Strategies for optimizing latency and resource utilization in multiple target UWB-based tracking

With the popularity of navigation applications and the integration of GPS in user devices, location-awareness is becoming an essential feature demanded by users. Nevertheless, location-awareness in indoor environments is still limited by the inability of GPS to operate indoors. With a centimeter-level ranging resolution, Ultra-Wideband (UWB) is one of the most promising technologies to provide indoor positioning, allowing the development of combined data transmission and location networks. Existing studies mainly focus on different distance estimation methods and position computation algorithms, but usually the implications of a real system such as transmission delay and resource constraints are not taken into account. Specifically, latency due to distance estimation and transmission has a negative impact on positioning accuracy, and limited availability of resources limits the amount of mobile nodes that can be tracked and the frequency of position updates. In this paper, the impact of an 802.15.4-based MAC layer is assessed, and different tracking system architectures, as well as different strategies for the acquisition and distribution of location information are proposed and evaluated in order to optimize the latency of position updates and the amount of resources needed.