一种结合传染路由的缓存调度算法

Buffer schedule algorithm combined with epidemic routing

延迟容忍网络是一种链路频繁断裂的无线网络,主要采用"存储-携带-转发"的方式来转发数据分组,不同于传统网络的"存储-转发"方式.然而在这种网络中,由于节点之间的接触时间周期较短,并且节点的缓存空间有限,在不考虑有效的缓存调度策略时,很容易造成网络中传输数据分组丢失.针对网络的这些特点,结合传染路由提出了一种基于当前节点的邻居节点与分组的目的节点之间的接触频率的按序转发数据缓存调度算法,并通过NS-2仿真工具进行性能评估.仿真结果表明,在网络资源有限的情况下,此算法能较好地提高数据分组交付率,降低传输时延,减少网络开销,使网络性能得到了较好改善.

The Delay-Tolerant network（DTN） is a wireless network,in which links between nodes may be disconnected frequently.In DTNs,packets are mainly delivered in a ＂store-carry-forward＂ manner,which is different from the ＂store-and-forward＂ method used in conventional networks.However,due to the short contact duration between nodes in network and the limited buffer size of the nodes,the packets in the forwarding path may be easily lost without considering an effective buffer schedule policy.For the above characteristics of the network itself,in this paper we propose a buffer schedule algorithm to forward data in the nodal buffer in order of the average contact frequency between the current node＇s neighbor nodes and the corresponding packet＇s destination node combined with the epidemic routing protocol.And the performance of the proposed algorithm is evaluated on the NS-2 simulation platform.Final simulation results show that its performance metrics,including the increase in data delivery rate,decrease in end-to-end delay and reduction of network overhead,are improved significantly with limited network resources.