JP2002033844A - Communication device using ISDN line - Google Patents

Abstract

[PROBLEMS] To absorb a difference in propagation delay time between a plurality of B channels and accurately transmit and receive data even in communication using a plurality of B channels simultaneously. . SOLUTION: When connected to ISDN lines 422, 404 having a plurality of B channels, at the time of call setting, each of the B channels used by the partner communication device and the B channel used by the own communication device are set.
An ISDN interface circuit 403 for establishing a call connection on a plurality of B channels by associating with each of the channels and dividing predetermined data into the plurality of channels for transmission
And a B-channel data storage circuit 412 for storing data in another communication channel until the communication channel receiving the data finally receives the data, and when the data is received in all the B channels, A switching circuit for outputting data in a predetermined order and a data storage input / output control circuit 416 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication apparatus using an ISDN line, and more particularly to a communication apparatus using a plurality of communication channels at the same time and combining the data rates of the plurality of communication channels with one communication rate. IS for doing
The present invention relates to a communication device using a DN line.

[0002]

2. Description of the Related Art In a basic ISDN interface, one B channel (64 kb) is established by one call connection.
ps). Therefore, in a conventional communication method using an ISDN line, the maximum data rate of a line that can be transferred by one call connection is the data rate of one B channel (64 kbps),
When performing digital communication for transmitting and receiving data at a speed of 64 kbps or more, a digital leased line or a primary group speed interface has been used.

As a method for solving this problem, ISDN
By using two channels of B1 and B2 of the basic interface simultaneously, up to 128 kbp
It is possible to correspond to the communication speed of s.

[0004]

However, as described above, since both channels B1 and B2 cannot be set simultaneously by one call connection, the B1 channel and the B2 channel are call-connected for each channel. It is necessary to do.

As described above, when a call connection is made for each of the B1 channel and the B2 channel, a connection path differs for each channel, and a difference occurs in the propagation delay time of each channel. In addition, there is a problem that it is not possible to correspond to the channel used between the communication devices at the time of call connection for each channel.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ISDN line which absorbs a difference in propagation delay time between a B1 channel and a B2 channel, and
ISD that can transmit and receive data accurately even in communication using one channel and B2 channel simultaneously
An object of the present invention is to provide a communication device using N lines.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a communication apparatus connected to an ISDN line having a plurality of communication channels and transmitting and receiving one data using the plurality of communication channels. Means for making a call connection on the plurality of communication channels by associating each of the communication channels used by the communication device with each of the communication channels used by the communication device, and dividing predetermined data into the plurality of channels. Means for transmitting data to another communication channel until the communication channel receiving the data finally receives the data, and means for storing the data of all the channels when the data is received on all the channels. Means for outputting in a predetermined order, wherein the communication is performed by absorbing a delay difference between the plurality of communication channels.

By adopting such a configuration,
When making a call connection on an ISDN line, the correspondence between a plurality of communication channels used by a partner communication device and its own communication device does not deviate, and the delay difference in received data between the plurality of communication channels can be easily absorbed. And it is possible to perform data communication combining a plurality of communication channels.

[0009]

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

FIG. 1 is a block diagram of the ISDN basic interface B.
128k using 1 channel and B2 channel simultaneously
FIG. 1 is a diagram illustrating a configuration of a system that transfers image information at a communication speed of bps.

In FIG. 1, an image signal captured by a video camera 1 is converted from an analog signal to a digital signal by an image codec device 2 and output to an output signal line 4 by a terminal adapter 3. The signal is I
The signal is sent to the input signal line 5 via the SDN switching network 13. The terminal adapter 6 outputs the image signal received from the input signal line 5 to the image codec device 7. Then, the image signal is converted into an analog signal by the image codec device 7 and transmitted to the video monitor 8. Similarly, the image signals captured by the video camera 9 are the image codec device 7, the terminal adapter 6, the output signal line 10, the ISDN switching network 13, the input signal line 11,
It is output to the video monitor 12 via the terminal adapter 3 and the image codec device 2.

FIG. 2 shows a terminal adapter 6 and an ISDN
FIG. 3 is a diagram showing a signal transmission format between the switching network 13 and the network;

This format is composed of two 6 bits B1 and B2.
A data transfer channel having a speed of 4 kbps;
It comprises a D channel for call control at a data rate of 6 kbps, and other framing bits, DC balanced bits, D echo channel bits, auxiliary frame bits, and the like. This format is used as an ISDN basic interface.

FIG. 3 shows a call control sequence using the outgoing / incoming D channel, and a sequence for performing communication at a data transfer rate of 128 kbps by simultaneously using the B1 channel and the B2 channel, that is, the B1 channel and the B2 channel. FIG. 6 is a diagram showing a sequence for establishing synchronization of the above.

FIG. 4 is a block diagram showing the internal configuration of the terminal adapter.

In FIG. 4, reference numeral 403 denotes an ISDN switching network 1
ISDN interface circuit for interfacing with B. 3; 402, a synchronization pattern transmission circuit for generating and transmitting a synchronization pattern to be transmitted on the B channel; 412, a B channel data storage circuit for temporarily storing data on the B channel; Is a switching circuit, 416 is a data storage input / output control circuit for controlling the B channel data storage circuit 412 and the switching circuit 417, 406 is a switching circuit controlled by a synchronization pattern transmission circuit, and 425 is a synchronization pattern 1 on the B1 channel. A B1 channel synchronization pattern 1 detection circuit 426 for detecting the synchronization pattern 1 on the B2 channel, and a B2 channel synchronization pattern 1 detection circuit 410 for detecting the synchronization pattern 1 on the B2 channel
A B1 channel synchronization pattern 2 detection circuit 411 for detecting a synchronization pattern 2 on one channel, a B2 channel synchronization pattern 2 detection circuit 411 for detecting a synchronization pattern 2 on the B2 channel, and a reference numeral 414 detects a synchronization pattern 3 on the B1 channel. The B1 channel synchronization pattern 3 detection circuit 415 is a B2 channel synchronization pattern 3 detection circuit for detecting the synchronization pattern 3 on the B2 channel, 405, 407 to 40
9, 418, 420, 423, 424, and 428 to 430 are signal lines of each circuit.

The operation will be described below with reference to FIG.

When making a call from the terminal adapter 3,
A call setup message [B1] connecting the B1 channel and a call setup message [B2] connecting the B2 channel are sent to the ISDN switching network 13 by the D channel. At this time, the channel information is set in the information element "calling subaddress" so that the terminal adapter 6 on the receiving side can determine which channel corresponds to the call setting message.

In response to the call setup messages [B1] and [B2] sent by the terminal adapter 3, the ISDN switching network 1
3 returns call setting acceptance messages [B1] and [B2]. This allows the B1 and B2 channels to be
N switching network, and synchronize pattern 1 with ISDN switching network 1.
3

On the other hand, the terminal adapter 6 on the receiving side is
The call setup message [B received from the ISDN switching network 13
1], the same channel as the B channel specified by the information element “source subaddress” of [B2] is sent to the response message [B
1] and [B2] are specified in the information element "channel identifier" and transmitted to the ISDN exchange network 13. In response to the response message, response confirmation messages [B1] and [B2] are returned from the ISDN switching network 13, thereby connecting the B channel to the ISDN switching network 13 and starting a synchronization sequence by the B channel.

Next, a synchronization sequence using the B channel will be described.

The terminal adapter 3 sends out a call setup message for the B1 and B2 channels, and receives a call setup acceptance message for each of the B1 and B2 channels.
It is transmitted to the DN switching network 13.

On the other hand, B1, B
2 When the response acknowledgment message arrives for each channel, the synchronization pattern 1
Is transmitted, and then the synchronization pattern 2 is transmitted to notify the terminal adapter 3 that the B channel is normally connected. Here, by switching from the synchronization pattern 1 to the synchronization pattern 2, it is possible to more reliably notify information.

At this time, the terminal adapter 6
It is in a state of receiving the synchronization pattern 1 continuously transmitted from the terminal adapter 3 (not shown).

On the other hand, the terminal adapter 3 receives the synchronization patterns 1 and 2 from the B1 and B2 channels, respectively, and recognizes that the B1 and B2 channels are connected normally. B1
The terminal adapter 3 that has recognized that the channel and the B2 channel are normally connected transmits the synchronization pattern 2 simultaneously to the B1 channel and the B2 channel, and then transmits the synchronization pattern 2 to the B1 channel and the B2 channel.
Synchronous pattern 3 is transmitted at the same time, and the synchronous pattern to be transmitted is simultaneously switched from synchronous pattern 2 to synchronous pattern 3.

The terminal adapter 6 detects that the synchronization pattern 2 for the B1 channel and the B2 channel, which has been continuously received from the terminal adapter 3, has changed to the reception of the synchronization pattern 3, respectively.
At this time, when the time when the B1 channel changes from the synchronization pattern 2 to the synchronization pattern 3 is earlier than the time when the B2 channel changes from the synchronization pattern 2 to the synchronization pattern 3,
Based on the time when the B1 channel changes from the synchronization pattern 2 to the synchronization pattern 3, the B2 channel is synchronized with the synchronization pattern 2
Is calculated (detected), and the calculated result is used as the data transmission delay difference between the B1 channel and the B2 channel. Also, the time when the B2 channel changes from the synchronization pattern 2 to the synchronization pattern 3 is the time when the B1 channel changes from the synchronization pattern 2 to the synchronization pattern 3
If it is earlier than the time when the B2 channel changes from the synchronization pattern 2 to the synchronization pattern 3,
The time difference between the time when the B1 channel changes from the synchronization pattern 2 to the synchronization pattern 3 is calculated (detected), and the calculation result is used as the data transmission delay difference between the B2 channel and the B1 channel.

As a result, the terminal adapter 6
B1 channel and B2 received from terminal adapter 3
The transmission delay difference of the channel can be recognized. Then, based on the transmission delay difference, the data buffer and the like are controlled to absorb the transmission delay difference, and the B1 channel and the B2
An operation for establishing synchronization with the channel is performed.

After that, the terminal adapter 3
In addition to displaying a communication enable state to the image codec apparatus 2 to indicate that communication is possible, transmitting a synchronization pattern 3 to the terminal adapter 6, making a communication start request, and receiving from the image codec apparatus 2 The divided image data is transmitted to the terminal adapter 6 in the B1 channel and the B2 channel.

On the other hand, when the terminal adapter 6 receives the synchronization pattern 3 from the terminal adapter 3 on the B1 channel and the B2 channel, the image codec device 7
, A communication enable display indicating that communication is possible is performed, and the synchronization pattern 3 is simultaneously transmitted to the terminal adapter 3 to the B1 channel and the B2 channel.

When the terminal adapter 3 receives the synchronization pattern 3, the terminal adapter 3 determines the above based on the time when the B1 channel changes from the synchronization pattern 2 to the synchronization pattern 3 and the time when the B2 channel changes from the synchronization pattern 2 to the synchronization pattern 3. By the same procedure as the terminal adapter 6,
B from terminal adapter 6 to terminal adapter 3
The transmission delay difference between the 1 channel and the B2 channel is determined, the data buffer and the like are controlled based on the data transmission delay difference, and the synchronization between the B1 channel and the B2 channel is established.

According to the above sequence, the synchronization between the B1 channel and the B2 channel is established in the transmission and reception between the terminal adapter 3 and the terminal adapter 6 in both directions, and the image data is transmitted and received.

When the data communication is completed, the image codec 2 sends the disconnection instruction information to the terminal adapter 3. Upon detecting the disconnection instruction information, the terminal adapter 3 recognizes that the data communication has ended, and sends out disconnection messages [B1] and [B2] to the ISDN exchange network 13. On the other hand, when the release messages [B1] and [B2] are received from the ISDN exchange network 13, the B1 channel and the B2 channel are disconnected from the ISDN line, and the communication enable information is transmitted to the image codec device 2. Is stopped, and a release completion message [B
1] and [B2].

On the other hand, the terminal adapter 6 is an ISDN
When the disconnection messages [B1] and [B2] are received from the switching network 13, the B1 channel and the B2 channel are set to ISDN.
At the same time as disconnecting from the line, the output of the communication enable indication information to the image codec device 7 is stopped, and release messages [B1] and [B2] are sent to the ISDN exchange network 13, and the ISDN is switched.
Release complete message [B1], [B
2], and terminates the communication.

Next, the operation of the terminal adapter shown in FIG. 4 at the time of transmission will be described.

First, the image codec device is connected to the signal line 401.
, The transmission to the ISDN interface circuit 403 is started. ISDN interface circuit 403
Sends the call setup message [B1] and the call setup message [B2] to the ISDN exchange network 13 via the signal line (transmission line) 404 in accordance with the activation request. On the other hand, a signal line (reception line) from the ISDN switching network 13
A call setup acceptance message [B1] is sent via ISD 422
When the N interface circuit 403 receives the signal, the signal line 40
5 to the synchronous pattern transmitting circuit 402 via the control unit 5 to activate the synchronous pattern transmitting circuit 402,
Also, a call setting acceptance message [B
2] is received by the ISDN interface circuit 403, the synchronous pattern sending circuit 402
To the synchronous pattern transmitting circuit 40.
Start 2 Further, the ISDN interface circuit 403 is provided between the signal line 404 and the signal line 402 and the signal line 4.
22 and the signal line 408 are respectively connected.

The synchronization pattern sending circuit 402 is connected to the signal line 4
At 20, the switching circuit 406 is controlled, and the signal lines 430 and 407 are connected. Next, the synchronous pattern sending circuit 40
Reference numeral 2 denotes a synchronous pattern 1 (8-bit data all '0') continuously transmitted to the corresponding B channel in synchronization with a signal transmitted from the ISDN interface circuit 403 and transmitted via the signal line 424. .

Next, the ISDN interface circuit 403
Transmits a signal of the format shown in FIG.
, The signal output from the signal line 424 identifies the data of the B1 channel or the data of the B2 channel, converts the signal into the format shown in FIG.

The ISDN interface circuit 403
Converts the signal received from the signal line 422 into a signal having the format shown in FIG. 5 and outputs the signal to the signal line 408. The B channel signal is converted into a B1 channel synchronization pattern 1 detection circuit 425 and a B2 channel synchronization signal. Pattern 1 detection circuit 426, B1 channel synchronization pattern 2 detection circuit 41
0, B2 channel synchronization pattern 2 detection circuit 411, B1
The signals are transmitted to the channel synchronization pattern 3 detection circuit 414, the B2 channel synchronization pattern 3 detection circuit 415, and the B channel data storage circuit 412.

Each circuit to which the signal line 424 is connected determines whether the signal transmitted through the signal line 424
One channel and B2 channel can be identified.

B1 channel synchronization pattern 1 detection circuit 42
5 and B2 channel synchronization pattern 1 detection circuit 426
Sync pattern 1 (8-bit data all '0') to 'n'
When the 1 'octet is detected, the B1 channel synchronization pattern 2 detection circuit 410 and the B2 channel synchronization pattern 2 detection circuit 411 are activated. When the B1 channel synchronization pattern 2 detection circuit 410 and the B2 channel synchronization pattern 2 detection circuit 411 detect the synchronization pattern 2 (8-bit data all '1') by 'n2' octets, the B1 channel synchronization pattern 3 detection circuit 414 , B2 channel synchronization pattern 3 detection circuit 415 and synchronization pattern transmission circuit 4
02 is started. The synchronization pattern sending circuit 402 outputs
When the activation request is received from both the channel synchronization pattern 2 detection circuit 410 and the B2 channel synchronization pattern 2 detection circuit 411, the synchronization pattern 2 is transmitted to the B1 channel and the B1 channel.
Switching circuit 406, IS
'N2' octets are sent out to the signal line 404 via the DN interface circuit 403, and then the synchronization pattern 3 (8-bit data all '0') is transmitted to B1
'N3' for both channel and B2 channel simultaneously
Send octets.

Further, the synchronization pattern sending circuit 402
After transmitting the synchronization pattern 2, a signal indicating that communication is possible is performed to the image codec device via the signal line 419.
The switching circuit 406 is controlled by the signal line 421, the switching circuit 406, and the image data from the image codec device.
Signal line 407 and ISDN interface circuit 403
To the signal line 404 via the. Note that the image codec device transmits image data after a lapse of time to transmit the synchronization pattern 3 by 'n3' octets after receiving the communication enable indication.

Next, when one of the B1 channel synchronization pattern 3 detection circuit 414 and the B2 channel synchronization pattern 3 detection circuit 415 detects the synchronization pattern 3, the other B channel is detected based on the detected time. Is changed (detected) to the synchronization pattern 3 (B1
The data storage input / output control circuit 406 detects the data transmission delay difference between the channel and the B2 channel, and based on the data transmission delay difference, the B channel data storage circuit 412.
Control. The B channel data storage circuit 412 absorbs the data transmission delay difference between the B1 channel and the B2 channel under the control of the data storage input / output control circuit 406, and
Establish synchronization between channel 1 and channel B2. In addition,
A detailed description of the operation for establishing this synchronization will be described later.

When the data communication is completed and the ISDN interface circuit 403 receives the disconnection instruction from the image codec device via the signal line 401, the ISDN interface circuit 403 sends a disconnection message or the like to the signal line 404, and performs a predetermined procedure. To perform a cutting process.

Next, the operation of the terminal adapter when receiving a call will be described.

First, the ISDN interface circuit 403
Receives the call setting message [B1] and the call setting message [B2] through the signal line 422, and sends the response message [B1] and the response message [B2] to the signal line 40.
4 On the other hand, the ISDN switching network 13 transmits the response confirmation message [B1] and the response confirmation message [B
2] is transmitted through the signal line 422, and the signal is transmitted through the signal line 405.
2 is started, and the signal lines 404 and 407 and the signal lines 422 and 408 are respectively connected.

The synchronization pattern sending circuit 402
When activated from the interface circuit 403, the synchronization pattern 1 is applied to the B1 channel and the B2 channel, respectively.
After transmitting 'n1' octets, the synchronization pattern 2 is continuously transmitted.

At this time, the B1 channel synchronization pattern 1 detection circuit 425 and the B2 channel synchronization pattern 1 detection circuit 426 detect the synchronization pattern 1, and thereafter, the B1 channel synchronization pattern 1
The channel synchronization pattern 2 detection circuit 410 and the B2 channel synchronization pattern 2 detection circuit 411 detect the synchronization pattern 2.

Next, when the B1 channel synchronization pattern 3 detection circuit 414 or the B2 channel synchronization pattern 3 detection circuit 415 detects the synchronization pattern 3, the data storage input / output control circuit 416 is activated. The operation of the data storage input / output control circuit 416 depends on the ISDN interface circuit 4
It differs depending on the relationship between the B1 channel and the B2 channel input from the signal line 03 through the signal line 408.

The operation of the data storage input / output control circuit 416 will be described below with reference to FIGS.

First, FIG. 6 is a diagram for explaining a case where there is no difference in reception delay (time) for data between the B1 channel and the B2 channel. The data storage input / output control circuit 416
If it is determined that there is no reception delay difference between the B1 channel and the B2 channel, the switching circuit 41
7 is activated to logically directly connect the signal lines 408 and 427.

Next, FIG. 7 is a diagram for explaining a case where the B2 channel is received later than the B1 channel. When the data accumulation input / output control circuit 416 is activated from the B1 channel synchronization pattern 3 detection circuit 414,
The B channel data accumulation circuit 412 is activated by the signal line 418, and the data D after receiving the synchronization pattern of the B1 channel is received.
1, D3,... Are accumulated. Thereafter, the B2 channel synchronization pattern 3 detection circuit 415 detects the synchronization pattern 3, and when the synchronization pattern 3 detection circuit 415 is activated, the signal line 409 activates the B channel data storage circuit 412 and the signal line 428. Activates the switching circuit 417. The B channel data storage circuit 412 sequentially stores the stored data D1, D3,...
Output to The switching circuit 417 alternately connects the signal line 429 and the signal line 408 to the signal line 427 under the control of the signal line 428, and outputs the received data (image data) to the image codec device.

Finally, FIG. 8 is a diagram for explaining a case where the B1 channel receives data later than the B2 channel. The data storage input / output control circuit 416 determines whether the B2
When activated by the channel synchronization pattern 3 detection circuit 415, the B-channel data storage circuit 41 is connected to the signal line 418.
2 are started and the data D2, D4,... After receiving the synchronization pattern 3 of the B2 channel are accumulated. Thereafter, when the B1 channel synchronization pattern 3 detection circuit 414 detects the synchronization pattern 3 and is started from the synchronization pattern 3 detection circuit 414, the B1 channel data accumulation circuit 4
12, and the switching circuit 417 is activated by the signal line 428. Also, the B channel data storage circuit 4
12 outputs the data D2, D4,... Accumulated under the control of the signal line 409 to the signal line 429.
The switching circuit 417 is controlled by the signal line 428 to
The signal line 429 and the signal line 408 are alternately connected to the signal line 427, and data (image data) is output to the image codec device.

By the above operation, the data reception delay difference between the B1 channel and the B2 channel is absorbed, and the data transfer is performed by establishing the synchronization between the B1 channel and the B2 channel.

Next, when the data communication is completed and the ISDN interface circuit 403 receives the disconnection message [B1] and the disconnection message [B2] from the ISDN switching network 13, the image codec device is transmitted to the image codec device via the signal line 401.
A signal for stopping the communication enable indication is transmitted, and disconnection processing is performed according to a predetermined procedure.

By the above operation, the B1 channel and B2
Channel and establish one data (128 kbp) using both the B1 channel and the B2 channel.
s) can be separated for communication.

[0056]

According to the present invention, the reception data transmission delay time difference between the B1 channel and the B2 channel (the reception data transmission delay time difference between a plurality of B channels) can be absorbed. As a result, a plurality of B1 channels (64 kbps) and B2 channels (64 kbps) can be used as one channel, and data communication can be performed at a transmission speed that is n times the B channel. The ISDN line of the interface can be used effectively.

When making a call connection on an ISDN line,
The correspondence between the other communication device and the multiple communication channels used by the own communication device does not deviate, and the delay difference of the received data between the multiple communication channels can be easily absorbed and the multiple communication channels are combined. It is possible to perform the data communication.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a configuration of an image information transfer system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a signal format of an ISDN line of a basic interface.

FIG. 3 is a sequence diagram illustrating the operation of the present invention.

FIG. 4 is a block diagram showing the internal configuration of the terminal adapter of the present invention.

FIG. 5 is a diagram showing a format of a B channel in the terminal adapter of the present invention.

FIG. 6 is a diagram illustrating the operation of the terminal adapter of the present invention when receiving data.

FIG. 7 is a diagram illustrating the operation of the terminal adapter of the present invention when receiving data.

FIG. 8 is a diagram illustrating the operation of the terminal adapter of the present invention when receiving data.

[Explanation of symbols]

 1, 9: video camera, 8, 12: video monitor, 3, 6: terminal adapter, 2, 7: image codec device, 4, 5, 10, 11 ... subscriber line 403: ISDN interphase circuit 402: synchronous pattern sending circuit 406, 417: switching circuit 425: B1 channel synchronization pattern 1 detection circuit 426: B2 channel synchronization pattern 1 detection Circuit, 410 ... B1 channel synchronization pattern 2 detection circuit, 411 ... B2 channel synchronization pattern 2 detection circuit, 414 ... B1 channel synchronization pattern 3 detection circuit, 415 ... B2 channel synchronization pattern 3 detection circuit, 412: B channel data storage circuit; 416: Data storage input / output control circuit.

Claims (1)

[Claims] 1. A communication device connected to an ISDN line having a plurality of communication channels and transmitting / receiving one data using the plurality of communication channels. Means for associating each of the communication channels used by the own communication device with a call connection in the plurality of communication channels, means for dividing predetermined data into the plurality of channels, and transmitting the data; Means for storing data in another communication channel until the communication channel receiving the data receives the data, and means for outputting the data of all the channels in a predetermined order when the data is received on all the channels. A communication device using an ISDN line, wherein communication is performed by absorbing delay differences between the plurality of communication channels.