JPS61148935A - Multiplex line concentrating system - Google Patents

Abstract

PURPOSE:To attain ease of retrieval of a line fault by providing a means for controlling the connection between a low-speed line and a relay line to be prescribed connection when no fault is detected in a relay line due to the returned test of a mudulator-demodulator. CONSTITUTION:If a fault takes place to a relay line 5-2, a modulator- demodulator 4 detects it and inputs a line quality deterioration signal to a line state supervisory circuit 36 of a multiplex line concentrator 3. The circuit 36 applies a control signal to a multiplex concentrator circuit 32 and a high- speed reception buffer 35, the transmission data of a low-speed line inputted to the circuit 32 is subjected to multiplex line concentration to the relay line 11-1 and outputted to a high-speed line transmission buffer 34 by the control. In retrieving a fault of the line 5-2 by connecting a measuring device 13 to the low-speed line 2-1, since the line quality deterioration signal to the device 3 is stopped by the reflected test of the device 4, the circuit 36 regards the relay line as normal, assigns the signal from the circuit 4 to the buffer 35 to low speed lines 2-1-2-4 and assigns the signal from a modulator-demodulator 10 to low-speed lines 2-5-2-8, the test signal from the measuring device 13 is returned and collated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multiplexing and concentrating system. In particular, the present invention relates to a method for searching for trunk line failures in multiplex concentrators.

〔overview〕

The present invention multiplexes and concentrates a large number of digital low-speed lines into a smaller number of relay lines, and when a failure occurs in one of the relay lines, automatically multiplexes and concentrates the lines to a relay line that is free of failure. In this method, if the fault in the trunk line is resolved by, for example, a repeat test of the modem, the fault in the trunk line can be searched for by connecting the low-speed line and the trunk line in a predetermined manner. It facilitates

□ [Prior Art] FIG. 2 is a block diagram showing an example of a communication device equipped with a multiplexing line concentrator. In this example, low-speed lines from eight terminal devices are connected to the communication control device of the host device through two relay lines.

Communication from the communication control device 1 to the terminal devices 9-1 to 9-8 (from the local station to the opposing station) is performed as follows.

That is, digital data input to the multiplexing line concentrator 3 through the low-speed lines 2-1 to 2-8 is multiplexed, then modulated by the modulators 4 and 10, and transmitted to the terminals through the trunk line 5-1, 11-1. Side modem 6.12
The data is demodulated by the modulator/demodulator 6.12, inputted to the multiplexing line concentrator 7, separated into data for each terminal device 9-1 to 9-8 by the multiplexing line concentrator 7, and transmitted to the low-speed line 8- 1 to 8-8 to each terminal device 9-1 to 9-8.

The transmission of data from each terminal device 9-1 to 9-8 to the communication control device 1 is via the modem device 6.
12 to the modem 4 and lO, the trunk line 5-
The difference is that a trunk line 5-2.11-2 is used instead of 1.11-1.

In such a communication device, a case where a failure occurs in the trunk line 5-2 will be explained as an example.

FIG. 3 is a diagram showing the flow of data when a failure occurs at the point marked with an x on the trunk line 5-2.

When a failure occurs in the trunk line 5-2, the modem 4 detects the line failure and sends a carrier detection failure or line quality failure signal to the multiplexing line concentrator 3.

The multiplexing line concentrator 3 determines that the trunk line 5-2 is defective and sends 8
Transfer all data from low-speed lines 2-1 to 2-8 to relay line 1
Concentrate multiple lines to 1-1. At the same time, it notifies the multiplexing line concentrator 7 of the opposing game that all eight low-speed lines are being multiplexed and concentrated on the relay line 11-1 using the relay line 5-1. In response to this notification, the multiplexing line concentrator 7 multiplexes and concentrates the data from the eight terminal devices to the relay port [11-2.

[Problem that the invention seeks to solve]

However, the faulty first trunk line (trunk line 5)
-1.5-2) When a return test is performed on the modem 4 on the side, a signal appears on the receiving output of the modem 4, so the multiplex concentrator 3 assumes that the trunk line 5-2 has become normal. I judge that. Furthermore, the multiplexing line concentrator 7 continues to determine that there is a fault in the trunk line 5-2. Therefore, the multiplexing line concentrator 3 returns to the normal state where it multiplexes the low-speed lines by four lines and sends them to the trunk line 5-1.
The low-speed lines are multiplexed and condensed and continue to be sent to the trunk line 11-2.

Therefore, for example, when the measuring instrument 13 is connected to the first low-speed line of the multiplexing line concentrator 3, the signal sent out by the measuring instrument 13 and returned by the modem 4 and the signal transmitted from the relay line 11-2
The data of the first low-speed line of the game input via
They are simultaneously input to the measuring device 13.

For this reason, there was a drawback that the measuring device 13 could not accurately measure only the test signal.

The present invention solves the above-mentioned drawbacks, and when the two relay lines from your own station to your opponent's station are normal, and when one of the relay lines from your opponent's station to your own station is defective and the other is normal, a measuring device is installed at your own station. The purpose of the present invention is to provide a multiplexing line concentration system that can search for line failures by connecting and performing loopback tests on defective relay lines.

[Means for solving problems]

The multiplex concentrator system of the present invention is connected between a large number of digital low-speed lines and a plurality of relay lines, and includes a multiplex concentrator circuit, and when a failure occurs in one of the relay lines, the low-speed line is In the multiplex concentrator system, the multiplex concentrator is provided with a means for automatically controlling the multiplex concentrator circuit so as to condense the multiplex concentrator circuit to a trunk line without a fault, and the controlling means is configured to ensure that there is no fault in any of the trunk lines. The present invention is characterized in that it includes a control means for connecting the low-speed line and the relay line in a predetermined manner when the low-speed line and the relay line are detected.

[Function] The multiplexing line concentration system of the present invention, when it is determined that there is no fault in the trunk line through a loopback test of the modem, etc., allocates the data on the low-speed line of the own station to the two trunk lines in a fixed manner. Discard received data from unallocated games. Thereby, it is possible to search for a failure without being affected by the signal from the opposing station.

〔Example〕

FIG. 1 is a schematic diagram of a multiplexing line concentrator according to an embodiment of the present invention.

The multiplexing line concentrator 3 includes a low-speed line transmission/reception buffer 31-
1 to 31 to 8, a multiplexing line concentrator circuit 32, a first high-speed line transmission buffer 33, a second high-speed line transmission buffer 34, a high-speed side receiving buffer 35, and a line state monitoring circuit 36.

The low-speed line transmission/reception buffers 31-1 to 31-8 transmit and receive digital data to and from the low-speed lines 2-1 to 2-8, respectively. Low-speed line transmission/reception buffers 31-1 to 31
-8 is connected to the multiplex concentrator circuit 32. The multiplexing line concentrator circuit 32 is connected to the modem 4 via a first high-speed line transmission buffer 33 and a second high-speed line transmission buffer 34.
It is connected to the modem 10 via.

The modem 4.10 is connected to a multiplexing concentrator 32 via a high-speed receiving buffer 35. Further, in the modem 4.10, the 0 line state monitoring circuit 36 connected to the line state monitoring circuit 36 is connected to the multiplexing concentrator circuit 32 and the high speed side receiving buffer 35.

The modem 4 is connected to a first relay line, that is, a transmission relay line 5-1 and a reception relay line 5-2. The modem 10 is connected to a second relay line, that is, a transmission relay line 1i-i and a reception relay line 11-2.

First, trunk lines 5-1.5-2.11-1 and 11
Transmission and reception when there is no failure in -2 will be explained.

Data input from the low-speed lines 2-1 to 2-8 is input to the multiplexing line concentrator circuit 32 via the low-speed line transmission/reception buffers 31-1 to 31-8. These data are multiplexed into two sets by the multiplex concentrator circuit 32, one set is output to the trunk line 5-1 via the first high-speed transmission buffer 33 and the modem 4, and the other set is output to the trunk line 5-1. The signal is output to the trunk line 11-1 via the second high-speed transmission buffer 34 and the modem 10.

In addition, game data input from the relay lines 5-2 and 11-2 to the modem 4.10 is input to the high-speed side receiving buffer 35, and is further separated for each low-speed line by the multiplexing concentrator circuit 32. , are output to each low-speed line transmission/reception buffer 31-1 to 31-8. Each low-speed line transmission buffer 31-1 to 31-8 converts the signal into a signal that matches the interface with the line, and transmits the signal to each low-speed line 2-1 to 2-8.
Output to.

Next, a case where a failure occurs in the trunk line 5-2 will be explained.

The modem 4 detects a line fault and notifies the line status monitoring circuit 36 of the multiplex concentrator 3 of a carrier detection failure or line quality failure signal. This signal is transmitted to the multiplex concentrator 3
The signal is input to the line status monitoring circuit 36. The line status monitoring circuit 36 monitors the line status of the trunk line 5-2 and the trunk line 11-2, and outputs a control signal according to the line status to the high-speed receiving buffer 35 and the multiplexing line concentrator circuit 32. At this time, since a fault has occurred in the relay line 5-2, the control signal from the line status monitoring circuit 36 is transmitted to the normal relay port m1.
Multiple lines are concentrated on the l-1 side, and the second high-speed line transmission buffer 34
Control the output to .

In this state, a low-speed line, for example, low-speed port flJjj2-1
The measuring device 13 is connected to the relay line 5-2 to search for a fault in the trunk line 5-2. At this time, the relay line 5-2 becomes normal due to the return test of the modem 4, and the modem 4 stops outputting the carrier detection failure or line quality failure signal to the multiplexing line concentrator 3. On the other hand, on the opposing side, the relay line 5-2 remains in a communication disabled state.

The feature of this embodiment is that the line status monitoring circuit 36 regards the relay lines 5-1.
The purpose of this control is to allocate the input from the modulator/demodulator 10 to the low-speed lines 2-1 to 2-4, and to allocate the input from the modulator/demodulator 10 to the low-speed lines 2-5 to 2-8. Therefore, the data on the first to fourth low-speed lines of the game is transferred to the relay line 11.
Even if input from -2, these data are discarded.

Data input from the high-speed receiving buffer 35 to the multiplexing line concentrator circuit 32 is separated and output to each of the low-speed lines 2-1 to 2-8.

Therefore, the test signal from the measuring device 13 connected to the first low-speed line 2-1 passes through the first low-speed line buffer 31-1, is multiplexed by the multiplexing concentrator circuit 32 to the second trunk line side, The signal passes through the first high-speed line transmission buffer 33 and is input to the modulation/demodulation device 4 . Since the modem 4 is performing a loopback test, the test signal is looped back as it is,
Input to the high-speed side receive buffer. Thereafter, the signal is input to the measuring instrument 13 via the multiplexing line concentrator circuit 32 and the low-speed line transmission/reception buffer 31-1 as described above. Data on the second trunk line is not input to the measuring device 13.

〔Effect of the invention〕

As described above, the multiplexing line concentration method of the present invention allows accurate measurement of test signals when searching for a defective trunk line by loopback testing. Therefore, it has the effect of making it easier to search for line failures.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a multiplexing line concentrator according to an embodiment of the present invention. FIG. 2 is a block configuration diagram showing an example of a communication device equipped with a multiplexing line concentrator. FIG. 3 is a diagram showing the flow of data when a failure occurs in one relay line. 1... Communication control device, 2-1 to 2-8... Low speed line, 3.7... Multiplexing line concentrator, 4.6.10.12.
...Modulator/demodulator, 5-1.5-2.11-1.11-2
...Relay line, 8-1 to 8-8...Low speed line, 9-
1 to 9-8...terminal device, 31-1 to 31-8...
Low-speed line transmission/reception buffer, 32... multiplexed line concentrator circuit,
33... First high-speed line transmission buffer, 34... Second high-speed line transmission buffer, 35... High-speed side reception buffer, 36... Line status monitoring circuit.

Claims (1)

[Claims] (1) It is connected between a large number of digital low-speed lines and multiple trunk lines, and includes a multiplexing concentrator circuit, and when a failure occurs in one of the trunk lines, the low-speed lines are multiplexed to a trunk line that is free of failure. In the multiplexing concentrator system, which includes means for automatically controlling the multiplexing concentrator circuit to perform continuous concentrating, when it is detected that there is no fault in any of the trunk lines, the controlling means: A multiplexing line concentration system characterized by comprising a control means for connecting the low-speed line and the relay line so that the connection is as determined in advance.