DTN Content Sharing Among Commuters

When discussing vehicular networking we have also to consider the multitude of commuters daily travelling to work through public transportation means such as buses, metros, and trains. Indeed, through their smartphones, commuters can generate communication traffic while moving, thus embodying a significant part of an urban communication scenario. In this context, we discuss in this article a way to port the P2P paradigm into mobile disconnected networks composed by commuters’ smartphones. Different from classical P2P file-sharing systems, our solution is designed to specifically leverage on the mobility pattern of commuters. In essence, users can exchange multimedia contents when in proximity with each other; they can also leverage on peer mobility and encounters in order to extend a requesting peer reacharea to other local disconnected networks. This is achieved by implementing a DTN-like store-delegate-and-forward communication model over underlying social networks where a peer can delegate unaccomplished file download tasks to frequently encountered peers: e.g., other commuters sharing a part of the path between home and workplace. We show how involving only frequently encountered peers/commuters improves the success ratio for the file search task while reducing useless communication overhead.