signal is not detected, and therefore the cell disassembling means and the encoding / cell assembling means are switched to compress and encode the voice.
Decoding, cell assembly, and cell disassembly are performed.

According to a fourth aspect of the present invention, in the third aspect of the invention, when the voice band signal obtained from the exchange is made into cells without compression encoding and is transparently transmitted, cell relay signal generation is performed. The least significant bit of the band signal is bit stealed by the means to set the control information, and the identification signal inserting means inserts the identification signal to transmit the relay section as a cell.

According to the present invention, the method of inserting a cell is changed according to the voice compression method of the cell to be relayed, and control information indicating the cell insertion position and the compression method is included in the position of the least significant bit (LSB).

According to a fifth aspect of the present invention, there is provided a voice band signal transmission system comprising a voice transmission device for transmitting a FAX signal in a waveform and a FAX.
It has a network in which voice transmission devices that demodulate and transmit signals are mixed, and the cells received from the transmission path are decomposed by cell decomposition / decoding means and compression-decoded to return to a voice band signal,
A plurality of types of predetermined identification signals are inserted into the voice band signal obtained by compression and decoding by the identification signal inserting means and output to the exchange, and the cell, the cell insertion position and the compression method are shown in the signal band to be output to the exchange. The signal with the control information inserted is generated by the cell relay signal generating means, and the identification signal detecting means detects that the voice band signal from the exchange includes a plurality of predetermined types of identification signals, and the signal is obtained from the exchange. When the voice band signal is compression-encoded, it is assembled into cells by the cell assembling means and transmitted to the transmission line, and when the same identification signal as that inserted by the identification signal inserting means by the identification signal detecting means is detected, the switching means is switched to switch from the exchange. The cell inserted in the signal band of the signal is extracted by the cell extracting means, and the identification signal is output according to the type of the voice transmission device connected via the exchange and the voice transmission device connected via the transmission line. By switching the identification signal to be inserted by the input means, it is possible to compress or decode the cell received from the transmission path and return it to the voice band signal, or to transmit the relay section as a cell without compressing and decoding it into the voice band signal. It has a voice transmission device for switching.

According to the present invention, it is possible to provide a section for cell relay transmission operation even in a network in which a voice transmission device that demodulates a FAX signal to form a cell and a voice transmission device that waveform-transmits a FAX signal coexist. It is possible to reduce the number of times of voice compression encoding and decoding.

A voice band signal transmission system according to a sixth aspect of the present invention has a network in which voice transmission devices in which different algorithms for compressing and encoding a voice signal are mounted are mixed and received from a transmission line. The cell is decomposed by the cell disassembling / encoding means, compression-decoded back to a voice band signal, and a plurality of predetermined identification signals are inserted into the voice band signal obtained by compression decoding by the identification signal inserting means to the exchange. A cell relay signal generation unit generates a signal in which control information indicating a cell and a cell insertion position and a compression method is output in a signal band to be output to the exchange, and a plurality of types of voice band signals from the exchange determined in advance are generated. It is detected that the identification signal is included by the identification signal detecting means, the voice band signal obtained from the exchange is compression-coded, the cell is assembled by the cell assembling means and transmitted to the transmission line, and the identification is performed. When the same signal as the one inserted by the identification signal inserting means is detected by the signal detecting means, the cell extracting means extracts the cell inserted in the signal band from the exchange by switching the switching means, and the cell is inserted through the exchange. By switching the identification signal to be inserted by the identification signal insertion means according to the type of the connected audio transmission device and the type of the audio transmission device connected via the transmission line, the cell received from the transmission line is compressed and decoded to obtain the audio band. It has a voice transmission device that switches between returning to a signal or transmitting a relay section as a cell without compression and decoding into a voice band signal.

According to the present invention, even in a network in which voice transmission devices having different voice compression encoding systems are mixed,
It is possible to provide a section for cell relay transmission operation, and it is possible to reduce the number of times of voice compression encoding and decoding.

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates using FIG.

(Embodiment 1) FIG. 1 is a block diagram showing a schematic configuration of a voice transmission apparatus according to an embodiment of the present invention. In the figure, the sound transmission apparatus 1 exchange interface to the transmission line interface full E over scan portion 10
And a full E over the scan unit 20.

The transmission line interface section 10 transmits / receives cells to / from a transmission line (not shown). The changeover switch 11 uses the cells received from the transmission line for the cell disassembling unit 1.
2 or to the cell relay signal generation unit 13. The cell disassembling unit 12 disassembles the cell received from the transmission path into incidental information and a voice compression signal. Cell relay signal generation unit 13
Generates a cell relay signal by inserting a cell in the signal band to the exchange.

The voice compression / decoding unit 14 has one or a plurality of voice compression systems, and switches the voice compression system according to the contents of the header of the cell to perform compression / decoding. The identification signal insertion unit 15 inserts a plurality of predetermined types of identification signals into the voice band signal output to the exchange. The identification signal information detection unit 16 controls the change of the identification signal to be inserted into the identification signal insertion unit 15 based on the identification signal information received from the transmission line.

The exchange interface full E over scan unit 20 receives the audio band signal from the exchange (not shown), or transmits the voice band signal to the exchange. The identification signal detection unit 21 detects a plurality of types of predetermined identification signals from the received voice band signal. The changeover switch 22 inputs the received voice band signal to either the cell extraction unit 23 or the voice compression encoding unit 24 depending on the detection state of the identification signal.

The cell extraction unit 23 extracts cells inserted in the signal band received from the exchange. The voice compression encoding unit 24 has one or a plurality of voice compression methods and performs compression encoding of a voice signal. The cell assembling unit 25 assembles a cell by dividing a voice compression coded signal into frames and adding a header which is additional information such as a compression method. Identification signal information sending unit 2
Reference numeral 6 identifies the type of the voice transmission device connected through the exchange from the pattern of the identification signal detected by the identification signal detection unit 21, converts the identification signal information into cells, and outputs the cells to the transmission line interface unit 10. First, the operation of this embodiment will be described. First, in the initial state, the changeover switch 1
1 outputs the cell received from the transmission line interface unit 10 to the cell disassembling unit 12, and the changeover switch 22 outputs the voice band signal received from the exchange interface unit 20 to the voice compression encoding unit 24.

When the voice transmission devices 1 are connected to each other by the exchange, the identification signal detection section 21 detects that the signal from the voice transmission device 1 of the relay connection partner includes a predetermined identification signal. If detected identification signal is a same signal as the identification signal is inserted by the identification signal inserting section 15, switching <br/> Ri exchange e to the selector switch 11 cell relay signal generation unit 13 side, the changeover switch 22 is switched to the cell extraction unit 23 side to start the cell relay transmission operation.

Similarly, the voice transmission device 1 of the relay connection partner
Also enters the cell relay transmission operation. In the cell relay transmission operation, the cell relay signal generation unit 13 generates a cell relay signal by inserting the cell received from the transmission line into a part of the 64 kbit / s band to the exchange, and the identification signal insertion unit 15 inserts the identification signal. After that, output to the exchange side.

On the contrary, a cell embedded in the 64 kbit / s band is extracted by the cell extracting unit 23 from the signal received from the voice transmission device 1 of the relay connection partner via the exchange and is output to the transmission path side. While the relay connection is being made, the identification signal detecting section 21 is constantly detecting the identification signal, and the cell relay transmission operation is maintained.

After the call, the voice transmission device 1 is switched by the exchange.
Since the connection between them is cut off, the identification signal is not detected by the identification signal detection unit 21, and the changeover switch 11 is changed over to the original cell decomposition unit 12 side and the changeover switch 22 is changed over to the voice compression encoding unit 24 side.

Further, when the voice transmission device 1 is connected to the telephone, the FAX, and the modem by the exchange, the identification signal is not detected.
On the side, the changeover switch 22 is set to the side of the voice compression encoding unit 24, so that voice compression encoding, decoding, cell assembly, and cell disassembly are performed.

When cell transmission is performed using a plurality of audio compression methods according to the usage status of the transmission path and the type of signal to be transmitted,
Depending on the compression method of the cell received from the transmission line side during the cell relay transmission, the ratio of the cell to be inserted into the 64 kbit / s band output to the exchange side and the insertion position change.

The voice compression method is recognized from the header area of the cell having the information about the voice compression method, and the cell relay signal generation unit 13 changes the cell insertion method. The cell relay signal generation unit 13 inserts control information indicating the insertion position of the inserted cell and the compression method. Further, the cell extraction unit recognizes the cell insertion position and the compression method from the control information inserted in the 64 kbit / s band from the signal from the exchange, and extracts the inserted cell accordingly.

FIG. 2 shows a signal example of the cell relay signal. The method of inserting a cell in the 64 kbit / s band is changed according to the voice compression method of the cell to be relayed. Least significant bit (LS
The position B) includes control information indicating a cell insertion position and a compression method. The LSB always contains an identification signal.

(Embodiment 2) FIG. 3 shows a voice transmission device 1.
3 is a configuration diagram showing an example of a network including a plurality of voice transmission devices 1A to 1F having the same configuration as FIG. In the figure, voice transmission devices 1A, 1B, 1E, and 1F are voice transmission devices that demodulate FAX signals to form cells, and the voice transmission device 1
It is assumed that C and 1D are voice transmission devices that compress and code FAX signals, form cells, and transmit waveforms.

The voice transmission devices 1A and 1B are connected by a transmission line 2A, the voice transmission devices 1C and 1D are connected by a transmission line 2B, and the voice transmission devices 1E and 1F are connected by a transmission line 2C.

The voice transmission device 1A is connected to the exchange 3A, the voice transmission devices 1B and 1C are connected via the exchange 3B, the voice transmission devices 1D and 1E are connected via the exchange 3C, and the voice transmission device 1F. Is connected to the exchange 3D. The exchange 3A has a telephone terminal 4A and a FAX terminal 5
A is connected, and a telephone terminal 4B and a FAX terminal 5B are connected to the exchange 3D.

In the initial state, the voice transmission devices 1A, 1B,
1E and 1F insert an identification signal (identification signal A) for a voice transmission device that demodulates the FAX signal into cells and uses the identification signal insertion unit 15 to insert the identification signal into the voice transmission devices 1C and 1D. Identification signal for voice transmission device (identification signal B
Is inserted by the identification signal insertion unit 15. Identification signal A
And the identification signal B are different identification signals.

The voice transmission devices 1B and 1C are exchanged by the exchange 3B.
Are connected, and the voice transmission devices 1D and 1E are connected by the exchange 3C.
, The voice transmission devices 1C and 1D receive the identification signal A output from the voice transmission devices 1B and 1E via the exchange.

Audio transmission device 1C which receives the identification signal A
Sends the identification signal information of the identification signal A into cells and sends it to the voice transmission device 1D. Similarly, the voice transmission device 1D that has received the identification signal A converts the identification signal information of the identification signal A into cells and sends the cells to the voice transmission device 1C. Upon receiving the cells of the identification signal information of the identification signal A, the voice transmission devices 1C and 1D switch the identification signal inserted by the identification signal insertion section 15 from the identification signal B to the identification signal A under the control of the identification signal information detection section 16.

In both the voice transmission devices 1B and 1C, the identification signal detecting section 21 detects the identification signal A which is the same identification signal as that inserted by the identification signal inserting section 15, and the changeover switch 1
By switching between 1 and 22, the cell relay transmission operation is started.

During the cell relay transmission operation, the voice transmission device 1A
The FAX signal demodulated in step S1 and sent to the cell directly arrives at the voice transmission device 1F, is re-modulated by the voice transmission device 1F, and is output to the terminal FAX 5B to realize the FAX transmission.

Next, in the network having the configuration shown in FIG. 3, the voice transmission devices 1A and 1B are voice transmission devices that demodulate a FAX signal to form cells, and the voice transmission devices 1C to 1F are F.
It is assumed that the audio transmission device compresses and encodes the AX signal and transmits the waveform.

In the initial state, in the voice transmission devices 1A and 1B, the identification signal insertion section 15 inserts the identification signal (identification signal A) for the voice transmission device that demodulates and transmits the FAX signal, and the voice transmission devices 1C to 1F. Is an identification signal insertion unit 1 for identifying an identification signal (identification signal B) for a voice transmission device that waveform-transmits a FAX signal.
5 inserts. The identification signal A and the identification signal B are different identification signals.

The voice transmission devices 1B and 1C are exchanged by the exchange 3B.
Are connected, and the voice transmission devices 1D and 1E are connected by the exchange 3C.
When the audio transmission device 1C is connected to the audio transmission device 1C,
The identification signal A output by B is received via the exchange, and the identification signal information of the identification signal A is notified to the voice transmission device 1D. Similarly, the voice transmission device 1D receives the identification signal B output by the voice transmission device 1E via the exchange, and notifies the voice transmission device 1C of the identification signal information of the identification signal B.

The audio transmission device 1C, since the identification signal received from the identification signal information and audio transmission device 1B which has received from the audio transmission device 1D is different, without the example replacement off the identification signal to be inserted by the identification signal inserting section 15 , And continues to insert the identification signal B. In the voice transmission devices 1B and 1C, the identification signal inserted by the identification signal insertion unit 15 and the identification signal received via the exchange do not match, so that the cell relay transmission operation is not started.

When performing FAX transmission, the voice transmission device 1
The FAX signal demodulated by A and made into a cell is the voice transmission device 1
It is re-modulated by B and input to the voice transmission device 1C via the exchange 3B. The FAX signal input to the voice transmission device 1C is compression-encoded and cellized. Audio transmission device 1D and 1
Since E is a cell relay transmission operation, the cells made into cells by the voice transmission device 1C arrive at the voice transmission device 1F as they are, and the FAX signals are waveform-transmitted between the voice transmission devices 1C to 1F. As a result, FAX transmission is realized.

By using the voice transmission device and method thus configured, cell relay is performed even in a network in which a voice transmission device that demodulates a FAX signal to form a cell and a voice transmission device that waveform-transmits the FAX signal coexist. It is possible to provide a section for transmission operation, and it is possible to reduce the number of times of voice compression encoding and decoding.

(Embodiment 3) Further, in a network in which voice transmission devices having different voice compression coding algorithms are mixed, cell relay transmission can be performed by switching identification signals. The embodiment will be described below.

In the network having the configuration shown in FIG. 3, the voice transmission devices 1A, 1B, 1E and 1F are voice transmission devices that encode voice by a certain voice compression coding system (compression coding system A). 1C and 1D are different from the compression coding method A in audio compression coding method (compression coding method B)
It is assumed that this is a voice transmission device that encodes voice.

In the initial state, the voice transmission devices 1A, 1B,
1E and 1F are identification signal insertion units 1 for identifying signals (referred to as identification signals A) for a voice transmission device that implements the compression encoding method A.
5 is inserted, and in the voice transmission devices 1C and 1D, the identification signal insertion unit 15 inserts the identification signal for the voice transmission device in which the compression coding method B is mounted (referred to as identification signal B). The identification signal A and the identification signal B are different identification signals.

The voice transmission devices 1B and 1C are exchanged by the exchange 3B.
Are connected, and the voice transmission devices 1D and 1E are connected by the exchange 3C.
, The voice transmission devices 1C and 1D receive the identification signal A output from the voice transmission devices 1B and 1E via the exchange. The voice transmission device 1C that has received the identification signal A converts the identification signal information of the identification signal A into cells, and outputs the voice transmission device 1D.
Send to.

Similarly, the voice transmission device 1D which has received the identification signal A converts the identification signal information of the identification signal A into cells and sends it to the voice transmission device 1C. Upon receiving the cells of the identification signal information of the identification signal A, the voice transmission devices 1C and 1D switch the identification signal inserted by the identification signal insertion section 15 from the identification signal B to the identification signal A under the control of the identification signal information detection section 16.

In both the voice transmission devices 1B and 1C, the identification signal detecting section 21 detects the identification signal A which is the same identification signal as that inserted by the identification signal inserting section 15, and the changeover switch 1
By switching between 1 and 22, the cell relay transmission operation is started.

During the cell relay transmission operation, the voice transmission device 1A
The voice signal compression-encoded and cellized in (1) arrives at the voice transmission device 1F as it is, is compression-decoded by the voice transmission device 1F, and is output to the telephone terminal 4B to realize voice transmission.

In the network having the configuration shown in FIG. 3, the voice transmission devices 1A and 1B are voice transmission devices that encode voice by a certain voice compression coding system (compression coding system A). Is a voice transmission device that encodes voice by a voice compression encoding system (compression encoding system B) different from the compression encoding system A.

In the initial state, in the voice transmission devices 1A and 1B, the identification signal insertion section 15 inserts the identification signal (identification signal A) for the voice transmission device in which the compression coding method A is mounted, and the voice transmission devices 1C to 1F. Is an identification signal insertion unit 1 for identifying an identification signal (identification signal B) for a voice transmission device that implements the compression coding method B.
5 inserts. The identification signal A and the identification signal B are different identification signals.

The voice transmission devices 1B and 1C are exchanged by the exchange 3B.
Are connected, and the voice transmission devices 1D and 1E are connected by the exchange 3C.
When the audio transmission device 1C is connected to the audio transmission device 1C,
The identification signal A output by B is received via the exchange, and the identification signal information of the identification signal A is notified to the voice transmission device 1D.

Similarly, the voice transmission device 1D receives the identification signal B output by the voice transmission device 1E via the exchange and notifies the voice transmission device 1C of the identification signal information of the identification signal B.
In the voice transmission device 1C, the identification signal information received from the voice transmission device 1D and the identification signal received from the voice transmission device 1B are different, so that the identification signal inserted by the identification signal insertion unit 15 is not switched and the identification signal B is transmitted. Continue to insert.

In the voice transmission devices 1B and 1C, the identification signal inserted by the identification signal insertion unit 15 and the identification signal received via the exchange do not match, so that the cell relay transmission operation is not started. In the case of voice transmission, the voice transmission device 1A compression-encodes using the compression encoding method A, and the cellized voice signal is compression-decoded by the voice transmission device 1B, and transmitted to the voice transmission device 1C via the exchange 3B. Is entered.

The audio signal input to the audio transmission device 1C is compression-encoded and cellized using the compression-encoding method B. Since the voice transmission devices 1D and 1E are in the cell relay transmission operation, the cells converted into cells by the voice transmission device 1C are
The voice transmission is realized by arriving at the voice transmission device 1F as it is and compressed and decoded by the voice transmission device 1F.

[0063]

As described above, by using the voice transmitting apparatus and method of the present invention, the voice transmitting apparatus that demodulates the FAX signal to form cells and the voice transmitting apparatus that waveform-transmits the FAX signal coexist. In some cases, even in a network in which voice transmission devices that implement different voice compression encoding algorithms are mixed, by identifying a relay section in which cell relay transmission in which ATM cells are directly transferred without being decoded is identified, An advantageous effect that the number of times of voice compression encoding and decoding can be reduced and voice quality deterioration and delay time increase can be prevented can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a voice transmission device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of signals to be relayed and transmitted in the present invention.

FIG. 3 is a block diagram showing a network configuration example of a voice band transmission system according to an embodiment of the present invention.

[Explanation of symbols]

1, 1A-1F voice transmission device 2A to 2C transmission line 3A-3D switch 4A, 4B telephone terminals 5A, 5B FAX terminal 10 Transmission line interface 11 Changeover switch 12 Cell disassembly section 13 Cell relay signal generator 14 Audio compression / decoding unit 15 Identification signal insertion section 16 Identification signal information detector 20 Switch interface section 21 Identification signal detector 22 Changeover switch 23 Cell extractor 24 Speech compression coding unit 25 Cell assembly department 26 Identification signal information sending unit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-10-23573 (JP, A) JP-A-9-261239 (JP, A) JP-A-9-55753 (JP, A) JP-A-9- 98169 (JP, A) JP-A-9-284816 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 11/04 H04L 12/28 H04L 12/56 H04M 3/00

Claims (6)

(57) [Claims] 1. A cell disassembling / decoding means for disassembling a cell received from a transmission line, compressing and decoding it, and returning it to a voice band signal, and inserting a plurality of predetermined identification signals into this output signal and outputting it to a switch. Identification signal insertion means, cell relay signal generation means for generating a signal in which cells are inserted in the signal band to be output to the exchange, and voice band signals from the exchange include a plurality of types of predetermined identification signals. Identification signal detecting means for detecting that, the switching means for switching when the same identification signal as the one inserted by the identification signal inserting means is detected by the identification signal detecting means, and the voice band signal obtained from the exchange is compressed. Coding and cell assembling means for assembling and transmitting to the transmission line, and cell extracting means for extracting cells inserted in the signal band from the exchange, Received from the transmission line by switching the identification signal to be inserted by the identification signal inserting means according to the type of the voice transmission device connected via the transmission line and the voice transmission device connected via the exchange. A voice transmission device, which switches between compressing and decoding a cell to return to a voice band signal or transmitting the relay section as a cell without compressing and decoding the voice band signal. 2. When the voice band signal obtained from the exchange is made into cells without compression coding and transmitted transparently, the cell relay signal generating means bit steals the least significant bit of the band signal to obtain control information. 2. The voice transmission device according to claim 1, wherein the relay section is transmitted as a cell by setting and inserting the identification signal by the identification signal inserting means. 3. A cell receiving means for decomposing cells received from a transmission line by means of cell decomposing means, compressing and decoding them back into a voice band signal, and identifying a plurality of types of identification signals predetermined in the voice band signal obtained by the compression decoding. The signal is inserted by the inserting means and output to the exchange, and the cell relay signal generating means generates a signal in which the control information indicating the cell and the cell insertion position and the compression method is inserted in the signal band to be output to the exchange, and the voice from the exchange It is detected by the identification signal detecting means that the band signal includes a plurality of types of predetermined identification signals, the voice band signal obtained from the exchange is compression-coded, assembled into cells by the cell assembling means, and transmitted to the transmission line. When the identification signal detecting means detects the same identification signal as that inserted by the identification signal inserting means, the switching means is switched to insert a signal in the signal band from the exchange. By the cell extracting means, and switching the identification signal to be inserted by the identification signal inserting means according to the type of the voice transmission apparatus connected via the transmission line and the voice transmission apparatus connected via the exchange. According to the method, the cell received from the transmission path is compressed and decoded to return to a voice band signal, or the relay section is transmitted as a cell without compression and decoding into a voice band signal. . 4. When the voice band signal obtained from the exchange is made into cells without compression coding and transmitted transparently, the cell relay signal generating means bit steals the least significant bit of the band signal to obtain control information. 4. The voice transmission method according to claim 3, wherein the relay section is transmitted as a cell by setting and inserting the identification signal by the identification signal inserting means. 5. A network having a voice transmission device for transmitting a FAX signal in a waveform and a voice transmission device for demodulating and transmitting the FAX signal mixedly, wherein a cell received from a transmission line is decomposed by a cell disassembly / decoding means. Then, the signal is compressed and decoded to return to the voice band signal, and a plurality of types of predetermined identification signals are inserted into the voice band signal obtained by the compression and decoding by the identification signal inserting means and output to the exchange, and the signal to be output to the exchange. A cell relay signal generating unit generates a signal in which control information indicating a cell and a cell insertion position and a compression method is generated in the band, and the voice band signal from the exchange includes a plurality of predetermined identification signals. Is detected by the identification signal detecting means, the voice band signal obtained from the exchange is compression-encoded, assembled into cells by the cell assembling means and transmitted to the transmission line, and the identification signal detecting means performs the identification. When the same identification signal as that inserted by another signal insertion means is detected, the switching means is switched to extract the cell inserted in the signal band from the exchange by the cell extraction means, and the cell is connected via the exchange. By switching the identification signal to be inserted by the identification signal inserting means according to the type of the audio transmission device connected to the audio transmission device via the transmission line, the cell received from the transmission line is compression-decoded and voiced. A voice band signal transmission system having a voice transmission device for switching between returning to a band signal or transmitting a relay section as a cell without compression / decoding to a voice band signal. 6. A network having a mixture of voice transmission devices in which different algorithms for compressing and encoding a voice signal are implemented, wherein a cell received from a transmission line is decomposed by a cell decomposition / encoding means. A signal band that is compressed and decoded to return to a voice band signal, and that a plurality of types of predetermined identification signals are inserted into the voice band signal obtained by the compression and decoding by the identification signal insertion means and output to the exchange, and output to the exchange. A cell relay signal generation unit generates a signal in which control information indicating a cell and a cell insertion position and a compression method is generated, and the voice band signal from the exchange includes a plurality of predetermined identification signals. Is detected by the identification signal detecting means, the voice band signal obtained from the exchange is compression-encoded, is assembled into cells by the cell assembling means, and is transmitted to the transmission line. When the same identification signal as that inserted by another signal inserting means is detected, the switching means is switched to extract the cell inserted in the signal band from the exchange by the cell extracting means, and the cell is connected through the exchange. By switching the identification signal to be inserted by the identification signal inserting means according to the type of the audio transmission device connected to the audio transmission device via the transmission line, the cell received from the transmission line is compression-decoded and voiced. A voice band signal transmission system having a voice transmission device for switching between returning to a band signal or transmitting a relay section as a cell without compression / decoding to a voice band signal.