The American Global Positioning System and its Russian cohort GLONASS have two fundamental flaws: They don’t work indoors, and they only really operate in two dimensions.
Now, these limitations are fair enough; we’re talking about an extremely weak signal that has traveled 20,200km (12,600mi), after all. Passing through concrete and other solid obstacles is hard enough for a strong, short-range cellular signal — you can’t seriously expect a 50-watt signal traveling 12,000 miles to do the same. Detecting a GPS signal on Earth is comparable to detecting the light from a 25-watt bulb from 10,000 miles.
The situation is a little more complex when it comes to detecting a change in altitude; GPS and GLONASS can measure altitude, but generally the data is inaccurate and too low-resolution (on the order of 10-25 meters) for everyday use. Even with these limitations, though, space-based satellite navigation systems have changed almost every aspect of society, from hardware hacking to farming to cartography to finding a girlfriend.
What if we had a navigation system that worked indoors, though? What if we had an Indoor Positioning System (IPS)? Believe it or not, we’re very nearly already there.
Google Maps for Android began introducing floor plans of shopping malls, airports, and other large commercial areas. Nokia, too, is working on an indoor positioning system, but using actual 3D models, rather than 2D floor plans. Just last week, Broadcom released a new chip (BCM4752) that supports indoor positioning systems, and which will soon find its way into smartphones.
Unlike GPS and GLONASS, there isn’t a standard way of building an indoor positioning system. Google’s approach tracks you via WiFi — it knows where the WiFi hotspots are in a given building, and through signal strength triangulation it can roughly work out where you are. Nokia’s solution is similar, but it uses Bluetooth instead of WiFi, making it higher resolution (but it would require the installation of lots of Bluetooth “beacons”). Other methods being mooted involve infrared, and even acoustic analysis. None of these approaches are accurate or reliable enough on their own, though — in spaces that are packed with different materials, and roving groups of attenuating meatbags, these signals are simply too noisy.
The Broadcom chip supports IPS through WiFi, Bluetooth, and even NFC. More importantly, though, the chip also ties in with other sensors, such as a phone’s gyroscope, magnetometer, accelerometer, and altimeter. Acting like a glorified pedometer, this Broadcom chip could almost track your movements without wireless network triangulation. It simply has to take note of your entry point (via GPS), and then count your steps (accelerometer), direction (gyroscope), and altitude (altimeter).
In short, indoor positioning systems are coming — first to built-up and heavily-touristed areas (in the next year or two), and then, as smartphone saturation reaches 100%, everywhere else.
Life with IPS
What does it mean to be able to track your movements, in real time, at any location in the world, inside, outside, and underground?
Before we begin, it’s important to point out that — just like GPS — IPS doesn’t necessarily betray your location to third parties. IPS can be entirely local to your smartphone (or other portable navigation device). IPS, like GPS, can establish a location fix completely passively. The whole doomsday scenario of Rockefellers and global megacorps tracking your every move is unlikely to come to fruition without plenty of warning (and ample time to stage a rebellion).
Starting out in the shallow end, IPS would enable a whole new range of “real life analytic’s” apps. If you love how that Nike+ GPS app tracks your running speed and distance, an IPS version would blow your mind. IPS could track exactly how many steps you take and how many stairs you climb — and calculate, quite precisely, how many calories you burnt in the process. IPS could keep a perfect record of how many minutes you spend in the gym (and on which machines). IPS could tell you how many hours you spend in bed, commuting, in the office, and on the toilet.
The true power of IPS, though, would come from linking your real life analytics to other streams of data, such as social graphs and payment systems. IPS could track where and when you are most likely to use Facebook or Twitter, and tell you which locations are conducive to happy (or sad) status updates. IPS could be used to create beautiful heatmaps of where you spend money; you could even play it back in real time and watch your avatar as it bounces around a Google Map, first to Starbucks, then to the train ticket machine, then to the office vending machine, and so on.
Then, imagine if shops and other commercial locations broadcast their current special offers (which could simply be an internet RSS feed that your phone periodically downloads). If IPS detects that you are near a store with a special offer, your phone could alert you. Likewise, your phone could tell you if you’re about to go into Starbucks, but a nearby coffee house is cheaper. Again, this could be done passively, without giving away your location (though I wouldn’t be surprised if some special offers are only available to people who opt into being tracked).
IPS could replace (usually criminally expensive) audio guides in museums — just hold your smartphone up to your ear. Edging towards Big Brother territory, IPS could give parents the ability to track their kids — it could even automatically initiate a phone call, if your kid happens to wander into a store that you don’t approve of (or an R-rated movie). IPS, it goes without saying, would massively simplify indoor augmented reality, too.
Perhaps most excitingly, IPS could herald the creation of real life social networks. By tying into Facebook, IPS could tell you, right this moment, if there’s someone nearby who also wants to play squash or watch an art house film. You could be walking down the street, and your phone could alert you that, just one block over, there’s someone who shares your passion for early DC comics, or some other esoteric topic. We touched on this in another post recently, but IPS could also tell you exactly how many men (or women) are at a given nightclub — or, less contentiously, the nearest venue with a high concentration of <insert topic> geeks.
These real life social networks would require you to share a lot of data with those around you, but think about it: This could finally be an application of mobile computing that turns your attention outwards to those around you, instead of eternally gazing downwards at your smartphone screen.