A Novel Fiber-Constrained Protection Scheme for Passive Optical Networks

Due to increasing use of Internet in all walks of life user's demand for fast and highly available Internet is rapidly increasing. Passive optical network (PON) is a key technology to satisfy the rapidly growing Internet traffic demand in access networks. However, PON is highly prone to fiber failures which may result to poor service availability to users. Therefore, PON needs to be protected to improve availability. During provisioning protection, a dedicated and geographically disjoint backup fiber is deployed to protect each working fiber, thereby requiring large number of backup fibers. In practice, in densely populated urban areas, the working and backup fibers are laid through the existing ducts and conduits, as digging of trenches and installation of ducts and conduits in dense urban areas are cost-exhaustive. Moreover, in many circumstances, digging of new trenches may not be permitted in dense urban areas. The existing ducts and conduits may be heavily congested due to existing copper wires and cables. Therefore, it is required to efficiently use the available space of existing ducts and conduits. In this regard, in this paper, we propose a novel protection scheme, referred to as multi-hop bypass-based protection (MHBP) scheme, wherein we provision to deploy the minimum number of backup fibers to provide protection against working fiber failure. Simulation results show that proposed protection scheme efficiently utilises the existing ducts and conduits.