Fuzzy metric approach for routing in B-ISDN

Routing algorithms are required to guarantee the various quality of service (QoS) characteristics requested by the wide range of applications supported by broadband integrated services digital networks (B-ISDN). However, it is known that such a routing problem, with two or more additive or multiplicative QoS metrics in any possible combination is NP-complete. We propose a heuristic approach based on fuzzy logic. For each metric, a fuzzy membership function is defined to reflect the QoS requirements from that metric. A fuzzy-inference rule base is implemented to generate the fuzzy cost of each path based on the crisp values of the different metrics possibly used in the network links. The proposed approach is tested with different loads and the effect on different measures of performance is analyzed. Simulation results demonstrate the capability of this approach to increase the throughput and utilization of the communication network, and provide a fair distribution of different connection requests