Protection for a ring-based EPON architecture

Ethernet passive optical network (EPON) was proposed to overcome the bandwidth bottleneck at the access networks due to its simplicity, cost effectiveness and wide spread deployment. A failure in access networks can cause serious problems, because access networks transmit aggregated high-speed traffic from hundreds of subscribers. Protection and restoration mechanisms have been applied in backbone networks, but access networks are not considered significantly in the scope of survivability. In this paper, we propose a cost effective protection scheme for a novel ring-based EPON architecture. The protection scheme is capable of fault detection within 2 ms, assuring zero packet loss. Furthermore, this novel approach also has the potential of inter-ONU connectivity, which can bring LAN support in access environment.