Locate an iPhone reliably indoors?

Question

I\'m writing an app for a museum tour. I\'d like my app to know where the user is in the building, if the user is standing in a particular room, in front of a particular work, e

Answer 1

I suggest Bluetooth. I did some preliminary work on a similar problem, played around with some code for watching which bluetooth devices were visible to the phone while walking between rooms of my house.

You don't have to pinpoint precisely where the bluetooth devices actually are; if you can see device A and B but not C then you're in this area, if you can see all three then you're in this area, etc. With a little bit of "watching" the signal changes you can pinpoint their location more closely, e.g. I can see A but not B or C and 10 seconds later I can see A and B then odds are good that I'm towards the A-only side of the A+B area; when 10 seconds later I can see B+C but no longer A then odds are good I'm closer to the area where you cross from A+B to B+C, etc.

Though I didn't test it exhaustively, my results were sufficiently positive to advise my client that some more robust, real-worldish testing was worthwhile, that this would likely work just fine. There might be issues with signal bounce that might require some shielding or that kind of thing, but it does seem feasible.