JP3031251B2 - Low-speed transmission signal interface unit with internal monitoring function and its internal fault monitoring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-speed transmission signal interface unit used in an SDH (Synchronous Digital Hierarchy) network, and more particularly to a low-speed transmission signal with an in-unit monitoring function for monitoring a fault inside the unit when in an offline state. The present invention relates to an interface unit and an internal fault monitoring method.

[0002]

2. Description of the Related Art FIG. 5 shows the configuration of a conventional example of this kind of low-speed transmission signal interface unit. This conventional example is 4
It is accommodated in the transmission device for the channel low-speed transmission signal, and performs interface processing for each channel under the control of a central processing unit (not shown). Each of the channels 1 to 4 receives a bipolar low-speed transmission signal, performs a bipolar / unipolar signal conversion, and then outputs the signal to a stuff operating unit. Line interface units 111 and 12 for inputting a signal and performing unipolar / bipolar signal conversion and outputting the bipolar signal
1, 131, 141, stuff operation units 112, 122, 132, and 142 for performing stuff operation on unipolar signals from the line interface unit, and stuffed signals from the stuff operation unit are mapped to frames in the transmission device. , Mapping units 113, 123, and 13 for outputting the mapped signals as mapping output signals
3, 143, and a line control selector A114 for selecting a mapping input signal mapped to an input frame in the transmission apparatus in the online state and selecting a mapping output signal input from the map unit of the own channel in the offline state. , 124, 134, and 144, and demapping units 115, 125, and 135 that perform demapping by inputting the selected signal from the line control selector A.
145, a destuff operation unit 116 for inputting a demapped signal from the demap unit and performing a destuff operation.
126, 136, and 146.

The channel 4 further includes an off-line pattern generator (hereinafter, referred to as an off-line PG) 148 for outputting a random pattern signal for monitoring a failure inside the interface unit in an off-line state.
When a fault is monitored, the destuffed signal from the destuff operation unit of channel 4 is compared with the random pattern signal from the offline PG to determine whether the two signals match or not, and outputs a fault determination signal. An off-line error detection unit 149 selects the destuffed signal output from the destuff operation unit of channel 4 in the on-line state, and the off-line PG in the off-line state.
And a line control selector B 147 for selecting a random pattern signal from the CPU.

Furthermore, a line state signal is used to input / output a bipolar signal from the outside to the transmission / reception side of the line interface unit of each channel with the outside in the online state. The low-speed transmission signal receiving side relays 150, 152, 154, and 156 for switching the bipolar signal output from the interface unit to the input side and outputting the bipolar signal to the line interface unit, and the line interface unit for the online state. The low-speed transmission signal transmission side relays 151, 153, 155, and 157 for outputting the bipolar signal to the outside and switching the bipolar signal to the low-speed transmission signal reception side relay of the next channel in the off-line state are arranged. I have.

Therefore, in the internal fault monitoring method in the off-line state according to the conventional example, a random pattern is generated by the off-line PG 148 in the off-line state, and this pattern is generated by the line control selector B 147, the line interface unit 141, and the low-speed transmission signal. Transmission side relay 15
7, low-speed transmission signal receiving side relay 150, line interface unit 111, staff operation unit 112, map unit 11
3, line control selector A114, demapping unit 115,
Destuff section 116, line interface section 111,
Low-speed transmission signal transmission side relay 151, low-speed transmission signal reception side relay 152, line interface unit 121, stuff operation unit 122, map unit 123, line control selector A 124, demap unit 125, destuff operation unit 12
6, line interface section 121, low-speed transmission signal transmission side relay 153, low-speed transmission signal reception side relay 154, line interface section 131, staff operation section 132,
A map unit 133, a line control selector A 134, a demap unit 135, a destuff operation unit 136, a line interface unit 131, a low-speed transmission signal transmission side relay 155, a low-speed transmission signal reception side relay 156, a line interface unit 141, a stuff operation unit 142, The pattern passes through the map unit 143, the line control selector A 144, the demap unit 145, and the destuff operation unit 146 in this order, and is finally input to the offline error detection unit 149. The random pattern generated by the off-line PG 148 is compared, and if they match, the fault is monitored as “no fault”, and if they do not match, the fault is monitored as “failure”.

[0006]

The first problem of the above-described conventional offline monitoring method is that the relays 151, 153, and 15 on the low-speed transmission signal transmitting side during execution of the offline monitoring.
5, 157 and low-speed transmission signal receiving relays 150, 15
Driving a plurality of relays 2, 154 and 156 consumes excessive power. In other words, a drive current is applied to drive the low-speed transmission signal transmission side relay and the low-speed transmission signal reception side relay and the contacts of the relays are closed, so that an amount of power at this time is required. The disadvantage is that more space is required due to the use of such a large number of relays.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small-sized low-speed transmission signal interface unit which consumes less power when monitoring an internal fault and solves the above-mentioned drawback, and a fault monitoring method therefor.

[0008]

According to the present invention, a low-speed transmission signal interface unit having an in-unit monitoring function receives a bipolar low-speed transmission signal coming from outside a transmission apparatus in each of four channels in an on-line state. After performing signal conversion by the bipolar / unipolar signal conversion unit, a unipolar signal is output through the loopback control selector. A line interface section for performing signal conversion by a unipolar / bipolar signal conversion section and outputting the bipolar as a low-speed transmission signal to the outside of the transmission device; a staff operation section for performing a staff operation on the unipolar signal from the line interface section; The stuffed signal from the operation unit A mapping unit that maps to a frame in the transmission apparatus and outputs a mapped signal as a mapping output signal; and, in an online state, selects a mapping input signal mapped to a frame in the transmission apparatus to be input; A line control selector A for selecting a mapping output signal input from a channel map unit, a demapping unit for inputting a selected signal from the line control selector A to perform demapping, and a signal demapped from the demapping unit And a destuffing operation unit for performing destuffing operation and inputting, and outputting a mapping output signal from another channel input to the line control selector A in the off-line state to the channel 1, For channel 2, channel 3 and channel 4, it Is, channel 2, channel 3, channel 4 and channel 1, or, respectively, channel 4, channel 1,
7 is a mapping output signal from channel 2 and channel 3. Further, an off-line pattern generator for outputting a random pattern signal for monitoring a fault inside the interface unit in an off-line state to any one of the four channels, and a destuff operation unit for the channel when monitoring the fault. An off-line error detection unit that compares the destuffed signal with a random pattern signal from the off-line pattern generator to determine whether the two signals match or not, and outputs a failure determination signal; A line control selector B for selecting a destuffed signal output from the destuff operation section of the above, and selecting a random pattern signal from an offline pattern generator in an off-line state. In the off-line state, the random pattern signal from the line control selector B is looped back to the loopback control selector and output via the loopback control selector, and the random pattern signal is overwritten with the alarm display signal by the AIS insertion unit. And input to the unipolar / bipolar signal converter, and output to the outside after the bipolar signal conversion. Of the four channels, the line interface units of three channels other than the channel including the pattern generator for offline use each of the channel interface units in the offline state. The random pattern signal from the destuff operation unit is returned to the loop-back control selector and output through the loop-back control selector, and the alarm display signal is overwritten on the random pattern signal by the AIS insertion unit. And by input to the unipolar / bipolar signal conversion unit,
After the bipolar signal conversion, the signal is output to the outside.

The line control selector A, the line control selector B, and the loopback control selector each perform selection switching according to a line state signal output from the central processing unit. On the other hand, according to the method of monitoring a fault inside the unit by the low-speed transmission signal interface unit with the monitoring function in the unit according to the present invention, a random pattern signal is generated in a channel provided with an off-line pattern generator in an off-line state, To the line interface unit via the line control selector B, and loops back to the low-speed transmission signal receiving side by the loopback control selector, and to the line control selector A for the previous or next channel via the stuff operation unit and the map unit. Then, each channel other than the channel having the offline pattern generator is placed in the off-line state. Next, the random pattern signal input from the map unit of the next or previous channel is sequentially applied to each line control select. A, the random pattern signal is input to the line interface unit via the demapping unit and the destuffing operation unit, and is looped back to the low-speed transmission signal receiving side by the loopback control selector. Output to the line control selector A of the previous or next channel, the map section of the last channel inputs the random pattern signal to the line control selector A of the channel having the pattern generator for offline, and finally the pattern for offline. The channel including the generator causes the random pattern signal input to the line control selector A to be input to the offline error detection unit via the demapping unit and the destuff operation unit, and the offline error detection unit converts the random pattern signal to the offline error detection unit. pattern Compared to a random pattern signal inputted separately directly from Enereta, if both random pattern signal matches "no fault", if inconsistencies as "Faulty", and outputs a failure determination signal.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a low-speed transmission signal interface unit according to the present invention.

Each of channel 1, channel 2, channel 3 and channel 4 receives or transmits a bipolar signal to / from the outside, and has a line interface unit 11, 21, which inputs and outputs a corresponding unipolar signal inside the unit. 31 and 41 and staff operation units 12, 22 and 3 for performing staff operations on unipolar signals from the line interface units 11, 21, 31 and 41.
2, 42, and a map unit that maps stuffed signals from the stuff operation units 12, 22, 32, and 42 to frames in the transmission device and outputs the mapped signals as mapping output signals 1, 3, 5, and 7. 13, 23, 3
3, 43, and the mapping input signals 2, 4, 6, 8 mapped to the frame in the transmission apparatus by the line state signal 9 in the online state, and the map section of the adjacent channel by the line state signal 9 in the offline state. 23, 3
Line control selectors A 14, 24, 34, 44 for selecting mapping output signals output from 3, 43, 13
And a demapping unit 15 that receives signals from the line control selectors A14, 24, 34, and 44 and performs demapping.
25, 35, 45 and demapping sections 15, 25, 35, 4
5 is provided with destuff operation units 16, 26, 36, and 46 for performing destuff operation on the signal demapped from the signal 5.

An off-line pattern generator (hereinafter abbreviated as an off-line PG) 48 for outputting a random pattern signal for monitoring a fault in the interface unit is provided on a channel 4 (hereinafter abbreviated as a CH 4).
The destuffed signal from the destuff operation unit 46 of CH4 and the random pattern signal from the off-line PG 48 are input and compared, and a match / mismatch is detected.
When there is a mismatch, an off-line error detection unit 49 which outputs a failure determination signal, and in the on-line state, a destuffed signal from the destuff operation unit 46 of the CH 4 is selected based on the line state signal 9. A line control selector B47 for selecting a random pattern signal from the off-line PG 48 according to the signal 9; and a line interface section for channel 1, channel 2 and channel 3 (hereinafter abbreviated as CH1, CH2 and CH3). 11, 21, and 31 receive the signals from the destuff operation units 16, 26, and 36, and
The line interface unit 41 receives a signal from the line control selector B47. The above-mentioned line state signal 9 is output by the central processing unit, and is a signal indicating the online state and the offline state, respectively, depending on the level of the signal.

Next, the line interface units 11, 21, 31, and 41 of each channel will be described with reference to FIG. Both line interface units receive a bipolar low-speed transmission signal coming from outside the transmission device, and
B / U unit 51 for performing bipolar / unipolar signal conversion
When the line status signal 9 indicates the online status, B /
When the unipolar signal from the U unit 51 is selected, and when the offline state is indicated, a random pattern signal (unipolar signal) destuffed by the destuff operation unit is selected.
A loop-back control selector 53 for outputting to the stuff operation unit, and when the line state signal 9 indicates the online state, the unipolar signal de-stuffed by the destuff operation unit is passed as it is, and when the line state signal 9 indicates the offline state, a random pattern is used. AIS insertion unit 5 which overwrites a signal (unipolar signal) with an alarm indication signal (Alarm Indication Signal: hereinafter referred to as AIS) and outputs the signal.
4 and a U / B 52 that performs unipolar / bipolar signal conversion on the unipolar signal from the AIS insertion unit 54.

FIG. 3 is a schematic diagram showing the configuration of the off-line error detecting section 49 shown in FIG. The CH4 offline error detection unit 49 compares the destuffed signal from the CH4 destuff operation unit 46 input at the time of fault monitoring in the offline state with the random pattern signal from the offline PG 48 and matches them. EX-OR that detects a mismatch and outputs a failure determination signal when the mismatch is detected
A unit 55 and an AND unit 56 that prohibits the output from the EX-OR unit 55 in the online state and outputs the failure determination signal in the offline state.

Next, the operation of the embodiment of the present invention, in particular, the failure monitoring operation in the offline state will be described in detail with reference to FIG.

In the off-line state, the line interface signals 11, 21 and 31 are supplied to the line interface sections 11, 21 and 31 by the loopback control selector 53 by the line state signal 9, and the unipolar signals from the destuff operation sections 16, 26 and 36 are transmitted by the loop back control selector 53. Is looped back to the low-speed transmission signal receiving side.
For 1, loopback control is performed to loop back the random pattern signal from the line control selector B47 to the low-speed transmission signal receiving side. Therefore, a random pattern signal is generated by the off-line PG 48, and this signal is transmitted to the off-line control selector B47, the line interface unit 4 of the CH4.
1. CH4 staff operation unit 42, CH4 map unit 4
3, a line control selector A34 for CH3, a demapping unit 35 for CH3, a destuff operation unit 36 for CH3, a line interface unit 31 for CH3, a stuff operation unit 32 for CH3, a map unit 33 for CH3, a line control selector 24 for CH2, CH2 demapping unit 25, CH2 destuffing operation unit 26, CH2 line interface unit 21,
CH2 staff operation unit 22, CH2 map unit 23,
CH1 line control selector A14, CH1 demapping unit 15, CH1 destuffing operation unit 16, CH1 line interface unit 11, CH1 stuffing operation unit 1
2, the map unit 13 of CH1, the line control selector A44 of CH4, the demapping unit 45 of CH4, and the destuffing operation unit 46 of CH4 pass in this order, and are finally input to the offline error detecting unit 49. Therefore, the off-line error detection unit 49 compares the input pattern with the random pattern generated by the off-line PG 48, and if they match, “no failure”, and if they do not match, “failure”.
Monitor the fault as. In the above description, the random pattern signal from the offline PG 48 is CH4 → CH3
It is assumed that the circuit makes a round in the order of → CH2 → CH1 → CH4, but in the reverse direction CH4 → CH1 → CH2 → CH3 → CH4
It is clear that the circuit may go around in this order.
Further, the offline PG 48, the offline error detection unit 49, and the line control selector B47 may be installed in any channel other than CH4.

[0017]

As described above, according to the present invention, a random pattern signal is generated by an off-line pattern generator installed on a specific channel for monitoring the internal failure of the low-speed transmission signal interface unit in the off-line state. To each channel sequentially,
When comparing the original signal pattern and determining whether the two signals match, the loopback control selector of the line interface unit is used to loop back the random pattern signal so that the power consumption can be transmitted at a low speed using a conventional control relay. There is an effect that the number of relays can be reduced as compared with the method and apparatus for returning a signal, and the number of relay components in the low-speed transmission signal interface unit can be reduced to downsize the unit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a low-speed transmission signal interface unit of the present invention.

FIG. 2 is a detailed block diagram of a line interface unit of FIG.

FIG. 3 is a detailed circuit diagram of an off-line error detection unit in FIG. 1;

FIG. 4 is a block diagram for explaining the operation of the embodiment of FIG. 1;

FIG. 5 is a block diagram showing a configuration of a conventional low-speed transmission signal interface unit.

[Explanation of symbols]

 Reference Signs List 1 CH1 mapping output signal 2 CH1 mapping input signal 3 CH2 mapping output signal 4 CH2 mapping input signal 5 CH3 mapping output signal 6 CH3 mapping input signal 7 CH4 mapping output signal 8 CH4 mapping input signal 9 line state signal 11 CH1 line interface section 12 CH1 stuff operation unit 13 CH1 map unit 14 CH1 line control selector A 15 CH1 demap unit 16 CH1 destuff operation unit 21 CH2 line interface unit 22 CH2 stuff operation unit 23 CH2 map unit 24 CH2 line control selector A 25 CH2 demap unit 26 CH2 Destuff operation unit 31 CH3 line interface unit 32 CH3 staff operation unit 33 CH3 map unit 34 CH3 line control Selector A 35 CH3 demapping unit 36 CH3 destuffing operation unit 41 CH4 line interface unit 42 CH4 stuffing operation unit 43 CH4 mapping unit 44 CH4 line control selector A 45 CH4 demapping unit 46 CH4 destuffing operation unit 47 line control selector B 48 Off-line pattern generator 49 Off-line error detection unit 51 B / U unit 52 U / B unit 53 Loopback control selector 54 AIS insertion unit 55 EX-OR unit 56 AND unit

Claims (3)

(57) [Claims] An interface unit accommodated in a transmission device for transmitting four-channel low-speed transmission signals and performing interface processing for each channel under the control of a central processing unit of the transmission device, comprising: a channel 1, a channel 2, a channel 3, and a channel. 4 receives a bipolar low-speed transmission signal coming from the outside of the transmission device in the on-line state, and
After performing the signal conversion in the unipolar signal conversion unit, a unipolar signal is output through the loopback control selector, and the unipolar / bipolar signal conversion is performed on the unipolar signal destuffed by the destuff operation unit of the corresponding channel. A line interface unit that performs signal conversion in the unit and outputs this bipolar signal as a low-speed transmission signal to the outside of the transmission device; a stuff operation unit that performs stuff operation on a unipolar signal from the line interface unit; A mapping unit that maps the stuffed signal from the unit to a frame in the transmission device and outputs the mapped signal as a mapping output signal; and a mapping input signal that is mapped to the frame in the transmission device that is input in an online state. Select Offline A line control selector A for selecting a mapping output signal input from a map unit of another channel in a state; a demapping unit for inputting a selected signal from the line control selector A to perform demapping; A destuff operation unit that inputs a signal demapped from and performs destuff operation to output the signal;
The mapping output signals from other channels input to the line control selector A in the off-line state are channel 2, channel 3, and channel 3 for channel 1, channel 2, channel 3, and channel 4, respectively. , Channel 4 and channel 1, or mapping output signals from channel 4, channel 1, channel 2 and channel 3, respectively. An off-line pattern generator that outputs a random pattern signal for monitoring a fault, and a de-stuffed signal from the de-stuff operation unit of the channel and a run from the off-line pattern generator during the fault monitoring. An off-line error detection unit that compares the two signals to determine whether they match or disagrees by comparing the two signals with each other and outputs a failure determination signal, and a destuffed output that is output from the destuff operation unit of the channel in the online state. A line control selector B for selecting a signal and selecting a random pattern signal from the off-line pattern generator when in an off-line state. The random pattern signal is returned to the loop-back control selector and output through the loop-back control selector, and the random pattern signal is overwritten with an alarm display signal by an AIS insertion unit to the unipolar / bipolar signal conversion unit. Input After the bipolar signal conversion, the line interface units of the three channels out of the four channels other than the channel having the pattern generator for offline use output the random pattern signal from the destuff operation unit of the corresponding channel in the offline state. An AIS insertion unit overwrites the random pattern signal with an alarm display signal and inputs it to the unipolar / bipolar signal conversion unit. Low-speed transmission signal interface unit with internal monitoring function that outputs to the outside after conversion. 2. The apparatus according to claim 1, wherein each of said line control selector A, said line control selector B, and said loopback control selector performs selection switching according to a line state signal output from said central processing unit. Low-speed transmission signal interface unit. 3. The method for monitoring an internal failure of a low-speed transmission signal interface unit according to claim 1, wherein a random pattern signal is generated in a channel including an offline pattern generator in an offline state. Is input to the line interface unit via the line control selector B of the corresponding channel, looped back to the low-speed transmission signal receiving side by the loopback control selector, and the line control of the previous or next channel is performed via the stuff operation unit and the map unit. Selector A
Then, each of the channels other than the channel having the pattern generator for offline use sequentially receives the random pattern signal input from the map unit of the next or previous channel by the respective line control selectors A in the offline state. Select, input the random pattern signal to the line interface unit via the demapping unit and the destuffing operation unit, loop back to the low-speed transmission signal receiving side by the loopback control selector, and forward through the stuffing operation unit and the map unit. Alternatively, the random pattern signal is output to the line control selector A of the next-order channel, and the map unit of the last-order channel inputs the random pattern signal to the line control selector A of the channel having the offline pattern generator. Prepare The channel causes the random pattern signal input to the line control selector A to be input to the off-line error detection unit via the demapping unit and the destuff operation unit, and the off-line error detection unit outputs the random pattern signal from the off-line pattern generator. Compared to the random pattern signal directly input separately, if both random pattern signals match, “no fault” is output. If they do not match, a fault determination signal is output as “failure”. How to monitor faults.