KR20000032611A - Overhead storing apparatus of supervisory channel - Google Patents

Abstract

PURPOSE: An overhead storing apparatus of supervisory channel is provided to restrain an occurrence of a warning by other station obstacle or a warning of a low-level layer by informing an obstacle detecting fact to in a backward direction or a next station in a forward direction. CONSTITUTION: A data communication channel demultiplexed by a demultiplexer(101) is transmitted to an optical transmitting interval control unit. Registers(102-109) temporarily stores an optical signal warning detecting signal, line obstacle supervisory information, state supervisory information, interval searching information, an optical quality value, information to a number of optical channels, supervisory channel warning detecting information and a BIP value transmitted from the demultiplexer(101).

Description

Overhead Storage of Watch Channel

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead storage device of a supervisory channel, and more particularly to an optical transmission section (OTS) in a multi-channel wavelength division multiplexing (WDM) optical transmission system. An overhead storage device of a supervisory channel for supervisory control of a layer is provided.

In general, the functions that can be considered when realizing the supervisory control function in the optical transmission interval layer include the maintenance monitoring function of the own station and the other station (remote), the line fault monitoring function, the signal quality monitoring function, the connectivity monitoring function, the channel capacity monitoring function, and the data. Communication channel function, orderwire function, etc. are required.

The maintenance monitoring function of the own station and the counter station (remote) includes loss of optical signal (LOS) and loss of optical supervisory (LOS_SV) that can be detected from the main optical signal and the monitoring channel signal in the system. This function informs the next station (i.e., node) in the opposite direction in the opposite direction or the progress direction of failure detection such as signal and LOF (loss of supervisory frame). It can be suppressed and it can also help to detect the location of the disorder, so that it can cope effectively with the disorder.

The line fault monitoring function is a function that can suppress the occurrence of an alarm by informing the fact that such information is disturbed to the next station because an alarm can be generated in all repeaters when a repeater or a relay line failure occurs. This feature can use this information to block optical signals for fault location detection or operator protection.

The signal quality monitoring function is a function necessary for monitoring and informing a signal because a line or a device is not in a faulty state, but its characteristics are deteriorated and a transmission performance of a main optical signal or a monitoring channel signal may be degraded.

The connectivity monitoring function checks whether a transmitting station to which a signal is to be transmitted and a receiving station to be received match with each other, which detects an incorrect path if not received and informs the other station of an incorrect path. This prevents the reception of unwanted signals.

The channel capacity monitoring function is a function for effectively managing maintenance information that may vary depending on the number of channels by recognizing the number of multiplexed optical channels mounted in the optical multiple section.

The data communication channel function is a function necessary for exchanging maintenance information between systems and data necessary for network management.

The short circuit function is a function required for voice communication between system operators.

However, in the conventional case (for example, US Patent 5500756, etc.) for realizing the supervisory control function in the optical transmission section layer, only the very basic functions such as maintenance function, data communication channel, and tripping line function are used. There is a problem that can not effectively perform the monitoring control because there is no way to suppress the alarm that can occur in multiple cases or to inform the fact that the alarm occurs.

Accordingly, the present invention has been made to solve the above problems, the maintenance monitoring function of the local station and the counterpart station (remote), the line failure monitoring function, the signal quality monitoring function, connectivity monitoring function, channel capacity monitoring function, data communication The OTS layer of the terminal or repeater can be efficiently operated and maintained by accommodating all data communication channel (DCC) functions and orderwire functions to the overhead of the OTS monitoring channel. It is an object of the present invention to provide an overhead storage device for enabling the same.

1 is a block diagram of a wavelength multiplexed optical transmission system to which the present invention is applied.

2 is a block diagram of an optical transmission interval layer of the WDM system of FIG.

3 is a block diagram of an optical transmission interval layer of the repeater type WDM system of FIG.

Figure 4 is a block diagram of an embodiment of an overhead storage device for the monitoring channel according to the present invention.

5 is a block diagram of another embodiment of an overhead storage device of a monitoring channel according to the present invention;

Figure 6 is a structure diagram of an embodiment of the overhead of the monitoring channel applied to the present invention.

7 is a detailed structural diagram of an overhead byte applied to FIG. 6;

FIG. 8 is an explanatory diagram of a failure 1 between the optical signal alert detection information byte and the state monitoring information byte defined in FIG.

Fig. 9 is an explanatory diagram of faults 2 and 3 of the optical signal alert detection byte and the status information monitoring byte defined in Fig. 7;

FIG. 10 is an explanatory diagram of a fault 4 between the optical signal alert detection information byte and the state monitoring information byte defined in FIG. 7; FIG.

FIG. 11 is an explanatory diagram for a failure 5 between the line fault monitoring information byte and the state monitoring information byte defined in FIG. 7; FIG.

FIG. 12 is an explanatory diagram illustrating the application of a BIP value byte, an optical quality value byte and an interval tracking information byte defined in FIG. 7; FIG.

FIG. 13 is an explanatory diagram illustrating the application of the number of optical channel bytes, data communication channel bytes, and other pruning line bytes defined in FIG. 7; FIG.

Explanation of symbols on the main parts of the drawings

101: demultiplexer 102, 202: optical signal alarm detection information register

103, 203: line fault monitoring information register 104, 204: state monitoring information register

105 and 205: interval tracking information registers 106 and 206: optical quality value registers

107, 207: Fiber Channel Number Register

108, 208: monitoring channel alarm detection information register

109, 209: BIP value register

110, 210: data communication channel receiver

111, 211: rudder wire receiver

201: multiplexer

In order to achieve the above object, the present invention, in the overhead storage device of the monitoring channel, by demultiplexing the monitoring channel signal input from the outside, optical signal alarm detection information, line failure monitoring information, status monitoring information Demultiplexing means for outputting interval tracking information, optical quality value, information on the number of optical channels, alarm detection information of a monitoring channel and a bit interleaved parity (BIP) value; First storage means for temporarily storing the optical signal alert detection information; Second storage means for temporarily storing the line failure monitoring information; Third storage means for temporarily storing the state monitoring information; Fourth storage means for temporarily storing the section tracking information; Fifth storage means for temporarily storing the light quality value; Sixth storage means for temporarily storing information on the number of optical channels; Seventh storage means for temporarily storing alarm detection information of the surveillance channel; And eighth storage means for temporarily storing the BIP value.

In addition, the present invention provides an overhead storage device for a monitoring channel, comprising: first storage means for temporarily storing optical signal alert detection information input from an external source; Second storage means for temporarily storing line failure monitoring information input from the outside; Third storage means for temporarily storing state monitoring information input from the outside; Fourth storage means for temporarily storing interval tracking information input from the outside; Fifth storage means for temporarily storing an optical quality value input from the outside; Sixth storage means for temporarily storing information on the number of optical channels input from the outside; Seventh storage means for temporarily storing alarm detection information of a monitoring channel input from the outside; Eighth storage means for temporarily storing a BIP value input from the outside; And the optical signal alarm detection information, the line fault monitoring information, the state monitoring information, the section tracking information, the optical quality value, the information on the number of optical channels, the alarm detection information of the monitoring channel, and the bit interleaved parity. ) And multiplexing means for multiplexing and outputting the value.

In particular, the present invention has implemented the monitoring control functions of the optical transmission interval using the following method.

First, the maintenance monitoring function of the own station and the counterpart (remote) is realized by using the maintenance signals of forward defect indication (FDI), backward defect indication (BDI) and backward defect indication of supervisory channel (BDI_SV). If possible, the type of disability could be reported to the other country. In this case, the FDI inserts when a malfunction occurs in the transmitting station and informs the power station to recognize the fact, or when the received signal state detects LOS and FDI, it notifies the lower OMS and OCH interval layers (downFDI). Suppress alarms that may occur at lower levels. In addition, the BDI is a signal for informing the counter station of the fact that the reception main optical signal state is detected by the LOS and the FDI.

Second, the BDI_SV is a signal for informing the counter station of the detection when the reception monitoring channel signal state is detected as LOS_SV or LOF.

Third, line fault monitoring functions include repeater number, line state (normal or LOS state), mode (i.e. state detected in the home station or bypass state detected in the other station in the preceding stage) and remote reporting of fault state (e.g. normal Or occurrence). At this time, if the line fault is detected when the repeaters are connected in parallel, the detected node inserts the repeater number, the fault state and the detection mode, and informs the downstream node and informs the front end node of the fault state by using the remote report. When the next node recognizes the failure state and detection mode sent from the node that detected the failure, it suppresses the alarm and inserts it into the bypass mode along with the failure state to propagate to the next node. In this way, an alarm due to a failure is generated only at a node that detects a line failure, and the remaining trailing nodes do not generate an alarm. In addition, when the remote report is detected as a generation state, it is possible to recognize that a failure has occurred in the optical signal sent from the own node, so that the output optical signal can be blocked to protect the operator or administrator during maintenance.

Fourth, the signal quality monitoring function should monitor the performance degradation of the main optical signal and the monitoring channel signal. Since the main optical signal cannot have an electrical connection, the information of the input optical power of the transmitting station and the output of the receiving station Indirectly checks signal-to-noise characteristics using optical power information to monitor performance degradation of the optical line, and calculates bit interleaved parity (BIP) at the transmitting station because the signal of the monitoring channel can have electrical connections The performance degradation can be monitored by detecting the error of the transmission bit by inserting the data, and comparing the BIP calculation value of the data transmitted from the receiving station with the BIP value transmitted.

Fifth, the connectivity monitoring function can monitor the transmission to the correct position by comparing the bit pattern sent from the transmitting station with the received bit pattern using the interval tracking bit patterns of the transmitting station and the receiving station in the same manner.

Sixth, the channel capacity monitoring function inserts the number of optical channels mounted and multiplexed at the transmitting station, and reads and uses them at the receiving station.

Seventh, the data communication channel function and the short circuit function are realized by inserting DCC data and voice data at the transmitting station and receiving them at the receiving station.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a configuration diagram of a wavelength multiplexed optical transmission system to which the present invention is applied, and is composed of a single station type WDM system 1 and a repeater type WDM system 2.

Here, the single station type WDM system 1 includes an optical transmission section layer 11, an optical multiple section layer 12, and an optical channel section layer 13.

Meanwhile, the repeater type WDM system 21 includes only the optical transmission interval layer 21 as a 1-R repeater.

The signal transmitted from the repeater-type WDM system 2 is transmitted to point-to-point by receiving it from the end-station WDM system 1, and the dependent signals inputted into the fiber channel section are transmitted after being multiplexed and received. The optical signal is demultiplexed and then the dependent signal is extracted.

FIG. 2 is a block diagram of the optical transmission interval layer of the single station type WDM system of FIG. 1, which includes a power amplifier 31, WDM couplers 32 and 37, and electric / optical. The conversion unit 33, the monitoring channel overhead storage unit 34, the optical transmission section control unit 35, the optical / electrical conversion unit 36, the pre-amplifier ( 38).

The operation of the optical transmission interval layer of the single station type WDM system of FIG. 1 having such a structure will be described below.

The optical signal transmitted from the optical multiple section in the upward direction is amplified through the power amplifier 31, and the OTS supervisory channel monitors the overhead of the supervisory control by the command of the optical transmission section controller 35. ), Then converted into an optical signal through the pre / optical conversion unit 33, and then the optical signal amplified by the power amplifier unit 31 and the monitoring channel optical signal are coupled through the WDM coupler 32. Send to repeater.

The optical signal received by the repeater is separated into a main optical signal and a monitoring control optical signal by the WDM coupler 37, and then the main optical signal is amplified by the preamplifier 38 and then transmitted to the optical multiple section. do.

At this time, the supervisory control optical signal is converted into an electrical signal through the optical / electric converter 36 and then transmitted to the supervisory channel overhead storage 34, and the supervisory channel overhead storage 34 is then received. The control information is temporarily stored and transmitted to the optical transmission section control unit 35.

3 is a block diagram of an optical transmission section layer of the repeater-type WDM system of FIG. 1, which includes line amplifiers 41 and 48, WDM couplers 42, 47, 49, and 53; Light conversion units 46 and 52, supervisory channel overhead storages 45 and 52, optical transmission interval controller 45, supervisory channel overhead storages 44 and 51, It consists of all conversion parts 43 and 50.

The operation of the optical transmission interval layer of the repeater type WDM system of FIG. 1 having the structure as described above will be described below.

The optical signal received in the single station system is separated into the main optical signal and the supervisory control optical signal by the WDM couplers 42 and 49, and then the main optical signal is amplified by the line amplifiers 41 and 48 to transmit the optical signal. It is transmitted to the controller 45. At this time, the supervisory control optical signal is converted into an electrical signal by the optical / electric conversion 43, 50 and then transmitted to the supervisory channel overhead storages 44, 51. Subsequently, the monitoring channel overhead storage units 44 and 51 temporarily store the signal transmitted from the optical / electric conversions 43 and 50 and transmit the temporary signal to the optical transmission section control unit 45.

The transmission OTS supervisory channel temporarily stores the supervisory control overhead in the supervisory channel overhead storage units 44 and 51 by the command of the optical transmission interval control unit 45 and then transfers the supervisory / control unit 46 and 52 to the pre / optical conversion units 46 and 52. do.

In this way, the generated supervisory control overhead is converted into an optical signal by the front / light conversion units 46 and 52 and transferred to the WDM couplers 47 and 53.

Subsequently, the WDM couplers 47 and 53 couple the optical signal amplified through the line amplifiers 41 and 48 and the monitoring channel optical signal transmitted through the pre / optical converters 46 and 52 to the single station system. send.

On the other hand, such a configuration is bidirectional.

4 is a diagram illustrating an embodiment of an overhead storage device of a monitoring channel according to the present invention.

As shown in FIG. 4, the overhead storage device for the monitoring channel according to an embodiment of the present invention includes a demultiplexer 101, optical signal alarm detection information transmitted from the demultiplexer 101, and line faults. Registers 102 to 109 for temporarily storing the monitoring information, the status monitoring information, the section tracking information, the optical quality value, the information on the number of optical channels, the monitoring channel alarm detection information, and the BIP value, respectively, and the data communication channel receiving unit 110. ), And the other short-circuit receiver 111.

That is, the monitoring channel signal converted into an electrical signal by the optical / electric conversion unit is separated by the overhead of the individual monitoring channel by the demultiplexing unit 101 so that the optical signal alarm detection information register 102 and the line failure monitoring information Register 103, status monitoring information register 104, interval tracking information register 105, optical quality value register 106, optical channel number register 107, monitoring channel alarm detection information register 108 and BIP value register ( 109 is temporarily stored and then transmitted to the optical transmission section controller.

The data communication channel demultiplexed by the demultiplexer 101 is transmitted to the optical transmission section controller through the data communication channel receiver 110.

Here, the demultiplexer 101, the data communication channel receiver 110, and the other short-circuit receiver 111 are well known technologies.

5 is a configuration diagram of another embodiment of an overhead storage device of a monitoring channel according to the present invention.

As shown in FIG. 5, an overhead storage device for a surveillance channel according to another embodiment of the present invention includes a multiplexer 201 for multiplexing transmitted signals and an optical signal alert detected from the optical transmission interval controller. Registers 202 to 20 that temporarily store information, line failure monitoring information, status monitoring information, section tracking information, optical quality values, information on the number of optical channels, monitoring channel alarm detection information and BIP values, respectively, and transmit them to the multiplexer 201. 209, a data communication channel receiver 210 for transmitting the data communication channel transmitted from the optical transmission interval controller to the multiplexer 201, and a haptic line receiver 211.

Here, the multiplexer 201, the data communication channel receiver 110, and the other short-circuit receiver 111 are well known technologies.

The operation of this is as follows.

Optical signal alarm detection information, line fault monitoring information, status monitoring information, section tracking information, optical quality value, optical channel number, monitoring channel alarm detection information and BIP value transmitted from the optical transmission section controller are registers 202 to 209, respectively. The data is temporarily stored in and then transmitted to the multiplexer 201, and the data communication channel is transmitted to the multiplexer 201 through the data communication channel receiver 210.

In this way, each information transmitted to the multiplexer 201 is multiplexed and transferred to the all-optical converter.

6 is a structural diagram of an embodiment of the overhead of the monitoring channel applied to the present invention, frame information byte, line failure information byte, BIP byte, optical signal alarm detection information byte, status monitoring information byte, interval tracking information byte, optical It consists of quality value byte, fiber channel number recognition byte, monitoring channel alarm detection information byte, data communication channel byte, rudder line byte and reservation byte.

The frame information byte is a byte for detecting the position of the byte.

The line fault monitoring information byte is a byte for performing a line fault monitoring function.

The optical signal alarm detection information byte, the status monitoring information byte, and the monitoring channel alarm detection byte are bytes for performing a maintenance monitoring function of the main optical signal and the monitoring channel signal.

The interval tracking information byte is a byte for performing a connectivity monitoring function.

The light quality value byte and the BIP value byte are bytes for performing a signal quality monitoring function.

The optical channel number recognition byte is a byte for performing a channel capacity monitoring function.

The data communication channel byte is a data communication channel function byte for processing data communication channel data of 192 kbps.

The summing line byte is a byte for performing the summing line function.

The line fault information monitoring byte, the BIP value byte, the optical quality value byte, the number of optical channel bytes, the data communication channel byte, and the other short circuit line byte are operated in the repeater system, and the single station system operates all bytes. Surveillance information bytes are only allowed for surveillance.

FIG. 7 is a detailed structural diagram of an overhead byte applied to FIG. 6.

The line fault information byte has a repeater identifier, a line state (for example, normal and signal loss states), a detection and passing mode, and a remote state information remote reporting structure.

When the line failure is detected, the relay node inserts a relay number, a failure state, and a detection mode to notify the downstream node, and informs the front end node of the failure state by using a remote report.

When the latter node recognizes the failure state and detection mode sent from the node that detected the failure, the latter node inserts the pass state together with the failure state and propagates to the next node.

The BIP value byte stores a BIP value calculated at the time of transmission and a BIP value calculated at the other station at the time of reception.

The optical signal alert detection information byte indicates the normal state, FDI and BDI state of the main optical signal.

The status monitoring information byte indicates the status of the counterpart by indicating the failure status information (for example, LOS, LOS_SV, FDI, LOF, malfunction status, etc.) and the section tracking remote reporting (that is, the normal status and the section tracking mismatch status). To be recognized by.

The interval tracking information byte stores and recognizes a set pattern of a corresponding light path.

The light quality value byte indicates the input optical power information of the light transmission section.

The optical channel number recognition byte indicates the number of multiplexed optical channels.

The monitoring channel alarm detection information byte indicates the normal and BDI_SV status of the monitoring channel and a remote error indication (REI) status for reporting to an opposite station when an error is detected in the received BIP value.

The data communication channel byte and the batting line byte store data communication channel data and the batting line data.

FIG. 8 is an explanatory diagram for the failure 1 between the optical signal alert detection information byte and the state monitoring information byte defined in FIG.

As shown in FIG. 8, when failure 1 of line failure occurs between the single station WDM systems, a signal loss (LOS) is detected at the other station, and a BDI is inserted into the optical signal alarm detection information byte by the signal loss detection. Then, the other station is notified of the alarm detection, and the type of fault is informed by the status monitoring information byte (SISB).

In addition, down FDI is notified to the lower OMS and the OCH layer to suppress the alarm that may occur in the lower layer.

Here, the down FDI is not included in the OTS section overhead but is informed by a separate channel in the system.

Therefore, when the alarm of the upper layer is generated, the lower alarm is suppressed, and the counter station is notified to the other station to recognize that an abnormality has occurred in the signal sent from the other station, thereby performing an effective monitoring control function. In addition, the information can be used to search for the location of the failure.

FIG. 9 is an explanatory diagram of faults 2 and 3 of the optical signal alert detection byte and the status information monitoring byte defined in FIG.

Referring to FIG. 9, when a line failure (i.e., failure 2) occurs between OMS and OCH in a single station WDM system or the OTS monitoring channel is normal but a functional failure (i.e., failure 3) occurs in OTS, the transmitting station In this case, FDI is inserted into the optical signal alarm detection byte to inform the station.

The receiving station notifies the lower OMS and the OCH layer by FDI detection to suppress the alarm that may occur in the lower layer, and inserts a BDI into the optical signal alarm detection information byte to inform the counter station that the alarm is recognized. Surveillance Information Reports the type of failure recognized by the Surveillance Byte (SISB).

Therefore, by informing the counterpart station of the fact that its own station is detected, the counterpart station can perform an effective monitoring control function such as suppressing the lower alarm.

FIG. 10 is an explanatory diagram of a fault 4 between the optical signal alert detection information byte and the state monitoring information byte defined in FIG.

As shown in Fig. 10, when an OTS supervisory channel fault (i.e., fault 4) occurs in the transmitting station, the LOS_SV or LOF_SV is detected at the other station, and the BDI_SV is added to the supervisory channel alert detection information byte by LOS_SV or LOF_SV detection. In this case, the other station is notified of the alarm detection and the type of failure is indicated by the status monitoring information byte (SISB).

Therefore, when an alarm occurs on the monitoring channel of the transmitting station, the monitoring station signal is informed to the counter station to recognize that an abnormality has occurred in the transmitted monitoring channel signal, thereby performing an effective monitoring control function.

FIG. 11 is an explanatory diagram for a failure 5 between the line fault monitoring information byte and the state monitoring information byte defined in FIG.

Referring to FIG. 11, when the entire system is connected to a single station system, three repeater systems, and a single station WDM system, assuming that a line fault 5 occurs between the first and second repeaters, the signal loss at the second repeater ( LOS) is detected. At this time, to detect the detected information, the LOS status and detection mode are stored in the line fault detection information byte to inform the third repeater, and the first repeater stores the remote fault report in the line fault detection information byte as Let me know

The third repeater recognizes the occurrence of the line fault between the first and the second repeater using the line fault detection information byte sent from the second repeater, and stores the signal loss state and the pass mode in the line fault detection information byte to inform the station system.

The station system cannot insert the BDI to the left station system because the signal transmitted from the first station system could not be normally received due to a failure in the repeater, and the down FDI is inserted to suppress the alarm of the OMS and OCH layers. .

Therefore, the alarm caused by the failure is generated only at the node that detects the line failure, and the remaining trailing nodes do not generate the alarm, and can also search for the location of the failure by this information.

In addition, when the remote report is detected as the occurrence state in the first repeater, it is possible to recognize that a failure has occurred in the optical signal sent from the own node, so that the output optical signal can be blocked to protect the operator.

12 is an explanatory diagram illustrating the application of the BIP value byte, the light quality value byte and the interval tracking information byte defined in FIG. 7.

As shown in Fig. 12, if the signal transmitted from the left end station WDM system has degraded due to degradation of device characteristics of the transmission line or transmitting station, the optical quality value degradation is detected in the main optical signal, and the BIP error is detected in the monitoring channel. Is detected.

It also sends a REI to the transmitting station for BIP error detection. If the routing is incorrect, the receiving station detects a section tracking mismatch and informs the other station of the fact.

Therefore, it can be seen that it is possible to detect a decrease in performance of the host and an error in routing.

FIG. 13 is an explanatory diagram illustrating the application of the number of optical channel bytes, the data communication channel byte and the pruning line byte defined in FIG.

As shown in Fig. 13, the transmitting station transmits the multiplexed number of optical channels and the data communication channel byte and the summing line byte necessary for communication with the receiving station, and the receiving station receives and uses these data. These data are then transmitted in both directions.

Therefore, it can be seen that it is possible to effectively manage maintenance information such as performance data according to the change in the number of optical channels, and also to perform data communication channel communication and other short circuit communication.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, according to the present invention, if the overhead is used to realize the supervisory control function in the optical transmission interval layer, the other station is notified by informing the counter station or the next station (i.e., the node) in the opposite direction in the reverse direction or the progress direction. It is possible to suppress the occurrence of alarm due to the alarm or lower layer, help to search the fault location, and monitor the degradation of the transmission performance of the main light signal or the monitoring channel signal. It can be done effectively.

Claims (2)

In the overhead storage device of the monitoring channel, By demultiplexing the monitoring channel signal input from the outside, the optical signal alarm detection information, line fault monitoring information, status monitoring information, section tracking information, optical quality value, information on the number of optical channels, alarm detection information of the monitoring channel and BIP ( demultiplexing means for outputting a bit interleaved parity) value; First storage means for temporarily storing the optical signal alert detection information; Second storage means for temporarily storing the line failure monitoring information; Third storage means for temporarily storing the state monitoring information; Fourth storage means for temporarily storing the section tracking information; Fifth storage means for temporarily storing the light quality value; Sixth storage means for temporarily storing information on the number of optical channels; Seventh storage means for temporarily storing alarm detection information of the surveillance channel; And Eighth storage means for temporarily storing the BIP value Overhead storage device for the surveillance channel comprising a. In the overhead storage device of the monitoring channel, First storage means for temporarily storing optical signal alert detection information input from the outside; Second storage means for temporarily storing line failure monitoring information input from the outside; Third storage means for temporarily storing state monitoring information input from the outside; Fourth storage means for temporarily storing interval tracking information input from the outside; Fifth storage means for temporarily storing an optical quality value input from the outside; Sixth storage means for temporarily storing information on the number of optical channels input from the outside; Seventh storage means for temporarily storing alarm detection information of a monitoring channel input from the outside; Eighth storage means for temporarily storing a BIP value input from the outside; And The optical signal alarm detection information, the line fault monitoring information, the state monitoring information, the section tracking information, the optical quality value, information on the number of optical channels, alarm detection information of the monitoring channel, and the bit interleaved parity (BIP) Multiplexing means for multiplexing and outputting values Overhead storage device for the surveillance channel comprising a.