Efficient Tradeoff of Restricted Epidemic Routing in Mobile Ad-Hoc Networks

Energy consumption for data transmission in mobile ad hoc networks can be reduced by decreasing the transmission range of each node. However, a transmission range that is too short reduces the node density to the extent that it becomes impossible to maintain a fully connected network. Consequently, each node has to rely on its mobility to first bring itself into the transmission range of another node before propagating the data packets, thereby leading to a longer delay in data delivery. On the other hand, if a network such as the Delay Tolerant Network (DTN) can tolerate this delay to some degree, using a short transmission range will be of great advantage to conserving transmission energy. Epidemic Routing is a protocol proposed for a DTN that consists of nodes with short transmission ranges. In this paper, we ascertain how Epidemic Routing works and address its drawbacks. Then we propose several schemes using different ways of restricting Epidemic Routing and evaluate the performance of each scheme. In order to evaluate the schemes we use a method of deriving the performance of each scheme and comparing the schemes from the standpoint of the tradeoff between energy consumption and time delay, while maintaining a fixed delivery rate. The efficacy of this method is shown through both evaluation and simulation results.