Geoff,
If
I follow your point correctly, we should be then speaking of “at most
two pairs of PHYs (one PHY for CNU and one PHY for CLT)” – is that what
you’re after ?
Marek
Chano-
It's exactly the difference betwen what you would consider "one PHY"
and what I would consider to be "one PHY" that is the reason for making
the change. From my point of view, we aren't done yet. EPON/EPoC are
not symmetrical systems and therefore require two PHYs to build any one
system (unlike most of the rest of Ethernet).
So we must fix the wording to handle that.
THEN
We must massage the wording further so that it expresses what we REALLY
mean with respect to duplicity, speeds and whether or not we intend to
accommodate:
- Multiple parallel systems on a single cable plant (presumably
via FDM)
- Multiple upstream systems (via FDM) on a single downstream system.
Many things have been bandied about.
We need to come to crisp decisions about many of them
and then
Write objectives that concisely reflect what we have decided upon
but can not be misinterpreted either w/i EPoC or by 802.3.
This is always harder than it would seem going in.
I know what I mean, and I am sure that you know what you mean,
but that isn't good enough in the standards business.
Best regards,
Geoff Thompson
On 85//12 11:05 AM, Gomez Chano (LQNA MED) wrote:
Hi,
I did not attend the last conference calls, but
I have been following progress through the reflector. I have a question
about the wording in Objective 1, which is now
"Specify at least one PHY to support
subscriber access […]"
while previous proposal was:
"Specify a PHY to support subscriber
access networks […] "
Can somebody clarify the rationale for the new
wording, which seems to "almost" encourage the group to develop more
than one PHY? We have all seen other IEEE groups that quickly yielded
to the temptation of adopting multiple PHYs as soon as they realized
that having the group agree on a single PHY was hard work. I would hate
to see the same thing happening in EPoC, as this would cause market
fragmentation and slow down adoption.
The objective should be "one PHY". Only if the
group finds at a later stage a very good reason to develop more than
one PHY then that option should be considered.
Just to be clear, for me it would be OK if the
PHY for downstream and upstream channels have different parameters. As
long as vendors do not have to face the decision of choosing between
multiple and equally valid PHY options when implementing their
products, that would still qualify as "one PHY" for me.
On May 8, 2012, at 9:38 AM, Noll, Kevin wrote:
<epoc_objectives_for_may_2012.pdf>
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