Fuzzy forwarding for opportunistic networks

Abstract

Routing in opportunistic networks is difficult due to the intermittently connected environment and lack of global view on network topology. In such scenarios, nodes attempt to transmit packets in a store-carry-and forward manner. The main issue is which forwarding mechanism achieves the best trade off between successful packet delivery ratio and cost. We address this challenge by proposing the Fuzzy Forwarding (FF) approach, in which packets are preferred jointly considering the knowledge of performance metrics (e.g., the mean delivery delay and average number of hops per packet) and that of node contacts (e.g., durations, times and locations). FF gives higher priority to packets, as compared to the heuristic knowledge, if they have shorter TTL (time to live) and smaller number of hops, and nodes desiring to relay them have higher delivery probability to destination. Furthermore, to deal with the incompleteness and uncertainty of such knowledge, a fuzzy logic engine is developed for the computation of packet preference. The trace-driven simulation results demonstrate that FF achieves significantly better cost compared to the state-of-the-art works, while keeping better delivery ratios and mean delivery delays under different TTL requirements.