Sufficient node density conditions on delay-tolerant sensor networks for wildlife tracking and monitoring

This paper investigates the performance limits of delay tolerant networks (DTNs) with intermittently connected nodes deployed for wildlife monitoring, wherein information is either transmitted or carried to static accesspoints by free-ranging animals whose movement is assumed to be random. Specifically, in such mobility-aided applications where routing is performed in a store-carry-and-drop manner, limited buffer capacity of a carrier node plays a critical role, and data loss due to buffer overflow heavily depends on access-point density. Driven by this fact, our focus in this paper is on providing sufficient conditions on accesspoint density that limit the likelihood of buffer overflow. Specifically, we first derive and prove sufficient access-point density conditions that ensure that the data loss rates are statistically guaranteed to be below a given threshold. We consider studying both the square and hexagonal accesspoint deployment structures. Then, we validate the derived theoretical results for each of the two studied structures through simulations.