There is an app where you have to give your whereabouts for one hour every day. If you don't fill it in or are unavailable at the location for that hour, you get a strike. Three strikes in a set period and you will get a ban as if you had been doping.

One problem with the system is that it relies on countries being strict with their athletes, which they aren't incentivized to do. Also, it's easy to "be available" but not get tested by going somewhere remote for a height camp for a few weeks.