[STDS-802-16] Comment 019
Title: Message
I've had a thought
in the back of my mind that we must meet is some requirement on the likelihood
of a MAC delivering an undetected error to the MSAP.
I went searching,
and its in IEEE 802-2001.
"
c) The probability
that an MSDU delivered at an MSAP contains an undetected error, due to
operation
of the MAC service provider, shall be less than 5 × 10-14 per octet
of MSDU length.
NOTE—For example,
(a) the worst-case probability of losing a maximum-length IEEE 802.3 frame (1518
octets) through physical-layer damage is to be less than 1.21 × 10-4, or
approximately 1 in 8250; (c) the worst-case probability that a similar frame,
which contains an MSDU of 1500 octets, is delivered with an undetected error is
to be less than 7.5 × 10-11, or approximately 1 in 13 300 000
000.
"
Unless we can
produce some sort of mathematical proof that we meet the following requirement,
then we should adopt comment 019. Otherwise the EC should rightly reject the
standard on the grounds that it doesn't meet the baseline 802
requirements.
I don't know about
others, but my experience with wireless systems tells me that a deep fading
killing off 8 continuous fragments is way more likely that 1 in 5E14 (per octet
as above).
So the objection
that it is an 'unlikely' event, while valid in principle, fails if 'unlikely' is
more likely that 1 in 5E14 and I suspect this is the case, although as usual,
the devil may be in the details. Either way, I strongly suggest we accept
comment 019 to be on the safe side.
DJ