Study On Social Routing Algorithm In Delay And Disruption Tolerant Networks

Delay/Disruption Tolerant Network is a special wireless network which suffers from dynamic topology change, long transmission delay and the inexistence of end-to-end path from source to destination at all time. Unlike traditional Ad-Hoc routing protocol, most routing strategy in Delay/Disruption Tolerant Network is based on store-carry-forward paradigm. With the unpredictability of the change of network topology, and the limitation of mobile nodes'capacity of storage and processing, however, it has been a great challenge to deliver packets in Delay/Disruption Tolerant Network efficiently.In this thesis, we induce social network theory to deal with routing in Delay/Disruption Tolerant Network and propose a social routing protocol, named SRF. In SRF, nodes are associated within a group based on their geographic location and two forwarding methods are engaged in message transmission. The Inner-Group forwarding algorism, which is a one-copy directional forwarding strategy, handles the messages that are forwarded between two nodes within a same group. While for messages transferred cross different groups, the group familiarity will be computed according to the social network theory and then the node viewed as with the most possibility to contact the destination will be selected as the next-hop.Meanwhile, different dropping policies are proposed in order to reduce the network overhead.We implemented and evaluated this social routing protocol in NS-2 network simulator. The function modules main include the data forwarding mechanism, cache management strategy and information maintenance, etc. We also use social mobility model to control the node's mobility to make our simulation closer to the scenarios in reality. The simulation results show that our social routing protocol can guarantee good packet delivery ratio, decrease end-to-end delay and reduce the load of network.Finally, conclusions are drawn that our social routing protocol is feasible in Delay/Disruption Tolerant Network thorough studies and precise experiments.