Localization services in hybrid self-organizing networks

In this paper we present a localization technique for tracking and positioning services in self-organizing hybrid networks, where both indoor and outdoor scenarios coexist. In the proposed framework, outdoor anchor nodes act as reference nodes for estimating the position of mobile nodes, which are moving in a neighboring indoor region. The mobile nodes share some location information for estimating their own position by using flooding communication scheme. Communications between mobile nodes are allowed by IEEE 802.16e technology. The outdoor reference nodes are equipped with Global Positioning Service network interface card. The cooperation among mobile and reference nodes, and the self-organizing network behavior guarantee fast positioning estimate. The accuracy of localization measurement - in terms of position and speed uncertainty - is assessed through the Dilution of Precision factor. Moreover, to minimize position and speed estimation errors of each node, an Extended Kalman Filtering technique is adopted. Simulation results demonstrate the effectiveness of the proposed approach.