基于雾计算的高速公路服务区内容访问技术研究

Study on content access of fog computing in highway service area

车联网(Vehicular Ad hoc Networks,VANETs)在高速公路上具有车辆高速行驶、密度低、通信基础设施稀缺、车辆连通性低等特点,使得高速公路上的车辆难以实现对其他车辆或路边单元(Road Side Unit,RSU)的内容访问。提出了一种在高速公路服务区利用雾计算以协助车辆获取感兴趣内容的模型。该车辆雾计算(Vehicle Fog Comput-ing, VFC)模型中,高速公路服务区收集来自各个地方的车辆提供的各种服务,将大量的停泊车辆和慢速行驶车辆作为雾设备。通过VFC本地化转发,不仅减少了通信延迟,还实现了令人满意的内容访问和实时数据流传输。此外,对通信能量消耗与系统延迟之间的关系进行公式化,并在雾计算中采用了外部近似(Outer Approximation,OA)算法来优化其权衡。仿真结果表明,通过采用雾计算和云计算结合的通信模式和均衡优化算法,随着能量消耗的增长,系统的通信延迟会明显地降低。

Vehicular Ad hoc Networks(VANETs)have special characteristics on the highway,such as high speed,low density,scarce communication infrastructure,and low vehicle connectivity.These characters make it difficult for vehicles on the highway to access to other vehicles or Road Side Units(RSUs).This paper presents a model which implements fog computing in highway service areas to assist vehicles in acquiring content of interest.In this Vehicle Fog Computing(VFC)model,the highway service area collects various services provided by vehicles from various places,and uses a large number of parked vehicles and slow-moving vehicles as fog devices.Localized forwarding through VFC not only reduces communication latency,but also achieves satisfactory content access and real-time data streaming.Moreover,this paper formulates the relationship between communication energy consumption and system delay,then uses the Outer Approximation(OA)algorithm to optimize its trade-off in fog computing.The simulation results show that the communication delay of the system will be significantly reduced with the increase of energy consumption by using the communication mode and equalization optimization algorithm combined with fog computing and cloud computing.