Design And Verification Of Fiber Line Searching System In Fiber Distrubution Room

For optical communication,speed,distance and large capacity is the development direction.Optical fiber communication technology becomes the mainstream technology in the future communications industry.At the same time,the pressure of the optical fiber distrubution room is increasing,so it is particularly important to manage and renovate the line of distrubution room.Especially,it is the most difficult problem to solve the problem of line management in the old fiber distrubution room.How to solve the problem of line management through low cost becomes an urgent problem in the market.Based on the analysis of the advantages and disadvantages of the two existing solutions in the market,this thesis designs a scheme to search the optical fiber lines for the old distrubution room.The system is designed into three parts:the optical transmitting unit,the optical receiving unit and the Ethernet transmitting unit.The optical transmitting unit mainly accomplishes the conversion of the electrical signal to the optical signal and transmits optical signal to the optical fiber.Laser driving circuit,system reset circuit,Bluetooth HCI-UART transceiver module,Hamming code module and laser power control algorithm module are designed in the optical transmitting unit.After testing,the laser driving circuit works well and the laser power can be controlled by Bluetooth.The instruction data can be encoded through the Hamming code and sent to the optical fiber to be searched.The optical receiving unit mainly accomplishes the conversion of the optical signal to electrical signal,and integrates its port information and equipment information into frames and sends them to the next module.It mainly includes the optical detection device,current voltage conversion circuit,filter circuit and decision circuit,Hamming code decoding module,CAN bus transceiver module.After testing,The optical receiving unit can correctly identify the port by the instruction data which is sent by the optical transmitting unit,and integrate the port information and the unit information into the frame,and send it to the Ethernet transmitting unit through the CAN bus.The Ethernet transmitting unit mainly receives the port information from the optical receiving unit,forms its own device information into a frame,sends the data packet to the server side with the TCP/IP data packet,and completes the last link of the data transmission.The Ethernet transmitting unit mainly accomplishes the hardware implementation of TCP/IP protocol and the design and optimization of Ethernet physical layer,data link layer,network layer and transport layer.The experiment proves that the Ethernet transmitting unit can make port ID,optical receiver unit ID and Ethernet transmission unit ID into TCP/IP packets and transmit them to PC servers.The system can locate the optical fiber position through the three level ID information and complete searching the optical fiber.Through the design of this thesis,the old fiber distrubution room can be upgraded in one time.The equipment cost is low,the future maintenance is convenient,the speed of the line searching is fast,the workload of the operator is light,and the system design requirements can be satisfied.