Modeling contacts and mobility for wireless mobile networks

Abstract

The inter-contact time between mobile human-carried devices is one of the key metrics in studying the mobility-assisted routing paradigms for wireless mobile networks. Recent studies on this topic are focused on the aggregated distribution integrating all the device pairs' inter-contact times. In this work, we study real-world inter-contact times from a new aspect. By dividing the device pairs in groups and by investigating the group-wise inter-contact time distribution, we find that for the frequently contacting pairs, there are three segments on the distribution curve. We use superposition of three stochastic contact processes caused by the devices' independent movements and human intentions to explain the segments. Furthermore, we propose a mobility model, where each node uses a priority queue to schedule its movement, to emulate real-world human mobility. Theoretical analysis shows that the priority queue results in a power-law inter-contact time and we also demonstrate that our model seamlessly integrates the three contact processes. Finally, simulation study testifies that our mobility model could reproduce the contacts with their inter-contact times resembling the empirical ones, therefore is accurate in characterizing the complexity of the device contacts in wireless mobile networks. © 2010 Springer-Verlag.