Energy-Constrained Mobility Control for Epidemic Routing in Disruption Tolerant Networks

Mobility plays an important role in the message transmission of Disruption Tolerant Networks (DTNs), and we need to control the mobility of nodes around the network to efficiently carry and relay messages around the network. This is a challenging problem since the nodes in the network may move arbitrarily and it is hard for us to determine how the nodes should move, faster or slower, to help with the data transmission. Moreover, in such network, the energy is usually limited, and we need to consider its complicated energy consumption. In this paper, we investigate the problem of energy-constrained mobility velocity control in epidemic routing of DTN. We first model the message dissemination process under variable mobility velocity by a continuous-time Markov model, then formulate the optimal mobility control problem, and finally obtain the optimal threshold policy from the solution of this optimization problem. Furthermore, extensive numerical results demonstrate that the proposed optimal threshold policy significantly outperforms the static policy with constant velocity, in terms of energy saving.