Performance evaluation of routing schemes for energy-constrained delay tolerant networks

In order to provide communication services in Delay Tolerant Networks (DTNs) where it lacks of end-to-end paths between the communication sources and destinations, a variety of routing schemes have been proposed. Consequently it is significant to accurately evaluate their performance to show their advantages and inferiority. At the same time, the energy is very limited in a large number of DTNs, such as sparse mobile sensor networks and emergency ad hoc networks, and it impacts the routing performance significantly. However, current related works ignore the influence of the energy constraint on the routing. In this paper, we investigate the performance of routing schemes for the energy-constrained DTNs. First, we model the two-hop relaying, epidemic routing and K-hop forwarding with energy constraint based on a two-dimensional continuous time Markov chain. Then, we obtain the system performance of message delivery delay and delivery cost by explicit expressions. By both simulation and numerical results, we demonstrate the accuracy of our proposed model and reveal that the energy constraint can actually avoid the message storms which are harmful to the systems in term of delivery cost and transmission contention.