An efficient resources allocation strategy for survivable WDM network under static lightpath demand

We present an optimized heuristic strategy for enhancing the utilization of network resources in survivable WDM networks under static lightpath demand (SLD). The primary as well as backup connection establishment is efficiently managed in the proposed strategy. For the establishment of primary connections, the requests are arranged in ascending order of the path lengths. If, for a connection request more than one shortest path/route is available in the network, then the route with the minimum wavelength index is selected. This results in uniform distribution of load among the links and avoids congestion. To enhance the backup lightpath establishment and increase restorability, a single wavelength of each link over the entire network is reserved in advance for setting up the path disjoint backup lightpaths. The effectiveness of the proposed strategy has been evaluated by undertaking extensive simulation experiments and the performance compared with respect to existing strategies of shared path protection (SPP) and hybrid connection approach (HCA). The network topologies of MESH, NATIONAL, and ARPANET have been used for the simulation. The results demonstrate that among all the strategies, the proposed strategy establishes maximum number of connections, avoids congestion, and uses the minimum network capacity (wavelength links).