Date Added: Aug 2009
Location based services are on the rise, many of which assume GPS based localization. Unfortunately, GPS incurs an unacceptable energy cost that can reduce the phone's battery life to less than ten hours. Alternate localization technology, based on WiFi or GSM, improve battery life at the expense of localization accuracy. This paper quantifies this important tradeoff that underlies a wide range of emerging applications. To address this tradeoff, the authors show that humans can be pro led based on their mobility patterns, and such pro les can be effective for location prediction. Prediction reduces the energy consumption due to continuous localization.