延迟容忍网络是一种缺乏持续连接的新型网络体系结构,采用存储-携带-转发的路由方式进行消息的转发.考虑到节点的特性及运动模式,基于分簇、社会网络的路由协议已成为近年来的一个研究热点.该文分析现有基于分簇、社会网络的路由算法的缺陷及社会网络的特点,提出了一种新型的混合路由算法CS-DTN (Clustering & Social Delay Tolerant Network):预测节点间的相遇概率并据此对节点进行分簇,簇内根据节点间相遇概率限定消息的副本数量,将消息以二分喷射的方式转发到更可能到达目的节点的中继节点；簇间对节点进行运动预测并结合节点的特性将消息不断地转发到更接近目的节点的中继节点.不同于已有的基于分簇、社会网络的路由算法,CS-DTN从多个角度结合了节点自身及节点间的特性,更考虑了对节点的运动预测,降低了由不必要的消息转发带来的资源浪费,同时也能更高效地将消息投递到目的节点.仿真结果表明CS-DTN较为明显地提升了消息的成功投递率并降低了消息的平均端到端延迟,在缓存足够的前提下,CS-DTN可以实现高达95％的投递率,而在资源有限的情况下也能获得80％以上的投递率.%Delay-Tolerant Network (DTN) is a new network architecture which uses store-carryforward communication model to forward messages since there isn't a persistent end-to-end path from source to destination. Taking into account the characteristics and movement pattern of nodes, some new routing protocols such as cluster-based and social-based have become a research focus in recent years. In this paper, defects of these protocols are analyzed and a new hybrid routing algorithm CS-DTN is proposed based on the analysis and the characteristic of social network. In CS-DTN, encounter probability is predicted and is used to clustering the nodes. And then copies of message, which number is limited according to the encounter probability, are binary sprayed to the relay node which is more likely to reach the destination node in intra-cluster. Meanwhile, in inter-cluster messages are forwarded to the relay node that is closer to the destination node based on the movement prediction and the active characteristic of nodes. Unlike the existing cluster-based and social-based routing protocols, CS-DTN combines nodes' own characteristics and relationship between nodes from multiple angles. What's more, movement prediction is considered. In this way, the waste of resources brought by unnecessary message forwarding is reduced and more efficient message delivery is brought. Simulation results show that CS-DTN significantly improves the message delivery rate and at the same time reduces the average end to end delay. With enough cache, 95% delivery rate can be achieved by CS-DTN. What's more, more than 80% delivery rate can be obtained even if limited resources can be used.
展开▼
