JPH09331330A - Voice compression cell processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice cell processing system in which entire congestion of an ATM communication network is avoided and sound quality deterioration is not caused through useless compression of a voice signal. SOLUTION: A network monitor circuit 11 in this voice compression cell processing system monitors congestion state information and voice connection path information in an ATM communication network 18 via an ATM interface circuit 15, and a control circuit 10 controls a silence detection threshold level in a silence detection circuit 12 based on the congestion state information and voice connection path information. The silence detection circuit 12 applies silence detection of the voice signal according to the silence detection threshold level set by the control circuit 10, a voice coding circuit 13 encodes the voice signal. A silence compression cell assembly circuit 14 applies cell processing only to the voice part of the coded signal coded by the voice coding circuit 13 and sends the cell processing signal to the ATM communication network 18 via the ATM interface circuit 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a voice compression cellizing system for accommodating a voice signal which is silently compressed in an ATM communication network.

[0002]

2. Description of the Related Art Conventionally, as a technique related to this type of voice cell conversion system, for example, there is a voice encoder disclosed in Japanese Patent Laid-Open No. 5-244104.

In this speech coder, in order to measure the application to the ATM communication network, the application range of silence compression is limited and the redundancy of the speech signal is suppressed to maintain the naturalness of the speech signal.

FIG. 5 is a block diagram showing the basic configuration of this speech coder. The speech coder here includes a signal compressor 301 that compresses and encodes an input signal from a telephone and outputs a coded signal, and a code compressor that inputs the coded signal and assembles cells to generate a cellized signal. Output cell assembler 302
And a transmission buffer 303 that temporarily stores a plurality of cells assembled in the cellized signal and sends them to the line as an output signal, and a detection signal indicating the result of detecting the cell storage amount in the transmission buffer 303 based on the output signal. The detector 304 for outputting the signal is compared with the cell storage amount based on the detection signal and the signal compressor 301 is controlled so as to increase the degree of signal compression when the cell storage amount is larger than the predetermined value. And a comparator 305 that outputs a control signal for

That is, regarding the operation of this speech encoder, first, the signal compressor 301 compresses and encodes the input signal from the telephone and outputs the encoded signal. Next, the cell assembler 302 inputs the coded signal from the signal compressor 301, assembles cells and outputs a cellized signal. Subsequently, the transmission buffer 303 receives the cellization signal, temporarily stores the assembled cells, and sequentially outputs the cells to the line as output signals.

On the other hand, the detector 304 inputs the output signal to detect the cell storage amount of the transmission buffer 303 and outputs the detection signal, and the comparator 305 inputs the detection signal to set the cell storage amount and a predetermined threshold value. As a result of comparison, as a result, when the cell storage amount is larger than a predetermined threshold value, a control signal for controlling the signal compressor 301 so as to increase the degree of signal compression is output.

Therefore, in this speech coder, when the cell storage amount of the transmission buffer 303 is smaller than a predetermined threshold value, the degree of signal compression is suppressed, so that the quality of the transmission signal is improved.

[0008]

In the case of the above-mentioned speech coder, since the degree of compression of the speech signal is controlled based on the absolute value of the cell storage amount in the transmission buffer of its own circuit, the output signal is There is a problem that it is not possible to perform control corresponding to the congestion state of the ATM lines other than the ATM line in which the own circuit is accommodated, in the voice path passing unit in the ATM communication network to be transmitted.

The present invention has been made in order to solve such a problem, and its technical problem is to avoid congestion of the entire ATM communication network and to compress the voice signal unnecessarily to reduce the sound quality. It is to provide a voice cell system that never comes.

[0010]

According to the present invention, in a voice compression and cell assembling system for compressing and cellizing an inputted voice signal and sending a cellized signal to an ATM communication network, a predetermined silence detection threshold value is used. Silence detecting means for detecting the silence of the voice signal based on the comparison, network monitoring means for monitoring the congestion situation of the voice path passage part in the ATM communication network, and threshold control means for controlling the silence detection threshold according to the congestion situation. When,
There is provided a voice compression cellization system having cellization means for obtaining a cellized signal by cellizing only the voiced part of the voice signal in which silence is detected.

Further, according to the present invention, in the above voice compression cellizing system, the silence detecting means is a silence detecting circuit for detecting the silence in the voice signal according to the silence detecting threshold, and the network monitoring means is the congestion state in the ATM communication network. A voice compression cellization system is obtained which is a network monitoring circuit for monitoring information and voice connection path information, and the threshold value control means is a control circuit for controlling a silence detection threshold value based on congestion status information and voice connection path information.

Further, according to the present invention, in any one of the voice compression cellizing systems described above, the cell converting means encodes a voice signal in which silence is detected and outputs a coded signal, and a coder. (EN) A voice compression cell assembling system comprising a silence compression cell assembling circuit for cellizing only a voiced part in a digitized signal and outputting a cellified signal.

In addition, according to the present invention, in any one of the above voice compression cell assembling systems, it has an ATM interface circuit for sending a cell assembling signal to an ATM communication network, and the network monitoring circuit comprises an ATM interface circuit. A voice compression cellization system for monitoring the inside of the ATM communication network is obtained through the above.

Further, according to the present invention, in any one of the voice compression cellizing systems described above, the voice compression cellizing system is provided with an external connection communication means connected to a control circuit for externally controlling the silence detection threshold. The system is obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A voice compression cellizing system of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the basic configuration of a voice compression cell assembling system according to an embodiment of the present invention.

The voice compression cellizing system includes a silence detecting means for detecting silence of a voice signal input from the voice signal line 16 based on comparison with a predetermined silence detection threshold value, and an AT.
The network monitoring means for monitoring the congestion status of the voice path passing portion in the M communication network 18, the threshold control means for controlling the silence detection threshold value according to the congestion status, and the cell for only the voiced portion of the silence signal detected. And cellizing means for obtaining a cellified signal.

Of these, the silence detecting means detects the silence in the voice signal according to the silence detection threshold value.
2, the network monitoring means is the network monitoring circuit 11 for monitoring the congestion status information and the voice connection path information in the ATM communication network 18, and the threshold control means sets the silence detection threshold value based on the congestion status information and the voice connection path information. It is a control circuit 10 for controlling.

The cell converting means encodes the voice signal in which silence has been detected and outputs the encoded signal.
3 and a silence compression cell assembling circuit 14 for converting only the voiced portion of the encoded signal into cells and outputting the cellized signal.

Further, in this voice compression cell conversion system,
ATM for sending a cell signal to the ATM communication network 18
The network monitoring circuit 11 has an interface circuit 15 and an AT
The inside of the M communication network 18 is monitored.

FIG. 2 exemplifies the basic configuration of an ATM communication network system including such a voice compression cellizing system. Here, the voice terminal 20 is accommodated in the ATM communication network 18 via the voice signal line 16, and the voice terminal 21 is accommodated in the ATM communication network 18 via the voice signal line 17. Further, four ATM relay nodes 22 to 25 are arranged inside the ATM communication network 18, and each of the ATM relay nodes 22 to 25 has four ATM relay lines 26 to 29.
Are connected respectively.

Therefore, it is assumed that a voice path via the node 22, the node 23, and the node 24 is set between the voice terminal 20 and the voice terminal 21, and each constituent circuit of the voice compression cellizing system shown in FIG. Is implemented in the node 22, and the congestion status of the ATM trunk lines 26 and 27 is shown by the relationship of the line utilization rate as a quantification parameter with respect to the time (t) axis as shown in FIG. To do.

In such a case, in the voice compression cellizing system, the voice path is AT in the network monitoring circuit 11.
Inside the M communication network 18, node 22, node 23, node 2
4 is recognized and the voice connection path information is transmitted to the control circuit 10, and at the same time, the congestion status information of the ATM relay lines 26 and 27 is notified. Control circuit 10
Then, it is determined by the line usage rate of the trunk line having the highest line usage rate among all the relay lines of the voice path passing unit.

In the case of the example shown in FIG. 3, in the control circuit 10,
The line congestion status is managed in three states according to the line utilization rate, and the line utilization rate is from 80% to 100% in state A, 60.
Since% -80% is the state B and 0% -60% is the state C, the congestion state of the relay line with the highest line usage rate among all the relay lines of the voice path passing unit is the state A.
If so, the silence detection threshold is A ′, and if state B, B ′,
If the state is C, then C '(however, here A'> B '>C'
Holds). Therefore, in the control circuit 10, FIG.
At each time of a, b, c, d, and e, the silence detection threshold is set to C ′ during time a, B ′ during time b,
Let it be A'during time c, B'during time d, and C'during time e.

That is, in the voice compression cellizing system shown in FIG. 1, the control circuit 10 controls the silence detection threshold value at the time of silence detection in accordance with the congestion state of the voice path passage part in the ATM communication network 18, and then the silence compression is performed. In the cell assembling circuit 14, the cellized signal obtained by cellizing only the voiced part of the voice signal detected as silence is A
Since the data is transmitted to the TM communication network 18, it is possible to avoid congestion of the entire ATM communication network and prevent deterioration of sound quality due to useless voice compression.

Specifically, in the control circuit 10, a high silence detection threshold is set when the network congestion occurs or is expected to occur in the voice path passing portion of the ATM communication network 18, but the network resource If there is sufficient network congestion and no network congestion is expected, a low silence detection threshold is set.
When congestion occurs or is expected to occur in the voice path passing part in the communication network 18, the silence detection threshold is set to a high value and a cell signal is sent to the ATM communication network 18 to reduce voice cells. Therefore, congestion avoidance of the entire ATM communication network is measured.

On the other hand, when there are sufficient network resources in the voice path passing section in the ATM communication network and congestion is not expected, the silence detection threshold is set to a low value and the cell signal is set to A.
By transmitting to the TM communication network 18, deterioration of sound quality due to useless voice compression can be prevented.

FIG. 4 is a block diagram showing the basic structure of a voice compression cell assembling system according to another embodiment of the present invention.

In this voice compression cell system, compared with the system of the previous embodiment, a console interface is newly connected to the control circuit 10 as an external connection communication means for externally controlling the silence detection threshold. A circuit 30 is provided.

This console interface circuit 30
Since the silence detection threshold can be changed from the console terminal by being connected to the console terminal, the user of the ATM communication network 18 can programmatically determine the silence detection threshold. For example, the control program may have a timekeeping function, and the silence detection threshold may be fixedly set low in a specific time zone to emphasize voice quality, or the silence detection threshold may be fixedly set high in a specific time zone. A user-specific operation that emphasizes avoiding congestion of the ATM communication network 18 becomes possible. In addition, the voice terminals 20 and 21 accommodated in the ATM communication network 18 are given priority, and only voice signals from a specific voice terminal are fixedly detected with a low silence detection threshold to maintain voice quality. Is possible.

[0031]

As described above, according to the voice compression cellizing system of the present invention, the threshold control means is provided in accordance with the congestion status of the voice path passing part in the ATM communication network obtained by monitoring by the network monitoring means. In addition to controlling the silence detection threshold at the time of detecting silence, the cellized signal in which only the voiced part of the voice signal detected as silence by the cellizing means is sent to the ATM communication network, the congestion of the entire ATM communication network is caused. It is possible to avoid the above-mentioned problem and to prevent the sound quality from being deteriorated by uselessly compressing the sound signal. That is, when congestion occurs or is expected to occur in the voice path passing part in the ATM communication network, the silence detection threshold is set to a high value to reduce the voice cells of the cellization signal to be sent to the ATM communication network. By doing so, congestion avoidance of the entire ATM communication network is measured, and if there is sufficient network resources in the voice path passage part in the ATM communication network and congestion is not expected, the silence detection threshold is set to a low value By sending the encoded signal to the ATM communication network, it is possible to prevent the sound quality from being deteriorated by useless voice compression.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a voice compression cellization system according to an embodiment of the present invention.

FIG. 2 is an AT including the voice compression cellizing system shown in FIG.
It is a block diagram which illustrated the basic composition of the M communication network system.

FIG. 3 is a diagram showing a congestion situation of a local ATM relay line in an ATM communication network of the ATM communication network system shown in FIG. 2 in a relation of a line utilization rate as a quantification parameter with respect to a time axis.

FIG. 4 is a block diagram showing a basic configuration of a voice compression cellization system according to another embodiment of the present invention.

FIG. 5 is a block diagram showing a basic configuration of a conventional speech encoder.

[Explanation of symbols]

 10 Control Circuit 11 Network Monitoring Circuit 12 Silence Detection Circuit 13 Voice Encoding Circuit 14 Silence Compression Cell Assembly Circuit 15 ATM Interface Circuit 16-17 Voice Signal Line 18 ATM Communication Network 20-21 Voice Terminal 22-25 ATM Relay Node 26-29 ATM trunk line 30 Console interface circuit 301 Signal compressor 302 Cell assembler 303 Transmission buffer 304 Detector 305 Comparator

Claims (5)

[Claims] 1. A voice compression cellizing system for transmitting a cellized signal obtained by compressing and cellizing an input voice signal to an ATM communication network, wherein the silence of the voice signal is detected based on comparison with a predetermined silence detection threshold value. Silence detecting means for detecting, network monitoring means for monitoring the congestion situation of the voice path passing part in the ATM communication network, threshold control means for controlling the silence detection threshold according to the congestion situation, and the silence detection. And a cellizing unit that obtains the cellified signal by cellizing only the voiced part of the voice signal. 2. The voice compression cellization system according to claim 1, wherein said silence detecting means is a silence detecting circuit for detecting silence in said voice signal according to said silence detecting threshold, and said network monitoring means is said ATM communication network. In the network monitoring circuit for monitoring the congestion status information and voice connection path information in, the threshold control means is a control circuit for controlling the silence detection threshold based on the congestion status information and the voice connection path information Voice compression cell conversion system. 3. The voice compression cellization system according to claim 1, wherein the cellization means encodes the voice signal in which the silence is detected and outputs a coded signal, and the coded circuit. A voice compression cell assembling system comprising: a silence compression cell assembling circuit which outputs only the cellized signal by converting only the voiced portion of the coded signal into cells. 4. The voice compression cellization system according to claim 2, further comprising an ATM interface circuit for sending the cellification signal to the ATM communication network, and the network monitoring circuit includes the ATM interface circuit. A voice compression cell assembling system for monitoring the inside of the ATM communication network through the system. 5. The voice compression cellization system according to claim 2, further comprising an external connection communication means connected to the control circuit to externally control the silence detection threshold value. A voice compression cell conversion system characterized by the above.