CN201918994U

CN201918994U - FTTH (Fiber To The Home) passive optical link monitoring system

Info

Publication number: CN201918994U
Application number: CN2010206359655U
Authority: CN
Inventors: 荆亚新; 陈卫明
Original assignee: SUZHOU NEW SEA TELECOM TECHNOLOGY Co Ltd
Current assignee: SUZHOU NEW SEA TELECOM TECHNOLOGY Co Ltd
Priority date: 2010-12-01
Filing date: 2010-12-01
Publication date: 2011-08-03
Anticipated expiration: 2020-12-01

Abstract

The utility model relates to an FTTH (Fiber To The Home) passive optical link monitoring system comprising an optical distribution network (ODN). The ODN is connected with an optical network unit (ONU), the input end of the ODN is connected with the system end of an optical line terminal (OLT) used for monitoring and feedback, and the system end of the OLT is also connected and provided with a server for monitoring software, which is taken as a monitoring center; the system end of the OLT is accessed into an optical fiber channel together with an OLT device, an optical time domain reflectometer (OTDR) and a main control ONU detecting device by a combiner, and the OTDR and the main control ONU detecting device are connected with a computer by a communication interface; and the ODN comprises an optical branching device which is connected to be in a pyramid type by optical fiber. The FTTH passive optical link monitoring system can position and maintain fault points rapidly and timely, thereby guaranteeing the transmission quality of an optical network.

Description

FTTH passive optical link monitoring system

Technical field

The utility model relates to the communications field, in Fiber to the home (Fiber To The Home, be called for short FTTH) engineering, to a kind of monitoring system and the method for passive optical link.

Background technology

Because optical communication has transmission frequency bandwidth, big, the signal transmission quality advantages of higher of message capacity, optical fiber becomes the backbone in the communication link gradually.Connect local side and user side with optical fiber as transmission medium, to become the main flow mode of optical fiber communication in the future, insert user's degree according to optical fiber, be divided into optical fiber again to commuting case (Fiber To The Cabinet, be called for short FTTC), Fiber-To-The-Building (Fiber To The Building, be called for short FTTB), Fiber to the home (Fiber To The Home, be called for short FTTH) etc., be main flow so that Fiber to the home again wherein,, data directly can be sent to client from local side by Fiber to the home, be the preferred plan that solves Access Network part in the fiber optic communication network, can merge traditional voice comprehensively, data, CATV, the access service that high definition IPTV etc. are nearly all.

In FTTH, EPON is the light chained technology of tool advantage, this network architecture as shown in Figure 1, it is made of optical line terminal OLT, Optical Distribution Network ODN and optical network unit ONU three parts, by the optical line terminal incoming light signal, light signal arrives a plurality of output ports by Optical Distribution Network, finally is connected to the user side optical network unit, thereby realizes that point inserts to the light signal of multiple spot.

The characteristics of EPON cover the region and have a wide reach, the network line complexity, especially the branched optical cable number of links is huge, when optical fiber damage or fracture appear in optical transmission chain, realize that fault location is quite difficult with investigation fast, therefore how each branch's light path is carried out trouble shooting, and after finding there is fault, the fault point is positioned the key that just becomes guarantee optical-fiber network transmission quality.

Summary of the invention

Be directed to the problems referred to above, it is a kind of in the FTTH network engineering that the utility model provides, the system and method that the optical link in the EPON is monitored automatically.Its objective is by this passive optical link monitoring system, all optical link states in automatic monitoring and the recording light network, energy Real-time Alarm when the optical link fault occurring, and can carry out the location and the demonstration of fault point, thereby shorten the optical link repair time greatly, reduce the maintenance difficulty, reduce the line upkeep cost in a large number.

For achieving the above object, the technical scheme that provides of the utility model is as follows:

A kind of FTTH passive optical link monitoring system, comprise Optical Distribution Network ODN, Optical Distribution Network ODN connects optical network unit ONU, the input of described Optical Distribution Network ODN is connected with and is used to the optical line terminal OLT system end of monitoring and feeding back, and also is connected and installed with the server of monitoring software on the optical line terminal OLT system end as Surveillance center.At first each bar optical link in the EPON is numbered, and be saved in the database, receive the optical link Monitoring Data that OLT system end computer is sent simultaneously, status data and the related preservation of optical link numbering with these optical links, and real-time update, the employing graphical interfaces shows that the administrative staff of Surveillance center can consult the current state of arbitrary optical link at any time.Simultaneously monitoring software is judged the current state of optical links according to these data, and when optical link broke down, prompt alarm reached the purpose of real-time monitoring.

The optical line terminal OLT system end passes through together incoming fiber optic channel of mixer by optical line terminal OLT equipment, optical time domain reflectometer OTDR and master control ONU checkout equipment, and by communication interface optical time domain reflectometer OTDR is connected with computer with master control ONU checkout equipment.Optical time domain reflectometer OTDR is the instrument of optical fiber state in a kind of testing optical network, it is made according to the back scattering and the Fresnel inversion principle of light, by launching light pulse in optical fiber, receiving the information of returning at the OTDR port then tests, this equipment can be tested by computer control at present, and by communication interface test data is transferred to computer.Utilize this equipment energy measurement optical fiber attenuation, fiber failure point location and optical fiber along loss distribution situation of length etc., if optical fiber damage or fracture are arranged, OTDR can locate and damage the position, but in FTTH in the optical-fiber network of this point-to-multipoint, OTDR is difficult to distinguish for branch's light path, therefore also needs master control ONU checkout equipment to assist its test.

The ODN distribution network is that main devices connects into the pyramid form with optical fiber and optical branching device, to user side, can with optical branching device be node therebetween with input channel demultiplexing output channel, and optical link is numbered; User side is based on ONU, and ONU can receive the data that optical line terminal OLT equipment sends, and also can receive the test instruction that master control ONU checkout equipment sends and provide response signal.

By the sending and feed back the information that obtains of signal, the monitor staff can obtain the position of optical link fault point rapidly, and the very first time keeps in repair the fault point, in time removes fault, has ensured the quality of optical-fiber network transmission.

Description of drawings

The FTTH network architecture schematic diagram that Fig. 1 mentions for the utility model;

Fig. 2 is the system architecture diagram of the utility model passive optical link monitoring system;

Fig. 3 is the flow chart of the monitoring software in the monitoring central server in the utility model;

Fig. 4 is the flow chart of the computer software of OLT system end in the utility model.

Embodiment

Below in conjunction with drawings and the specific embodiments the utility model is further described.

Set up a Surveillance center, this Surveillance center's platform mainly is made of server and monitoring software, and server is equipped with systems soft ware, database software and monitoring software, and server can link to each other with other computer by communication port (generally adopting network interface).The server hardware of Surveillance center is configured to: the above CPU of 2G, the above internal memory of 1G, the above hard disk of 200G, display more than 17 inches.Operating system can adopt WINDOWS2003 Server, and database can adopt SQL SERVER 2003.

According to the actual light network configuration, wherein all optical links are numbered, for example, as shown in Figure 2, with the optical branching device is node, the input optical fibre of optical distribution network is numbered A, the output of first order optical branching device is numbered B1, B2 ... Bn, the output of second level optical branching device is numbered C1, C2, Cn, then each bar optical link has all had numbering, for example an AB1C1 in this optical-fiber network from the OLT system end to user side, and this link is again by A, B1, three sections compositions of C1, in the database of monitoring central server, link number and fragment number can be preserved, and corresponding one by one with it preservation of Link State data that test is obtained, thereby obtain Link State situation in the overall optical network.Certainly, according to different optical-fiber networks, also can adopt different numberings.

Monitoring central server links to each other with the computer of OLT system end by network and communicates according to communication protocol, Fig. 3 is the monitoring software flow chart in the monitoring central server, after server receives the packet that computer sends, according to communication protocol packet is resolved, and the validity of data judged and analyze, if be judged as invalid data then abandon, if be judged as valid data then data preserved into database, then the Link State data in the database are judged, whether check has link unusual, if have then alarm, if not then show normal by graphical interfaces.

At the OLT system end, OLT equipment, optical time domain reflectometer OTDR and master control ONU checkout equipment are passed through together incoming fiber optic channel of mixer, and optical time domain reflectometer OTDR is connected with computer with master control ONU checkout equipment by communication interface.Master control ONU checkout equipment adopts timesharing frequency multiplexing technique timing each ONU in optical-fiber network to send test instruction and receive response data, the response data of ONU represents then that correctly this link is unobstructed, otherwise represent that this link has communication failure, transfers to computer with this status data; When optical link appearance communication was obstructed, computer sent test instruction to OTDR, and OTDR tests all passive optical link states, and test data is sent to computer; Computer receives the Monitoring Data of OTDR and the Monitoring Data of master control checkout equipment, and faulty line numbering and position of failure point data are analyzed and drawn to data, and Surveillance center is preserved and sent to these data.

Fig. 4 is the computer software flow chart of OLT system end, after computer receives the test data of master control checkout equipment by communication interface, resolve this data, normal response data to these data and ONU are compared, if data consistent then show that optical link communication is normal, Surveillance center is preserved and be sent to data, if data exception then show have optical link to break down, send test instruction to OTDR, and read the test data of OTDR, obtain the fault point data after data are analyzed, data are preserved packing be sent to Surveillance center.

Claims

1. FTTH passive optical link monitoring system, comprise Optical Distribution Network ODN, Optical Distribution Network ODN connects optical network unit ONU, it is characterized in that: the input of described Optical Distribution Network ODN is connected with and is used to the optical line terminal OLT system that monitors and feed back, also is connected and installed with the server of monitoring software in the optical line terminal OLT system as Surveillance center.

2. FTTH passive optical link monitoring system according to claim 1, it is characterized in that: described optical line terminal OLT system end passes through together incoming fiber optic channel of mixer by optical line terminal OLT equipment, optical time domain reflectometer OTDR and master control ONU checkout equipment, and by communication interface optical time domain reflectometer OTDR is connected with computer with master control ONU checkout equipment.

3. described FTTH passive optical link monitoring system according to claim 1 and 2, it is characterized in that: described Optical Distribution Network ODN comprises optical branching device, and optical branching device connects into the pyramid form by optical fiber.