A dynamic routing and wavelength assignment algorithm for WDM networks based on bottleneck link avoidance

In order to maximize the number of connections and reduce the blocking probability of wavelength division multiplexing (WDM) optical networks, a dynamic routing and wavelength assignment (RWA) algorithm is studied in this paper. In the absence of wavelength converter, the network performance deterioration is more likely caused by bottleneck links of the network, which is related to static factors (such as the particular network topology), and dynamic factors (such as the number of idle wavelength). This paper proposes a dynamic algorithm based on bottleneck links avoidance, named Bottleneck Links Avoidance with Load Balancing (BLALB) Algorithm, which gives a solution to the RWA problem in both the link level and the network level. By minimizing load variance and proactively avoiding `bottleneck links', our BLAMLV algorithm can improve the network performance. Simulation results show that the algorithm has lower blocking probability and higher link utilization compared with fixed-path least-congestion (FPLC) algorithm and the minimum load distribution variance algorithm.