KR20010060690A - A device of fault detection for optical signal path - Google Patents

Abstract

PURPOSE: An apparatus for detecting the troubles of an optical signal transfer path is provided to discriminatively detect troubles generated on an optical line and an electronic circuit board by generating an alarm signal indicating that faults have been generated on the paths of the electronic circuit board if Pin LOS signals are detected from a part of 16-divided channels and generating a LOS signal indicating that faults have been generated on the optical path if Pin LOS failure alarms are detected from all the channels at the same time. CONSTITUTION: An optical cable(10) transmits an STM-16 signal of 2.48832Gbps in serial. An OEC(Optical to Electric Converter)(20) divides a bit rate of STM-16 2.48832Gbps into 16 channels and outputs serial signals of 155.52Mbps by the 2 bytes in parallel. The first 16 frequency dividers(110), respectively receiving the data signals divided into 16 channels and supplied from the OEC(20) at a bit rate of 155.52Mbps, divide the bit rate into two channels having a bit rate of about 78Mbps. The second 16 frequency dividers(120) divide the 78Mbps bit rate into two channels having a bit rate of about 39Mbps. The third 16 frequency dividers(130) divide the 39Mbps bit rate into two channels having a bit rate of about 19Mbps. Sixteen Pin LOS detection parts(140), receiving the signals of the highest level channel among the signals divided from the third 16 frequency dividers(130) and outputted by channels, detect trouble generation by channels. An OR gate(150), receiving all the output signals of the Pin LOS detection parts(140), outputs a LOS alarm signal in case that fault generation alarm signals are detected from the Pin LOS detection parts(140) at the same time.

Description

A DEVICE OF FAULT DETECTION FOR OPTICAL SIGNAL PATH}

The present invention relates to a device for detecting a trouble occurring in an optical signal transmission path of an optical communication system. In particular, an optical cable path and an electronic circuit board for transmitting a 2.48832Gbps signal using an optical cable The present invention relates to a device capable of distinguishing and detecting a fault occurring in a transmission path by a part of an electric circuit board.

A device for transmitting the 2.84432Gbps signal using an optical cable is called a STM-16 (Synchronous Transmission Module-16), and a fiber cut or optical fiber for transmitting the high speed data signal as described above. A case in which a data signal is not transmitted due to a laser failure of a laser generator, which is a signal generator, is called LOS (Los Of Signal).

In the case of the LOS in which the data signal is not transmitted as described above, there is a case where an optical cable break and a laser generator failure occur in a path in which the data signal is transmitted as described above. The LOS may be generated due to a failure of some paths on the electronic circuit board or a failure of the circuit board. However, the failure of the optical cable or the laser generator and the failure of the electronic circuit board cannot be distinguished. There was.

Hereinafter, a failure detecting apparatus for an optical signal transmission path according to the prior art will be described with reference to the accompanying drawings.

1 is a frame structure diagram of a typical STM-16 class transmission signal, and FIG. 2 is a functional block diagram of an apparatus for detecting a failure of an optical signal transmission path according to an embodiment of the prior art.

Referring to FIG. 1, the STM-16 class data frame structure having a rate of 2.48832 Gbps is A1 and A2 having an 8-bit data area as a regeneration section overhead. Frames of J0, B1, E1, F1, D1, D2, and D3 are allocated an area of 144 * 3 bytes, and an AU pointer is allocated an area of 144 bytes. B2, K1, K2, D4, D5, D6, D7, D8, D9, D10, D11, D12, S1, M1, having an 8-bit data area as a multiple section overhead. A frame of E2 is allocated an area of 144 * 5 bytes, and is 81 * 9 * 16 bytes in an area called payload of STM-16 as a data area to be transmitted at the same time. (Byte) Allocate a signal in serial.

In the STM-16 data frame structure, the A1 and A2 frames of the regeneration section overhead are always fixedly recorded without changing the data of '11110110' and '00101000', and the STM-16 It is used as a kind of synchronous signal to indicate the start of a data frame.

In the prior art illustrated in FIG. 2, an apparatus for detecting a failure of an STM-16 class optical signal transmission path of 2.48832Gbps includes an optical cable 10 for transmitting an optical signal,

Receives an optical signal of 2.48832 Gbps transfer rate through the optical cable 10, converts an electric signal into a 2.48832 Gbps transfer rate signal, and converts it into an electronic circuit. An optical to electric converter 20 which is divided into a transmission rate of 155.52 Mbps suitable for processing in an electric circuit board and outputs through 16 channels;

When the optical signal is not transmitted by receiving the signal output from the photoelectric converter 20, the LOS detector 30 outputs a Loss Of Signal (LOS) alarm signal. An OR gate 31 for ORing a signal applied to each channel and outputting the OR;

An exclusive or gate (X-OR Gate) 32 that receives the output signal of the or gate 31 as an input signal and outputs it after a continuous comparison with the previous output signal;

The output signal of the exclusive OR gate 32 is applied as a data signal, and an input data signal is input to the input side of the exclusive OR gate 32 and a failure detection unit 34 to be described later by a clock signal that is separately applied. D-Flip Flop (D-FF) 33 to output,

The fault detection unit detects and outputs a case where the signal applied from the depreflop 33 does not have a change in the digital level for 100 μs corresponding to a length of 4/5 frames of the STM-16 signal. 34) and,

A normal motion detector 35 which detects the signal output from the photoelectric converter 20 and detects whether the signal is continuously applied for 250 μs corresponding to two frames of the STM-16 signal; ,

The failure detection unit 34 is configured to output a LOS alarm signal when the signal is applied, and when the signal is applied from the normal operation detection unit 35 comprises a failure declaration unit 36 to stop the output of the LOS alarm signal.

Hereinafter, an apparatus for detecting a failure of an optical signal transmission path according to the related art having the above configuration will be described in detail with reference to the accompanying drawings.

When the 2.48832Gbps optical signal having the same frame structure as that shown in FIG. 1 is applied through the optical cable 10, the photoelectric converter 20 converts the electrical signal into an electrical signal and simultaneously converts a 2.48832Gbps high-speed signal at a transmission rate of 155.52 Mbps. It is divided into (Serial) signal and outputs in parallel to 16 channels. Therefore, the LOS detection unit 30 of the next stage does not have to operate at a processing speed of 2.48832 Gbps or more, and may be capable of processing a serial signal of 155.52 Mbps.

The exclusive OR gate 32 is divided into 16 channels from the photoelectric converter 20 and applied in parallel, and OR is performed by the OR gate 31 in a signal applied as a serial signal of 155.52 Mbps for each channel. The output signal of the depreflop 33 is applied to the other input terminal of the exclusive OR gate 32 at the same time.

Therefore, the exclusive OR gate 32 may continuously perform an exclusive OR operation continuously on the input signal and the currently input signal, and then output the result.

As described above, the signal output from the exclusive OR gate 32 is applied to the depreflop 33 as a data signal, and at the same time, the input data signal passes after one cycle of the clock signal. Is output.

The signal output after one clock period from the depreflop 33 is applied to the exclusive or gate 32 and the failure detection unit 34, and the failure detection unit 34 outputs 4 STM-16 signals. In the case where there is no level change in the applied digital signal of 155.52 Mbps for 100 μs corresponding to ½ frame, that is, when the synchronization signal of A1 and A2 is not detected, the optical cable 10 Detecting that a failure has occurred in a laser generating device that generates a cut or an optical signal is detected.

At the same time, the normal operation detection unit 35 is divided into 16 channels from the photoelectric converter 20 and outputs a signal that is output at a transmission rate of 155 Mbps for each channel. When the synchronization signal of A1 and A2 is detected during the transmission time, i.e., 250 mu s, a signal saying that a signal of 2.48832Gbps is normally transmitted through the optical cable 10.

The failure declaration unit 36 receives a detection signal indicating that a failure occurs in the optical cable 10 or the laser generating device from the failure detection unit 34 and a detection signal that operates normally without a failure from the normal operation detection unit 35. When a failure detection signal is applied from the failure detection unit 34, a LOS (Loss Of Signal) signal, which is a major failure alarm signal, is output, and a normal operation detection signal is output from the normal operation detection unit 35. When is received, the output of the LOS alarm signal is stopped.

However, the failure detection apparatus of the optical signal transmission path according to the prior art as described above is for detecting the occurrence of a failure in the optical cable 10 and the laser generation device which is an optical signal generator. In some embodiments, an electronic circuit corresponding to a part of a channel among the 16 divided channels transmits a corresponding signal due to a poor soldering or a component defect. In other words, there is a problem in that a case where a failure occurs in some paths in the electronic circuit cannot be detected separately from a case where a failure occurs in the optical cable 10.

In other words, even if the optical cable or the laser generator does not fail, and even if a failure occurs in some paths of the electronic circuit board, a failure alarm of the LOS is generated. After inspecting all the installed sections and checking whether the laser generating device is faulty, there was a problem of operating difficulties and time and manpower that was checked for faults in the electronic circuit board.

The present invention divides an optical signal transmitted at a high speed of 2.48832 Gbps into 16 channels, and when a pin LOS signal is detected from a specific part of a channel, a failure occurs in a path of an electronic circuit board. If a pinross fault alarm is detected on all channels at the same time, a Loss (LOS) signal indicating that a fault has occurred in the optical path is generated, thereby distinguishing the fault occurring on the optical path and the electronic circuit board. It is an object to provide a device that can be detected.

The present invention has been made in order to achieve the above object, a plurality of channels that are separately applied to the signal is applied to the transmission rate of the optical signal is divided by a plurality of channels from the photoelectric converter, and the transmission rate is divided in half and each outputs A plurality of second dividers for receiving a signal of the highest channel among the signals which are separately transmitted and the transmission rate is divided from the first divider, and dividing the transmission rate in half and outputting each channel; A plurality of third dividers for receiving a signal of the highest channel among the signals output from the second divider and separately outputting the signals, and dividing the transfer rate in half and outputting each channel; A plurality of channels that detect a failure by each channel by receiving a signal of the highest channel among signals output from each channel divided by A failure detection device of an optical signal transmission path including a loss detector and an or gate which receives both outputs of the plurality of pinloss detectors and outputs a loss signal when a failure occurrence signal is detected from all the pinloss detectors. do.

1 is a frame structure diagram of a general STM-16 transmission signal,

2 is a functional block diagram of an apparatus for detecting a failure of an optical signal transmission path according to an embodiment of the prior art;

3 is a functional block diagram of an optical signal transmission path failure detection device according to the present invention;

4 is a detailed functional block diagram of a pin loss detector according to the technique of the present invention,

5 is a data division form diagram showing a state in which a transmission rate is divided according to the technique of the present invention.

** Explanation of symbols on the main parts of the drawing **

10: optical cable 20: photoelectric converter

30: Loss detector 31,150: Or gate

32,141: exclusive or gate 33,142: depreflop

34, 143: fault detection unit 35, 140: normal operation detection unit

36: failure declaration unit 100: failure detection device

110, 120, 130: frequency divider 140: pin loss detector

145: fault alarm generating unit

Hereinafter, an apparatus for detecting a failure of an optical signal transmission path according to the technique of the present invention will be described with reference to the accompanying drawings.

Figure 3 is a functional block diagram of the optical signal transmission path failure detection apparatus according to the technique of the present invention, Figure 4 is a detailed functional block diagram of the pin loss detector according to the technique of the present invention, Figure 5 is by the technique of the present invention It is a data division form showing a state in which the transmission speed is divided.

Referring to the accompanying drawings, the failure detection device 100 of the optical signal transmission path according to the technique of the present invention, the optical cable for transmitting a signal of 2.48832Gbps, a high speed optical signal of STM-16 class in serial 10,

The STM-16-class 2.48832 Gbps output rate from the optical cable 10 is divided into 16 channels, and the serial signal having a transmission rate of 155.52 Mbps for each of the 16 channels is divided into 16 bits (Bit) or 8 bits (Bit). Optical to Electric Convertor (OEC) 20 outputting in parallel in units of 2 bytes with 1 byte as 1 byte,

16 channels which are divided into 16 channels from the photoelectric converter 20 and separately receive data signals applied at a transmission rate of 155.52 Mbps, respectively, and are divided into two channels having a transmission rate of about 78 Mbps, respectively. First divider 110,

From the first divider 110, the transmission rate is connected to the highest channel among the channels divided by the 78 Mbps output, and the 16 Mbps to divide the 78 Mbps transmission rate into two channels of about 39 Mbps transmission rate The second divider 120,

Sixteenth channels are connected to the highest channel among the channels in which the transmission rate is divided into 39 Mbps from the second divider 120 and is outputted by dividing the 39 Mbps transmission rate into two channels of about 19 Mbps. 3 divider 130,

It is connected to each of the third divider 130 separately, and receives the signal applied from the corresponding third divider 130 and the output signal of the depreflop 142 which will be described later to perform an exclusive OR operation Exclusive XOR gate 141; The depreflop which causes the signal output from the exclusive OR gate 141 to be output by one cycle later by a period of a clock signal separately applied from a clock part not shown in the diagram of the failure detecting apparatus 100. (D-FF) 142; During the predetermined time, the signal applied from the depreflop (D-FF) 142 is, for example, 100 μs time corresponding to 4/5 periods of the frame unit signal of the STM-16 signal. A failure detection unit 143 which outputs a failure detection signal when there is no level change of the signal; During the predetermined time period, the signal applied from the corresponding third frequency divider 130 is, for example, during the 250 μs time corresponding to two frame units of the STM-16 signal, the applied signal is applied. Normally, the normal motion detection unit 144 for outputting a normal motion detection signal when it occurs without a failure; A fault alarm that generates a pin LOS fault alert signal indicating that a fault occurs in a specific path among the paths of the 16 channels by signals applied from the fault detector 143 and the normal motion detector 144. 16 Pin LOS detectors 140 comprising a generator 145,

When all the outputs of the sixteen pinrose detectors 140 are applied and a failure occurrence alarm signal is detected from the sixteen pinrose detectors 140, the optical line 10 is cut or optical signal. It is composed of an OR gate 150 that outputs a LOS alarm signal, which is a major alarm signal that a failure occurs in the laser which is a generator.

Hereinafter, an apparatus for detecting a failure of an optical signal transmission path according to an embodiment of the present invention will be described with reference to the accompanying drawings using the above configuration.

When the STM-16 data signal of 2.48832Gbps, which is a high speed transmission rate, is applied through the optical cable 10, which is the optical path, the photoelectric converter (OEC) 20 converts the 2.48832Gbps optical signal to 2.48832Gbps. To convert to an electrical signal.

Since the 2.48832Gbps high-speed signal is not easy to process as an electronic circuit, and the processable electronic component is very expensive, the transmission speed at which a relatively inexpensive electronic circuit can be relatively easily processed is 155.52. It outputs in parallel to 16 channels or paths by dividing at the transmission speed of Mbps.

That is, the signal output through the 16 channels or paths becomes a signal corresponding to 2 bytes when 8 bits are 1 byte. Each path has a transmission rate of 155.52 Mbps, and a data signal is output.

The first divider 110 is connected to the 16 transmission paths, respectively, and receives a signal of 155.52 Mbps, and divides the transmission rate in half again, thereby providing two channels at a transmission rate of 77.76 Mbps or about 78 Mbps. Output through

As described above, the state in which the transmission rate of 155.52 Mbps is divided into two transmission rates of 77.76 Mbps or about 78 Mbps is shown in detail in FIG.

Referring to the accompanying FIG. 5, a state or method of dividing a transmission rate of 155.52 Mbps is data output from the photoelectric converter 20 in the order of 155 Mbps in series, 16 in 2 byte units as an embodiment. When a bit signal is applied, odd-numbered data, that is, 1, 3, 5, 7, 9, 11, 13, 15th data, is applied to the upper channel divided by the first divider 110. Alternatively, the data signal output through the path and applied evenly, that is, the second, fourth, sixth, eighth, tenth, twelve, fourteenth, and sixteenth data signals is output through the lower channel or the path.

The sixteen first dividers 110 connected to the sixteen channels or the paths of the photoelectric converter 20 operate as described above, and the first divider 110 has the first channel or the path of the first divider 110. Two dividers 120 are connected respectively.

The second divider 120 divides the signal received at the transmission rate of 78 Mbps through the upper path of the first divider 110 at the transmission rate of 39 Mbps, and then outputs it through each channel or path. do.

The method of dividing the 78Mbps transmission rate into the 39Mbps transmission rate by the second divider 120 is the same as the dividing method of the first divider 110, and is shown in detail in FIG. have.

In the case of the second divider 120, an odd-numbered data signal is output to an upper channel or a path, and an even-numbered data signal is output to a lower channel or a path, respectively.

The third divider 130 is connected to upper channels of the 16 second dividers 120, respectively, and a 39 Mbps transfer rate signal received from the second divider 120 is converted into a 19 Mbps transfer rate signal. In the same manner as described above, an odd-numbered signal is output to an upper channel or a path, and the shape of the data signal divided by the third divider 130 is shown in detail in FIG. 5.

The pin loss detectors 140 are individually connected to upper channels of the sixteen third dividers 130, and a signal applied at 19 Mbps is 4 / time of a frame unit time of the STM-16 signal. If there is no level change for 100 μs corresponding to 5, the pin LOS signal is outputted. If it is normally output for 250 μs corresponding to two of the frame unit time, the pin LOS signal is outputted. ) Release the signal.

As described above, the pin loss detector 140 receives an signal from the third divider 130 and a signal output from the depreflop 142, and performs an exclusive OR operation repeatedly. Or gate 141,

The signal applied from the exclusive OR gate 141 is sequentially output one signal at a cycle by a clock signal separately applied from a clock unit not shown in the diagram of the failure detection apparatus 100. .

As described above, the signal output from the depreflop 142 is applied to the input terminal of the exclusive or gate 141, and is simultaneously applied to the failure detection unit 143 to detect a failure if there is no level change during the 100 μs time. A signal is output to the failure alert generator 145.

In addition, the normal operation detector 140 detects a signal applied from the third divider 130 for 250 μs time, and continuously outputs a normal data signal when the signal is normally output for 250 μs time. Output to the failure alarm generating unit 145.

When the failure detection signal is applied from the failure detection unit 143, the failure alarm generation unit 145 outputs a Pin LOS failure alarm signal and operates normally from the normal operation detection unit 140. When the detection signal is applied, the Pin LOS fault alarm signal is canceled.

Since the pin LOS signal refers to each path or channel, it can be confirmed that a failure occurs in the electronic circuit of the corresponding channel or path.

When the OR gate 150 receives all signals output from the sixteen pin loss detectors 140 and all of the pin LOS signals are detected from all of the pin loss detectors 140, an important alarm ( Outputs a Loss Of Signal (LOS) Alarm signal, which is a Major Alarm signal.

Therefore, when the LOS signal is output, a failure occurs in the optical cable 10 or the optical fiber made of a laser, and when a pin LOS signal is detected, the corresponding path It notifies that a failure has occurred in the electronic circuit.

Therefore, it is possible to clearly identify whether a failure occurs in the optical path or the electronic circuit portion, and, in addition, when a failure occurs in the electronic circuit, it is possible to easily and accurately identify the portion of the path in which the failure occurs.

The present invention as described above, in the maintenance of the optical communication equipment, to clearly distinguish whether the failure occurs in the optical path and the circuit board for processing the signal generated by the optical generator and the laser generating device for generating an optical signal This has the effect of minimizing the time, expense and effort consumed by the operating personnel.

In addition, when a failure occurs in the electronic circuit board, it is possible to immediately identify the path in which the failure occurs, and there is an industrial use effect of improving reliability of the optical communication system by rapid failure recovery.

Claims (3)

A plurality of dividers for individually receiving signals to be divided and applied to each channel and dividing a transmission rate to output signals of the divided channels, respectively; A plurality of pin loss detectors which are divided from the plurality of dividers and receive a signal of the highest channel among the signals input for each channel and detect a failure occurrence for each channel; And an OR gate receiving all outputs of the plurality of pin loss detectors and outputting a loss signal when a failure occurrence signal is detected from all the pin loss detectors. According to claim 1, The plurality of dividers may receive a signal for dividing the transmission rate of the optical signal into a plurality of channels from the photoelectric converter, and divide the applied transmission rate in half, and then output the upper channel signal for each channel. A plurality of first dividers, A plurality of second dividers for receiving a signal output for each channel from the first divider, dividing a transmission rate in half, and then outputting a signal of an upper channel for each channel; And a plurality of third dividers for receiving signals output from the second divider for each channel, dividing the transmission rate in half, and outputting signals of the upper channel for each channel. Fault detection device. The method according to claim 1 and 2, The pin loss detector includes: an exclusive or gate configured to receive an exclusive OR operation by receiving a signal applied from the third divider and an output signal of a depreflop to be described later; A depreflop which causes the signal output from the exclusive OR gate to be output by one cycle by a period of a clock signal separately applied; A failure detector for outputting a failure detection signal when the signal applied from the depreflop has no level change for a predetermined time; A normal motion detector for outputting a normal motion detection signal when an error-free signal is applied for a predetermined time from the third frequency divider; And a failure alarm generator for generating a pinrose failure alarm signal by a signal applied from the failure detector and the normal motion detector.