基于吞吐率的Prophet路由在DTN中的应用

Application of Probabilistic Routing Based on Throughput Ratio in DTN

在延迟容忍网(delay tolerant network,DTN)中,节点采用复制和转发的机制把消息从当前节点传输给连接节点,直到消息到达目的节点或节点的生命周期耗尽。Prophet路由作为DTN中重要的路由之一,主要思想是比较携带消息的节点与目的节点的接触概率和相遇节点与目的节点的接触概率来决定是否把消息传递给相遇节点。但是,在Prophet路由算法中,并没有考虑到与节点的能量、带宽和自身缓存等性能相关的节点吞吐率这一对网络性能指标有重要影响的因素。对此,在Prophet路由的基础上,给出了基于节点的历史吞吐率的Prophet路由策略。改进后的路由策略中的节点传递消息时,在与目标节点相遇概率相同的节点中选择吞吐率较大的节点作为消息的转发节点。仿真结果表明,基于节点历史吞吐率的Prophet路由策略在消息的递交率、开销率及平均时延方面均优于Prophet路由。

In the delay tolerant network（ DTD）,the node uses the mechanism of replication and forwarding to transfer the message from the current node to the connection node until the message arrives at the destination node or the lifecycle of the node is exhausted.Probabilistic routing is one of the important routing in DTN,whose main idea is to compare the probability of meeting between the node carrying the message and the destination node and the probability of meeting node and the destination node to decide whether to pass the message to the meeting node.However,the Prophet routing algorithm does not take into account the node throughput associated with the performance of the node＇s energy,bandwidth and its own cache,which has a significant impact on network performance.For this,according to the Prophet routing,we give a Probabilistic routing strategy based on the historical throughput of nodes.When the node in the modified routing policy transmits the message,the node with the higher throughput is selected as the forwarding node of the message in the node with the same probability of encountering the target node.The simulation shows that the Probabilistic routing strategy based on node historical throughput is superior to Probabilistic routing in terms of message delivery rate,overhead rate and average delay.