Date Added: Aug 2009
The authors propose a new message routing mechanism based on the concept of immunity for Disruption Tolerant Networks (DTNs). The new mechanism allows more efficient utilization of limited buffer space at the nodes, by removing redundant copies of messages that have already been delivered. They first develop a new mathematical model for estimating the Message Delivery Ratio (MDR) and Average Delivery Delay (ADD) under a variant of epidemic routing with the immunity mechanism. They implement the proposed mechanism in ns2 simulator and demonstrate that the model provides accurate estimates of the MDR and ADD for varying traffic load and buffer size at the nodes. Secondly, they compare the performance of the epidemic routing with immunity against that of the original epidemic routing and spray-and-wait algorithms.