光纤保护旁代时的通道切换方案

光纤保护在定检、旁代时，需要进行通道切换。文中介绍了几种通道切换方案，比较了它们的性能、实现的难易程度和使用的可行性。插拔尾纤法使用简便可靠，但需移动尾纤，较为不使。光开关切换法技术先进，但由于工艺和成本位得应用受到限制。脉冲编码调制(PCM)时隙切换法使用方便，但只限于复用通道且需通信人员配合。光纤接线盒法综合了上述3种方法的优点，并克服其不足，既简便可靠，又成本低廉，并可用于复用、专用光纤保护，现已在工程中得到广泛应用。

CHANNEL SWITCH SCHEME OF FIBER PROTECTION WHEN BYPASS BREAKER USED AS LINE BREAKER

Fiber protection must have channel switch during the routine maintainance or when bypass breaker used as line breaker. Several channel switch schemes are discussed. The performance comparison, complexity and application feasibility of these schemes are also given out. Receptacle fiber scheme is easy to use, but it needs to move the fiber, which is inconvenience. Fiber switcher scheme is a more advanced technology, but due to the manufacture technology and the high price, this scheme is seldom used. PCM time-slot exchange scheme also is easy to use, but it can only be used in multiplexing channel and it needs the cooperation of communications. Fiber connection box scheme synthesizes the advantages of the above three schemes and overcomes their shortages. It is cheap and easy to use and can be used in both multiplexing channel and fiber channel. It has been widely used now.