Cont2: Social-Aware Content and Contact Based File Search in Delay Tolerant Networks
Kang Chen, Haiying Shen · Proceedings of the International Conference on Parallel Processing · 2013
In this paper, we focus on distributed file search over a delay tolerant network (DTN) formed by mobile devices that exhibit the characteristics of social networks. Current file search methods in MANETs/DTNs are either content-based or contact-based. The former builds routing tables for node contents but is not resilient to high node mobility, while the latter exploits node contact patterns in the social networks but may lead to high latency. Recent research also reveal the importance of interests in realizing efficient file dissemination in DTNs. In this paper, we first analyze node interest and mobility from real traces, which confirms the shortcomings of a contact based method and show the importance of considering both content/interest and contact in file search. We then propose Cont2, a social-aware file search method which leverages both node social interests (content) and contact patterns to enhance search efficiency. First, considering people with common interests tend to share files and gather together, Cont2 virtually groups common-interest nodes into a community to direct file search. Second, considering human mobility follows a certain pattern, Cont2 exploits nodes that have high contact frequency with the queried content. Third, Cont2 also exploits active nodes that have more connections to others as a complementary approach to expedite file search. Trace-driven experimental on the real-world GENI test bed and NS-2 simulator show that Cont2 can significantly improve the search efficiency compared to current methods.