聚焦长距离无源光网络生存性机制研究, 针对单共享风险链路组故障提出一种基于连接可用性的成本有效规划方法.首先, 设计了一种基于故障概率的连接可用性模型, 计算每个光网络单元的连接可用性.对于不满足连接可用性要求的每个工作光网络单元, 为其分配备用光网络单元, 其中每个备用光网络单元需要为工作光网络单元预留备用容量.然后, 在不同光网络单元之间部署备用光纤, 确保每对工作和备用光网络单元之间至少存在一条备用光路径.当一个工作光网络单元因为光纤链路故障而遭遇连接中断时, 可将其业务通过备用光路径转移到备用光网络单元承载.通过仿真对所提方法在备用光纤部署成本方面的性能进行了分析.结果表明, 该方法能实现比传统邻居保护方法更低的备用光纤部署成本, 可解决备用容量分配和备用光纤部署的联合优化问题, 在满足连接可用性要求的前提下, 通过最小的备用光纤部署成本实现所有业务完全保护.

Focusing on the survivability of long-reach passive optical network against single shared-risk link group failure, a cost-efficient planning approach based on connection availability was proposed. First, a connection availability model based on failure probability was designed to estimate the connection availability of each optical network unit. Each primary optical network unit not satisfying the connection availability requirement would be allocated some backup optical network units, each of which needed to reserve the backup capacity for the primary optical network unit. Then, deployed the backup fibers among different optical network units to establish at least one backup-optical-path between each pair of primary and backup optical network units. Through the computational simulation, the performance of proposed approach in deployment cost of backup fibers was analyzed. Results show that the proposed approach can achieve much lower deployment cost than the previous neighbor protection approach. The proposed approach would solve the problem of the joint optimization of backup capacity allocation and backup fibers deployment. The objective was to fully protect all traffic demand in the network by the minimum deployment cost of backup fibers, while guaranteeing the connection availability requirement.