Rethinking routing information in mobile social networks: Location-based or social-based?

With the rapid development of wireless communication technologies, mobile social networks (MSNs) become more and more popular and have attracted much attention from researchers. In this paper, we address the routing issue in MSNs where a set of social related mobile devices communicate opportunistically and intermittently. Existing routing strategies are mostly based on location information (i.e., geographical coordination and physical distance) and social information (i.e., the number of friends and the strength of social ties). These two kinds of information indeed represent two different levels of human behaviors: the location information is concrete and corresponds to the physical property of human activity; while the social information is logical and represents virtual human interactions. In the context of data routing, a rising question is: does the concrete location information outperform the logical social information in designing routing strategies in MSNs? To address the question, we devise a comprehensive social-based routing strategy called Soc and a general location-based strategy called Loc. We provide comprehensive performance comparisons of Soc and Loc together with other social-based and location-based strategies. Our experiment results show that the social-based strategy and the location-based strategy have no significant difference in routing performance: they perform closely in delivery ratio, delay and delivery cost with a slight difference less than 5% in most cases. This indicates that concrete location information is not always necessary to be the key consideration for routing design and logical social information could be potential substitute. Since collecting location information needs dedicated equipment and arguably violates user privacy, our work implies that the proposed social-based routing strategy is safe and effective for MSNs.