Even with new developments in receiver technology and assisted-GPS, achieving strong positioning performance indoors remains a major challenge. Complimentary technologies such as inertial sensors and Wi-Fi are being explored to increase performance. At the same time, many developments are being carried out in order to tackle the indoor reality of low power levels and high signal disruption.
Many observers believe that the ‘indoor problem’ will be progressed, maybe even fixed, over the next few years. The candidate technologies are already in place and significant progress is already being made. This revolution has already started with assisted-GPS, where the almanac and ephemeris (precise satellite location) data is uploaded to reduce the search window, resulting in quicker Time To First Fix (TTFF) and the ability to acquire lower power signals, including limited ability to navigate indoors. At the user level, we are seeing new applications, falling prices and better performance. GNSS is appearing everywhere.
Wi-Fi positioning is, however, rapidly gaining acceptance as a complement and supplement to GNSS positioning for indoor environments. Wi-Fi hotspots are prevalent in the very areas where GNSS starts to struggle and many ‘smart’ devices are already equipped with Wi-Fi technology that can support positioning applications. Numerous service providers are offering the essential databases that enable the overall positioning capability.
Spirent systems are available with a wide range of features designed to enable development, integration, verification and certification testing. Test systems are available that simulate GPS, Galileo, GLONASS and SBAS signals in a controlled and repeatable way including actual historical GPS system problems. An Interactive remote control interface enables hardware in the loop testing. For indoor positioning, Spirent’s GNSS systems enable testing in low power, high multipath environments.
A unique test system is also available from Spirent that provides a controlled and repeatable environment of observable Wi-Fi hotspots to support Wi-Fi positioning test. This patented product may be integrated with Spirent’s GNSS solutions to provide a hybrid stimulation package.
