Delay tolerant firework routing: a geographic routing protocol for wireless delay tolerant networks

We present the Delay Tolerant Firework Routing (DTFR) protocol, a protocol designed for use in disconnected Delay Tolerant Networks (DTNs) that consist of a very large number of location-aware, highly mobile nodes. Networks with these properties appear frequently in many settings, notably in vehicular networks. Under DTFR, each data packet travels from the source to the estimated location of the destination using high-priority transmissions and a delay-tolerant variant of geographic forwarding. Once there, a number of packet replicas are created, and the replicas proceed to travel through the area where the destination is expected to be. Using simulations in an urban setting, we compare DTFR with two baseline protocols (Flooding and Spray and Wait), one recently proposed state-of-the-art protocol (GeoDTN+Nav), and an idealistic protocol of our design which we term Bethlehem Routing (BR). For a wide range of environmental parameters, DTFR performs significantly better than the other realistic protocols, in terms of throughput and delay, and close to the upper performance bounds of BR. We also develop an analytical framework based on stochastic geometry tools, a number of simplifying assumptions, and a small number of judiciously chosen approximations. Using this framework, we develop approximate closed form expressions for the average end-to-end throughput and delivery delay of DTFR and BR.