Is this meant for receiver-only, or bidirectional transfer? (he says bidirectional in the ted talk, but only talks about phones using their cameras to receive).
Seems a little like a technology in search of a problem.
You avoid interference in the same way you avoid it for radio wave communication: multiplexing. It could be time-based (time slots for each sender), frequency-based (different colors) or code-based (look up CDMA).
Plus, you already have 'spatial multiplexing' because light doesn't pass through walls as opposed to RF.
You could always use radio waves for the upload band. That way, it will still increase both download and upload speeds (uploads will can have a wider band now that they don't compete with downloads for the same airspace), it just won't increase upload speeds as much.
This is the right idea for sure. Data usage is almost always asymmetric - people download much more than they upload. So let's widen the download channel using visible light and still use the sufficiently large RF channel for the up stream.
Is this meant for receiver-only, or bidirectional transfer? (he says bidirectional in the ted talk, but only talks about phones using their cameras to receive).
Seems a little like a technology in search of a problem.