JPH1168794A - Voice signal cell processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice cell processing system by which a frequency band is effectively utilized by selecting a voice compression system based on a band width of a voice passing section set in an asynchronous transfer mode ATM communication network. SOLUTION: A voice cell assembling circuit 6 has a voice cell processing circuit that executes non-voice compression and a voice cell processing circuit that executes no non-voice compression and the selection of the voice cell processing circuit is controlled based on private branch of exchange PBX signaling information from from a PBX signaling detection circuit 1 and on network configuration information of an ATM communication network from a network monitor circuit 2. In the case of setup of a voice path and when a small frequency band width is in existence in a route through which the voice path passes, the voice cell processing circuit to execute non-voice compression is selected and when no small frequency band is in existence, the voice cell processing circuit that does not execute non-voice compression is selected. The selected voice cell processing system is informed to a voice cell disassembly circuit of an opposite station based on an identifier added to a header part of the voice cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio signal celling system, and more particularly, to an ATM (Async) configured via a WAN (Wide Area Network).
The present invention relates to an audio signal celling system for accommodating a private branch exchange (PBX) in a hronous transfer mode (asynchronous transfer mode) network.

[0002]

2. Description of the Related Art Conventionally, this type of voice cell system limits the applicable range of silence compression when a voice encoder is applied to an ATM communication network, as shown in, for example, Japanese Patent Laid-Open No. 5-244104. It is used for the purpose of keeping the naturalness of the audio signal while suppressing the redundancy of the audio signal.

FIG. 8 is a block diagram showing the configuration principle of a conventional speech encoder. As shown in FIG. 8, a conventional speech encoder includes a signal compressor 301 for compressing and encoding a signal from a telephone, and a cell assembler 302 for assembling a cell by receiving an output from the signal compressor 301. And a transmission buffer 303 for temporarily storing a plurality of assembled cells and sequentially transmitting the cells to a line, a detector 304 for detecting a cell storage amount of the transmission buffer 303, and comparing the detected cell storage amount with a predetermined value. And a comparator 305 for controlling the signal compressor 301 so as to increase the degree of signal compression when the cell storage amount is larger than a predetermined value.

Next, the operation of the conventional speech encoder shown in FIG. 8 will be described. The signal compressor 301 compresses and encodes the signal from the telephone, and the cell assembler 302 receives the output from the signal compressor 1 to assemble the cell. The transmission buffer 303 temporarily stores the plurality of assembled cells and sequentially transmits the cells to the line.

[0005] Then, the detector 304 sets the transmission buffer 3
03, the comparator 305 compares the detected cell storage amount with a predetermined value. If the cell storage amount is larger than the predetermined value, the comparator 305 performs signal compression so as to increase the degree of signal compression. The control unit 301 is controlled. Therefore, the transmission buffer 3
When the cell storage amount of No. 03 is smaller than the predetermined value, the degree of signal compression is suppressed, so that the quality of the transmission signal is improved.

[0006]

However, the above-mentioned conventional speech encoder has the following problems.

The first problem is that when a voice signal cell passes through the ATM network, the amount of cells cannot be controlled by the transmission bandwidth of the path through which the voice signal cell passes. , There is a possibility that effective use of bandwidth may not be possible.

The reason for this is that the control of the degree of audio signal compression is controlled by the absolute value of the cell storage amount in the transmission buffer of the audio encoder.

A second problem is that it is difficult to realize a speech decoder for reconstructing and restoring a speech signal compressed and encoded by the speech encoder.

The reason is that the degree of compression of the audio signal is varied by the audio encoder, but there is no means for notifying the audio decoder of the degree of audio signal compression. .

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to switch a voice compression method according to a bandwidth of a voice path passing unit set in an ATM communication network and to effectively use a band. It is to provide a possible voice cellization scheme.

[0012]

To achieve the above object, a voice cell assembling circuit according to the present invention uses a signaling information from a PBX to convert a coded voice signal from a call origination to a termination of a voice call to a CBR (constant) signal. An on-demand cell assembling circuit for converting a cell into a bit rate), a silence detecting circuit for detecting speech / non-speech of an encoded voice signal, and a PBX
The signaling information and the silence information from the silence detection circuit are used to cellify only the voiced portion of the encoded speech signal from the time the voice call is made until the end of the call, and to add a silence compression identifier information to the header of the speech cell. , A discriminating circuit for discriminating an optimal voice celling method at the time of call setting based on PBX signaling information and network connection configuration information of an ATM communication network, and an instruction of the discriminating circuit.
A selection circuit for switching a voice cell to be transmitted to the ATM communication network.

Further, the voice cell decomposing circuit of the present invention has an ATM
A header monitoring circuit that monitors a header portion of a voice cell received from a communication network to check whether or not a silence compression identifier is inserted; and a CBR as it is without silence compression reproduction of an input voice cell. An on-demand cell disassembly circuit that disassembles cells, a silence compression cell disassembly circuit that silences and reproduces input voice cells, and disassembles the cells;
A selection circuit for switching an encoded audio signal to be sent to an audio encoding / decoding circuit according to an instruction of the header monitoring circuit;
It is characterized by having.

In the present invention, when a portion having a small transmission bandwidth exists in the ATM communication network, the voice signal cell is
Depending on whether it passes through a small part of the transmission bandwidth,
When the audio signal cell passes through a portion having a small transmission bandwidth, the audio signal is converted into a compressed cell, the transmission line bandwidth is effectively used, and the audio signal cell is converted to a transmission bandwidth. When the audio signal does not pass through the small portion, the audio signal is transmitted without being compressed, thereby preventing a decrease in sound quality.

[0015]

Embodiments of the present invention will be described below. In the preferred embodiment, the voice signal celling system of the present invention has means for detecting signaling information from the PBX (1 in FIG. 1) and means for monitoring the network connection configuration of the ATM communication network (2 in FIG. 1). )have.

Further, a means (12 in FIG. 2) for converting the coded voice signal from the outgoing call to the end of the voice call into cells in a CBR (constant bit rate) by the PBX signaling information; Based on the means for detecting voice / non-voice (13 in FIG. 2), and the PBX signaling information and the voiceless information of the coded voice signal, only the voiced portion of the coded voice signal from the start of the voice call to the end of the voice call is used as a cell. Means (Fig. 2)
14).

Further, there is provided a means for selecting an optimum voice cell conversion system at the time of setting up a voice call. Specifically, P
Based on the BX signaling information and the network connection configuration information of the ATM communication network, means (11 in FIG. 2) for determining an optimum voice cell conversion method at the time of call setup, and means for switching voice cells to be transmitted to the ATM communication network (FIG. 2) 15).

Further, there is provided a means for decomposing voice cells by the same method as the selected voice cell conversion method. Specifically, means for inserting silence compression identifier information into the header part of the voice cell after assembling the cell by the silence compression method (14 in FIG. 2), and monitoring the header part of the voice cell received from the ATM communication network. Means for checking whether a silence compression identifier has been inserted (24 in FIG. 3), and means for decomposing the input voice cells as they are in CBR without silence compression regeneration (22 in FIG. 3). Means for silently regenerating the input voice cell and decomposing the cell (23 in FIG. 3), and means for switching the coded voice signal to be sent to the voice coding / decoding circuit (21 in FIG. 3). ,including.

In the embodiment of the present invention, the selection of the voice cell system is determined based on the PBX signaling information and the network connection configuration information of the ATM communication network. The celling scheme can be selected.

The voice path set in the ATM communication network is
When passing through a portion of the network having a small bandwidth, the silent cell compression method is selected as the voice cell conversion method, so that the number of voice cells transmitted to the ATM communication network is reduced, and as a result, the transmission bandwidth of the transmission path having a small bandwidth is reduced. Bandwidth can be used effectively.

If the voice path set in the ATM communication network does not pass through a small portion of the bandwidth in the network, an on-demand system that does not perform silence compression is selected as a voice cell system, so that there is no useless voice. A decrease in sound quality due to compression can be prevented. When the silent cell compression method is selected as the audio cell assembling method, the silent cell identification information is inserted into the header of the audio cell, so that the cell disassembly is performed in the same manner as the cell assembly by the audio cell disassembly circuit. Can be implemented.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

FIG. 1 is a block diagram showing the configuration of a voice celling system according to one embodiment of the present invention. Referring to FIG.
In the voice cell conversion system according to one embodiment of the present invention, the PBX signaling detection circuit 1 detects PBX signaling information from the PBX interface circuit 3 and transfers the information to the voice cell assembly circuit 6 via the ATM interface circuit 5. A network monitoring circuit that is connected to the ATM communication network, monitors network connection configuration information of the ATM communication network, and transfers the information to the voice cell assembling circuit;

The audio signal input from the PBX accommodating line 8 is input to the audio signal encoding / decoding circuit 4 via the PBX interface circuit 3 and becomes an encoded audio signal. Is converted to AT
The data is transmitted to the ATM communication network via the M interface circuit 5.

On the other hand, the voice cell input from the ATM communication network 9 is input to the voice cell decomposing circuit 7 via the ATM interface circuit 5, converted into a coded voice signal, and further converted to a voice signal coding / decoding circuit. 4 and decrypted by PB
The data is transmitted to the PBX accommodation line 8 via the X interface circuit 3.

FIG. 2 is a block diagram showing a configuration example of the voice cell assembling circuit 6 in one embodiment of the present invention. Referring to FIG. 2, the voice cell assembling circuit 6 receives the input PB
On-demand cell assembling circuit 1 that converts a coded voice signal from a call origination to a termination of a voice call into cells in a CBR (constant bit rate) based on X signaling information.
2, the input PBX signaling information, and the silence information from the silence detection circuit 13, the silence compression cell assembly for cellizing only the speech part of the encoded speech signal from the start of the voice call to the end of the call. And a circuit 14. The silence compression type cell assembling circuit 14 is used in the final process of cell assembling.
Silence compression identifier information indicating that the cell has been assembled by the silence compression method is inserted into the header of the voice cell.

Further, the voice assembling circuit 6 has a discriminating circuit 11 for discriminating an optimal celling system at the time of call setting of a voice call, based on the two pieces of information of the input PBX signaling information and ATM communication network connection configuration information. Have. The selection circuit 15 selects the cell assembling circuit according to the instruction of the determination circuit 11.

FIG. 3 is a block diagram showing a configuration example of the voice cell decomposition circuit 7 in one embodiment of the present invention. Referring to FIG. 3, the voice cell disassembly circuit 7 has a header monitoring circuit 24 that monitors a header of an input voice cell, and instructs the selection circuit 21 to make a selection instruction based on the cell assembly scheme identifier inserted in the header. ing. Further, the voice cell decomposition circuit 7
Is an on-demand cell decomposing circuit 22 that decomposes input speech cells without performing silence compression and reconstructs the cells as they are in CBR,
And a silence compression type cell decomposition circuit 23 for cell decomposition.

The input voice cell is input to both an on-demand type cell decomposition circuit 22 and a silent compression type cell decomposition circuit 23, and is divided into cells by the respective cell decomposition circuits. The coded voice signal obtained by cell decomposition in the same manner as when the cell is assembled is output from the voice cell decomposition circuit 7.

FIG. 4 is a flowchart for explaining the operation of the voice cell assembling circuit 6 in one embodiment of the present invention.
FIG. 5 is a diagram showing a speech cell disassembly circuit 7 according to an embodiment of the present invention.
5 is a flowchart for explaining the operation of FIG. FIG. 2 is a block diagram of a network system configuration for explaining an operation of one embodiment of the present invention. Next, the operation of the embodiment of the present invention will be described in detail with reference to FIGS.

Referring to FIG. 4, voice cell assembly circuit 6
The internal determination circuit 11 (see FIG. 2) monitors the call request information input from the PBX signaling detection circuit 1 (step 101). When there is a call request, the ATM is determined by the network connection configuration information from the network monitoring circuit 2.
Recognize the voice path route in the communication network (step 10)
2).

Here, the determination circuit 11 determines whether or not there is a portion where the transmission path bandwidth is smaller than a preset fixed value in the voice path passing portion in the ATM communication network (step 103).

An example of this determination method will be described in more detail with reference to FIG.

In FIG. 6, ATM switches 37 to 42
Are connected via a WAN 43.

The transmission path band between the ATM switches 37 and 38 and the WAN (wide area network) 43 is 1.5 Mbps.
(Megabits / second), and the transmission band between the ATM switches is 155 Mbps. In FIG. 6, PBX3
3 and the PBX 34, an audio path 44 is
Assume that an audio path 45 is set up between 31 and the PBX 35. It is also assumed that a fixed value set in advance as a determination reference in the determination circuit 11 is 2 Mbps.
In this case, since there is no bandwidth smaller than 2 Mbps in the voice path 44, it is determined that there is no small bandwidth portion. In the voice path 45, the bandwidth between the ATM switch 37 and the WAN 43 and the bandwidth between the ATM switch 38 and the WA are different.
1.5Mbp of bandwidth smaller than 2Mbps between N43
Since s exists, it is determined that there is a small bandwidth portion.

Needless to say, a fixed value for bandwidth determination can be arbitrarily set.

Referring again to FIG. 4, when the discriminating circuit 11 (see FIG. 2) inside the voice cell assembling circuit 6 determines that the bandwidth is small in the voice path passing portion, it selects the silent compression method (step 104). On the other hand, if it is determined that the bandwidth of the voice path passing portion is not small, the on-demand system is selected (step 105).

Either the on-demand type cell assembling circuit 12 or the voice cell converted into a cell by the silence compression type cell assembling circuit 14 is transmitted to the ATM communication network 9 (step 106). Voice cell assembly circuit 6 is ATM
While transmitting voice cells to the ATM communication network 9 via the interface circuit 5, the on-demand type cell assembling circuit 12 and the silence compression type cell assembling circuit 14 monitor call disconnection information from the PBX. (Step 107). When the call disconnection is detected, the on-demand cell assembling circuit 12 and the silence compression type cell assembling circuit 14 stop sending the voice cells (step 108).

Referring now to FIG. 5, the header monitoring circuit 24 inside the voice cell disassembly circuit 7 has
The absence is monitored (step 201). When a voice cell is received, the header monitoring circuit 24 analyzes the header of the voice cell (step 202) and checks whether silence compression identifier information indicating whether cell assembly has been performed by the silence compression method is inserted. (Step 203). Here, if the silence compression identifier has been inserted, the silence compression cell decomposition circuit 23 is selected (step 204). If the silence compression identifier has not been inserted, the on-demand cell decomposition circuit 22 is selected (step 204). Step 205).

By the above operation, the cell can be disassembled in the same manner as when the cell is assembled.

A second embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram showing a configuration of the second exemplary embodiment of the present invention. 7, elements having the same functions as those in FIG. 1 are denoted by the same reference numerals.

Referring to FIG. 7, in a second embodiment of the present invention, a console interface circuit 10 is provided. The console interface circuit 10 is connected to the voice cell assembling circuit 6 and has a function of externally controlling the determination circuit 11 (see FIG. 2) inside the voice cell assembling circuit 6.

When the console terminal is connected to the console interface circuit 10, the voice cell assembly circuit can be switched from the console terminal. Therefore, a user using the ATM communication network 9 can programmably select the voice cell format.

For example, a control program may be provided with a timekeeping function. In a certain time zone, an on-demand system is fixedly selected, and voice quality is emphasized. In a certain time zone, a silent compression system is fixed. It is possible to select and perform user-specific operations that place importance on avoiding congestion in the entire ATM communication network. In addition, a service can be provided in which priority is added to PBXs accommodated in the ATM communication network 9 and only audio signals from a specific PBX are fixedly converted into cells in an on-demand system to maintain audio quality. .

[0045]

As described above, according to the present invention, the following effects can be obtained.

The first effect of the present invention is that, when there is a portion having a small transmission bandwidth in a voice path passing portion in an ATM communication network, the number of voice cells transmitted to the ATM communication network is reduced, and as a result, the transmission bandwidth is reduced. This means that the bandwidth can be effectively used on a transmission line with a small bandwidth.

The reason is that, in the present invention, when a transmission path having a transmission path band smaller than a predetermined value exists in a voice path passing section in an ATM communication network, a silent cell compression method is used as a voice cell conversion method. This is because the system is selectively adopted.

A second effect of the present invention is that when there is no portion having a small transmission bandwidth in a voice path passing portion in an ATM communication network, it is possible to prevent a decrease in sound quality due to useless voice compression.

The reason is that, in the present invention, when there is no transmission path having a transmission path band smaller than a predetermined value in the voice path passing section in the ATM communication network, silence compression cell conversion is performed as a voice cell conversion method. This is because there is no on-demand cell conversion method selectively adopted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a speech signal celling system according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a voice cell assembly circuit according to one embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration example of a voice cell decomposition circuit according to an embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of the voice cell assembling circuit in one embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation of the voice cell decomposition circuit in one embodiment of the present invention.

FIG. 6 is a block diagram for explaining the operation of one embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a second exemplary embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a conventional speech encoder.

[Explanation of symbols]

 Reference Signs List 1 PBX signaling detection circuit 2 Network monitoring circuit 3 PBX interface circuit 4 Audio signal encoding / decoding circuit 5 ATM interface circuit 6 Audio cell assembly circuit 7 Audio cell disassembly circuit 8 PBX accommodation line 9 ATM communication network 10 Console interface circuit 11 Discrimination Circuit 12 On-Demand Cell Assembly Circuit 13 Silence Detection Circuit 14 Silence Compression Cell Assembly Circuit 15 Voice Cell Selection Circuit 21 Encoded Audio Signal Selection Circuit 22 On-Demand Cell Decomposition Circuit 23 Silence Compression Cell Decomposition Circuit 24 Header Monitoring Circuit 31 ~ 36 PBX 37 ~ 42 ATM switch 43 WAN 44 ~ 45 Voice path 301 Signal compressor 302 Cell assembler 303 Transmission buffer 304 Detector 305 Comparator

Claims (5)

[Claims] An on-demand cell assembling circuit for converting a coded voice signal from a call origination to a termination of a voice call into cells in a CBR (constant bit rate) based on signaling information from a PBX, and a coded voice signal. A silence detection circuit for detecting the presence / absence of speech, and the PBX signaling information and the silence information from the silence detection circuit to convert only the speech portion of the encoded speech signal from the start of the voice call to the end of the call. And a silence compression cell assembling circuit for inserting silence compression identifier information into a header portion of a voice cell, and an optimum voice cell conversion method at the time of call setup is determined based on PBX signaling information and network connection configuration information of an ATM communication network. A discriminating circuit for performing the operation, and selecting one of the on-demand type cell assembling circuit and the silence compression type cell assembling circuit according to an instruction from the discriminating circuit, A selection circuit for switching a voice cell to be transmitted to a TM communication network. 2. A header monitoring circuit for monitoring a header portion of a voice cell received from an ATM communication network to check whether or not a silence compression identifier is inserted, and a voiceless compression / reproduction of an input voice cell. An on-demand cell disassembly circuit that decomposes cells as it is in CBR, a silence compression cell disassembly circuit that silently compresses and reproduces an input voice cell, and disassembles the cells; A selection circuit for selecting one of a demand type cell disassembly circuit and the silence compression type cell disassembly circuit and switching an encoded audio signal to be sent to an audio encoding / decoding circuit. circuit. 3. A PBX signaling detection circuit for detecting signaling information from a PBX, a network monitoring circuit for monitoring a network connection configuration of an ATM communication network, a voice cell assembling circuit according to claim 1, and a voice cell assembly circuit according to claim 2. A speech cell decomposition method, comprising: a speech cell decomposition circuit; 4. A voice cell assembly circuit according to claim 1, further comprising: a PBX signaling detection circuit for detecting signaling information from the PBX; a network monitoring circuit for monitoring a network connection configuration of an ATM communication network; A voice cell assembling circuit, comprising: a voice cell assembling circuit including means for variably setting a determination of a voice celling method from outside; and the voice cell decomposing circuit according to claim 2. 5. The method according to claim 1, wherein the determining circuit selects a silent-compression-type cell assembling circuit for performing silent compression when a route having a small bandwidth exists in a route through which the voice path passes when setting up a call for the voice path. 2. The voice cell assembling circuit according to claim 1, wherein the on-demand type cell assembling circuit is selected when there is no portion having a small band.