Message dissemination in delay tolerant networks DTN closely depends on the opportunistic contact between nodes. However, the contact is related to the beaconing rate of nodes. In particular, the node has more chances to contact with others if it has bigger beaconing rate, but this will need more energy. In this paper, we study the optimal beaconing policy in DTN with limited energy. In particular, we focus on the case with multiple destinations. According to whether the destinations forward the message to others, we explore the non-replicative and replicative cases, respectively. First, we introduce a theoretical model for each case, which can be used to evaluate the performance under different beaconing rates. Then, based on these models, we present the corresponding optimization problems. Through Pontryagin's Maximal Principle, we obtain the optimal beaconing rate and prove that the optimal policies conform to the threshold form in both cases. Simulations show the accuracy of our theoretical models. Extensive numerical results show that the performance of the replicative case is better when the energy is limited. Copyright © 2014 John Wiley & Sons, Ltd.
['Yahui Wu', 'Su Deng', 'Hongbin Huang']
Energy constraint beaconing control in delay tolerant networks with multiple destinations