JPH1079714A - Data communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically change a reception side separation mode based on a synchronizing signal by detecting the synchronous relation of a communication data and switching a separation mode of the communication data on the reception side. SOLUTION: When a mode selection signal to a frame multiplex part 1 is at a data multiplex mode, A and B channel data are frame-multiplexed in a specified synchronous relation maintained state in the multiplex part 1 and a carrier signal is transmitted through a modulation part 2. In the synchronous relation realizing period, the reception side operates at the separation mode corresponding to a transmission side multiplex mode and the synchronizing signal is transmitted to a frame separation part 4 so as to separate A and B channel data. When the selection signal is switched to a non-multiplex mode, the multiplex part 1 transmits non-multiplex data constituted of only an A channel to the modulation part 2. At that time, a detection part 5 does not detect a B channel pattern and therefore the transmission of the synchronizing signal to the separation part 4 is stopped. Thus, the separation part 4 outputs only A channel data of non-multiplex data to the reception side A channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication apparatus, and more particularly to a technique for multiplexing and transmitting data of a plurality of channels.

[0002]

2. Description of the Related Art Conventionally, in this type of data communication apparatus, a transmitting side transmits a channel configuration of multiplexed data to a receiving side, and the receiving side transmits the multiplexed data based on the channel configuration received from the transmitting side. The separation of the data of each channel is controlled.

For example, Japanese Patent Application Laid-Open No. 63-194448 discloses a technique for switching channels by a rate sequence means. In this technique, a rate sequence is transmitted from a transmitting apparatus to a receiving apparatus by transmitting a rate sequence from a transmitting apparatus to a receiving apparatus while transmitting the rate sequence to a receiving apparatus. In addition, Japanese Patent Application Laid-Open No. 1-19666 discloses a technique for switching channels by transmitting address information. This technique uses a multiplexing operation at a master station where several channels are concentrated on a single common transmission channel, and data is demultiplexed at the other end of the common transmission channel by a slave station that sends data to a destination. In the system, a symbol including address information is transmitted on the active channel of the master station, and the slave station determines the channel configuration selected by the master station from the bit pattern of the symbol.

[0004]

The problem of the above-mentioned prior art is that a rate sequencer is used. In other words, when switching the multiplex mode frequently,
It is necessary to transmit the rate sequence on the training signal each time, and at this time, a training signal that is originally unnecessary for transmitting the rate sequence is transmitted. The point is that data cannot be sent. The second problem is that the multiplex mode is switched based on the address information, and it is necessary to add address information to the data, thereby lowering the transmission efficiency. .

The present invention has been made in view of the above-mentioned problems, and has the following objects. (1) To provide a data communication device capable of automatically switching a reception signal separation mode. (2) To provide a data communication device capable of receiving multiplexed data without lowering transmission efficiency.

[0006]

In order to achieve the above object, as a first means, multiplexed data obtained by frame-multiplexing data of a plurality of channels or non-multiplexed data consisting only of data of a specific channel. In a data communication apparatus which transmits and receives the communication data as communication data, the receiving side detects a synchronization relationship of the communication data and switches the communication data separation mode based on the synchronization relationship.

[0007] As a second means, a data communication apparatus which transmits and receives multiplexed data obtained by frame-multiplexing data of a plurality of channels or non-multiplexed data consisting only of data of a specific channel as communication data is received. Means for detecting a synchronization relationship of communication data, a frame detection unit that outputs a synchronization signal when a specific synchronization relationship is detected, and a frame separation unit that switches a separation mode of communication data based on the synchronization signal. Adopted.

[0008]

According to the present invention, the receiving side detects the synchronous relationship of the frames of the communication data received from the transmitting side, and switches the communication data separation mode based on the synchronous relationship. For example, the frame detection unit detects a synchronization relationship of the received communication data, and outputs a synchronization signal when a specific synchronization relationship is detected. Then, the frame separation unit operates to switch the communication data separation mode based on the synchronization signal output from the frame detection unit. That is, the transmitting side can automatically switch the demultiplexing mode according to the multiplexing mode of the transmitting side without transmitting a special signal indicating the content of the frame multiplexing from the transmitting side to the receiving side.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a data communication device according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a communication system to which the present embodiment is applied. In this figure, reference numeral 1 denotes a frame multiplexing unit, and 2 denotes a modulation unit, each constituting a transmission device. The frame multiplexing unit 1 multiplexes data respectively input from the A channel and the B channel in a specific frame pattern based on a mode selection signal applied from the outside, generates multiplexed data, and modulates the multiplexed data as one of communication data. Output to section 2.

The frame multiplexing unit 1 generates non-multiplexed data only from the data of the A channel without multiplexing the data of the A channel and the B channel depending on the mode selection signal, and modulates the data as the other communication data. It is configured to output to the unit 2. Note that the mode selection signal is
In the transmitting apparatus, the multiplexing mode of the data of each channel is specified.

Here, since the frame multiplexing unit 1 multiplexes the data of the A channel and the data of the B channel by frame, the multiplexed data output from the frame multiplexing unit 1 includes the data of the A channel and the data of the B channel. And a specific synchronous relationship is established. The modulation unit 2 modulates the multiplexed data frame-multiplexed by the frame multiplexing unit 1 or the non-multiplexed data consisting of only the A channel data based on a predetermined modulation method, and outputs the modulated data to the transmission path as a carrier signal. I do.

Subsequently, reference numeral 3 denotes a modulation unit, 4 denotes a frame separation unit, and 5 denotes a frame detection unit, each of which is a component constituting a receiving apparatus. The demodulation unit 3 receives the carrier signal via a transmission path, and demodulates and extracts communication data generated on the transmission side. The frame detection unit 5 detects the synchronization relationship of the communication data formed by the transmission device, and extracts a frame pattern in the communication data.

When the frame pattern is detected, that is, the data of the A channel and the data of the B channel are multiplexed on the transmitting side to form multiplexed data, and a specific data between the data of both channels is formed. When the synchronization relationship is detected (period), the frame detection unit 5 outputs a synchronization signal indicating that the synchronization relationship is detected to the frame separation unit 4.

The frame separating section 4 separates communication data in accordance with the channel configuration on the transmitting side. That is, during the period in which the synchronization signal is being input from the frame detection unit 5, the frame separation unit 4 uses the multiplexed data formed by multiplexing the communication data with the A channel data and the B channel data. Assuming that the multiplexed data exists, the multiplexed data is separated, the data of the A channel is output to the A channel, and the data of the B channel is output to the B channel.

On the other hand, when the synchronization signal is not input, that is, when the non-multiplexed data formed only by the A channel data is input from the demodulation unit 3, the frame separation unit 4 The data on the A channel on the transmitting side is extracted and output to the A channel on the receiving side.

Next, the switching operation of the separation mode in the data communication device will be described. First, in the transmitting device, when the mode selection signal supplied to the frame multiplexing unit 1 indicates the data multiplexing mode, the data of the A channel and the data of the B channel are combined with the frame multiplexing unit 1.
Thus, frames are multiplexed while maintaining a specific frame pattern (synchronous relationship), and multiplexed data is generated. Then, the multiplexed data is modulated by the modulation unit 2 based on a specific modulation scheme, and is transmitted to a transmission path as a carrier signal.

When the carrier signal generated in this way is received, in the receiving apparatus, the demodulation section 3 demodulates the carrier signal and restores the multiplexed data. The multiplexed data obtained by the demodulation is input to the frame detection unit 5 and the synchronization relationship of the multiplexed data is detected. And
During the period in which this synchronization relationship is established, the receiving apparatus operates in the separation mode corresponding to the multiplexing mode on the transmission side, and the synchronization signal is transmitted from the frame detection unit 5 to the frame separation unit 4.
Is output to

The multiplexed data is also input to the frame separation unit 4 from the demodulation unit 3 and the multiplexed data is input to the frame separation unit 4 during the period when the synchronization signal is input to the frame separation unit 4. It is separated into A channel data and B channel data. That is, of the multiplexed data, the data of the A channel on the transmission side is output to the A channel on the reception side, and the data of the B channel on the transmission side is output to the B channel on the reception side.

In the case where the mode selection signal is switched to a state not instructing the data multiplexing on the transmitting side, the frame multiplexing unit 1 operates in the non-multiplexing mode, thereby demultiplexing only the A channel data. Modulate data 2
Output to Since the non-multiplexed data in this case is formed only from the data of the A channel, the synchronous relationship is not established when the data of the A channel and the data of the B channel are frame-multiplexed as described above.

Therefore, when receiving this non-multiplexed data, the receiving device operates in the demultiplexing mode corresponding to the non-multiplexing mode on the transmitting side. That is, since the frame detection unit 5 does not detect a frame pattern based on the data of the A channel and the data of the B channel, the frame separation unit 4
The output of the synchronization signal to is stopped. As a result, the frame separation unit 4 outputs only the data of the channel A on the transmission side extracted from the non-multiplexed data to the A channel on the reception side.

[0022]

As described above, the data communication device according to the present invention has the following effects. (1) In a data communication apparatus for transmitting and receiving multiplexed data obtained by frame-multiplexing data of a plurality of channels or non-multiplexed data consisting only of data of a specific channel as communication data, the receiving side has a synchronization relationship of the communication data. Is detected and the separation mode of the communication data is switched based on the synchronization relationship. Therefore, when the multiplexing mode of the transmission side is changed, this is detected, and the reception side is automatically detected based on the synchronization signal indicating the detection result. Can be changed. (2) Since the separation mode on the receiving side can be changed without transmitting a special signal from the transmitting side, the transmission efficiency does not decrease.

[Brief description of the drawings]

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

[Explanation of symbols]

1 ... frame multiplexing unit, 2 ... modulation unit, 3 ... demodulation unit,
4 ... frame separation unit, 5 ... frame detection unit

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yuichiro Shida 5-7-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation

Claims (2)

[Claims] 1. A data communication apparatus for transmitting and receiving multiplexed data obtained by frame-multiplexing data of a plurality of channels or non-multiplexed data consisting only of data of a specific channel as communication data. A data communication device, wherein a synchronous relationship is detected, and a separation mode of communication data is switched based on the synchronous relationship. 2. A data communication apparatus for transmitting and receiving multiplexed data obtained by frame-multiplexing data of a plurality of channels or non-multiplexed data consisting only of data of a specific channel as communication data. A frame detection unit that detects a relationship and outputs a synchronization signal when a specific synchronization relationship is detected; and a frame separation unit that switches a communication data separation mode based on the synchronization signal. Communication device.