Social Network Analysis Based Multicasting Algorithm For DTNs

Delay-Tolerant Networks (DTNs) are a class of emerging Mobile Ad Hoc Networks(MANETs). Due to the great application potential on Deep Space Communication,military networks, wildlife tracking and habitat monitoring sensor networks, DTNs getconsiderable attention. Communication infrastructures don’t exist in any DTN, thedissemination of messages depends on the collaboration of nodes. Furthermore, nodemobility, limited radio range and resources lead to the frequent disruption of links. As aresult, most of the time, there are no end-to-end paths from sources to destinations.Therefore, DTNs utilize Store-and-Forward strategy to delivery messages. However, underthis forwarding scheme, messages will be buffered at relay nodes for a long period of time,which will lead to the ascent of end-to-end delay.The specific characteristics of DTNs make message routing become a challenge.Improving message delivery ratio, reducing end-to-end delay and routing overhead are theissues that need to be considered when designing routing algorithms for DTNs.Multicasting for DTNs aims to delivery a message to a group of receivers respectively.And comparing with designing a unicasting algorithm, proposing a multicasting algorithmfor DTNs is more difficult. This paper focuses on the applications of DTNs in socialnetwork scenarios. Based on social network analysis, we propose an Egocentric NetworkFocused Community Aware Multicast Routing Algorithm (ENCAR), which is a utilitybased and hierarchical routing algorithm. ENCAR considers the cluster phenomenonexisting in social network, and divides the dissemination of messages into two cases:source and destination come from the same community and different communities.Correspondingly, ENCAR contains two different forwarding schemes to deal with the twocases. Since ENCAR is social network analysis based, the simulation of ENCAR has to bedone on the mobility model that matches the mobility of nodes in social network scenarios.Hence, the Community Based Random Way Point Mobility Model (CB_RWP) also isproposed. The effectiveness of CB_RWP is mathematically proven and further validatedthroughF2test.On the Opportunistic Network Environment (ONE), the performance of ENCAR is evaluated, and the simulation results show that ENCAR achieves a good globalperformance in terms of message delivery ratio, end-to-end delay, routing overhead andhop count. What’s more, ENCAR also performs better than the most existing routingalgorithms, such as STBR, DTBR, Epidemic and EBMR.