Leveraging clustering for efficient communication in opportunistic networks
Mehedi Bakht · 2012
The overarching goal of my research is to design protocols for efficient communication in delay tolerant networks (DTNs), with a particular focus on pocket switched networks (PSNs), an emerging class of ad hoc networks made up of smartphones and other portable mobile devices carried by humans. Commu-nication in such an infrastructure-less scenario is inherently opportunistic since it relies extensively on detecting, as well as utilizing, unplanned encounters between nodes. While existing solutions look at the nodes in isolation, we propose that the clustering of nodes, which is a common phenomenon observed in different types of DTNs including PSNs, can be leveraged for significantly improving the efficiency of different components of opportunistic communication. The first step in enabling opportunistic communication is neighbor discovery. In this context, we have developed Searchlight, an asynchronous neighbor discovery protocol that uses systematic probing to considerably decrease discovery latency while allowing nodes to operate at low duty cycles. However, for an individual node, performing continuous neighbor discovery can still be too expensive with a high-power radio like 802.11. On the other hand, relying only on a low-power, short-range radio for detecting neighbors will result in significantly fewer available contacts. To mitigate this problem, we