Wi-Fi assistance to SUPL-based Assisted-GPS simulators for indoor positioning

The Global Positioning System (GPS) has been the most popular choice for positioning in open-sky environments, but its difficulty in dealing with signal blockage from buildings, trees and the like has limited its operation in urban environments, underground and especially indoors. Recent advancements in location technology have led to the development of Assisted GPS (A-GPS) technology that can operate satisfactorily in many challenging environments using aiding information. As technology testing is a major development component, this paper describes a low cost approach to augment conventional GPS simulators with A-GPS testing support. The A-GPS support is provided using the concept of Wi-Fi positioning technology and IP address location. The communication between the simulator and the receiver is in accordance with the Secure User Plane Location (SUPL) protocol. Currently only high-end simulators support testing of A-GPS receivers as it involves assistance generation and delivery to the receivers in addition to GPS signal generation.