Effective Ad Hoc Social Networking on OLSR MANET using Similarity of Interest Approach Teerapat Sanguankotchakorn 1 , Shradha Shrestha 1 and Nobuhiko Sugino 2 1 School of Engineering and Technology, Asian Institute of Technology, Thailand teerapat@ait.asia, shres.shradha@gmail.com 2 Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Japan sugino.n.aa@m.titech.ac.jp Abstract. Recently, social networking over MANETs has attracted the attention of research community, due to its flexibility, cost saving and infrastructure-less architecture. However, various problems namely, to efficiently find nodes of similar interest and network partition, exist in such environment. For enabling ad hoc social networking in an intermit- tent network scenario, Delay Tolerant Network (DTN) emerges as one of the solution. This paper proposes a novel algorithm allowing users to find friends of similar interest both in their neighborhood and in entire network by using DTN on OLSR MANET. We investigate and com- pare the similarity of users interest using four similarity metrics: Cosine Similarity, Jaccard, Correlation and Dice Coefficient. We simulate the algorithms assuming that users change their interest at fixed and ran- dom time (normal and uniform distribution). The simulations results show that Cosine Similarity provides the highest number of similar in- terest matching. In addition, by implementing the proposed algorithm on DTN with the normal distributed users interest-changing time, the success ratio of finding matches increases significantly. Keywords: MANETs, OLSR protocol, ad hoc social networking, interest match- ing, similarity metrics, DTN (Delay Tolerant Network) 1 Introduction A large number of people have colossal interest in social networks over past sev- eral years. Social networking applications like Facebook, Twitter, Hi5, Google+, MySpace, etc., have millions of participants, for sharing information, making friends and etc. Such online applications and social networking services rely on infrastructure connectivity. However, in practice, rather than pre-established so- cial network, there exists a wondrous need of constructing social networks that rely upon opportunistic connections between mobile devices. When it comes into social networking, abundant people are associated with web-based social networking services. These social sites are pre-built networks