Current technologies and location based services

This paper examines the benefits and drawbacks of these services, reviewing differences in infrastructure, power requirements, sensing devices, and other factors. Technologies covered include Radio Frequency Identification, GSM, GPS, A-GPS, Smart Antennas, Distributed Antenna Systems, Localization by Cell-ID, Localization by Prediction (Dead Reckoning method), Angle of Arrival (AOA), Localization by Finger Printing, Localization by Time of Arrival (TOA), Localization by Observed Time Difference of Arrival (TDOA), and Hybrid Localization-based AOA-TOA.