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GPS is not Good Enough--I Need WiFi (or Something Else) for Indoor Positioning

By Eng-Hua Yap On June 1, 2010
Wireless
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“OK! We’ve got you checked in @ Restaurant XYZ. Your phone thinks you’re a little far from Restaurant XYZ, so no points or badges for this checkin. Sorry!”

But, I’m ALREADY in the restaurant, eating my edamame and drinking my mojito!

If you are familiar with the situation above, you’re probably like me—one of those people with a smartphone who’ve jumped onto the bandwagon of using foursquare, the latest buzz in mobile social applications. If you’re not familiar with foursquare, it’s a location-based game that allows users to earn points by checking into venues and to earn a “mayorship” title if you are the most frequent patron of a venue (on foursquare, that is). The message above was (understandably) put in place by foursquare in their attempt to crack down on cheaters by preventing invalid check-ins outside the immediate vicinity of the venue.

Unfortunately, foursquare relies on a phone’s positioning capability to produce an accurate location, which may well not be reliable if you’re already inside a restaurant. Most smartphones rely on GPS (or A-GPS) to determine their location, but GPS is just not good enough when you’re indoors or in the majority of urban environments. To address the limitations of GPS in these situations, some smartphones use ‘hybrid’ positioning technologies that combine GPS with WiFi or other network-based positioning technologies (such as AFLT or Cell-ID). Unfortunately, I have one of those smartphones that only use a single technology. The limitations of my phone certainly became clear to me when one night, as I was reading yet another dreaded message from Foursquare saying “You are too far…”, my friend sitting across the table was able to check-in and steal the mayorship away from me!

At the moment, WiFi positioning technology is quickly gaining popularity as the preferred approach to augmenting GPS technology. As a technologist, with my mobile fused to my hip 24/7, I expect to get accurate and fast position fixes from my mobile anytime and anywhere – I don’t want to have to care if I’m indoors or in dense urban areas. Right now, the most likely way for that to happen is for me to choose a device with Wi-Fi plus GPS, because WiFi works best in areas where GPS doesn’t and vice versa. One of the most established players in WiFi positioning is Skyhook, but more players are entering the market as the technology becomes more popular. Another interesting non-GPS positioning network-based technology that caught my eye recently is from Rosum which uses broadcast GPS and TV signals for positioning. I’m very impressed with their initial trial results and curious to see how they can develop and commercialize this technology.

Whatever the outcome, I can’t wait for any of these technologies to perform well enough to produce fast and accurate position information anywhere, at any time. How about you? Do you have interesting (or horror) stories to share as a result of the inaccuracy of GPS in your phone?

 

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