JPH08125653A - Communication backup method, time division multiplexer and communication system - Google Patents

Abstract

PURPOSE: To realize communication backup with respect to each node equipment being opposite destinations of plural communication blocks at a low cost through the use of an ISDN public line. CONSTITUTION: A high speed digital line interface multiplexer/demultiplexer section 14 receives data outputted from a terminal equipment 2 through a bus control unit 12, the data are subject to time division multiplex and the result is outputted to an SD line 4 and sent to an equipment of an opposite destination. When the SD line 4 is open, a common control section 18 selects a bus changeover switch 141 to connect the multiplexer/demultiplexer section 14 to an ISDN interface unit 15 via a common bus 17. Then a unit 15 makes a call to an opposite destination to secure a transmission channel, then the multiplexer/ demultiplexer section 14 sends multiplexed data to the opposite destination through the ISDN public line 5. The unit 15 multiplexes the data further in the case of data input from the plural multiplexer/demultiplexer sections 14 and sends the data to each opposite destination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time division multiplexer for time-division-multiplexing data for communication using a dedicated line, and particularly for backup of communication using ISDN public network when the dedicated line fails. The present invention relates to a method, a time division multiplexing apparatus using this method, and a communication system constructed using this time division multiplexing apparatus.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a configuration example of a conventional time division multiplexing apparatus of this type. Reference numeral 1 is a time division multiplexing apparatus for time-division multiplexing data for communication, 2 is a terminal such as a personal computer, 3 is a standard interface cable for connecting the terminal 2 and the time division multiplexing apparatus 1, and 4 is time division multiplexing. A high-speed digital leased line (SD line) for connecting the device 1 and the opposite device on the opposite side, 5 is an ISDN (NET64) public line used for communication backup between the time division multiplexing device 1 and the other device when the SD line is not connected. .

The time division multiplexer 1 has a terminal interface unit 11 for transmitting and receiving data to and from a terminal 2, a bus control unit 12 for organizing data transmitted and received from a plurality of terminal interface units 11, a bus control unit 12 and a high speed. Concentrated data bus 13 for connecting digital line interface multiplexer / separator 14, high-speed digital line interface multiplexer / separator 14 for multiplexing data and separating multiplexed data, and data transmission / reception using ISDN public line 5. ISDN interface unit 15 for controlling, multiplex bus 16 for connecting terminal interface unit 11 and bus control unit 12, high-speed digital line interface multiplexer / separator 14, and ISDN
Communication block 10 comprising ISDN interface connection bus 17 for connecting interface unit 15
It is composed of 0, 200, and 300.

Next, the operation of the above-mentioned conventional time division multiplexer will be described. For example, the communication block 100 of the time division multiplexing apparatus 1 receives the data output from the terminal 2 at the terminal interface unit 11 via the standard interface cable 3. The data received by the terminal interface unit 11 is input to the bus control unit 12 via the multiplexing bus 16 and concentrated. The data concentrated by the bus control unit 12 is the concentrated data bus 13
After passing through a, it is input to the high-speed digital line interface multiplexer / separator 14 and multiplexed, and then output on the SD line 4.

If the SD line 4 is disconnected,
The multiplexed data output from the high speed digital line interface multiplexer / separator 14 is passed through the ISDN interface connection bus 17 to the ISDN interface unit 1.
5 is input. At this time, the ISDN interface unit 15 performs a call process to the ISDN public line 5 for the required time slot, and secures a backup communication path with the opposite multiplexer, and the multiplexer / demultiplexer is provided. ISDN public line 5
Print on top.

FIG. 6 is a block diagram showing an example of a communication system constructed by using the above-mentioned conventional time division multiplexing apparatus. The time division multiplexer 1 as shown in FIG. 1, which is the master station of the A node, and the time division multiplexers of the nodes B, C, and D are connected by the SD line 4 and the ISDN public line 5 as shown in the figure. It is connected. The time-division multiplexer 1 performs the series of data communication operations described above with the time-division multiplexer of each node B, C, D.

However, as shown in FIG. 6, when there are a plurality of nodes on the opposite side of the time division multiplexer 1 of the master station, the time division multiplexer 1 and each node B,
3 ISDN public lines 15 must be connected to C and D, and multiple ISDNs must be connected for communication backup.
Since the public line 15 is connected, there is a drawback that the communication cost becomes high. In addition, multiple ISDN public lines 5
In order to connect the above, the ISDN interface units 15 for a plurality of lines must be mounted on the time division multiplexing device 1 side, and there is a drawback in that the cost is high here as well.

[0008]

As described above, by using the conventional time division multiplexer having a plurality of communication blocks,
When communication is performed by a time division multiplexer of a plurality of nodes, the time division multiplexer must draw a plurality of ISDN public lines for communication backup to the equipment of each node, which is costly. As a result, there is a drawback that the communication cost becomes high. In addition, multiple line ISDN
In order to connect the public line, the ISDN interface units 15 for a plurality of lines must be mounted on the side of the time division multiplexing device, which also has a disadvantage of high cost.

In view of the above, the present invention eliminates the above-mentioned drawbacks and makes it possible to perform a communication backup for a device of each node at the opposite end of a plurality of communication blocks at a low cost by using one ISDN public line. An object of the present invention is to provide a time division multiplexing apparatus using this method and a communication system constructed using this time division multiplexing apparatus.

[0010]

The invention according to claim 1 is provided with a plurality of high-speed digital line interface multiplexing / separating units, and each high-speed digital line interface multiplexing / separating unit is dedicated to an opposite device independently. In the communication backup method when the dedicated line in the time division multiplexing apparatus, which performs the communication of the multiplexed data independently with the plurality of the opposite apparatuses by being connected by the line, is provided. ISD the multiplexed data with the other device
One ISDN interface unit having a function of transmitting and receiving by using N public lines, and a connection bus for connecting and disconnecting this ISDN interface unit and all of the high-speed digital line interface multiplexing / separating unit are provided. High-speed digital line interface High-speed digital line interface that monitors the status of the leased line connected to the multiplexer / demultiplexer and detects that the leased line is disconnected. After the multiplexer / separator and the ISDN interface unit are connected by the connection bus, the ISDN interface unit makes a call to the device to which the leased line is disconnected, and then the high-speed digital line interface multiplexing is performed. / The multiplexed data output from the demultiplexer is transferred to this ISDN A method of transmitting from the face unit to said connection destination device through ISDN public line.

A second aspect of the present invention is a method for cyclically monitoring the state of a dedicated line connected to each high-speed digital line interface multiplexer / separator.

According to a third aspect of the present invention, the fact that the dedicated line in use is cut off means that the state of the high-speed digital line interface multiplexer / separator for transmitting / receiving data using this dedicated line is the device of the other party. This is a method of detecting that synchronization has not been established with the.

According to a fourth aspect of the present invention, the ISDN interface unit transmits and receives data using the B channel.
The D channel is a method of sharing the call control of the multiple high-speed digital line interface multiplexer / separator.

According to a fifth aspect of the present invention, the ISDN interface unit transmits and receives data using the B channel,
Furthermore, the D channel is also used individually for each of the plurality of high-speed digital line interface multiplexer / demultiplexers.

The invention of claim 6 is provided with a plurality of high-speed digital line interface multiplexer / demultiplexers, and each high-speed digital line interface multiplexer / separator is independently connected to a device at the other end by a dedicated line. Due to
A function for transmitting / receiving multiplexed data to / from a plurality of destination devices using an ISDN public line in a time division multiplexing device that independently performs communication of multiplexed data with the plurality of destination devices. A single ISDN interface unit, a connection bus connecting and disconnecting this ISDN interface unit and all of the high-speed digital line interface multiplexer / demultiplexer, and monitoring the state of each high-speed digital line interface multiplexer / demultiplexer And a detecting means for detecting from the state of the high-speed digital line interface multiplexer / separator monitored by the monitor that the dedicated line connected to the multiplexer / separator is disconnected. When the detecting means detects that the dedicated line is disconnected, the high Switching means for connecting the digital line interface multiplexer / demultiplexer to the ISDN interface unit through the connection bus, and connection when the high-speed digital line interface multiplexer / demultiplexer is connected to the ISDN interface unit by the switching means The ISDN interface unit is provided with call control information for making a call to the opposite party of the high-speed digital line interface multiplexer / separator, and this ISDN interface unit is called to establish a communication path with the opposite party apparatus. A control means for establishing the communication is provided, and data communication between the high-speed digital line interface multiplexer / demultiplexer and the opposite device is performed by the ISDN interface unit using the ISDN public line.

According to a seventh aspect of the present invention, the monitoring means cyclically monitors the state of each high-speed digital line interface multiplexer / separator.

According to an eighth aspect of the present invention, the state of the high-speed digital line interface multiplexer / separator for transmitting and receiving data by using the leased line is detected by the detecting means when the leased line in use is disconnected. This is a configuration for detecting that synchronization has not been established with the opposite device.

According to a ninth aspect of the present invention, when the ISDN interface unit has a plurality of high-speed digital line interface multiplexing / separating units connected via the connection bus, the respective high-speed digital line interface multiplexes are provided. / The data input from each of the multiplexing / separating units is further multiplexed by using the channels assigned to the separating / separating units, and is transmitted to the device opposite to each of the multiplexing / separating units.

According to a tenth aspect of the present invention, in the case where the ISDN interface unit has a plurality of destination devices for data communication, the data received from each destination device is separated for each destination, and the separated data is separated. In this configuration, the high-speed digital line interface multiplexer / separator corresponding to the destination is assigned.

The invention according to claim 11 is characterized in that the time division multiplexer according to claim 6 and a plurality of nodes are connected via a dedicated line, and a single ISDN interface unit in the time division multiplexer is provided. The plurality of nodes are combined into one ISD
In this configuration, the connection is made using N public lines.

The invention of claim 12 is a structure in which the leased line has a multiple access service function.

[0022]

According to the communication backup method of the first aspect of the present invention, the ISD of the multiplexed data is transmitted between a plurality of opposite devices.
One ISDN interface unit having a function of transmitting and receiving by using N public lines, and a connection bus for connecting and disconnecting this ISDN interface unit and all of the high-speed digital line interface multiplexing / separating unit are provided. High-speed digital line interface High-speed digital line interface that monitors the status of the leased line connected to the multiplexer / demultiplexer and detects that the leased line is disconnected. After the multiplexer / separator and the ISDN interface unit are connected by the connection bus, the ISDN interface unit makes a call to the device to which the leased line is disconnected, and then the high-speed digital line interface multiplexing is performed. / The multiplexed data output from the demultiplexer is transferred to this ISDN Transmitting from the face unit in the apparatus of the destination through the ISDN public line.

In the communication backup method according to the second aspect of the present invention, the state of the dedicated line connected to each high-speed digital line interface multiplexer / separator is cyclically monitored.

In the communication backup method according to the third aspect of the present invention, the fact that the private line in use is cut off,
This is detected when the state of the high-speed digital line interface multiplexer / separator for transmitting and receiving data using this dedicated line has not been established with the other party's device.

In the communication backup method of the invention of claim 4, the ISDN interface unit transmits and receives data using the B channel, and the D channel performs call control of the plurality of high-speed digital line interface multiplexing / separating units. Share.

In the communication backup method according to the invention of claim 5, the ISDN interface unit transmits and receives data using the B channel, and the D channel is also provided to each of the plurality of high speed digital line interface multiplexing / separating units. Used individually.

In the time division multiplexing apparatus of the sixth aspect of the present invention, the single ISDN interface unit has a function of transmitting / receiving the multiplexed data to / from a plurality of opposing apparatuses using the ISDN public line. The connection bus is ISDN
The interface unit and all of the high speed digital line interface multiplexer / separator are connected and disconnected. The monitoring means monitors the status of each high speed digital line interface multiplexer / separator. The detecting means detects from the state of the high-speed digital line interface multiplexing / separating section monitored by the monitoring means that the dedicated line connected to the multiplexing / separating section has been cut off. The switching means, when the detecting means detects that the dedicated line is disconnected, the switching means connects the ISDN to the high-speed digital line interface multiplexing / separating unit connecting the disconnected dedicated line through the connection bus. Connect to the interface unit. The control means, when the high-speed digital line interface multiplexer / separator is connected to the ISDN interface unit by the switching means, call control information for making a call to the opposite side of the connected high-speed digital line interface multiplexer / separator. To the ISDN interface unit to call the ISDN interface unit and establish a communication path with the device at the opposite end. Data communication between the high-speed digital line interface multiplexer / demultiplexer and the opposite device is performed by the ISDN interface unit using an ISDN public line.

In the time-division multiplexing apparatus of the invention of claim 7, the monitoring means cyclically monitors the state of each high-speed digital line interface multiplexing / separating unit.

In the time-division multiplexer of the present invention, the detecting means indicates that the in-use leased line has been cut off by high-speed digital line interface multiplexing for transmitting and receiving data using this leased line. / It is detected that the state of the separation unit has not been established with the opposite device.

In the time-division multiplexer of the invention of claim 9, the ISDN interface unit is provided with a plurality of high-speed digital line interface multiplexer / separator units connected via the connection bus. The data input from each multiplexing / separating unit is further multiplexed by using the channel assigned to the high-speed digital line interface multiplexing / separating unit, and the multiplexed data is transmitted to the device at the opposite side of each multiplexing / demultiplexing unit.

In the time division multiplexing apparatus of the tenth aspect of the present invention, the ISDN interface unit separates the data received from each of the destination devices for each destination when there are a plurality of destination devices for data communication. Then, the separated data is distributed to the high-speed digital line interface multiplexing / separating unit corresponding to the destination.

In the communication system of the eleventh aspect of the present invention, the time division multiplexing apparatus of the sixth aspect performs data communication with a plurality of nodes via a dedicated line, and when the dedicated line is not connected, the time division multiplexing is performed. A single ISDN
The interface unit performs data communication with the plurality of nodes using one ISDN public line.

In the communication system according to the twelfth aspect of the present invention, the leased line provides multiple access service.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the time division multiplexing apparatus of the present invention. Reference numeral 1 is a time division multiplexing apparatus for time-division multiplexing data for communication, 2 is a terminal such as a personal computer, 3 is a standard interface cable for connecting the terminal 2 and the time division multiplexing apparatus 1, and 4 is time division multiplexing. A high-speed digital leased line (SD line) connecting the device 1 and the opposite partner device, 5 is an ISDN public line used for communication backup between the time division multiplexing device 1 and the opposite partner device.

The time division multiplexing apparatus 1 includes a terminal interface unit 11 for transmitting / receiving data to / from the terminal 2, a bus control unit 12 for organizing bus signals transmitted / received from a plurality of terminal interface units 11, and a bus control unit 12. Concentrated data bus 13 that connects high-speed digital line interface multiplexer / separator 14, high-speed digital line interface multiplexer / separator 14 that performs data multiplexing and separation of multiplexed data, and data that uses ISDN public line 5. ISDN for controlling transmission / reception (NET150
0) Interface unit 15, multiplexing bus 16 for connecting terminal interface unit 11 and bus control unit 12, and high-speed digital line interface multiplexing /
ISDN interface connection bus 17 and ISD for connecting the separation unit 14 and the ISDN interface unit 15
It comprises a common control unit 18 for performing backup communication control by the N public line 5, and a common control bus 19 for connecting the common control unit 18, the bus control unit 12 and the ISDN interface unit 15.

In this example, two terminal interface units 11, one bus control unit 12 each,
Communication block 100 comprising a high-speed digital line interface multiplexer / separator 14 having a time division multiplexing function
There are 4 blocks of 400, and each has 1 block in common.
The ISDN interface unit 15 and the common control unit 18 are provided. Further, each communication block is connected to the opposite device through the SD line 4. Furthermore, ISDN
The interface unit 15 is connected to one ISDN public line 5. Therefore, the high-speed digital line interface multiplexer / separator 14 of each communication book is
Each high-speed digital line interface multiplexing / separating unit 14 has a built-in bus changeover switch 141 for switching between connection to the D line 4 and connection to the ISDN interface unit 15 via the ISDN interface connection bus 17.

Next, the operation of this embodiment will be described. The data output from the terminal 2 is input to the terminal interface unit 11 of the communication block 100 of the time division multiplexer 1 through the standard interface cable 3. The terminal interface unit 11 outputs the input data to the bus control unit 12 through the multiplexed bus 16 (transmission). The bus control unit 12 concentrates the input data and outputs the concentrated data to the high-speed digital line interface multiplexer / separator 14 through the concentrator bus 13a. The high-speed digital line interface multiplexer / separator 14 time-division-multiplexes the input data to generate the SD line 14
Print on top. However, the bus changeover switch 141 normally built in the high-speed digital line interface multiplexing / separating unit 14 is switched to the SD line 4 side.

On the other hand, the high-speed digital line interface multiplexer / separator 14 separates the multiplexed data input from the SD line 4, distributes the separated data to each destination by the bus control unit 12, and then the terminal interface. It is sent to the destination terminal 2 via the unit 11.

The case where the SD line 4 connected to the communication block 1 is cut off due to some accident will be described below. The common control unit 18 cyclically controls the common control bus 19 while the time division multiplexing apparatus 1 is operating.
Also, the operating state of the high-speed digital line interface multiplexer / demultiplexer 14 of each communication block is monitored via the bus control unit 12. When the common control unit 18 monitors the state of the high-speed digital line interface multiplexing / separating unit 14 of the communication block 1 and it is confirmed that the synchronization with the opposite time division multiplexer is not established, the SD line 4 Judge that he was cut off due to some accident.

When the common control unit 18 judges that the SD line 4 is disconnected, it is built in the high-speed digital line interface multiplexing / separating unit 14 of the communication block 1 via the common control bus 19 and the bus control unit 12. The bus control switch 141 is controlled to switch from the SD line 4 side to the ISDN interface connection bus 17 side, and the common control unit 18 causes the ISDN interface unit 15 to face the high-speed digital line interface multiplexing / separating unit 14 of the communication block 1. The data for establishing the communication path with the time division multiplexing device of the above is established on the ISDN public line via the common control bus 19 and the bus control unit 12.
Send to the interface unit 15.

As a result, the high-speed digital line interface multiplexer / separator 14 of the communication block 1 is connected to the ISDN interface unit 15 through the ISDN interface connection bus 17, and the ISDN interface unit 15 makes the high-speed digital line interface multiplexer / demultiplexer. The data multiplexed by the high-speed digital line interface multiplexer / separator 14 will be transferred from the ISDN interface unit 15 to the ISD in order to establish a communication path with the time division multiplexer of the destination of the separator 14.
It is transmitted through the N public line 5 to the destination time division multiplexer.

The ISDN interface unit 15
Receives the transmission data from the opposite time division multiplexer through the ISDN public line 5, and distributes the received data to the high speed digital line interface multiplexer / separator 14 in the destination communication block. The high-speed digital line interface multiplexer / separator 14 further separates the data thus input and sends it to the destination terminal 2.

FIG. 2 is a block diagram showing details of the ISDN interface unit 15 shown in FIG. 5 is I
SDN (NET1500) public line, 17a, 17b,
17c and 17d are ISDN interface connection buses, 1
9 is a common control bus, 151a, 151b, 151c, 1
51d is an input / output circuit, 152a, 152b, 152c,
152d is an internal data bus, 153a, 153b, 15
3c and 153d are ISDN primary group speed interface units, 154a, 154b, 154c and 154d are phase absorption units, 155 is line data multiplexing / demultiplexing unit, and 156 is D-.
Channel insertion / separation unit, 157 ISDN primary group trunk control unit, 158 ISDN data bus, 159 IS
DN input / output circuit, 160 is a unit internal control bus, 16
1 is a memory / buffer unit, 162 is a CPU, 163 is a memory, 164 is a relative timer, 165 is an internal bus input / output interface, 166 is an interrupt control unit, and 167 is a common control bus unit.

Next, the operation of the above ISDN interface unit 15 will be described with reference to FIG. SD
When the line 4 is disconnected, the bus changeover switch 141 is switched as described above. The high speed digital line interface multiplexer / separator 14 is connected to the ISDN interface 15 through the ISDN connection bus 17. Thereafter, the multiplexed data output from the high speed digital line interface multiplexing / separating unit 14 is input to the input / output circuit 151a via the ISDN interface connection bus 17a, where the amplitude level is converted, and then the internal data bus 152a. Through the ISDN primary group velocity interface unit 153a. The ISDN primary rate interface unit 153a synchronizes the input multiplexed data with a frame, sends it to the phase absorbing unit 154a, removes the phase difference and performs phase matching, and then outputs it to the line demultiplexing unit 155. .

The line demultiplexing unit 155 multiplexes the multiplexed data sent from each ISDN primary group speed interface unit 153a or another ISDN primary group speed interface unit 153 into the ISDN (NET1500) frame structure again. . At this time, the line multiplexer / demultiplexer 1
Allocation of each time slot of the multi-frame by 55 is performed under the control of the internal CPU 162. That is, the common control unit 18 determines the S based on the input configuration information.
When the fact that the D line 4 has been disconnected is recognized on the status of the high-speed digital line interface / multiplexing unit 14,
A control signal for interrupting the internal CPU 162 via the common control bus 19 is sent to the common control bus unit 167.
Send to

When the internal CPU 162 receives the interrupt signal via the common control bus unit 167, it issues a command to the line demultiplexer 155 to execute time slot allocation. As a result, the line demultiplexing unit 155
Assigns the time slot to the input multiplexed data, multiplexes the data described above, and then 2
D channel inserting / separating unit 1 for duplicating multiplexed data
Output to 56.

The D channel inserting / separating unit 156 inserts the D-channel sharing the primary group call control (telephone number of the other party) into the input multiplexed data, and then IS
It outputs to the DN primary group velocity interface section 153. However, the D channel inserting / separating unit 156 receives the data of the primary group call control from the ISDN primary group trunk control unit 168 and performs the above operation. Further, the ISDN primary group trunk control section 168 transfers the data of the primary group call control to the common control section 18 of FIG.
From the common control bus 19 and the internal CPU 162.

ISDN primary velocity interface unit 15
3 is ISDN by changing the speed of the input multiplexed data
After synchronizing with the network, the ISDN I / O circuit 15
Output to the ISDN public line 5 via 9.

Here, the internal CPU 162 controls the entire ISDN interface unit 15, and the memory 16
Reference numeral 3 stores various data necessary for the operation of the CPU 162, and the memory buffer 161 temporarily stores these data and control signals in order to match the transmission / reception timing of data and control signals transmitted / received by the internal CPU 162. The relative timer 164 is for measuring the timing of operating the ISDN interface unit 5 after the disconnection of the SD line 4 is notified via the common control bus 19. The internal bus input / output interface 165 inputs / outputs signals between the common control unit 167 and the unit internal control bus 160.

On the other hand, the data sent from a node (not shown) via the ISDN public line 5 is IS sent from the ISDN input / output circuit 159 through the ISDN data bus 158.
It is input to the DN primary group speed interface 157, adjusted to the speed in the interface here, and then input to the D channel inserting / separating unit 156. The D channel inserting / separating unit 156 separates the D channel from the input data, and then the line multiplexing / separating unit 155 only the remaining B channel.
Output to. The line data multiplexer / separator 155 separates the input B channel data for each destination and outputs the separated data to the phase absorber 154 corresponding to each destination. The phase absorption unit 154 matches the phases of the input data, and then the data is input to the ISDN primary group velocity interface unit 153.
To the ISDN interface connection bus 17 through the internal data bus 152 and the input / output circuit 151. As a result, the data received by the ISDN interface unit 15 is input to the high speed digital interface demultiplexing unit 14 of the communication block corresponding to the destination. However, in FIG. 2, a,
Each code added with b, c and d is the communication block 10 of FIG.
It is assumed that the communication paths of 0, 200, 300, and 400 are supported.

According to the present embodiment, the high-speed digital line interface multiplexer / separator 14 of each block uses the built-in bus changeover switch 141 for the SD line 4 side or IS.
The connection can be switched to the DN interface unit 15 side, and the ISDN interface unit 15 multiplexes high-speed digital line interface multiplexing /
Since the multiplexed data from the demultiplexing unit 14 can be further multiplexed and transmitted to each opposite device, a single ISDN can be used.
The interface unit 15 can perform communication backup using the ISDN public line 5 of multiplexed data transmitted / received by a plurality of blocks. Therefore, even if there are a plurality of devices at the opposite end, the configuration is such that only one ISDN public line 5 is connected to the single ISDN interface unit 15, so that the communication cost can be reduced.

FIG. 3 is a block diagram showing an embodiment of a communication system of the present invention constructed using the time division multiplexing apparatus shown in FIG. Reference numeral 1 is a time division multiplexing apparatus which is a master station of the A node, and is composed of four communication blocks 100 to 400,
Each of the communication blocks 100 to 400 uses the SD line 4 for the B node time division multiplexer, the C node time division multiplexer,
It is connected to the time division multiplexer of the D node and the time division multiplexer of the E node. The communication blocks 100 to 400 of the time division multiplexing apparatus 1 of the A node are connected to a common ISDN interface unit 15 by an ISDN interface unit connection bus 17. This IS
The DN interface unit 15 is an ISDN public line 5
Thus, communication backup is performed when the SD line 4 connected to each of the communication blocks becomes disconnected.

When the communication block 100 of the time division multiplexing apparatus 1 of the A node is performing data transmission with the time division multiplexing apparatus of the B node using the SD line 4, this SD
When the line 4 is disconnected, the communication block 100 is connected to the ISDN interface unit 15 by the ISDN interface unit connection bus 17. At the same time, the ISDN interface unit 15 performs a calling process to the B node to secure a data communication path, and the communication block 100 causes the ISDN interface unit 15 to perform data transmission using the ISDN public line 5 at the time of the B node. Start with the division multiplexer.

In this state, if the communication block 200 of the time division multiplexing apparatus 1 of the A node and the SD line 4 used for data transmission between the C nodes become disconnected, the communication block 200 also has the ISDN interface as in the above. After being connected to the unit 15, data transmission using the ISDN public line 5 is performed with the time division multiplexer of the C node. At this time, the ISDN interface unit 15 further multiplexes the multiplexed data output from the communication block 100 and the communication block 200, and transmits the data to the opposite nodes A and B using the ISDN public line 5. ISDN interface unit 15 is SD line 4
When communication is not possible, the communication block 10 of the time division multiplexer 1
The multiplexed data output from 0 to 400 can be further multiplexed to perform data communication with each node B, C, D, E.

At this time, the D-channel of the ISDN public line 5 is commonly used for all communication blocks, and ISDN
If the line has 23 B channels and 1 D channel, then I
SDN interface unit 15 is 64Kb per ground
A total of 23 ps-unit data channels can be supported, and if the data for each ground is only one channel, communication backup of up to 23 nodes can be performed. If the D channel is individually used for each communication block, communication backup of up to 24 channels or up to 24 nodes can be performed for one node. Moreover, the ISD connected to the time division multiplexer 1 of the master station
Since there is only one N public line 5, the communication system can be constructed at low cost.

FIG. 4 is a block diagram showing another embodiment of the communication system of the present invention constructed by using the time division multiplexing apparatus of the present invention shown in FIG. In this example, the time division multiplexing apparatus 1 of the master station of the A node and the nodes B, C, D and E are connected using the SD line 4 using the multiple access service. Therefore, one S is included in the time division multiplexer 1.
The D line 4 and one ISDN public line 5 connected to the ISDN interface unit 15 common to each communication block of the time division multiplexer 1 are connected.
This example also has the same effect as the previous example shown in FIG. 4, but in particular, the SD line 4 connected to the time division multiplexer 1 of the A node is set to 1
It can be a book, and the construction cost of the communication system can be further reduced.

[0057]

As described above, according to the invention of claim 1 or 6, a single I connecting a single ISDN public line is used.
There is an effect that communication backup with a plurality of destination devices can be performed inexpensively by using the ISDN public line by using the SDN interface unit.

According to the invention of claim 2 or 7, there is an effect that the state of each high-speed digital line multiplexer / demultiplexer can be monitored at regular intervals.

According to the invention of claim 3 or 8, there is an effect that it can be surely detected that the dedicated line connected to each high-speed digital line multiplexing / separating unit has been cut off.

According to the invention of claim 4, the maximum number of B channels of data can be transmitted / received to / from one opposite device, and the maximum of B channels can be transmitted in the case of data communication of one B channel. There is an effect that it is possible to perform data communication with the same number of destination devices as the number of channels.

According to the fifth aspect of the present invention, the maximum number of B channels + 1 channel data can be transmitted / received to / from one opposite device, and if the data of one B channel data is communicated. Thus, there is an effect that data communication can be performed to the opposite device in the same number as the maximum number of B channels + 1.

According to the invention of claim 9, a single ISDN is used.
There is an effect that the interface unit can perform communication backup with a plurality of destination devices.

According to the invention of claim 10, a single ISD is provided.
There is an effect that the N interface unit can perform communication backup with a plurality of destination devices.

According to the invention of claim 11, since there is only one ISDN public line, there is an effect that communication backup using this ISDN public line can be performed at low cost.

According to the invention of claim 12, the number of dedicated lines is also one.
There is an effect that it can be done with a book, and the construction cost of the communication system can be further reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a time division multiplexing apparatus of the present invention.

FIG. 2 is a block diagram showing a detailed configuration example of an ISDN interface unit shown in FIG.

FIG. 3 is a block diagram showing an embodiment of a communication system of the present invention using the time division multiplexing apparatus shown in FIG.

FIG. 4 is a block diagram showing another embodiment of the communication system of the present invention using the time division multiplexing apparatus shown in FIG.

FIG. 5 is a block diagram showing an example of a conventional time division multiplexing apparatus.

6 is a diagram showing an example of a conventional communication system constructed by using the conventional time division multiplexing apparatus shown in FIG.

[Explanation of symbols]

1, A, B, C, D ... Time division multiplexer 2 ... Terminal 3 ... Standard interface cable 4 ... SD line 5 ... ISDN public line 11 ... Terminal interface unit 12 ... Bus control unit 13 ... Concentrated data bus 14 ... High speed Digital line interface multiplexing / separating unit 15 ... ISDN interface unit 16 ... Multiplexing bus 17, 17a to 17d ... ISDN interface connection bus 18 ... Common control unit 19 ... Common control bus 141 ... Bus changeover switches 151a-15
1d ... Input / output circuit 152a-152d ... Internal data bus 153a-153d ... ISDN primary group high-speed interface section 154a-154d ... Phase absorption section 155 ... Line data multiplexing / separation section 156 ... D-channel insertion / separation section 157, 168 ... ISDN primary group trunk control unit 159 ... ISDN input / output circuit 160 ... Unit internal control bus 161 ... Memory / buffer unit 162 ... CPU 163 ... Memory 164 ... Relative timer 165 ... Internal bus input / output interface 166 ... Interrupt control unit 167 ... Common Control bus unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication H04L 1/22 12/02 29/14 H04M 11/00 303 9371-5K H04L 13/00 311 (72 ) Inventor Akiyoshi Asami, 1-share company, Toshiba Hino Plant, 3-chome, Asahigaoka, Hino-shi, Tokyo (72) Inventor, Aki Kurihara 3-1-1, Asahigaoka, Hino-shi, Tokyo 1 Toshiba Toshiba Communication Systems Engineering Co., Ltd.

Claims (12)

[Claims] 1. Multiplexed data is provided by comprising a plurality of high-speed digital line interface multiplex / separation units, and each high-speed digital line interface multiplex / separation unit is independently connected to an opposite device by a dedicated line. In the communication backup method when the dedicated line in the time division multiplexing device that independently performs the communication of the plurality of opposite devices, the multiplexed data between the plurality of opposite devices is provided. And an ISDN interface unit that has the function of transmitting and receiving the ISDN public line.
A connection bus for connecting and disconnecting the SDN interface unit and all of the high-speed digital line interface multiplex / separation units is provided to monitor the status of the dedicated line connected to each high-speed digital line interface multiplex / separation unit. When detecting that the dedicated line has become disconnected, after connecting the high-speed digital line interface multiplexing / separating unit to which the disconnected dedicated line is connected and the ISDN interface unit by the connection bus,
After calling from this ISDN interface unit to the device to which the leased line is disconnected, the multiplexed data output from the high-speed digital line interface multiplexer / separator is sent from this ISDN interface unit through the ISDN public line. A communication backup method comprising transmitting to the device of the connection destination. 2. The communication backup method according to claim 1, wherein the state of the leased line connected to each high-speed digital line interface multiplexing / separating unit is cyclically monitored. 3. The state of the high-speed digital line interface multiplexing / separating unit for transmitting and receiving data using the leased line is synchronized with the other party's device when the dedicated line in use is disconnected. The communication backup method according to claim 1, wherein the communication backup method is detected when the communication is not established. 4. The ISDN interface unit transmits and receives data using a B channel, and the D channel shares the call control of the plurality of high speed digital line interface multiplexer / demultiplexers. 3. The communication backup method according to any one of 3. 5. The ISDN interface unit transmits and receives data using a B channel, and the D channel is also used individually for each of the plurality of high speed digital line interface multiplexers / demultiplexers. Item 4. The communication backup method according to any one of Items 1 to 3. 6. Multiplexed data is provided by comprising a plurality of high-speed digital line interface multiplexer / demultiplexers, and each high-speed digital line interface multiplexer / separator is independently connected to an opposite device by a dedicated line. In a time division multiplexing apparatus that independently performs the communication of a plurality of destination devices, a single unit having a function of transmitting / receiving multiplexed data to / from a plurality of destination devices using an ISDN public line. One ISDN interface unit and this I
A connection bus for connecting and disconnecting the SDN interface unit and all of the high-speed digital line interface multiplexer / demultiplexers, a monitoring means for monitoring the state of each high-speed digital line interface multiplexer / demultiplexer, and a monitor by this monitor means. The high-speed digital line interface detecting means for detecting from the state of the multiplexer / demultiplexer that the leased line connected to this multiplexer / demultiplexer has become disconnected, and this detector means makes the leased line disconnected. When it is detected, the switching means for connecting the high-speed digital line interface multiplexer / demultiplexer connecting the disconnected dedicated line to the ISDN interface unit through the connection bus, and the switching means for high speed Digital line interface multiplexer / separator in ISDN interface unit When continued, the ISDN interface unit is provided with call control information for calling the destination of the connected high-speed digital line interface multiplexer / separator, and the ISDN interface unit is called to call the destination. Control means for establishing a communication path with the device, and data communication between the high-speed digital line interface multiplexer / demultiplexer and the opposite device is performed by the ISDN interface unit using the ISDN public line. A time division multiplexing device characterized by performing. 7. The time division multiplexing apparatus according to claim 6, wherein said monitoring means cyclically monitors the status of each high-speed digital line interface multiplexer / separator. 8. The high-speed digital line interface multiplexing / separating unit for transmitting and receiving data using the leased line indicates that the detecting unit is disconnected from the device at the other end. The time division multiplexing apparatus according to claim 6 or 7, wherein the detection is performed when synchronization is not established between the two. 9. The ISDN interface unit is assigned to each high-speed digital line interface multiplexer / separator when there are a plurality of high-speed digital line interface multiplexer / separators connected via the connection bus. 9. The data input from each of the multiplexers / demultiplexers is further multiplexed by using the allocated channels and transmitted to a device at the opposite end of each of the multiplexers / demultiplexers. The time division multiplexing apparatus described. 10. The ISDN interface unit separates the data received from each of the destination devices for each destination when there are a plurality of destination devices for data communication,
9. The time division multiplexer according to claim 6, wherein the separated data is distributed to a high-speed digital line interface multiplexer / separator corresponding to a destination. 11. The time division multiplexer according to claim 6 and a plurality of nodes are connected via a dedicated line, and a single ISDN interface unit in the time division multiplexer and the plurality of nodes are connected. A communication system characterized by being connected using one ISDN public line. 12. The communication system according to claim 11, wherein the dedicated line has a multiple access service function.