[jimiasty]

You are definitely right and there are technology limitation just to stick 3 sensors and triangulate the signal.

We believe the whole indoor-navigation idea is wrong. There is no need to map every inch of the physical world and get X,Y coordinates.

It's all about the context and placing tiny beacons in the doors, next to check-out, next to GoPro camera in the Best Buy.

They you detect the proximity and the context and trigger an action.

Of course if you would like to navigate down to inches and get X,Y you could just narrow the range of beacons and stick as many as possible - you will be very accurate and the multipath propagation is not an issue.