Feeder fiber and OLT protection for ring-and-spur long-reach passive optical network

Ring-and-spur long-reach passive optical network (LR-PON) is the optimal network architecture for next-generation passive optical network (NG-PON). Several protection architectures for LR-PON have been proposed and demonstrated. However, this paper introduces two protection architectures namely; OLT-only protected and OLT-and-ring protected architecture. The significance of the proposed protection architectures is to guarantee high quality of service to all users in the network with low cost. This is obtained by protecting the most critical elements in the network which are the OLT and the fiber ring where the single fault causes a huge impact and almost all the users being unconnected. The failure impact robustness (FIR), the cost and the availability of the proposed architectures are calculated and compared with other well-known protection architectures. This paper shows that protecting OLT and fiber ring (where the fault with these elements is affects all users) increase the availability of the network up to 99.993% with 0.09% increase in the cost compared with the ring-only protected architecture.