CN1863025B - Method and system for processing damage in WDM system - Google Patents

Abstract

The invention discloses an error handling method and system for wavelength division multiplexing system. The method includes the following steps: detecting capability and synchronization/spending for the signal in channel to gain error starting information; shielding the error and orienting the error, if it is the wavelength division system protecting error, continuing to step 3, else reliving the shield; repairing the error and reliving shield and return to step 1. The system includes protecting rearrange and wavelength division device, signaling processor, photoelectricity receiver, power detector, protecting rearrange controller, light emitter, frame generator and 1: n switch circuit.

Description

Troubleshooting method and system for wavelength division multiplexing system

technical field

The invention relates to a fault handling method and system of a wavelength division multiplexing system, in particular to a method and system for performing protection switching coordination control between a service layer network and a client layer network of the wavelength division multiplexing system.

Background technique

The evolution of the current WDM (Wavelength Division Multiplex, Wavelength Division Multiplex) optical network is very similar to the SDH (Synchronos Digital Hierarchy) network, from the perspective of network composition. SDH has several network elements such as TM, ADM, and DXC. The network topology has passed through several development stages of point-to-point, self-healing ring and DXC-based mesh network. The WDM optical network is also similar to this. There are several network elements such as back-to-back WDM terminals, OADM, and OXC. The network topology also goes through several development stages of point-to-point linear systems, WDM self-healing rings, and OXC-based mesh networks. . Compared with SDH network. WDM optical network has larger capacity, is transparent to business, and has faster protection speed.

The WDM system has a large business load, and security is particularly important. Due to the huge amount of transmitted traffic, it is very important to implement protection in the event of network failure. There are two main schemes for constructing a WDM self-healing network: applying optical cross-connect equipment (OXC) to construct a self-healing network in the physical layer mesh network topology; applying optical add-drop multiplexing equipment ( OADM) to construct a self-healing network.

The protection and recovery capabilities of the transport network are very important. What it needs to solve is to take rapid emergency measures without manual intervention in case of network failure, so as to ensure that the user's data (service) is not lost or the loss is minimized. When performing network protection, it is necessary to pre-configure backup transmission resources (such as optical fibers, wavelength channels, VC-n particles, etc.) for a part of the network before a network failure occurs. damage. Typical forms of protection switching include 1+1 linear protection, n:m linear protection (n and m are natural numbers), ring protection, etc. It is aimed at a specific network topology and implemented using specific backup resources.

SDH/SONET network has various protection switching functions (International Telecommunication Union standards G.841, G.842, G.873.1, G.873.2), protection switching forms include channel protection and multiplex section protection, and the implementation method of protection switching is : Carry in-band signaling through the overhead bytes in the client signal (such as K1, K2 bytes in SDH signals, ODUk in OTN signals), for example, in 1:1 protection, when the receiving end finds signal defects, through in-band signaling The defect indication (protection switching request) is sent to the upstream through the reverse transmission link, the upstream node starts the protection switching function of the transmitting end after identification, and realizes selective reception after the downstream identification.

Similar to the SDH system, there are two protection modes in the WDM ring network, the line protection switching ring and the wavelength channel protection switching ring. In the line switching, the recovery of the fault is performed between the adjacent nodes where the fault occurs. In channel switching, the restoration of the optical path failure is performed between the source node and the termination node of the optical path. The signaling process to realize protection switching is similar to SDH/SONET, the difference is that an independent optical monitoring channel is generally used to carry signaling.

When the WDM system bears the weight of the client layer network (such as SDH), there are multiple layers of protection. When a fault occurs, protection switching only needs to occur on one layer, and the network priority of the service layer must be guaranteed. However, in an actual system, due to the processing speed of the service layer network and the client layer network, it may happen that the faster one will switch, or the two layers will switch at the same time. The current solution to this is to set a delay in the client layer network and wait for the lower layer switching to occur. However, due to the layered design of the network, the client layer network does not know the network resource status and control process of the service layer, and blindly waits, which directly leads to the extension of the protection switching time, which will lead to the loss of some signals.

Contents of the invention

In view of the above-mentioned problems and deficiencies in the protection switching coordination control in the existing WDM system, the purpose of the present invention is to provide a fault handling method and system for a reliable wavelength division multiplexing system that is simple to implement and can improve network protection performance.

The present invention is achieved like this: a kind of fault processing method of wavelength division multiplexing system, comprises the following steps:

1) Perform performance detection and synchronization/overhead detection on each wavelength signal in the channel, and if the failure information is obtained, enter step 2);

2) shielding the fault and locating the fault according to the fault occurrence information at the same time, if there is a protection fault in the WDM system, then enter step 3), otherwise unshield and return to step 1);

3) Unshield and return to step 1) after repairing the fault.

Preferably, the masking is to send a pseudocode to the opposite end, the pseudocode is an electrical signal conforming to the mapping structure required by the network input interface of the opposite end, and includes identifiable overhead bytes, message packets, and the like.

Preferably, the performance detection in step 1) refers to signal power detection.

Preferably, the restoration is specifically implementing channel protection switching and overhead byte rewriting; channel protection switching refers to enabling a standby channel to replace a faulty channel.

Preferably, the protection switching mode includes traditional optical channel 1+1 protection, optical channel 1:N protection, optical multiplex section 1+1 protection, and the like.

A fault handling system for a wavelength division multiplexing system, including a protection switching and wavelength splitting device, a signaling processor, a photoelectric receiver for n wavelength channels, a power detector, a protection switching controller, and light emission for n wavelength channels device, a frame generator and a 1:n switch circuit, wherein the protection switching and wave splitting device is connected to the signaling processor, n photoelectric receivers are respectively connected to the output branches of the protection switching and wave splitting device, and the power detection The device is connected with the photoelectric receiver to realize fault detection and fault repair detection, the protection switching controller is connected to the power detector to realize fault detection and fault repair detection, the protection switching controller is connected to the signaling processor at the same time, n optical The transmitter is correspondingly connected to n photoelectric receivers to send signals, the dummy frame generator is connected to the protection switching controller, the 1:n switch circuit is connected to n optical transmitters correspondingly, and the input end of the 1:n switch circuit is connected to the dummy Output of the frame generator.

Preferably, the system also includes a multiplexer and bridge device, which is connected to the signaling processor and connected to n optical transmitters and n photoelectric receivers in the other direction in order to multiplex the signals and send them.

Preferably, the system also includes a synchronization and/or overhead processor and n signal identification and overhead read/write circuits, the synchronization and/or overhead processor is connected to the protection switching controller, and is simultaneously connected with n signal identification and overhead read/write circuits The circuit connection, signal identification and overhead reading and writing circuits are respectively connected between the photoelectric receiver and the optical transmitter, and the identification and overhead reading and writing are performed before the signal is sent.

Preferably, the system also includes n photocouplers and photodiode arrays, wherein the photocouplers are connected between the protection switching and splitting device and the photoelectric receiver, and the photodiode arrays are connected to the photocouplers, Each output end of the photodiode array is connected to the input end of the power detector.

Preferably, a signal amplifier is connected between the photoelectric receiver and the light transmitter; a signal amplifier is connected between the dummy frame generator and the 1:n switch circuit.

Here, n, N, and m are all natural numbers.

The present invention is realized by adding pseudo-frame generation at the receiving end of the WDM system with protection switching capability. When the WDM system is used as the service layer network to carry the customer network (such as SDH), the protection resources of the service layer network and the client layer network can be integrated. Utilization avoids resource waste caused by multi-layer protection switching design. When the multi-layer protection structure exists at the same time, it avoids the simultaneous protection switching response to the same fault in the two systems, avoids the line connection confusion that may be caused thereby, and improves the reliability of network protection. At the same time, it also avoids blindly waiting and prolonging the protection switching time due to the fact that the client layer network does not understand the resource status and control process of the service layer network.

Description of drawings

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic structural view of another embodiment of the present invention;

Fig. 3 is a schematic diagram of a possible fault example in the present invention;

Fig. 4 is the fault processing flowchart of the present invention;

Fig. 5 is a schematic diagram of an application example of the present invention.

Description of figure number:

a, b: signal transmission direction

osc: WDM system optical monitoring channel processing

sc: protection switching controller

c: pseudo frame generator

s: unicast and broadcast 1:n switch

pt: power analyzer

D: Switching and splitting device at the receiving end of WDM system

M: WDM system transmitter multiplexer

W: work path

P: protection path

a31, a32, ..., a3n: photoelectric receiver at the receiving end in direction a

a41, a42, ..., a4n: optical transmitter at the receiving end in direction a

a11, a12, ..., a1n: photoelectric receivers at the transmitting end in direction a

a21, a22, ..., a2n: optical transmitters at the transmitting end in the direction a

a10, a20: channel-level protection optical receiver and transmitter of wavelength channel 1 in a direction

b11, b12, ..., b1n: b-direction transmitter photoelectric receiver photoreceiver, transmitter

b21, b22, ..., b2n: optical transmitters at the transmitting end in the b direction

b10, b20: Channel-level protection for wavelength channel 1 in the b direction

Ba: channel-level 1:1 protection bridging in a direction

Bb: channel-level 1:1 protection bridging in b direction

b51, b52, ..., b5n: b-direction synchronization recognition and overhead read and write

a61, a62, ..., a6n: a direction synchronization identification and overhead read and write

st: synchronization and overhead processor

d: coupler

p: optical power monitoring

W1, W2: WDM nodes

S1, S2, SN: SDH nodes

SW: Work routing for signal transmission between S1 and S2

SP: Protection routing for signal transmission between S1 and S2

WW: Working route for signal transmission between W1 and W2

WP: Protection routing for signal transmission between W1 and W2

Detailed ways

As shown in Fig. 1, the present invention includes protection switching and wave splitting device (D), WDM system signaling processor (osca), the photoelectric receiver (a31, a32, ..., a3n) of n wavelength channels at the receiving end , power detector (pt), protection switching controller (sc), dummy frame generator (c), 1:n switching circuit (s) with unicast and/or broadcast capability, optical transmitter for n wavelength channels (a41, a42, ..., a4n), the protection switching and demultiplexing device (D) is connected to the signaling processor (osc), and n photoelectric receivers (a31, a32, ..., a3n) are respectively connected to the protection Each output branch of the switching and splitting device (D) is connected correspondingly, and the power detector (pt) is connected with the photoelectric receiver phase (a31, a32, ..., a3n) to realize fault detection and fault repair detection, and protection switching The controller (sc) is connected to the power detector (pt) to realize fault detection and fault repair detection, the protection switching controller (sc) is connected to the signaling processor (osc) at the same time, n optical transmitters (a41, a42 ,..., a4n) are correspondingly connected with n photoelectric receivers (a31, a32,..., a3n) to send signals, and the 1:n switch circuit (s) is connected with n optical transmitters (a41, a42,. . . , a4n) are connected correspondingly, the input end of the 1:n switch circuit (s) is connected to the output end of the dummy frame generator (c). A signal amplifier is also connected between the photoelectric receivers (a31, a32, . . . , a3n) and the light transmitters (a41, a42, . . . , a4n).

To facilitate the description of the present invention, the above structure is defined as the receiving end of the direction a. Among them, the protection switching and demultiplexing device (D) is in accordance with the general design method of WDM system with protection switching function, and has the function of 1+1 selective selector or m:n cross selector function (ITU-T standard G.808.1, G.808.2), a combination of optical modules with wavelength splitting capability, which can realize protection switching selection under command control. The WDM system signaling processor (osc), according to the general design method of the WDM system, implements channel monitoring in the optical fiber transmission system, carries system performance detection messages and signaling messages, and performs corresponding message processing and forwarding. The photoelectric receiver (a31, a32, ..., a3n) of n wavelength channels can realize the reception of signals of each wavelength channel at the receiving end of the WDM system, perform photoelectric conversion and output electrical signals, and generally have electrical signal retiming, shaping, regeneration, etc. Function. The power detector (pt) can judge according to the intensity of the optical power received by the photoelectric receiver, so as to give an optical power defect indication. The optical transmitters (a41, a42, . . . , a4n) of n wavelength channels can modulate the regenerated electrical signal at the output of the laser to realize electro-optical conversion and complete optical forwarding. The photoelectric characteristics and structural mapping of the output signal meet the requirements of the client-layer network access carried by it, and are connected to the client-layer network input interface. The dummy frame generator (c) can generate an electrical signal conforming to the mapping structure required by the network input interface of the client layer, including identifiable overhead bytes, message packets, and the like. 1:n switch circuit(s) with unicast and/or broadcast capability A switch circuit with multiple outputs to send the signals generated by the dummy frame generator (c) separately or simultaneously to the optical transmitters (a41, a42, . .., a4n), to replace the electrical signal of each wavelength channel to drive the above-mentioned optical transmitter to realize the pseudo-code optical output. The protection switching controller (sc) can specifically implement protection switching coordination control. It has interfaces such as optical power defect indication input, dummy frame generator control output, WDM protection switching command input and output, etc.

The power detector (pt) detects the power of the signal received by the photoelectric receiver (a31, a32, ..., a3n), and inputs the detection result to the above-mentioned protection switching controller (sc), and the protection switching controller (sc) uses the Detect power to judge whether there is a fault, if there is a fault, control the above-mentioned pseudo-frame generator (c) to form a corresponding pseudo-code, and distribute it to the optical transmitter (a41, a42, ..., a4n) through the switch circuit (s), Drive the above-mentioned optical transmitters (a41, a42, ..., a4n) by replacing the line signal; if a fault occurs in the WDM system, the above-mentioned protection switching controller (sc) generates a protection switching command and a protection switching reply command, and the Make the processor (osc) send it to the upstream and downstream equipment of the system to realize protection switching and reply control.

As shown in FIG. 2 , on the basis of the embodiment shown in FIG. 1 , the present invention also includes a WDM system reverse sending end and overhead processing functions in each direction. The present invention also includes a direction b multiplexer and bridge device (M), a WDM system signaling processor (oscb), a photoelectric receiver (b11, b12, ..., b1n) of n wavelength channels at the transmitting end, an optical transmitter ( b21, b22, ..., b2n), b to the transmitting end of each wavelength channel signal identification and overhead read-write circuit (b51, b52, ..., b5n), a to the receiving end signal identification and overhead read-write circuit (a61 , a62, ..., a6n), synchronization and/or overhead processor (st). The synchronization/overhead processor (st) is connected to the protection switching controller (sc), and is connected to n signal identification and overhead read-write circuits (b51, b52, ..., b5n) at the same time, and the signal identification and overhead read-write circuits (b51, b52, . . . , b5n) are correspondingly connected between the photoelectric receiver and the optical transmitter, and perform identification and overhead reading and writing before signal transmission. Among them, the multiplexing and bridging device (M) is based on the general design method of WDM system with protection switching function, and has the function of 1+1 concurrency at the transmitting end or m:n switching and bridging function (ITU-T standard G.808.1, G.808.2) , a combination of optical modules with multiplexing capability, its m:n protection function can realize switching under command control. The photoelectric receivers (b11, b12, ..., b1n) of n wavelength channels in the direction b can realize the reception of signals of each wavelength channel at the transmitting end of the WDM system, and the photoelectric characteristics and structural mapping of the input signals meet the requirements of the carried client layer Network access requirements, connected to the client layer network output interface. The light emitters in the direction b (b21, b22, ..., b2n) are modulated on the output of the laser to realize electro-optic conversion and complete light forwarding. Its output signal conforms to the transmission requirements of WDM system (ITU-T standard G.692), so as to realize the multiplexing transmission with appropriate distance and appropriate wavelength interval. The signal identification and overhead read-write circuits (b51, b52, ..., b5n) of each wavelength channel in direction b are suitable for the client layer network carried by the channel i (i=1, 2, ..., n) at the transmitting end The electronic signal processing circuit of information can realize functions such as signal identification (such as synchronous extraction, rate identification, overhead identification) and overhead rewriting. Signal recognition and overhead read/write circuits (a61, a62, . . . , a6n) at the receiving end of direction a have the same function as direction b. The synchronization and/or overhead processor (st) has signal synchronization and identification functions, can judge the occurrence of defects through overhead identification, output defect indications, and can generate overhead bytes that meet the requirements of the customer network signal mapping format.

The protection switching controller (sc) can judge through the defect indication output by the processor (st), start the overhead processing function according to the situation, and control the pseudo code generator (c) to output the appropriate The electrical signal of the overhead processor (st) can be controlled to rewrite or transparently transmit the overhead byte of the client signal as required.

In addition, each wavelength channel of the present invention uses an optical coupler (d) for sampling, and realizes optical power detection by a photodiode (p) array. There are many methods for detecting optical power, which cannot be exhaustively listed here, but it does not exclude the use of any other specific design methods to achieve the purpose of this specification. Here, it is not ruled out that multiple pseudocode generators c are used to simultaneously generate multiple signals of different data formats, so as to shield the defects of multiple customer network signals carried by WDM at the same time. This requires the circuit(s) to have multi-input circuit crossover capability.

As shown in FIG. 3 , it is a typical example of a fault in a WDM system without loss of generality. The device shown in Figure 1 is used as the receiving end in the figure. The components involved in FIG. 2 are understood according to the functions described above. In the figure, the receiving end device in direction b has the same functional structure as the receiving end device in direction a, so it is only represented by a dotted line box. As an example of the protection type, for WDM multiplex section shared protection (1:1 or 1+1), two optical fiber transmission links are used as the working link (W) and the protection link (P) respectively.

As an example of the protection type, there is an optical channel (1:1) protection in FIG. 2 , and the channel indicated by the input port 0 of the transmitting end is used as the protection for the channel indicated by the port 1 . Optical receiver (a10), optical transmitter (a20), bridge (Ba) related to channel 0 in direction a, and optical receiver (b10), optical transmitter (b20), bridge (Ba) related to channel 0 in b direction Bb). In the figure, the protection switching controller (sc) in direction a has a control relationship with the optical channel protection bridge (Bb) in direction b; the function in direction b is similar to it. In the system shown in Figure 3, the occurrence of protected faults (marked as X in the figure) mainly includes the following types:

Fault 1: When there is multiplex section protection in WDM, taking the failure of the working optical fiber link (W) of the multiplex section in direction a as an example, the optical receivers (a31, a32, ..., a3n) of each wavelength channel in direction a detect light loss;

Fault 2: When there is channel protection in WDM, taking the failure of channel 1 optical transmitter (a21) in direction a as an example, the optical receiver (a31) of channel 1 at the receiving end in direction a has no light input, and the loss of light is detected;

Fault 3: When there is channel protection in WDM, take the failure of channel 1 optical receiver (a11) in direction a as an example, the optical receiver (a31) of channel 1 at the receiving end in direction a has light input, but the synchronization or overhead of the receiving end is lost.

The fault handling process of the present invention will be described in detail below. As shown in Figure 4, the processing procedure of the present invention includes:

1) Fault discovery: The WDM system obtains fault occurrence information by performing performance detection and overhead reading on the signals carried by each wavelength channel. For fault 1, the fault can be found through power detection. For the embodiment shown in FIG. 1 or FIG. 2 , the power detector (pt) generates a multiplex section optical power defect alarm indication and sends it to the protection switching controller (sc). For fault 2, the fault can be found through power detection. For the embodiment shown in FIG. 1 or FIG. 2 , the power detector (pt) generates an alarm indication of optical power defect of wavelength channel 1 and sends it to the protection switching controller (sc). For fault 3, the optical power at the receiving end is normal, but the synchronization is lost or the overhead is abnormal. For the embodiment shown in Figure 2, when the synchronization identification and/or overhead extraction (a61) of wavelength channel 1 at the receiving end finds an abnormality, the synchronization and overhead processor (st) sends a signal defect alarm indication and sends it to the protection switching controller (sc) .

2) Defect shielding: the WDM system realizes defect shielding by sending pseudo codes to the client layer network or rewriting overhead bytes. For fault 1, the protection switching controller (sc) instructs the pseudo-frame generator (c) to send a signal with a complete format according to the type of customer network signal carried by the system, and its overhead and mapping format are consistent with the type of customer network signal. (s) Distribute to the optical transmitters (a41, a42, ..., a4n) of each wavelength channel, and output to the client layer network to achieve the purpose of defect shielding. For example, when the client layer network is SDH, the frame synchronization byte in the regeneration section should be written as "A1A1A1A2A2A2". For fault 2, the protection switching controller (sc) instructs the pseudo-frame generator (c) to send a signal with a complete format according to the type of customer network signal carried by wavelength channel 1, and its overhead and mapping format are consistent with the type of customer network signal. The switch circuit (s) is distributed to the optical transmitter (a41) of the wavelength channel 1, and output to the client layer network to achieve the purpose of defect shielding. For fault 3, if the protection switching controller (sc) judges that the signal is lost according to the signal defect warning indication from the synchronization and overhead processor (st), then according to the customer network signal type carried by the wavelength path 1, the instruction dummy frame generator ( c) Send out a signal with a complete format, the overhead and mapping format of which match the signal type of the customer network, and distribute it to the optical transmitter (a41) of wavelength channel 1 through the switch circuit (s), and output it to the customer layer network to achieve defect shielding Purpose: If the protection switching controller (sc) judges that although the signal is not lost according to the signal defect alarm indication from the synchronization and overhead processor (st), but the overhead bytes are abnormal, then according to the type of customer network signal carried by wavelength channel 1, The instruction overhead processor (st) generates normal overhead bytes, inserts them into the signal carried by wavelength channel 1 through overhead read and write (a61), and outputs them to the client layer network to achieve the purpose of defect shielding; for example, when the client layer network is SDH , the multiplex section protection switching overhead bytes "K1", "K2", defect indication "AIS", etc. need to be processed.

When other unprotected faults occur, in the embodiment of the device shown in Fig. 1 and Fig. 2, the above shielding process is also completed according to the alarm indication.

3) Fault location: WDM system (such as alarm distribution and topology connection, etc.) judges the cause of the fault. For fault 1, fault 2, and fault 3, the protection switching controller (sc) judges that a protected fault occurs according to the system protection configuration.

If other unprotected faults occur in step 2), the protection switching controller (sc) judges that an unprotected fault occurs according to the system protection configuration.

4) Switching control; when it is confirmed that the fault occurs in the WDM system, implement protection switching control. For fault 1, the protection switching controller (sc) sends out a protection switching command, which is sent to the local and upstream in direction a through the WDM system optical monitoring channel processor (osc), and through the signaling process, the upstream multiplexer and bridge device (M) and the local The protection switching and wave splitting device (D) takes a protection switching action. For fault 2 and fault 3, the protection switching controller (sc) sends out a protection switching command, which is sent upstream in the direction a through the WDM system optical monitoring channel processor (osc), and the upstream bridge (Ba) takes a protection switching action through the signaling process .

5) Unshielding; the above step 5) WDM system protection switching is successful, or when the above step 3) confirms that the fault cannot be automatically repaired at the WDM system layer, the defect shielding of the above step 2) is released, that is, the protection switching controller (sc) issues an instruction For the dummy frame generator (c) and the overhead processor (st), turn off the output of the dummy frame generator (c) and stop interfering with the optical channel signal overhead.

In the device shown in Figure 2, when the time for realizing defect shielding in direction a exceeds the time for confirming faults in the client-layer network, resulting in a protection switching request in direction b, an appropriate overhead byte can be generated by the overhead processor (st), and in direction b The overhead reading and writing (b51, b52, ..., b5n) circuit shields the client layer protection switching instruction. For example, SDH equipment has a 24 frame delay (about 3ms) confirmation function for loss of frame (LOF). When the frame loss phenomenon has not recovered, it will send a protection switching request in the b direction and insert it into the signal overhead of the b direction (such as K1 , K2 bytes). After the system completes the above work process, the interference to the b-direction signal overhead is released.

The present invention does not exclude the application of the following method: when there is a WDM receiver in the direction a and cannot effectively detect the occurrence of a failure event, due to the SDH protection switching mechanism, there will be protection switching signaling in the b direction, and at this time WDM first blocks the SDH overhead , after the entire network completes automatic fault location, and then release the shielding as needed.

As shown in Figure 5, it is an application example in a complex networking state when WDM carries a customer network (SDH). The part between WDM nodes W1 and W2 in the figure is an SDH network carried by WDM, and S1, S2, ..., SN are SDH nodes, as part of a complex mesh network. Between the SDH nodes S1 and S2 there are a working route SW for signal transmission and a protection route SP. There is a working route WW and a protection route WP for signaling between WDM nodes W1 and W2.

When the signal from W1 to W2 in the routing WW fails, the WDM node W2 detects the failure, and outputs SDH dummy frames to S2 to implement defect shielding, so that the SDH network cannot detect the failure. When node W2 recognizes the fault as a recoverable fault, it initiates the protection switching between W1 node and W2 node through the WDM system signaling process, so that the service is switched from the original working path WW to the protection path WP, and the defect shielding is released after the service is restored.

When a signal failure occurs outside the routing WW, or an unrecoverable failure occurs within the routing WW, resulting in a signal defect between nodes S1 and S2, the WDM node also implements defect shielding through dummy frame output or overhead rewriting first, when it is judged that W1 When an unresolvable fault occurs between the node and the W2 node, the defect shielding is released immediately. Then, the protection switching is started between the nodes S1 and S2 through the SDH system signaling process, so that the working path is switched from the SW to the SP. 

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and All deformations should belong to the protection scope of the appended claims of the present invention.

Claims (9)

1. A method for troubleshooting a wavelength division multiplexing system, characterized in that the method may further comprise the steps: 1) Perform power detection and synchronization overhead detection on each wavelength signal in the channel, and if the failure information is obtained, then enter step 2); 2) shielding the fault and locating the fault according to the fault occurrence information at the same time, if there is a protection fault in the WDM system, then enter step 3), otherwise unshield and return to step 1); 3) After repairing the fault, remove the shielding and return to step 1), wherein the shielding is to send a pseudocode to the opposite end, and the pseudocode is an electrical signal conforming to the mapping structure required by the network input interface of the opposite end. 2. The fault handling method of the wavelength division multiplexing system according to claim 1, wherein the pseudo-code includes identifiable overhead bytes and message packets. 3. The fault handling method of a wavelength division multiplexing system according to claim 1, wherein the repairing is specifically implementing channel protection switching and overhead byte rewriting; channel protection switching refers to enabling a spare channel to replace a faulty channel. 4. The fault handling method of the wavelength division multiplexing system according to claim 3, wherein the protection switching mode includes optical channel 1+1 protection, optical channel 1:N protection, and optical multiplexing section 1+1 protection . 5. A fault handling system for a wavelength division multiplexing system, comprising protection switching and wave splitting devices, signaling processors, photoelectric receivers for n wavelength paths, power detectors, protection switching controllers, and n wavelength paths The optical transmitter, the protection switching and demultiplexing device are connected to the signaling processor, n photoelectric receivers are respectively connected to the output branches of the protection switching and demultiplexing device, and the power detector is connected to the photoelectric receiver to realize the failure Detection and fault repair detection, the protection switching controller is connected to the power detector to realize fault detection and fault repair detection, the protection switching controller is connected to the signaling processor at the same time, n optical transmitters are correspondingly connected to n photoelectric receivers To send signals, it is characterized in that the system also includes a pseudo frame generator and a 1:n switch circuit, the pseudo frame generator is connected with the protection switching controller, the 1:n switch circuit is connected with n optical transmitters correspondingly, 1: The input end of the n switch circuit is connected to the output end of the pseudo frame generator; The power detector detects the power of the signal received by the photoelectric receiver, and inputs the detection result to the protection switching controller. The protection switching controller judges whether there is a fault according to the detected power. If there is a fault, it controls the pseudo frame generator to form a corresponding pseudo code. Distributed to the optical transmitter through the switch circuit to replace the line signal to drive the above-mentioned optical transmitter. If a fault occurs in the wavelength division multiplexing system, the protection switching controller generates a protection switching command and sends it to the upstream and downstream equipment of the system through the signaling processor The protection switching is realized, wherein the pseudocode is an electrical signal of a mapping structure conforming to the requirement of the input interface of the peer network. 6. The fault handling system of the wavelength division multiplexing system as claimed in claim 5, is characterized in that, the system also includes a multiplexer and a bridge device, which is connected to the signaling processor, and is connected with n light beams in the other direction The transmitter and n photoelectric receivers are connected in sequence to combine the signals and send them. 7. The fault processing system of the wavelength division multiplexing system as claimed in claim 5 or 6, is characterized in that, this system also comprises synchronous and/or overhead processor and n signal recognition and overhead read-write circuit, synchronous and/or Or the overhead processor is connected to the protection switching controller, and is connected to n signal identification and overhead read-write circuits at the same time, and the signal identification and overhead read-write circuits are respectively connected between the photoelectric receiver and the optical transmitter, and are performed before the signal is sent. Identify and overhead reads and writes. 8. The fault handling system of the wavelength division multiplexing system as claimed in claim 5 or 6, is characterized in that, the system also includes n optical couplers and photodiode arrays, wherein the optical couplers are connected to the protection switching And between the splitting device and the photoelectric receiver, the photodiode array is connected with the photocoupler, and each output end of the photodiode array is connected with the input end of the power detector. 9. The fault handling system of the wavelength division multiplexing system as claimed in claim 5 or 6, is characterized in that, is connected with signal amplifier between described photoelectric receiver and optical transmitter; False frame generator and 1: n switching circuit A signal amplifier is connected between them.

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