RE: Clause 46 - Preamble
> I would think keeping an option to change the preamble size
> by a PHY may lead to confusion and PHY/RS/MAC un-interoperable
> implementations. It is not a restriction but an explicit specification
> that would keep all the PHYs and RS implementations STANDARD.
The length of the preamble has no interoperability implications.
This "option" has always been in our standard. The intent of my comment
#252 has been exactly that: not to eliminate it for 10Gb/s operation.
The way the MAC is defined, the receiver is supposed to wait for the
arrival of the SFD to recognize a valid MAC frame. If the SFD does not
arrive, the frame "never happened". Furthermore, we have always allowed
the preamble to shrink. Although we do not expect this to happen this
time, there is no good reason to disallow it.