Analysis of Core-Assisted Routing in Opportunistic Networks

Opportunistic networks (ONs) are a newly emerging type of delay tolerant network ( DTN) systems that opportunistically exploit unplanned contacts among nodes to share information. As with all DTN environments ONs experience frequent and large delays, and an end-to-end path from the source to destination may only exist for a brief and unpredictable period of time. Such network conditions present unique challenges to message routing. In this paper, we present the design and performance analysis of a novel core-based routing protocol for ON routing. Under the assumption that messages will have a delivery time constraint, we then provide a set of analytical results for rapid modeling and performance evaluation for the basic performance metrics of message delay, message delivery ratio, and buffer occupancy. We have implemented our protocol in ns-2, and our simulation results show that our protocol is quite effective and our analysis is accurate.