Adaptive Power Control and Selective Radio Activation for Low-Power Infrastructure-Mode 802.11 LANs

We present an integrated dual approach to reduce power consumption in infrastructure-mode 802.11 wireless LANs. A novel distributed power control algorithm adaptively adjusts the transmit power of the 802.11 radio/NIC to achieve power savings in the presence of mobility and RF noise. An adaptive radio activation algorithm selectively sleeps the 802.11 radio/NIC to reduce idle power consumption. We analyze the performance of these algorithms in an 802.11 testbed using Web traces of HTTP/TCP user data accesses. Our application-level architecture integrates the two approaches into an incrementally deployable and application-transparent solution for power management of the RF interface on 802.11-enabled laptops.