基于概率性能感知演化博弈策略的“云+边”混合环境中任务卸载方法

针对“中心云服务器+多个边缘服务器”构成的“云+边”混合环境中多任务卸载效率不足的问题，提出了一种基于概率性能感知演化博弈策略的任务卸载方法。首先，在一个“中心云服务器+多个边缘服务器”构成的“云+边”混合环境中，假设其中分布的边缘服务器具有时变波动的性能，采用一种基于概率性能感知演化博弈策略的任务卸载方法对边缘云服务器的历史性能数据进行概率分析，以获得演化博弈模型；然后，生成服务卸载的演化稳定策略（ESS），使每个用户都能在获得高满意度的前提下进行任务的卸载。基于云边缘资源位置数据集和云服务性能测试数据集进行模拟实验，在24个连续时间窗口上进行不同方法的测试比较。实验结果表明，所提方法在多个性能指标上都优于传统的贪婪（Greedy）算法、遗传算法（GA）和基于纳什均衡的博弈论算法等任务卸载方法。该方法的平均用户期望达成度相较于三个对比方法分别提升了13.7%、117.0%、13.8%，平均卸载时延分别降低了6.5%、24.9%、8.3%，平均货币成本分别降低了67.9%、88.7%、18.0%。

Task offloading method based on probabilistic performance awareness and evolutionary game strategy in"cloud+edge"hybrid environment

Aiming at the problem of low multi-task offloading efficiency in the “cloud+edge” hybrid environment composed of “central cloud server and multiple edge servers”， a task offloading method based on probabilistic performance awareness and evolutionary game theory was proposed. Firstly， in a “cloud + edge” hybrid environment composed of “central cloud server and multiple edge servers”， assuming that all the edge servers distributed in it had time-varying volatility performance， the historical performance data of edge cloud servers was probabilistically analyzed by a task offloading method based on probabilistic performance awareness and evolutionary game theory for obtaining the evolutionary game model. Then， an Evolutionary Stability Strategy （ESS） of service offloading was generated to guarantee that each user could offload tasks on the premise of high satisfaction rate. Simulation experiments were carried out based on the cloud edge resource locations dataset and the cloud service performance test dataset， the test and comparison of different methods were carried out on 24 continuous time windows. Experimental results show that， the proposed method is better than traditional task offloading methods such as Greedy algorithm， Genetic Algorithm （GA）， and Nash-based Game algorithm in many performance indexes. Compared with the three comparison methods， the proposed method has the average user satisfaction rate higher by 13.7%， 117.0%， 13.8% respectively， the average offloading time lower by 6.5%， 24.9%， 8.3% respectively， and the average monetary cost lower by 67.9%， 88.7%， 18.0% respectively.