MIT Technology Review: WifiSLAM

Whilst doing further research for my app idea, I came across this review article of a piece of technology which would be perfect for my app idea 'Find Your Way'. I spoke about possibly using Wifi to enable my app to work indoors, however I wasn't sure how this technology would work and I couldn't use NFC as Apple devices do not support this technology, which would limit my app to Android and other devices. This article explains how Wifi would work indoors to help people navigate around just using their phones.

GPS in mobile phones led to a rapid increase in location based app and services. However when you enter a building GPS often stops working, after all it is designed to help people navigate outside not indoors. What if there were apps/services that helped you navigate indoors? Using Wifi we could allow people to navigate inside various buildings, this technology has been developed and tested. Students from Stanford university founded this technology, which enables a phone to work out its position by using Wifi networks and information taken from the devices compass. However this technology is only accurate to within a 'couple of steps' says Anand Atreya, the cofounder of WiFiSLAM. He explains that this technology could be used in bigger and more complex building such as supermarkets, airports and even hospitals.
It explains the way WiFiSLAM and the device works together to find the exact location when you are stationary and when you are moving. It analyses the signal strength and unique IDs of all the Wifi networks around it, and the estimate location can be improved if the devices moves slightly allowing WiFiSLAM to gather specific information on that network and work out where you are.

http://www.technologyreview.com/news/424213/using­wi­fi­for­navigating­the­great­indoors/