Sorry I mismanaged my tabs, the second citation is just above the conclusion in the referenced paper (https://dl.acm.org/citation.cfm?id=2984565 https://dl.acm.

Sorry I mismanaged my tabs, the second citation is just above the conclusion in the referenced paper (https://dl.acm.org/citation.cfm?id=2984565 https://dl.acm.org/citation.cfm?id=2984565 ) "Interacting with Soli: Exploring Fine-Grained Dynamic Gesture Recognition in the Radio-Frequency Spectrum" > Suggesting one can go 10x as far (10000x power alone) and through walls is... creative. I was going for conservative. Typically thinking about open-space work environment. The device doesn't need line of sight like a camera would, it can be in your coworker pocket and listening to you. They are well founded and doing their own radio chips, I give them the credit they deserve and assume they can replicate a somewhat similar technology (6Ghz radar). It is better to use a logarithmic scale. The 10000x power (40dB gain) doesn't mean you will need to emit 10000x more power, in practice you will amplify the signal, by focusing the beam via antenna design, and amplifying which theoretically you can do relatively easily as long as you are above the Cosmic Microwave Background Radiation noise. Then you need to do some trickery to trade bandwidth for signal strength (which they do : FMCW). Then you still can integrate over time. A radar typically scan its whole surrounding, but if instead you chose to focus it at one place you can gather for longer.