一种基于功率调控的WiFi Direct节能优化机制

Energy-saving Optimization Mechanism for WiFi Direct Based on Power Control

WiFi Direct(WFD)是安卓系统广泛支持的Device-to-Device(D2D)通信技术.相比于蓝牙,WFD在传输速率和连接距离上更具优势;同时,WFD能够比WiFi热点更快速地创建连接.因此被广泛应用于构建D2D通信网络,用以支持边缘计算、流量卸载、移动众包等研究.但是WFD同时带来了更高的能耗,而能耗仍然是电池受限的嵌入式设备所关注的主要问题.现有的研究关注WFD的性能测量和组网技术,很少有对其能耗的研究.提出了一种基于功率调控的WFD节能机制.该机制对WFD默认节能算法进行了补充和优化.首先,搭建了一个基于WFD的D2D通信组,并对WFD默认节能机制进行了测量分析,测量结果表明,组主的消耗始终要高于组员的消耗.然后,详细阐述了所提出的WFD节能机制.该机制能够降低设备的传输能耗,并通过切换设角色来平衡组主的能耗.最后,仿真实验结果表明,该机制降低了11.86%的能耗,同时只损失了2%的吞吐量.

WiFi Direct(WFD)supported by Android has been widely used in device-to-device(D2D)communications.Compared with Bluetooth,WFD has advantages in data transmission rate and connection distance.At the same time,WFD can quickly create a connection than WiFi HotSpot.Therefore,it is widely used to form D2D communication networks and support edge computing,traffic offloading,mobile crowdsourcing,and other studies.However,it brings high energy consumption simultaneously,which is still a major concern for battery-constrained devices.Existing studies pay more attention to measuring and optimizing the performance of WFD-based networks,while few studies focus on the energy consumption.In this study,an energy-saving mechanism for the WFD based on power control is proposed,which makes a supplement to the default energy-saving mechanism of WFD.First of all,this study constructs a WFD-based communication group and a measurement analysis of the default energy-saving mechanism.Measurement results show that the energy consumption of the group owner is always higher than that of the group member.Then,the proposed energy-saving mechanism is described in detail,which can reduce the transmission consumption of devices and balance the energy consumption of the group owner by switching the role of the devices.At last,the proposed mechanism is evaluated with simulation experiments,and results show that the proposed mechanism can reduce 11.86% energy consumption with a throughput loss of 2%.