异构蜂窝网络中基于雾节点协作贡献度的计算卸载算法

Fog Node Contribution Degree Based Task Offloading Algorithm for Heterogeneous Cellular Network

通过雾计算可将基于云的服务拓展至无线网络边缘和多种场景。针对密集异构蜂窝网络雾计算系统中的协作计算卸载问题,提出一种基于雾节点协作贡献度的计算卸载算法。首先,对协作可行性、协作公平性和协作稳定性进行了建模设计;其次,定义了协作贡献度和协作贡献比系数;然后,结合雾节点的剩余计算容量阈值和协作贡献度阈值,在满足任务可容忍的最大时延约束下,提出以任务执行能耗和用户支付成本的加权和最小化为目标的优化问题,使用外部罚函数法和方向加速法(Powell法)得到最优卸载决策。仿真结果表明,所提算法在各种任务参数和时延约束下能够有效降低执行任务的总开销,并且能够在协作可行性、协作公平性之间进行权衡处理。

Cloud-based services can be extended to the edge of wireless networks in a variety of scenarios through fog computing.To solve the problem of fog computation task offloading in a dense heterogeneous cellular network,a computation task offloading algorithm is proposed.First,the feasibility and fairness of fog node cooperation are modeled and designed.Then,the contribution degree and contribution ratio coefficient of cooperation is defined.Combined with the threshold of the remaining computing capacity and the threshold of the cooperative contribution degree of the fog nodes,a cooperative fog node selection algorithm is proposed.Finally,an optimization problem is proposed to minimize the weighted sum of the task execution energy consumption and the user's payment cost under the constraint of the maximum tolerable delay of the task,and the optimal unloading decision is obtained by combining the external penalty function method and direction acceleration method(Powell).Simulation results show that the proposed algorithm can effectively reduce the total cost of the dense heterogeneous cellular network,with the trade-off between cooperation feasibility and fairness.