Optimal Forwarding and Beaconing Control of Epidemic Routing in Delay Tolerant Networks
Routing algorithms in Delay Tolerant Networks (DTN) need nodes to forward the message to others based on the opportunistic contact. The contact depends on the beaconing rate of nodes, and bigger beaconing rate can bring more contacts. However, this needs more energy. In addition, bigger forwarding rate can make the message be transmitted much faster, but this also needs more energy. Therefore, how to control the forwarding and beaconing rates efficiently to get a trade-off between the expenditure (e.g., energy consumption) and efficiency is very important. This paper proposes a theoretical model to evaluate the performance of the epidemic routing (ER) algorithm under different forwarding and beaconing rates, and then formulates a joint optimization problem. Through Pontryagin's Maximum Principle, this paper obtains the optimal policy and proves that both the optimal forwarding and beaconing rates conform to the threshold form in certain cases. Simulations show the accuracy of the theoretical model. Extensive numerical results show that the optimal policy obtained in this paper is the best among all the policies in the numerical results.
epidemic routing delay tolerant networks pontryagin's maximum principle optimal control