p-cycle design in survivable WDM networks with shared risk link groups (SRLGs)

The p-cycle survivable network design under the single link failure assumption has been studied extensively. Shared risk link group (SRLG) is a concept that better reflects the nature of network failures. An SRLG is a set of links that may fail simultaneously because of the common risk they share. The capability of dealing with SRLG failures is essential to network survivability. In this paper, we extend the p-cycle design from the single link failure model to the single SRLG failure model. An integer linear programming (ILP) formulation that minimizes spare capacity requirement is provided. To avoid enumerating all cycles of a network, we also provide an algorithm to generate a basic candidate p-cycle set that guarantees 100 % restorability in case of a single SRLG failure given enough spare capacities. Simulation results of optimal p-cycle design under the single SRLG failure model are presented. The spare capacity efficiency performance of the basic candidate p-cycle set is also evaluated. Finally, we give a brief overview of the SRLG failure detection problem and its impact on the restoration speed which is an important consideration of p-cycle design.