Fuzzy inference system for QoS 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. In this paper, 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.