Minimizing the Average Delay of Messages in Pigeon Networks

A type of disruption/delay tolerant networks, known as pigeon networks, utilizes controllable special purpose vehicles called pigeons to convey messages among segregated areas. This paper aims to provide optimization methods for the challenging problem that how a pigeon should design its route to minimize the average delay of messages. For small scale networks, we construct an exact optimization algorithm that shows significant reduction in delay over the existing heuristic algorithms. For large scale networks, we present both the lower bound and upper bound of the average delay, and devise partitioning-based optimization algorithms that perform close to the lower bound. Both theoretical analysis and numerical results show that the delay could be reduced by as much as 50% compared to the existing algorithm.