JPH0478248A - Atm cell composition system and decomposition system - Google Patents

Abstract

PURPOSE:To improve a silence compression rate and to avoid layer invasion by detecting voiced/non-voiced signal in the unit of samples of a voice signal, using the resulting data as a burst data so as to compose an ATM cell, sending the cell and allowing a receiver side to extract valid voice information. CONSTITUTION:An analog voice signal S1 is inputted to the system, and a voiced/non-voiced signal is detected by a voiced/non-voiced signal detection section 302 via an A/D converter section 301. The result of detection S3 is correctly reflected with the voiced/nonvoiced state of a digital voice signal S2. An ATM cell processing section 303 fetches a digital voice signal in the unit of one octet as user information and forms an ATM cell for each length of information part of the ATM cell and sends the cell. A reception system extracts valid voice information to recover the voice signal based on display information commanding valid voice information quantity inserted in the information part of the ATM cell.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to ATM (Asynchronous Tran)
The present invention relates to an ATM cell assembly method and disassembly method for setting up and disassembling ATM cells for analog telephone information in a communications network.

[Prior Art] An ATM communication network has been proposed as a communication network that can transmit voice, images, data, etc. over the same communication network. When transmitting voice information, which is analog telephone information, in such an ATM communication network, in order to suppress voice redundancy, the silent sections of the voice information are compressed5, and only the active sections of the voice information are converted into cells. It is proposed to transmit.

FIG. 2 is an explanatory diagram showing a conventional ATM cell assembly system having such a silent section compression function.

This conventional example detects utterance and silence on a cell-by-cell basis.
103>.

The input analog audio signal shown in FIG. 2(A) is subjected to analog/digital conversion and then subjected to cell processing. For digital audio signals, as shown in FIG. 2(C), whether a sound section 203 or a silent section 204 is detected for each cell. As a result of this detection, the voice section 203 that is detected to be audible is assembled into an ATM cell 205 (FIG. 2(D)) and sent out.

This ATM cell assembly method is called a message mode in the ATM adaptation layer.

The reason for detecting whether there is a sound or no sound in each ATM cell in this way is because the detection process can be performed in parallel with the cell storage process, as described in the above-mentioned literature. This is because there is a great advantage in terms of time.

Problem 1 to be Solved by the Invention However, the method of detecting voice/silence in each ATM cell described above has the following problems.

FIG. 2(B) shows an actual sound section 20 and a silent section 202 of the audio signal shown in FIG. 2(A).

As is clear from the comparison with Figure 2 (B) and (C),
If the detection is performed in units of cells, the active section 203 will be longer.
Cells into which silent audio information is inserted often occur at the beginning and end of voiced audio. That is, the silence compression rate is low.

Furthermore, considering the layer structure of the communication protocol, the voice detection and silence compression functions, which are functions of higher layers of layer 4 and above, perform processing with consideration for layer 1 A and TM cells. In other words, this violates the layer structure, making the division into layers meaningless, and making it difficult to change the configuration at the layer level.

Further, although configurations that realize voice detection and silence compression functions have already been proposed, they also have the problem that they cannot be used because the transfer method has been changed to ATM.

The present invention has been made in consideration of the above points, and is an ATM that has a high silence compression rate, can be divided into cells according to a layer structure, and can also be applied to existing voice detection and silence compression configurations. It is intended to provide cell assembly and disassembly methods.

[Means for solving the problem] In order to solve the problem, in the first invention,
The following means are provided in an ATM cell assembly method for converting voice information in a sound section into ATM cells.

In other words, the input audio information is processed in sample units.
A voice/silence detecting means for detecting silence, divides the audio information in sample units of the voice section for each news section of the ATM cell, and divides the voice information amount in the ATM cell at the end of the voice section. A voice information dividing means for inserting vacant information to fill in the shortage when the number is not reached by the information manager, and various transmission control information is added to the transmission information from the voice information dividing means to form an ATM cell. In addition, transmission control information adding means is provided which includes display information indicating the amount of effective audio information inserted into the information section of at least the ATM cell as transmission control information.

A second aspect of the present invention is an ATM cell assembled by the ATM cell assembly method of the first aspect of the present invention.
This relates to the method for disassembling the received ATM cell of a TM cell, and it is based on display information indicating the amount of effective voice information inserted in the information section of the incoming ATM cell. It extracts the audio information and reproduces the audio signal.

[Operations] The first ATM cell assembly system of the present invention is characterized in that the sound/silence detecting means detects sound/silence on a sample-by-sample basis with respect to input voice information.

Another feature is that the ATM cell is made up of voice information in a voiced section as one burst data. In other words, the audio information dividing means divides the audio information in samples of the sound section into each information section of the ATM cell, and if the number of information sections does not reach the number of information sections at the end of the busy section, it divides the audio information in units of samples in the sound section. to insert free information. The transmission control information addition means adds various types of transmission control information to the transmission information from the voice information division means to form an ATM cell, and inserts the transmission control information into at least the information part of the ATM cell. Include display information that indicates the amount of valid audio information being used.

Since the ATM cell assembled and transmitted in this way contains the above-mentioned display information, in the second aspect of the present invention, in which the ATM cell is transmitted and disassembled, the incoming ATM
Based on the display information indicating the amount of effective audio information inserted in the information section of the cell, the effective audio information inserted in the information section is extracted and the audio signal is reproduced.

Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

Here, FIG. 1 is an explanatory diagram showing the ATM cell assembly system of this embodiment, and FIG. 3 is a block diagram showing the cell assembly configuration of the embodiment.

In FIG. 3, the input analog audio signal S1 is
The analog/digital converter 301 converts it into a digital audio signal S2. This digital audio signal S2 is
The signal is given to the voice/silence detector 302 and the ATM cell generator 303.

The voice/silence detection unit 302 detects voice/silence of the digital audio signal S2 in units of one octet, which is a sample unit in the digital audio signal S2, and converts the voice/silence detection result S3 into an ATM cell generator 303. give to As the detection method performed by the voice/silence detector 302, an existing method using power, amplitude, zero crossing number information, etc. can be applied.

In this way, the feature of this embodiment is that voice/silence is detected not on a cell-by-cell basis but on an octet-by-octet basis.

The ATM cell forming section 303 is configured by, for example, firmware, and specifically includes a voice information dividing section 304, a transmission control information generating section 305, and a synthesizing section 306.

This ATM cell conversion unit 303 employs cell conversion according to a streaming mode that has been conventionally applied to cell conversion of data from a data terminal device. That is,
Audio information (user information) in units of 1 octet in the sound section
This is to convert the data into cells by treating it as one burst data.

Note that, as described above, conventionally, a cell system according to the message mode has been adopted for voice signals.

The audio information division section 304 is the analog/digital conversion section 3
The digital audio signal S2 given from 01 is sequentially accumulated as a data group in units of 1 octet, and when the accumulated amount reaches the amount of information in the ATM cell, the synthesizer 306
This gives the corresponding amount of audio information to the user. Here, the audio information dividing unit 304 starts the accumulation operation (dividing operation) after the voice/silence detection result S3 indicates the presence of voice. In addition, when the voice/silence detection result S3 changes to indicate silence, the voice information dividing unit 304 divides the voice information at that time even if information for the length of the ATM cell reporting section is not stored. The accumulated information is provided to the synthesis unit 306. At this time, the missing information is given to the synthesis section 306 together with the accumulated audio information as empty information.

The transmission control information generation unit 305 generates headers and trailers such as destination information and cell sequence numbers.
This generation operation is performed when the sound/silence detection result S3 indicates the presence of sound. The header and trailer generated by the transmission control information generation unit 305 are also provided to the synthesis unit 306.

In the case of this embodiment, the effective information transposition display information indicating the amount of effective voice information inserted into the information section of the ATM cell is converted into additional information of the ATM adduction layer (a layer with a function of converting the ATM cell into an ATM cell). For example, include it in the trailer. Effective information length display information is included not only when valid voice information is inserted into a part of the information section of an ATM cell, but also when valid voice information is inserted into all of the information section of an ATM cell. .

The synthesizing section 306 synthesizes the voice information from the voice information dividing section 305 and the header and trailer from the transmission control information generating section 305 to complete an ATM cell and send it out.

In the configuration shown below, when the analog audio signal S1 shown in FIG. 1 (A>) is input, this analog audio signal S1
is converted into a digital audio signal S2 by the analog/digital converter 301, and then the voice/silence detector 302 detects voice/silence. In the case of this embodiment, since voice/silence is detected in units of 1 octet,
The detection result S3 correctly reflects the presence/absence of the digital audio signal S2, as shown in FIG. 1(B). The ATM cell forming unit 303 performs the voice section], 01-
A digital voice signal of 1 octet is taken in as user information 103 (FIG. 1(C)), and an ATM cell 104 is formed and transmitted for each information section of the ATM cell. The sound/silence detection result S3 is from the sound section 101 to the silent section 10.
At the time t when the change to 2 occurs, the voice information 105a is sent from the information manager of the ATM cell to at least the missing information 105b.
Assemble ATM cell 105 as shown in FIG.
Assemble and send out.

Furthermore, the ATM cell 1 assembled in this way
Although not shown, the receiving system that receives 04.105 follows the sequence number of the ATM cell, and
Based on the display information indicating the amount of valid voice information inserted in the information section of the ATM cell, valid voice information is extracted 5 and the voice signal is reproduced.

Therefore, according to the above-mentioned embodiment, the presence/absence of a digital audio signal is detected in units of octets, and the data in units of octets of the voiced section are converted into node data.
When assembling a TM cell, display information indicating the amount of effective voice information inserted into the information section of the ATM cell is also inserted into the ATM cell.
By incorporating the information into the cell and transmitting it, the following effects can be obtained.

An ATM cell that spans both a sound section and a silent section is
When looking at one sound section, at most only one occurs at the end of the sound section, and the silence compression rate is improved compared to the conventional method.

In addition, even in ATM cells that span both a sound section and a silent section, since the silent section is made clear by the display information, the receiving side processes this section as a silent section (for example, by playing back noise). becomes possible. By the way, according to the conventional method of detecting voice/silence in each cell and converting the cells into cells, all cells that span a voice area and a silent area are treated as a voice area.

According to the above-mentioned embodiment, the voice/silence detection related to the higher layer is executed in units of 1 to 1 off terres, and since the FM cell is not considered, violation of the layer fill structure can be eliminated. In other words, it becomes possible to easily change the configuration of each layer.

Furthermore, since voice/silence detection is performed in units of octets, existing voice detection and silence compression configurations related to networks other than ATM communication networks can be applied.

Note that the display information indicating the effective amount of voice information inserted into the information section of the ATM cell may be included in the ATM cell, and its insertion position is not limited to that of the above embodiment.

[Effects of the Invention] As described above, according to the present invention, voice/silence is detected in each sample of an audio signal, and the data in each sample of a voice section is handled as burst data to enable ATM processing.
When assembling cells, display information indicating the amount of effective audio information inserted into the information section of the ATM cell is also included in the ATM cell and transmitted, and the receiving side uses the display information to transmit effective audio information. I took it out and played it, so
The silence compression rate can be improved compared to conventional methods, and
It is possible to realize an ATM cell assembly and disassembly method that does not cause layer violation and can also be applied to existing voice detection/silence compression configurations.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of an ATM cell assembly method according to the present invention, FIG. 2 is an explanatory diagram of a conventional method, and FIG. 3 is a block diagram showing the structure of the cell assembly side according to the above embodiment. 301...analog/digital conversion section, 302 sound/
Silence detection unit, 303...ATM cell conversion unit, 304...
- Audio information division unit, 305...transmission control information generation unit,
306...Synthesis department.

Claims (2)

[Claims] (1) In an ATM cell assembly method that converts voice information in a voice section into ATM cells, a voice/silence detection means detects voice/silence on a sample basis from input voice information, and a sample unit in a voice section. voice information dividing means for dividing the voice information for each information section of an ATM cell, and inserting empty information to fill in the shortage when the amount of voice information is less than the information section at the end of a sound section; , Add various types of transmission control information to the transmission information from this voice information dividing means to complete the ATM cell, and at least indicate the amount of effective voice information inserted in the information section of the ATM cell as the transmission control information. an ATM cell assembly method comprising transmission control information adding means that includes display information for displaying information. (2) In an ATM cell disassembly method for receiving ATM cells assembled by the ATM cell assembly method according to claim 1 and arriving via an ATM communication network, an effective value inserted in the information part of the arriving ATM cell is provided. An ATM cell disassembly method characterized in that, based on display information indicating the amount of audio information, effective audio information inserted in an information section is extracted and an audio signal is reproduced.