[RadioAstronomer]

Sorry for the multiple posts.

Note: before the radio frequency (RF) link is modulated with this digital bit stream, the commutation has already occurred. So all the RF link "sees" (and is modulated with) is a stream of continuous ones and zeros.

[VadeRetro]

Note: before the radio frequency (RF) link is modulated with this digital bit stream, the commutation has already occurred. So all the RF link "sees" (and is modulated with) is a stream of continuous ones and zeros.

Didn't see this before I posted my last. Clearly, there's some nesting of protocols.