A hybrid protection strategy based on node-disjointness against double failures in optical mesh networks

Abstract

As the size and the complexity of optical mesh networks are continuing to grow and the severe natural disasters are occurring more frequently in recent years, multiple failures (link failures or node failures) become increasing probable. Protection strategies against these failures generally provision backup paths for working paths based on link-disjointness or node-disjointness. Compared with linkdisjoint protection, node-disjoint protection means higher degree of risk isolation and can accommodate both link failures and node failures. This motivates us to propose a hybrid node-disjoint protection, named Segment and Path Shared Protection (SPSP), to provide 100% protection against arbitrary simultaneous double-node failures (the worst doublefailure case). For each service connection request, SPSP first provisions backup segments for the working segments, respectively, as the primary backup resources, then provisions a single backup path for the whole working path as the second backup resource. In addition to its complete protection capability and flexible scalability for double failures, SPSP can also obtain better network load balance and resource sharing degree by dynamic link-cost adjustment and reserved backup resource sharing. Simulation results show that SPSP can achieve a shorter average recovery time than path shared protection (PSP) and higher resource utilization and lower blocking probability than segment shared protection (SSP).

Optical signal-to-noise ratio restoration algorithm applied to optical network resilience to node failures

“…Bao et al [14] propose a hybrid protection strategy based on node-disjointness, named segment and path shared protection, against arbitrary simultaneous double-node failures in optical networks.…”