tailieunhanh - Optical Fiber Communications and Devicesan incorrectly Part 10

Tham khảo tài liệu 'optical fiber communications and devicesan incorrectly part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | In-Service Line Monitoring for Passive Optical Networks 215 Downstream signal light SMF BS-F Upstreamsignal light 1490 nm 10 km 200 m 1310 nm BS-F BFS assigned fiber x-Sp X-branched optical splitter Fig. 13. Experimental setup for in-service line monitoring Fig. 14. FER measurement with and without in-service line monitoring using 1650 nm OTDR test light. function and has no error recovery function such as forward error correction or retransmission Ishikura et al. 1999 . The relationship between FER and BER is given by FER 1- 1-BER Frame length bits 7 216 Optical Fiber Communications and Devices A BER of 10-12 corresponds to an FER of . In-service line monitoring was demonstrated under error free conditions in GE-PON. The PON monitoring method can perform the test with negligible degradation in transmission quality. 6. Conclusion I introduced an in-service measurement technique for monitoring PON fibers with individually assigned Brillouin frequency shifts and an optical fiber line testing system including 1650 nm Brillouin-OTDR. BFS assigned fiber can be designed for 8-branched PON fibers that have a GHz BFS separation. Moreover the 1650 nm band optical fiber line testing system measured B-OTDR traces with a dynamic range of 17 dB. Fault location carried out in branching fiber demonstrated that we could determine the length of eight BFS assigned fibers after an optical splitter. The PON monitoring system can also detect and locate connection losses in branching regions with high sensitivity. In-service line monitoring of a GE-PON transmission was achieved using a 1650 nm test light and the degradation in transmission quality was negligible. These techniques enable us to isolate a fiber fault reduce maintenance costs and improve service reliability for access networks. 7. References Azuma Y. Shibata N. Horiguchi T. Tateda M. 1988 Wavelength dependence of Brillouin-gain spectra for single-mode optical fibers Electron. Lett. 24 5 pp. 251252 Mar. 1988 .