Towards Using Location Poly-Hierarchies for Energy-Efficient Continuous Location Determination

Location awareness is a key feature of mobile information systems. Typically, location is determined by interpreting a set of measured positions. Various approaches for position determination do exist. They vary greatly in their precision, applicability, and energy requirements. As mobile devices are battery-driven, energy is one of the most limiting factors for the system’s uptime. Locations have a hierarchical nature and location-based applications differ in their required precision. In this paper, we present three approaches that utilise location poly-hierarchies in order to reduce the energy demand of continuous location determination: (1) We analyse the dependencies among the different hierarchy levels, (2) we incorporate an adaptive delay between measurements based on the hierarchy level and the calculated minimal required time to change, and (3) we select appropriate positioning techniques for each hierarchy level. We implemented and evaluated our approaches.