A Robust Energy Efficient Epidemic Routing Protocol for Delay Tolerant Networks

A Delay Tolerant Network (DTN) is mostly suitable where there is intermittent connection between communicating nodes such as wireless mobile ad hoc network nodes. In general, a message sending node in a DTN copies the message and transmits it to nodes which it encounters. A receiving node, if it is not the destination of the message, stores the message and transmits a copy of the message to nodes it encounters. The process continues until the message reaches its destination or its life time expires. Various DTN routing protocols have been proposed to reduce the number of copies and improve the delivery probability of messages. However, very few of them consider the energy constraint of mobile nodes in routing protocols. Mobile nodes specially smart phones, tablets, PCs etc are powered by batteries and energy is limited. It is essential to consider energy constraint also while designing routing protocols for DTNs. In this paper, we proposed a robust energy efficient Epidemic routing protocol. Our aim is to extend the life expectancy of a DTN by extending lives of nodes in DTN by reducing energy consumption and at the same time increase the delivery probability of messages. We have achieved this by considering nodes´ remaining energy and available free buffer for receiving copies of messages. Only a node with higher energy value than the sending node will receive a copy of the message and store it to send to other nodes or the destination node. The simulation results show that our proposed protocol extends the life of a DTN as well as improve the delivery probability of messages. Moreover, the results also show that the performance of the routing protocol is not affected by the increase in number of nodes in DTNs.