Social-Based Data Routing Strategies in Delay Tolerant Networks

Delay Tolerant networks (DTNs) are intermittently connected mobile networks in which the end-to-end paths do not exist. Data delivery in such networks relies upon the contacts that use “store-carry-and-forward” paradigm to forward message from one node to another. However, such intuitive methodology encounters low message delivery ratio and high data transmission delay when applying to different data routing strategies. The design of effective and efficient data routing strategies based on limited knowledge of mobile nodes in DTNs is challenging. In this dissertation, we explore several aspects of social information that can be applied for data routing in DTNs. We discuss the problems of data routing in DTNs and study the using of different social information and network features to facilitate data routing in DTNs. Specifically, we propose three different data routing strategies relying on different types of social information obtained from mobile nodes: (a) a location-based social routing strategy applying different aspects of location-based social information; (b) an encounter-based social routing strategy relying on several encounter-based social factors of mobile nodes in the network; (c) a community-based routing strategy combining social and mobile factors as well as community structure. The proposed location-based social routing strategy is motivated by the fact that location information can provide the geographic distance and the direction of information propagation, which can guide the data to the destination effectively. The proposed location-based social strategy considers both geographic distance and user mobility pattern as factors and combines them into one utility function for data forwarding. We propose the encounter-based social routing strategy based on the fact that users in DTNs are interactively connected by encountering events. The design of encounter-based social strategy involves social centrality and social similarity. Compared to location-based social strategy, the usage of encounter-based social information is much less sensitive than location-based social information. By convoluting two social factors into utility function, the proposed algorithm can achieve competitive performance with location-based routing strategy.