An Eco-Friendly Routing Protocol for Delay Tolerant Networks

In sparse mobile networks, nodes are connected at discrete periods of time. This disconnection may last for long periods in suburban and rural areas. In addition, mobile nodes are energy and buffer sensitive, such as in mobile sensor networks. The limited power and storage resources, combined with the intermittent connection have created a challenging environment for inter-node networking. This type of networks is often referred to as Delay Tolerant networks (DTN). Routing protocols developed for DTN focused on minimizing the end-to-end delay as a means of maximizing number of delivered packets. Therefore, they tend to spread many copies of the same packet into the network, assuming the availability of sufficient storage space and power. A key factor to help maintain a clean environment, is the reduction of energy consumption which can be achieved by decreasing number of transmissions in the network. In this paper, we formulate a mathematical model for optimal routing in DTN to minimize number of transmissions. In addition, we study and analyze the DTN heuristic routing protocols. After that, we propose an eco-friendly routing protocol, EFR-DTN, that efficiently uses simple information provided from the network to deliver packets with higher delivery ratio and minimum energy consumption than the other protocols. Simulation results show the outperformance of the proposed protocol under different buffer capacities, traffic loads, packet TTL values, and number of nodes in the network.