RealTrac Technology Overview

This paper presents the overview of the RealTracTMtechnology developed by the RTL-Service ltd. It is based on the nanoLOC (IEEE 802.15.4a) radio standard. The RealTracTMtechnology features the local positioning system including the possibility of data transfer and voice communication. Radio access is provided by gateway units connected by wired network to a system server. Repeater units are used to increase the radio coverage area. Both gateway and repeater units serve as access points in a system. Channels for voice communication are supported by the Asterisk PBX software installed at the system server. Mobile handheld units periodically enter into active state and initiate the time-of-flight (ToF) ranging. Access points measure received signal strength (RSS) of the incoming radio signal. ToF and RSS data is processed by the server using a particle filter within localization algorithms. The following information is taken into consideration: ToF, RSS, structure of the building, air pressure value and inertial measurement unit data. The developed protocols for the communication in the system are discussed as well.