Combined tuning of RF power and medium access control for WLANs

Mobile communication systems like handhelds and laptops still suffer from low operation time due to limited battery capacity. We exploit the relative new approach of protocol harmonization to extend the time between battery charges in mobile devices using an IEEE 802.11 network interface. Many known energy saving mechanisms only concentrate on a single protocol layer while others only optimize the receiving phase by on/off switching. We show, that energy saving is also possible while sending. This is achieved by a combined tuning of the data link control and physical layer. In particular harmonized operation of power control and medium access control will lead to reduction of energy consumption. In the course of the paper we show a power and medium access control trade-off. Further on we discuss applications of the results in IEEE 802.11 networks