I’ve seen and heard a lot of talk about Apple’s new M7 motion co-processor and iBeacon feature after the iPhone announcement earlier this week, most of it pointing out that these features lay some of the foundation for indoor mapping. But I haven’t seen anything explaining exactly why they have this significance. It has been several years since I worked in this space, but here is some speculation of my own.
Your Are Here
First, some background. GPS doesn’t work indoors. Even if it did, it wouldn’t be sufficiently accurate for useful indoor mapping. Cellular tower triangulation does work indoors of course, but is much less accurate than GPS.
Another option is to triangulate position using data about Wi-Fi hotsposts in the vicinity. The iPhone has had this capability for some time, initially using Skyhook’s data, but switching to Apple’s own data in 2010. Apple also recently acquired WifiSLAM, which had “developed ways for mobile apps to detect a phone user’s location in a building using Wi-Fi signals”.
Then there is iBeacon, Apple’s support for Bluetooth Low Energy (BLE). This enables BLE devices in the vicinity of an iPhone to wake them up and give them some information. That information could be location, so you could imagine these little BLE devices scattered around the mall telling nearby iPhones “Hey! You are here.”
Or Are You?
These are important steps forward for indoor mapping, but probably not the whole solution. Even in a future where there is a lot of Wi-Fi data on hand and iBeacons installed all over the place, the system would be largely outside Apple’s control and probably unreliable.
Add to the challenge that we’ll be hard to please, with high expectations for accuracy and reliability for indoor location. We think at a higher resolution indoors — important differences are measured not in city blocks, but in yards or even feet. Small mistakes and inaccuracies will be frustrating, even if they only happen once in a while.
Enter motion sensors and the M7.
Filling the Gaps
If you have one good position measurement you can use motion sensors (accelerometer, gyro and compass) to measure your subsequent movements and keep track of your position. This can’t be the whole solution for two reasons:
- A lot rests on the accuracy of the initial position measurement. The last GPS measurement before losing the satellite is probably not good enough.
- Even if you can get a good initial measurement, every subsequent adjustment based on motion will have a tiny estimation error. These errors will accumulate over time and at some point the estimated position will be too inaccurate to be useful.
But it is conceivable that iBeacon- and Wi-Fi-based positioning will eliminate these problems for many indoor areas.
There is one remaining, huge, deal-breaking challenge for the approach of using motion-based positioning to fill in the gaps: It requires the motion hardware to be continuously measuring and processing your movements. Pre-5S, this would have drained the battery in short order. The M7 co-processor that Apple announced on Tuesday solves this problem.
Leading the Way
None of these technologies alone will make reliable indoor location possible, but together they might. It will probably take a while before we see indoor mapping in a keynote. There is lots of infrastructure involved that isn’t under Apple’s control (deploying all those beacons, for example). And we have to wait until the majority of iPhones in market have M7 and iBeacon support.
Also, Apple needs its competitors to support BLE with iBeacon-like features, because malls and airports and sports stadiums probably won’t be installing thousands of beacons for iPhones alone. So the ability to listen to beacons isn’t an opportunity to differentiate the iPhone.
Where they can differentiate, though, is in the gaps.
I think on Tuesday Apple revealed a key part of their strategy. Most of the subsequent talk about the M7 is focused on fitness oriented scenarios, and doing clever things when your phone detects certain activities (my car stopped, I sat down, etc.). Those might lead to nice apps and snazzy features, but I’m betting that Apple is interested in something much more fundamental: leading in the next frontier for mapping and location — indoors.
Posted: September 14th, 2013 under Mobile.