Rethinking Mobile Devices' Energy Efficiency in WLAN Management Services

Abstract

With the rapid popularization of large data stream mobile applications, wireless local area networks (WLANs) have been a top choice for mobile users (MUs), because of the high data rate and low monetary cost. However, the battery life of mobile devices, which is the most concerned feature of MUs, may suffer from WLAN management services, such as mobility management and load balancing services. Unfortunately, few existing WLAN systems take into account both the energy efficiency of mobile devices and the performance of management services. Even worse, to improve the performance of WLAN management services, various existing management mechanisms sacrifice mobile devices' energy. In this paper, we propose BELL, a novel WLAN system that provides two energy-efficient management services for its associated MUs by reproducing and scheduling the beacons broadcast from access points (APs). We name them BELL- handoff and BELL-2M services. We have implemented the proposed BELL-handoff using commercial Wi-Fi adapters. The experimental results reveal that BELL-handoff significantly decreases both mobile devices' energy consumption and latency during handoffs, compared with the commercial WLAN mobility management service. Furthermore, we conduct extensive simulations to evaluate APs' load and mobile devices' battery life within a large-scale deployment of BELL. Simulation results demonstrate that BELL not only balances the load among APs, but also prolongs the battery life of mobile devices.