Wikipedia: > On–off keying (OOK) denotes the simplest form of amplitude-shift keying (ASK) modulation that represents digital data as the presence or absence o

Wikipedia: > On–off keying (OOK) denotes the simplest form of amplitude-shift keying (ASK) modulation that represents digital data as the presence or absence of a carrier wave. https://en.m.wikipedia.org/wiki/On%E2%80%93off_keying https://en.m.wikipedia.org/wiki/On%E2%80%93off_keying Idk how you define modulation. Note that on/off isn't a worldwide switch, but only one for tiny units with respect to the whole energy grid