A Performance Study of Power-Saving polices for Wi-Fi Hot-spots

Wi-Fi hotspots are one of the most promising scenarios for mobile computing. In this scenario, a very limiting factor is the shortage of energetic resources in mobile devices. Legacy networking protocols are very inefficient in terms of energy management. This work focuses on a network architecture for energy-efficient mobile-Internet access through Wi-Fi hotspots (PS-WiFi). The proposed architecture is able to support any kind of (best effort) applications. In this paper we derive an analytical model of PS-WiFi to analyze the performance of the architecture and to tune its parameters. The model is validated exploiting measurements obtained by using an Internet prototype implementation. The validation shows that the model is able to predict the energy saved by the PS-WiFi architecture with a very good accuracy. Therefore, we used this model to better understand the behavior of PS-WiFi, and to assess its sensitiveness to the main Internet parameters, i.e., the throughput and the RTT.