JPH066320A - Multiplexer - Google Patents

Abstract

PURPOSE:To use the band efficiently by sending data to be sent when the data to be sent are in existence in the non-use state where no valid information is sent to a transmission line. CONSTITUTION:An SS signal being a voice control signal from a telephone set via an exchange is set to a ground level and a start signal is sent. An SS signal detection circuit 103 of a multiplexer 100 detects that the SS signal is set to a ground level and informs it to a control means 106. When the SS signal is set to a ground level, the control means 106 controls a transmission buffer 107 not to send data and commands cell processing of the voice signal to a voice cell processing circuit 104. The circuit 104 processes a time slot of the SS signal and the voice signal into a cell. A multiplexer circuit 108 multiplexes and sends the result. Furthermore, when the telephone set is not busy, the means 106 processes only the control signal of the SS signal and sends the result. In this case, the means 106 controls a buffer 107 to send a data cell.

Description

Detailed Description of the Invention

[0001]

The present invention relates to STM (Synchronous
Transfer Mode) multiplexer and ATM (Asynchronou)
s Transfer Mode) A STM multiplexer and an ATM multiplexer for efficiently transmitting SS / SR signals.
The present invention relates to a TM cell multiplexer and its transmission control method.

[0002]

2. Description of the Related Art An existing STM multiplexer for performing time division multiplexing allows a large capacity line with a low communication charge per unit to be used by bundling a plurality of transmission lines to increase the communication amount. . Also, the multiplexed signal is multiplexed and transmitted by being placed on a time slot position determined for each input transmission path. FIG. 6 is an explanatory diagram showing an example of multiplexing in the conventional STM multiplexer. In FIG. 6, the transmission lines a, b and c are connected to the multiplexing device 500, and the information transmitted on the transmission lines a, b and c is time-divided in the multiplexing device 500 for each time slot. The signals are multiplexed and sent to the multiplex transmission line 310. Since the STM multiplexer secures a time slot regardless of whether the time slot is in use or not, the time slot is allocated even when it is not used.

In an ATM multiplexer that divides data from each transmission line into cells, which are fixed-length blocks, and multiplexes them, the CCITT Recommendation I.S. As shown in 363, when AAL1 (ATM adaptation layer 1) is used, communication on the time division transmission line is a fixed speed service. FIG. 10 is an explanatory view showing an example of multiplexing in the conventional ATM multiplexer. In FIG. 10, each transmission line is connected to the multiplexing device 10, and the information transmitted on the transmission line is time-division multiplexed for each cell in the multiplexing device 10 and sent to the multiplex transmission line 300. . In this case, since the bit rate is fixed, a signal in an unused state (that is, a signal corresponding to silence) is transmitted as a cell even when there is no information on the transmission line and it is unused.

[0004]

In recent years, the role of communication in society has increased and the amount of communication continues to increase. In such a situation, there is an increasing demand for users who want to efficiently use a transmission line to reduce communication capacity and communication charges.

The existing STM time division multiplexer has the following
By bundling signals from a plurality of transmission lines to increase the amount of communication, a large-capacity line with a low communication charge per unit can be used. Further, the multiplexed signal is multiplexed and transmitted by being placed on the time slot position determined for each input signal. Therefore, since the time slot is secured regardless of whether the transmission path is in use or not, the signal in the unused state (that is, the signal corresponding to the silence) is transmitted even when it is not used, which is inefficient. .

Further, in place of the time division multiplexing method, there can be considered a device for efficiently multiplexing a transmission line in which a signal to be transmitted is made into ATM cells and cell-multiplexed. CCITT is a fixed-rate service for communication on time-division transmission lines.
Recommendation I. As indicated by 363, AAL1 (ATM adaptation layer 1) is used. Then, since the bit rate is fixed, when the transmission line is not used, the signal is also in an unused state (that is, an ATM cell signal corresponding to silence).
Will be sent and it is inefficient.

The present invention provides a multiplexer which can transmit data to be transmitted and can efficiently use a band when there is data to be transmitted in an unused state where valid information is not transmitted on a transmission line. The purpose is to

[0008]

In order to solve the above problems, the present invention provides a multiplexing circuit which is connected to a plurality of transmission lines, multiplexes information on each transmission line, and sends the multiplexed information to the multiplexed transmission line. In a multiplexer having a demultiplexing circuit for demultiplexing information from a multiplexed transmission line, transmission control signal detecting means for monitoring a voice control signal input to the demultiplexing circuit, and audio output from the demultiplexing circuit Reception control signal detecting means for monitoring the control signal for use, storage means for accumulating data other than voice input to the multiplexing circuit, and voice by the detection signals from the transmission control signal detecting means and the reception control signal detecting means. Is transmitted and received, and a control means for controlling to transmit the data of the storage means when the voice is not transmitted and received.

[0009] The data may be data in which the position of multiplexing is not fixedly assigned in advance.

As another solution, a multiplexing circuit which is connected to a plurality of transmission lines, multiplexes information on each transmission line and sends the multiplexed information to the multiplexed transmission line, and information from the multiplexed transmission line is separated. In a multiplexer having a demultiplexing circuit for
Control signal detecting means for monitoring a voice control signal input to the multiplexing circuit and detecting a transmission / reception request from the voice control signal; storage means for accumulating data other than voice input to the multiplexing circuit; The control signal detecting means detects that the voice is not being transmitted by the detection signal, and outputs the data from the storage means when the voice is not being transmitted. Reception control signal detecting means for monitoring the voice control signal, the control signal detecting means sends a voice control signal to be sent to the other side to the multiplexing circuit, and the reception control signal detecting means is When a predetermined voice control signal is detected, it can be output as if a ringing tone was received. Further, it may be further provided with a cellizing means for dividing the information on the transmission path into a predetermined fixed amount of cells and a decellizing means for returning the received cell to the original.

A multiplexing method for multiplexing and transmitting a plurality of pieces of information in a multiplexer, which stores data, detects a voice control signal between a transmitting side and a receiving side, and transmits and receives voice. If not, the above problem can be solved by a multiplexing method of multiplexing and transmitting data.

[0012]

The storage means stores data that may be delayed. The transmission control signal detection means monitors the voice transmission control signal input to the multiplexing circuit and detects a transmission request or a receivable control signal. The reception control signal detecting means monitors the voice reception control signal output from the separation circuit. The control means controls so as to send the data of the storage means when the voice is not transmitted / received by the detection signals from the transmission control signal detection means and the reception control signal detection means.

Further, the transmission control signal detecting means sends the audio control signal to the multiplexing circuit, and the multiplexing circuit
When transmitting data from the storage means, the data from the storage means is multiplexed with the voice control signal instead of multiplexing the voice signal. As a result, the voice control signal can be transmitted even when transmitting data. The cellization means divides the information on the transmission path into a predetermined fixed amount of cells, and the decellization means restores the received cells to the original.

When the control signal detecting means is provided, the audio control signal input to the multiplexing circuit is monitored,
A send / receive request is detected, and the corresponding SS signal in the send direction is'
Data transmission is performed instead of the voice signal which is'geki '.
In this case, when the reception control signal detecting means detects a predetermined signal from the voice control signal, the reception side is notified that the ringing tone has been received.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.
In FIG. 1, reference numerals 100 and 200 denote ATM multiplexers for demultiplexing ATM cells. 101, 15
Reference numerals 1, 201, and 251 denote voice transmission paths, which are connected to the multiplexers, respectively. 102, 152, 202
Data transmission lines 252 and 252 are connected to the multiplexing device, respectively. Reference numerals 103 and 253 denote SS signal detection circuits of the transmission control signal detection means, which detect the SS signal for each cell from the information transmitted on each transmission path and output the detection signal. Reference numerals 153 and 203 denote SR signal detection circuits of the reception control signal detection means, which detect an SR signal for each cell from the information of the demultiplexing circuit and output a detection signal. The SS / SR signal is a voice control signal for monitoring the line status on the digital line which has been used conventionally, and the connection can be controlled by the SS / SR signal. In, it uses this signal to detect whether it is in use or unused. Multiplexer 1
On the 00 side, the SS signal detection circuit 103 uses the transmission line 101
The SR signal detection circuit 153 monitors the SS signal from
The SS signal from the transmission line 151 is monitored. Reference numerals 104 and 254 denote voice cell conversion circuits, which can be converted into cells when the voice data on each transmission line is not divided into cells of a predetermined fixed length block. 15
Reference numerals 4 and 204 denote voice decelerating circuits, which decellize the cells cellized by the voice cellifying circuits 104 and 254 into original continuous voice data. Reference numerals 105 and 255 are data cell conversion circuits, which can be converted into cells when the data on each transmission line is not divided into cells of a predetermined fixed length block. 155
Reference numerals 205 and 205 denote data decellizing circuits, which decellize the cells cellized by the data cellizing circuits 105 and 255 into original continuous data. 106 and 256 are cell transmission control circuits of the control means, and SS
The signal detected by the signal detection circuit and the SR signal detection circuit 153 controls whether or not data is transmitted. The cell transmission control circuits 106 and 256 control the voice cell conversion circuits 104 and 254 so as not to transmit voice cells when the detection signals from the SS signal detection circuit 103 and the SR signal detection circuit 153 are unused. Then, the cell is controlled to be transmitted to each of the data cell transmission buffers 107 and 257. Reference numerals 107 and 257 denote data cell transmission buffers of the storage means, which accumulate data cells. In this case, the data stores data that may be delayed. Reference numeral 108 denotes a cell multiplexing circuit, which multiplexes cells from a plurality of transmission lines,
It is sent to the ATM multiplex transmission path 300. A cell separation circuit 109 separates the cells from the ATM multiplex transmission path 300 into respective transmission paths.

Further, FIG. 2 shows an explanatory view of the actual positioning of the multiplexer. In FIG. 2, 150 and 250 are exchanges, which exchange signals with destinations. 16
0 and 260 are voice terminals such as a telephone. 170
Reference numerals 270 and 270 are data terminals, and 300 is an ATM multiplex transmission line. FIG. 3 is a diagram showing only the SS / SR signals, showing the SS / SR relationship between the exchanges. 4 shows a sequence diagram of the exchange of SS / SR signals between the private branch exchange 150 and the private branch exchange 250 when the telephone 160 shown in FIG. 2 is activated to talk with the telephone 260.

First, the operation in the case of starting from the telephone 160 shown in FIG. 2 and making a call with the telephone 260 will be described with reference to the block diagram shown in FIG. 1 and FIG. 4, and then, when the telephone is not busy. The operation of will be described.

From the telephone 160 via the exchange 150, the SS signal of the voice control signal becomes "ground" and the activation signal is transmitted. In the multiplexing device 100, the SS signal detection circuit 103 detects that the SS signal is “ground” and notifies the control means 106. The SS signal detection will be described later. When the SS signal is “earthly”, the control means 106 controls not to send the data from the transmission buffer 107 because it is transmitting, and instructs the voice cell conversion circuit 104 to convert the voice signal into cells. To do. In the voice cell conversion circuit 104, S of the voice control signal is used.
The S signal is converted into cells, and the time slot of the voice signal is converted into cells. The cell formation will be described later. Further, when the cells are already made into cells and input to the multiplexer, the cell assembling circuit and the decellizing circuit can be omitted. The multiplexing circuit 108 multiplexes each cell to multiplex the transmission line 30.
Send to 0. The opposing separating circuit 109 separates the multiplexed cells, and the voice decellerizing circuit decelerates the cells back to the original voice information and voice control signal. On the multiplexing device 200 side, the SS transmitted on the multiplexing device 100 side
The SR signal detection circuit 203 detects the signal “ground” as the SR signal “ground” and transmits it to the cell transmission control circuit 256. The SS signal detection circuit 253 on the side of the multiplexing device 200 does not detect the SS signal "ground", but the cell transmission control circuit 256 controls the voice cell conversion circuit 254,
The cell of the voice signal on the transmission side corresponding to the detected SR signal and the cell of the control signal for voice are transmitted. Switch 250
Then, the SR signal is set to "ground", the SS signal is set to "ground", and the start signal is sent. After that, the telephone 160 and the telephone 260 talk with each other as shown in FIG. When the call ends, the SS signal of the voice control signal is set to '
It is turned off and sent as a disconnection signal. In the example shown in FIG. 4, the exchange 150 “disconnects” the SS signal of the voice control signal.
I have to. In response to this, the exchange 250 sets the SS signal to "disconnected" and sets it as a restoration completion signal. Multiplexer 100
The cell output from the demultiplexing circuit 109 is decellized by the voice decelling circuit to return the cell to the original voice information and the voice control signal, and the SR signal detection circuit 153 monitors the SR signal. The SR signal detection circuit 153 detects “break” and “ground” of the SR signal and notifies the control means 106. In the control means 106, in the SS signal detection circuit 103, the SS signal is “ground” or SR
In the signal detection circuit 153, when the SR signal is “earthly”, it is determined that transmission / reception is in progress, and control is performed so that an audio signal is transmitted. That is, the SS signal detection circuit 103
While either "Ground" is being detected by either of the SR signal detection circuit 153 and the
The data in the transmission buffer 107 is not transmitted.

When the telephone is not busy, that is, the SS signal detection circuit 103 and the SR signal detection circuit 1
In 53, when the SS signal is "disconnected" and the SR signal is "disconnected", the cell transmission control circuit 106 makes only the control signal of the SS signal into cells and transmits the cells, and does not perform the cell transmission of the voice signal. In this way, the voice cell conversion circuit 104 is controlled. At this time, the cell transmission control circuit 106 controls the data cell transmission buffer 107 to transmit the data cell. In addition, regarding decellization, an unused signal (that is, an ATM cell signal corresponding to silence) is transmitted to the voice decelling circuit 204 of the multiplexer 200 by the amount of the data signal transmitted by the transmitter of the multiplexer 100. Since it does not arrive, the voice decelerating circuit 154 performs the decelerating operation for the amount of the silent signal forcibly in the unused state. The operation in the direction from the multiplexer 200 to the multiplexer 100 is similar. The reception side can judge whether the non-arrival of the cell is due to the efficiency improvement according to the present invention or due to the failure by observing the SR signal.

In the case of one-way communication, the cell transmission control circuit 256 may not be controlled by the SR signal detected by the SR signal detection circuit 203 on the multiplexer 200 side.

FIG. 11 shows how cells are multiplexed in the ATM multiplexer 100. FIG. 11 shows a case in which information that has already been converted into cells is input. Figure 11
As shown in FIG.
The voice cell input to 0 is'SS signal or SR signal '.
When the ground 'is not detected, it is determined that the call is not in progress, and the data cell accumulated in the transmission buffer 107 is inserted instead.

In the above embodiment, a data transmission line may be further provided and a position for multiplexing may be assigned in advance.

Next, the detection of the SS signal will be described. FIG. 12 shows the format of the control signal. 12
As shown in, the voice control signal on the transmission path 101 is assigned to TS0 corresponding to each time slot. The audio information is assigned to TS1 to TS31. The control signal of each time slot is assigned to the signal bit of TS0 by configuring a multiframe. The SS signal detection circuit 103 monitors the signal bit of TS0 and detects the control signal corresponding to each time slot.

Next, the operation of forming an ATM cell will be described.
FIG. 9 shows the format before and after the conversion into ATM cells.

In FIG. 9, in the cell assembling circuit 104, S
Information from the transmission line is input via the S signal detection circuit 103. The input information is switched by the selector 500 according to an instruction from the cell transmission control circuit 106, divided into predetermined cell units, and temporarily stored.
Further, in the cell assembling circuit 104, the header of the identification information is added to the respective divided information, and as shown in FIG. 9, each time slot is made into cells and each cell can be transmitted.

In FIGS. 1, 2 and 3, as described above, the cell transmission control circuits 106 and 256 have the SS
The unused state is detected from the signal detection circuits 103 and 253. At that time, the cell transmission control circuits 106 and 256
Is a voice cell conversion circuit 10 so that voice cells are not transmitted.
4 and 254 to control the data cell transmit buffer 10
7 and 257 are controlled to transmit cells. Therefore, it is possible to transmit a signal in an unused state (that is, an ATM cell signal corresponding to silence) when there is no valid information and the transmission line is unused.

According to this embodiment, the band can be efficiently used by transmitting other data because the data is not transmitted when the voice is not used.

Next, a second embodiment will be described with reference to FIG.

In the present embodiment, the SR signal detection circuit is not provided and only the SS signal of the SS signal detection circuit is monitored.

In FIG. 5, the multiplexer 100 and the multiplexer 200 are independent of each other, and the SS detection circuit 103 and the SS detection circuit 103, respectively.
The SS / SR signal is taken out by the detection circuit 253, and when the SS signal is "ground", the cell transmission control circuits 106 and 256 are so arranged as to perform the cell transmission of the voice signal and the cell transmission of the SS signal.
Control voice cell conversion circuits 104 and 254, respectively. Then, the voice cell is not transmitted except when the KP signal, the selection signal is transmitted, or during the call. In this case, the SR signal detection circuit of the reception control signal detection means for monitoring the voice control signal output from the separation circuit is further provided, and the SR signal detection circuit is called when a predetermined KP signal is detected. The reception side can be notified that the sound has been received. Alternatively, the initiating exchange may emit a ringing tone.

When not in use, that is, when the SS signal is "disconnected", the cell transmission control circuits 106 and 2
56 controls to transmit data to the data cell transmission buffer.

On the other hand, on the reception side of the voice cell, the data signal is transmitted on the transmission side, so that the unused signal is not transmitted. Even if there are no such cells, the voice decellizing circuits 154 and 204 decellize as an unused state. Whether the cell is not transmitted due to efficiency improvement or a failure is determined based on the received SS / SR signal.

As described above, when not in use, the band can be efficiently used because the other data can be transmitted because the voice signal is not transmitted.

Next, an embodiment of the STM multiplexer will be described with reference to FIGS. 7 and 8. FIG. 7 is an explanatory diagram showing an example of multiplexing in the STM multiplexer. In FIG. 7, the transmission lines a, b, c and d are connected to the multiplexing device 510, and the information transmitted on the transmission lines a, b and c is in the multiplexing device 510 for each time slot. Time-division-multiplexed and multiplexed transmission line 310
Sent to. The data transmitted on the transmission path d is accumulated in the transmission buffer 107. STM multiplexer 510
Then, when the time slot is not in use, the data accumulated in the transmission buffer 107 is inserted into the position of the time slot allocation when it is not used. Figure 8
The whole figure in the STM multiplexer is shown. In FIG. 8, reference numeral 510 denotes an STM multiplexer, which multiplexes and demultiplexes each time slot into a predetermined time slot position. Reference numerals 101, 151, 201, and 251 are voice transmission paths, and are connected to the multiplexers, respectively. 10
Reference numerals 2, 152, 202 and 252 denote data transmission paths, which are connected to the multiplexers, respectively. Reference numerals 103 and 253 denote SS signal detection circuits of the transmission control signal detection means, which detect the SS signal for each cell from the information transmitted on each transmission path and output the detection signal. 106 and 256 are cell transmission control circuits of the control means, and SS
The signal detected by the signal detection circuit controls whether or not data is transmitted.

Also in this embodiment, like the above-mentioned ATM multiplexer, when the unused state is detected by the SS signal detecting circuit, the data time slot can be inserted instead of the voice time slot.

According to this embodiment, other data can be transmitted when it is not used.

[0038]

According to the present invention, when there is data to be transmitted in the unused state where valid information is not transmitted on the transmission line, the data to be transmitted can be transmitted and the band can be used efficiently.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a system configuration diagram showing the actual positioning of an ATM multiplexer.

FIG. 3 is an explanatory diagram showing SS / SR signals.

FIG. 4 is an explanatory diagram showing an SS / SR transmission / reception relationship.

FIG. 5 is a block diagram showing another embodiment of the present invention.

FIG. 6 is an explanatory diagram of time slots showing an example of multiplexing in a conventional STM multiplexer.

FIG. 7 is an explanatory diagram of STM time slots showing a multiplexing example of the STM multiplexer according to the embodiment of the present invention.

FIG. 8 is an overall view of an STM multiplexer according to an embodiment of the present invention.

FIG. 9 is a format before and after conversion to an ATM cell.

FIG. 10 is an explanatory view showing ATM multiplexing of a conventional example.

FIG. 11 is an explanatory diagram showing ATM multiplexing according to the embodiment of this invention.

FIG. 12 is a format of a control signal.

[Explanation of symbols]

100/200 ... ATM multiplexer, 101/151.
201.251 ... Time division multiplexing transmission line, 102.152.
202.252 ... data transmission path, 103.253 ... SS
Signal detection circuit, 153.203 ... SR signal detection circuit, 1
04.254 ... voice cell conversion circuit, 154.204 ... voice decellization circuit, 105.255 ... data cell conversion circuit, 155.205 ... data decellization circuit, 106.
256 ... Cell transmission control circuit, 107/257 ... Data cell transmission buffer, 108 ... Multiplexing device, 109 ... Separation device, 150.250 ... Private branch exchange, 160. 260 ...
Telephone, 170/270 ... Data terminal, 300 ... ATM multiplex transmission line.

Claims (7)

[Claims] 1. A multiplexing circuit, which is connected to a plurality of transmission lines, multiplexes information on each transmission line, and sends out to the multiplexed transmission line.
In a multiplexing device having a demultiplexing circuit for demultiplexing information from a multiplexed transmission line, a transmission control signal detecting means for monitoring a voice control signal input to the multiplexing circuit, and a voice output from the demultiplexing circuit. Reception control signal detecting means for monitoring the control signal for use, storage means for accumulating data other than voice input to the multiplexing circuit, and voice by the detection signals from the transmission control signal detecting means and the reception control signal detecting means. And a control unit for detecting that the data of the storage unit is not transmitted and receiving and transmitting the data of the storage unit when the voice is not transmitted and received. 2. The multiplexing device according to claim 1, wherein the data is data in which a multiplexing position is not fixedly allocated in advance. 3. A multiplexing circuit, which is connected to a plurality of transmission lines, multiplexes information on each transmission line, and sends out to the multiplexed transmission line.
In a multiplexing device having a demultiplexing circuit for demultiplexing information from a multiplexed transmission line, a control signal detecting means for monitoring a voice control signal input to the multiplexing circuit and detecting a transmission / reception request from the voice control signal. A storage means for accumulating data other than voice input to the multiplexing circuit, and detecting that the voice is not being transmitted by the detection signal from the control signal detecting means. It has a control means for controlling to transmit the data of the storage means, and a reception control signal detecting means for monitoring the voice control signal output from the other party, and the control signal detecting means transmits to the other party. A voice control signal for transmitting to a multiplexing circuit, and the reception control signal detecting means outputs a ringing tone as being received when a predetermined voice control signal is detected. Multiplexing device. 4. The cell assembling means according to claim 1, wherein the information on the transmission path is divided into a predetermined fixed amount of cells.
A multiplexing device, further comprising: decellizing means for returning the received cell to the original state. 5. One or more voice terminals and one or two
The above data terminals are connected via a transmission line, and a multiplexing circuit that multiplexes information from each terminal and sends it to the multiplexed transmission line and a demultiplexing circuit that separates information from the multiplexed transmission line are provided. In a multiplex communication system in which multiplex devices provided are arranged in pairs via multiplex transmission paths, the multiplex device includes a transmission control signal detecting means for monitoring a voice control signal from the voice terminal, and a partner device. Reception control signal detection means for monitoring the voice control signal output from the multiplexer, storage means for accumulating data from the data terminal, detection signals from the transmission control signal detection means and the reception control signal detection means. By detecting that voice is not being transmitted / received, and controlling the data in the storage means to be sent to the other multiplexing device when voice is not being transmitted / received. Multiplex communication system characterized by. 6. One or more voice terminals and one or two
The above data terminals are connected via a transmission line, and a multiplexing circuit that multiplexes information from each terminal and sends it to the multiplexed transmission line and a demultiplexing circuit that separates information from the multiplexed transmission line are provided. In a multiplex communication system in which multiplex devices provided are arranged in pairs via multiplex transmission paths, the multiplex device monitors a voice control signal from the voice terminal and detects a transmission / reception request from the voice control signal. Control signal detecting means, storage means for accumulating data from the data terminal, and detection of the fact that voice is not being transmitted by the detection signal from the control signal detecting means. The control signal detecting means has a control means for controlling so as to send out the data of the means, and a reception control signal detecting means for monitoring the voice control signal output from the multiplexing device on the other side. A voice control signal to be transmitted to a multiplexing device on the side, and the reception control signal detection means outputs a ringing tone as being received when detecting a predetermined voice control signal. Multiplex communication system. 7. A multiplexing method for multiplexing and transmitting a plurality of pieces of information, wherein data is accumulated, a control signal for voice is detected between a transmitting side and a receiving side, and voice is not transmitted / received, A multiplexing method that multiplexes and sends data.