Dual-Failure Restorability of Meta-Mesh Networks

Abstract

The meta-mesh approach was previously proposed as an innovative method for improving the capacity efficiency of span restoration in sparse network topologies. The fundamental idea is to route lightpaths that fully transit chains of degree-2 nodes onto logical bypass spans that physically traverse the chain, but which are allowed to fail back to the anchor nodes or degree-3 nodes of the chain. From the transiting lightpath perspective, the effect is an increase in network connectivity from which a decrease in required spare capacity is allowed. Prior work on the meta-mesh approach considered only single span failure restorability. The work herein addresses the issue of dual-failure survivability by developing an ILP design model that produces a minimum-cost meta-mesh network design that is fully restorable in the event of all possible dual span failures scenarios.