Buffer Management in Opportunistic Networking

Opportunistic Networks are a powerful tool for deploying a class of delay tolerant network applications in zones with scarce communications infrastructure. Unfortunately, these networks are highly stochastic and very sensible to changes in the nodes movement patters, as well as to changes in the data-flow patterns. On the other hand, opportunistic algorithms, while conceptually simple, are highly configurable and plastic but, for the same reason, many examples of such networks are notoriously hard to model and simulate. Thus, the algorithm's calibration is a challenging task. In this paper, we show how a combination of a synthetic mobility pattern, combined with simulation and a careful implementation permits to identify potentially disruptive behaviors and find solutions. In particular we show how a quite probable mobility pattern (i.e., data-carrying nodes converging to a data receiver simultaneously) has very bad performance when using a wide family of buffer management policies, FIFO among them. Furthermore, we propose and test an alternative buffer management policy which shows very encouraging results.