I think the paper is just a research project. Considering that you need a wifi on, it would not work very well on the go. But I am pretty sure there are device

I think the paper is just a research project. Considering that you need a wifi on, it would not work very well on the go. But I am pretty sure there are devices on the market just not for the use case presented here. There are a few papers that look at the applications of what you can do with radio waves as a way to detect movements.