Survivable Hybrid Passive Optical Converged Network Architectures Based on Reflective Monitoring

Hybrid passive optical converged access networks (HPCANs) are recognized as a cost-efficient and high-bandwidth solution to address the exponentially increasing demands of both fixed access and mobile users. HPCANs are expected to support high client count with different bandwidth requirements, long network spans, and high traffic. In that respect, survivability of such networks against fiber/equipment failures is a critical deployment feature. Consequently, rapid fault detection and subsequent restoration of services to users are gaining importance. Four survivable architectures that are compliant with the aforementioned HPCAN specifications are presented in this work. These architectures do not need to rely on upstream transmissions for loss-of-signal (LOS) activation, thereby making them suitable for use with sleep/doze mode transceivers for power saving. In networks that implement sleep/doze upstream transceivers, the transition into sleep/doze mode would result in no upstream signal transmission. If using conventional LOS activation rather than our proposed architectures to indicate equipment/fiber failure in the network, the absence of upstream transmission would result in erroneous triggering of false LOS alarm and subsequently unnecessary protection switching. We compare the four survivable HPCAN architectures against an unprotected HPCAN using illustrative examples of three different population densities, namely covering dense urban, urban, and rural areas, and three different deployment scenarios, namely brownfield, duct reuse, and greenfield. We perform detailed evaluations of connection availability, failure impact factor, yearly network energy consumption, and total network cost. Results from this study provide guidance for the choice of the best survivable HPCAN architecture to serve each of the three considered area densities under each of the three deployment scenarios.