7.6. Real-time Locating System

Real-time locating systems (RTLS) are used to automatically identify and track the location of objects or people in real time, usually within a building or other contained area. Wireless RTLS tags are attached to objects or worn by people, and in most RTLS, fixed reference points receive wireless signals from tags to determine their location. Examples of real-time locating systems include tracking automobiles through an assembly line, locating pallets of merchandise in a warehouse, or finding medical equipment in a hospital [69].

Schantz investigated an application of real-time locating system that operate at AM broadcast band (530-1710 kHz). Performance of QT-400 system of Q-Track company was discussed [54].

Richards et al. investigated omnidirectional transmitting loopstick antennas with ferrite core that operates low frequency band for RTLS. Simulations run under various parameters which were type of ferrite, form factor, coil covering factor, number of turns, wire gauge, wire spacing, and gap between coil and ferrite. Comparative results were not given in details. They noted that resistive losses in the coil of the loopstick antenna dominate over in the ferrite core like 5% was core and 95% was solenoid [48].

Near field channel model document is to provide IEEE P802.15 for evaluating near field location aware wireless systems [51].

Patents

Year	Name	Patent Number
2004	System and method for near-field electromagnetic ranging	US20040032363A1
2005	System and method for near-field electromagnetic ranging	US6963301
2014	Method of near-field electromagnetic ranging and location	US20140062792A1