Reducing energy consumption in prospective memory support system through hierarchical positioning algorithm

The 4W project system allows providing users with location and time contextualized cues that are generated automatically starting from user expressed needs. The system comprises a server side engine capable of reasoning to find out which location categories have to be searched for and a mobile device to track user location and provide intelligent cues to the user. One of the main weaknesses of the system is the high energy toll that continuously identifying the user location with high precision has on the mobile device battery. In this paper, we describe a novel ad-hoc algorithm that leverages a hierarchical approach to adaptively decide which is the current sweet-spot sufficient for providing the needed precision in location as well as the lowest energy impact. Our experiments show a significant reduction in the energy consumption