针对光纤故障参与保护倒换元器件多、保护资源开销大的问题,提出一种低开销混合式保护的高可靠波分/时分混合无源光网络(WDM/TDM-PON)结构。所提结构在光线路终端(OLT)中新设计了逻辑判定、备份收发以及保护路控制单元,使波分复用(WDM)部分只对故障部分器件执行倒换操作,实现了低开销的集中式保护;在时分复用(TDM)部分采用交叉总线形结构,实现了快速的分布式保护倒换。经分析证明,所提混合式保护结构有效地减少了保护资源开销,对馈入光纤(FF)、配线光纤(DF)和最后一个公里光纤(LMF)故障提供了1.5~2.4 ms恢复时间的快速全保护,且具有良好的扩展性。
To limit the number of components in the protection switching process and to accordingly reduce the protection cost, a new reliable Wave Division Multiplexing/Time Division Multiplexing Passive Optical Network (WDM/TDM-PON) architecture with cost-efficient hybrid protection was proposed. Firstly, the logic decision unit, protection path control unit and backup transceiver unit were designed in Optical Line Terminal (OLT) to only switch failure components to their backups in Wave Division Multiplexing (WDM) segment. Secondly, by employing the cross bus structure in Time Division Multiplexing (TDM) segment, fast protection switching was achieved in a distributed manner. According to the analytic results of the hybrid protection, the proposed architecture can provide fast and full protection in recovery time of 1.5 to 2.4 ms against Feed Fiber (FF), Distribution Fiber (DF) and Last Mile Fiber (LMF) failures. Certainly, the proposed architecture can also significantly reduce the protection overhead, and achieve great scalability.