Opportunistic networks: Minimizing expected latency

Even in the absence of a physical network infrastructure, it is important that mobile devices can take advantage of the opportunities presented to them to maintain communication. Opportunistic networks are a class of mobile networks that must rely on unscheduled sporadic meetings between nodes to achieve communication. The main challenge in these networks is to route messages towards a destination with high delivery probability, low average latency and efficient usage of network resources. Despite the numerous proposals for opportunistic routing protocols, there are relatively few analytical characterizations of their behaviour. In this paper, we propose both centralized and decentralized message forwarding algorithms that, under relatively strong assumptions about the network´s behaviour, minimize the expected latency to a destination. After presenting proofs of the optimality of our proposed algorithms, we confirm their improvement in system performance through numerical simulation.