光纤通信系统的超长距离传输方案

延长单段无中继光传输距离对于减少网络节点间的电中继和光中继，降低长距离传输成本具有很实际的意义。文章分析了光纤通信超长距离传输的关键技术，及其性能优势和经济效益，同时介绍了国内外超长距离光纤传输技术现状；提出了基于DRFA EDFA混合放大技术，实现传输速率为2．5Gbit／s、无中继距离为250km的传输技术解决方案。方案采用成熟的技术，使用了市场上比较常见的器件，具有很高的性价比。

Scheme for ultra-long span optical fiber communication system

Extending the distance of single segment unrepeated transmission can decrease the quantity of electric repeaters and optic repeaters among network nodes, there are practical significance for reducing cost of long distance transmission. The paper analyzes the key technique, performance advantage and economic benefit of ultra-long span transmission in optic communication, introduces the current status of technology development in China and other countries,ad presents; a transmission scheme of 2.5 Gbit/s over 250 km unrepeated span, which is based on the DFRA+EDFA hybrid amplification technology. This scheme adoptes mature technique, uses devices easily available,therefore has high ratio of quality over price.