A routing strategy with small world feature and node authority in energy constrained delay tolerant networks

In delay tolerant networks, the design of routing strategy is very challenging due to the characteristics of dynamic topology, long delay and intermittent connectivity. Most of existing routing strategies neglect the number limitation of intermediate nodes during forwarding messages. Owing to the small-world feature in delay tolerant networks, messages can reach destination nodes at most by five or six intermediate nodes. Since aggressively employing intermediate nodes will waste much more resources without improving the delivery probability, the routing strategy of TBSF (the-best-so-far) [1] is put forward by utilizing the small-world feature to limit the number of intermediate nodes. However, the issue of energy efficiency is not resolved in TBSF. In the actual situation, energy of nodes is constrained for the portability, and hence we propose an enhanced strategy with energy efficiency. In our strategy, we design the energy control mechanism, and investigate the node authority by extending the degree centrality to the case of multi-hop neighbor nodes. The extensive simulation results based on the real world traces validate that our proposed strategy can cut down the energy consumption as well as attain the high message delivery probability.