基于接收阈值的容延网络拥塞控制机制

摘要

In order to decrease the resource cost in delay tolerant networks,single-copy forwarding protocols have been proposed by researchers.However,recent research has pointed out that single-copy forwarding protocols lead to great unfairness of the nodes' traffic load and make the highly connected nodes suffer congestion.In order to bridge this gap,a congestion control mechanism based on accepting the threshold is put forward in this paper,which makes each DTN node dynamically adjust to its accepting threshold and accordingly to its congestion state.Moreover,the mechanism can be widely adopted,since it is independent of the forwarding protocols and does not affect the choice of the relay nodes made by the forwarding protocol.In order to validate the proposed mechanism,an algorithm named SimBetCC is proposed,which incorporates the congestion control mechanism with existing SimBet protocol.Experimental results show that SimBetCC can cope with congestion and also outperforms FairRoute with congestion control in many aspects,e.g.,the message delivery ratio,the delivery delay.%为了减少容延网络的资源开销,研究者提出了单副本转发路由算法.研究发现,这些转发算法导致节点流量负载极度不均衡,使得那些连接度较大的节点产生了拥塞.针对该问题,提出了一种基于接收阈值的拥塞控制机制,可以有效降低节点拥塞.该机制使每个DTN(delay tolerant network)节点根据自身的拥塞状况动态调整自己的拥塞控制机制,而且该机制独立于节点所运行的转发路由算法,不影响路由算法对中继节点的选择,具有很好的普适性.为了验证所提出机制的有效性,将该拥塞控制机制与现有的SimBet路由算法加以结合,提出了具有拥塞控制功能的SimBetCC算法.实验结果表明,SimBetCC算法在取得很好的拥塞控制的前提下,其递交率和递交时延等性能方面均优于具有拥塞控制功能的FairRoute路由算法.