Re: [802.3_EPOC] Latest objectives proposal

[Marek Hajduczenia <marek.hajduczenia@xxxxxx>]

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

 

From: Geoff Thompson [mailto:thompson@xxxxxxxx]
Sent: 08 May 2012 23:21
To: STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_EPOC] Latest objectives proposal

 

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.

 

Best Regards

 

Chano Gómez

Lantiq North America

 

On May 8, 2012, at 9:38 AM, Noll, Kevin wrote:

<epoc_objectives_for_may_2012.pdf>

 

 

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