Fault tolerance in survivable WDM optical networks using hybrid scheme: An analytical approach

Dynamic lightpath protection in survivable WDM networks requires finding a pair of diverse routes (i.e., a primary route and a backup route that are link-disjoint) that form a cycle upon the arrival of a new connection request. This paper presents a hybrid adaptive survivability algorithm that combines the positive effects of restoration and protection. The overall goal of the proposed approach is to improve the restoration efficiency by providing a tradeoff between proactive protection and dynamic restoration. Experimental results simulated by ns-2 network simulator and analytical results using MATLAB 7.3 are compared. In both the case hybrid scheme achieves significantly lower blocking probability than the conventional dynamic survivable techniques.