Positioning accuracy in Ultra Wide Band Low Data Rate networks of uncoordinated terminals

The 802.15.4a standard can open the way to the deployment of innovative position-based applications for low data rate (LDR) networks, thanks to the accurate ranging information provided by the selected ultra wide band (UWB) physical layer (PHY). In order to take full advantage of the UWB PHY capabilities, however, the standard, now under definition within the IEEE, will require innovative, UWB specific solutions for medium access. In our previous work we proposed the (UWB) ² MAC protocol for UWB LDR systems, based on a multichannel Aloha approach, and we evaluated its performance in presence of multi user interference (MUI) and multipath-affected channels. In this work we determine the accuracy of position information achievable by a distributed positioning protocol in an UWB LDR network adopting the 802.15.4a PHY and the (UWB)² MAC. The analysis takes into account number of nodes, MUI, ranging errors and channel characteristics. Simulation results show that the (UWB)² MAC protocol can support distributed positioning with high accuracy, even in presence of NLOS propagation conditions and high number of nodes