A software platform for measuring distances through round trip time in IEEE 802.11

Indoor positioning has focused the interest of researchers for years. Although there are several techniques proposed, they are difficult to reproduce and consequently to contrast and improve. This paper presents a modular location platform, which enhances the SoftMAC implementation in Linux with positioning capabilities. This platform can be deployed in any device running Linux kernel 2.6 or higher. The core of the platform is its software-based measuring system. This measuring system supports the 2-way TOA technique, but any time-based multilateration technique (e.g. passive TDOA) can be incorporated with minimum changes. Real data have been gathered to assess the performance of the measuring system. The RTTs estimated grow with the distance, which demonstrates the feasibility of the system.