Service-aware multi-constrained routing protocol with QoS guarantee based on fuzzy logic

Single-constrained QoS (Quality of Service) routing protocols have inherent shortcomings when they are applied to ad hoc networks. Only considering a single constraint parameter can’t always cope with the problems aroused by the uncertainty of ad hoc networks well. This paper proposes a multiconstrained QoS routing protocol based on fuzzy logic. The protocol is service-aware. It considers the QoS requirements asked by different kinds of services and takes different network state parameters as the constraint conditions. New route informing mechanism is proposed to support route update; speed of packets sending is adjusted in terms of the output of fuzzy system; and routing algorithm for real time traffic is optimized to assure that data are always transmitted through the route with the lowest delay. The simulation results show that the improved protocol has better features on delay, delay variation, packet loss rate and throughput compared to single-constrained QoS routing protocol.