时延容忍网络的蔓延路由协议的研究

蔓延路由广泛应用于时延容忍网络(DTNs)。然而，传统的蔓延路由存在资源消耗过多问题，如节点能耗和消息缓存空间。即使消息已传递到目的节点，消息可能仍停留于节点的缓存区，直至消息过期，这会增加能耗。为此，对节点缓存空间的释放时间进行研究，并提出基于释放时间预测的蔓延路由，其目的在于通过减少消息占用缓存的时间，降低资源开销。基于蔓延路由特性，建立基于常微分方程的消息传播模型，并预测消息到达目的节点的时间，再在确保消息被最多节点传染的前提下，推导从缓存区内删除消息的准确时间(释放时间)。实验数据表明，与传统的蔓延路由相比，采用预测释放时间的蔓延路由在维持同等路由性能的同时，降低了能耗和开销。

Study on Epidemic Routing Protocol in Delay-Tolerant Networks

Epidemic routing is widely used in delay tolerant networks (DTNs).However,the traditional epidemic routing protocol consumes too much resources,such as the energy and the buffer space.Even if the message reaches all destinations nodes,it remains in the buffer of nodes consuming the energy until the message expires.Therefore,release time of omitting message from nodes'' buffers is studied,then release time-based epidemic routing is proposed.The messages propagation model under the epidemic routing protocol by an ordinary differential equation is built,and the time at which the message arrives to all users is predicted and omitted from the buffer ensuring that the maximum number of nodes is already infected.Simulations results show that the proposed optimal control in epidemic routing context can reach the same performances of epidemic routing while minimizing the resource consumption.