Optimization of Bandwidth and Energy Consumption in Wireless Local Area Networks

In the recent years the proliferation of portable computers, handheld digital devices, and PDAs has led to a rapid growth in the use of wireless technologies for the Local Area Network (LAN) environment. Beyond supporting wireless connectivity for fixed, portable and moving stations within a local area, the wireless LAN (WLAN) technologies can provide a mobile and ubiquitous connection to the Internet information services. The design of WLANs has to concentrate on bandwidth consumption because wireless networks deliver much lower bandwidth than wired net-works, e.g., 2-11 Mbps [1] versus 10-150 Mbps [2]. In addition, the finite battery power of mobile computers represents one of the greatest limitations to the utility of portable computers [3], [4]. Hence, a relevant performance- optimization problem is the balancing between the minimization of battery consumption, and the maximization of the channel utilization. In this paper, we study bandwidth and energy consumption of the IEEE 802.11 standard, i.e., the most mature technology for WLANs. Specifically, we derived analytical formulas that relate the protocol parameters to the maximum throughput and to the minimal energy consumption. These formulas are used to define an effective method for tuning at run time the protocol parameters.