机会分流中一种改进声誉机制的评价算法

An Evaluation Algorithm for Improvement of Reputation Mechanism in Opportunistic Offloading

在SoWatch(Social-based Watchdog system)基础上,提出一种基于节点历史数据量期望与方差和转发数据时间延迟的声誉评价算法(EVRA,Expectation Variance based Reputation Algorithm)。控制中心基于转发节点的历史数据分流量,给予声誉评价;目的节点基于转发节点完成数据分流的时间给予声誉评价。通过综合考虑目的节点与控制中心的声誉评价,真实地反映转发节点在数据分流中的贡献。为了验证EVRA的有效性,EVRM分别与SoWatch、无声誉机制Prophet转发路由协议进行比较。实验结果表明,与SoWatch机制相比,EVRA平均数据分流时间降低了15%,平均跳数降低10%。EVRA比无声誉机制的Prophet平均完成数据分流时间降低了30%和平均完成数据分流的跳数降低25%。

Based on the SoWatch(Social-based Watchdog system),an EVRA(Expectation Variance based Reputation Algorithm)is proposed,which is based on historical data expectation,variance,and time delay of data forwarding.The control center provides a reputation score based on the historical data of the forwarding node.The destination node provides the reputation score of nodes by evaluating their performances during the real-time forwarding process.The weighted calculation of the previous evaluation scores is conducted to truly represent the contribution of the forwarding node in the opportunistic network.To test the performance of the proposed algorithm,it is compared with other rivals,including the non-incentive Prophet path protocol and SoWatch incentive mechanism.There are a lot of experimentation in demonstrate that,compared with the SoWatch mechanism,EVRA reduces the average data offload time by 15%and the average hop count by 10%.Comparison with Prophet,a typical non-incentive mechanism path protocol,the EVRA mechanism reduced the average data offload time by 30%and the average completed data offloaded hops by 25%.