CEET: Cooperative energy efficient tracking system using smartphones

The technological advances in smartphones have brought promising potentials to tracking systems. GPS and WLAN are widely used technologies in recent smartphones for positioning and communication, respectively. However, both GPS and WLAN have serious energy consumption problem. For large scale tracking systems, where tracked people are supposed to move in groups, the continuous usage of the individual smartphones GPS and WiFi is not an energy efficient solution. In this work, we propose a cooperative approach that exploits the coexistence of of multiple communication interfaces (WiFi and Bluetooth) in recent smartphones where nearby smartphones are cooperatively grouped to form a cluster. A cluster is a network of one dynamically selected cluster head and regular members that communicate locally via Bluetooth. The cluster head is responsible of positioning and sharing positioning information with the rest of cluster members. It, also, acts as a gateway between its regular members and the server. We present a clustering approach according to the available energy and the energy cost. Our approach doesnt require any modifications in the recent smartphones equipment. We have formulated the clustering construction problem as a mixed integer program using GAMS. The proposed clustering approach has been evaluated via extensive simulation experiments and the obtained results have been compared with the optimal solution which show very close performance.