Traffic pattern based connection-level active rerouting algorithm in all-optical WDM networks

This paper proposes a connection-level active rerouting algorithm in all-optical WDM networks with traffic grooming and alternate routing to reduce the connection blocking probability. The main idea of the proposed rerouting algorithm is to reroute the existing connections to a predefined routing path, which is called the best rerouting path, between the source-destination pair. The best rerouting path is obtained by solving a non-linear optimization problem in which the objective function is to minimize the approximate blocking rate. After obtaining best rerouting path, the rerouting algorithm is devised to immigrate the connections to the best rerouting path when a connection finishes transmission. Simulation results show that the proposed rerouting algorithm yields lower connection blocking probability than the case without rerouting algorithms. Besides, we also found that the rerouting overhead produced by the proposed algorithm is very small. The results show that the proposed rerouting algorithm is able to produce low connection blocking probability with small rerouting overhead.