Mobility Models and Context-Aware Data Delivery in Opportunistic Networks

Opportunistic networks, in which nodes opportunistically exploit any pair-wise contact to identify next hops towards the destination, are one of the most interesting technologies to support the pervasive networking vision. Opportunistic networks allow content sharing between mobile users without requiring any pre-existing Internet infrastructure, and tolerate partitions, long disconnections, and topology instability in general. This thesis deals with the three main research challenges in opportunistic networking. First, a model describing the patterns of real user movement is introduced, and its properties are evaluated both from an analytical and simulation standpoint. A realistic model of human movements is at the basis of any evaluation of networking protocols designed for a network of mobile users. Then, the problem of routing messages in such a network is described, and a social-aware solution, the HiBOp protocol, is proposed. This protocol is evaluated by means of simulations against other reference protocols for opportunistic networks. Finally, ContentPlace, a social-aware protocol for disseminating content (e.g., blog entries, music files, news) within an opportunistic network is presented. The performance of ContentPlace is thoroughly investigated both through simulation and analytical models.