Tame: Time Window Scheduling of Wireless Access Points for Maximum Energy Efficiency and High Throughput

Wi-Fi interface is one of the predominant energy consumers in Wi-Fi stations. Despite many researches on Wi-Fi energy management, energy wastage of Wi-Fi stations resulting from network contention among multiple access points(APs) has not been widely investigated. In this paper, we analyze the network contentions occur among multiple APs, and show that Wi-Fi power save mode performance could be severely affected by network contentions. In order to overcome the network contention problem, we propose a scheduling policy, Tame, to assign access points into different sub clusters, in each of which none of the access points have network contentions and data can be transmitted simultaneously without collision. Access points properly control Wi-Fi stations to switch states between sleep and active to avoid stations' packet receiving time overlapping, while the energy wastage from network contentions is mitigated and network performance is guaranteed. We simulate Tame in Qualnet and conclude that Tame, compared with the related work Sleep Well, enhances the average throughput of Wi-Fi stations by an average of 13% for CBR traffic. Simultaneously, the corresponding Wi-Fi interface energy is consumed more efficiently.