RE: Equalization
HI Ed
> From: "Edward Chang" <edward.chang@xxxxxxxxxxxxxxxx>
> To: "ghiasi" <Ali.Ghiasi@xxxxxxxxxxx>, <stds-802-3-hssg@xxxxxxxx>,
<wthirion@xxxxxxxxxxxx>, <SwansonSE@xxxxxxxxxxx>
> Subject: RE: Equalization
> Date: Tue, 25 Jul 2000 15:07:43 -0400
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>
> Ghiasi:
>
> The 3-PMD you chose was the set rejected by 802.3 in La Jolla by only
> getting 57% yes vote, and the parallel optics of 4-fibers failed by only
> getting 38% yes vote
Not bad for being added to the PMD vote just before the vote was taken.
.... 75% yes vote is required.
>
> If you propose the same thing again, we will be stuck there with only
> 1550/1310 serial PMDs forever.
>
> There are other choices which have much higher approval rate than those you
> have chosen.
Can you elaborate what these other PMD choices are?
>
> Please come up with more creative solutions, acceptable by 75% voters to
> help all HSSG including Sun to resolve the PMD issue.
the creative way to move forward is to define two low cost variant for
data center applications with 100 m reach, then add the 1300 nm CWDM
to support 300m. The data center market is very significant and will
keep the short-wave people happy help getting more vote.
Thanks,
Ali Ghiasi
Sun Microsystems
>
> Regards,
>
> Edward S. Chang
> NetWorth Technologies, Inc.
> EChang@xxxxxxxxxxxxxxxx
> Tel: (610)292-2870
> Fax: (610)292-2872
>
>
>
>
> -----Original Message-----
> From: owner-stds-802-3-hssg@xxxxxxxx
> [mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of ghiasi
> Sent: Tuesday, July 25, 2000 12:30 PM
> To: stds-802-3-hssg@xxxxxxxx; wthirion@xxxxxxxxxxxx;
> SwansonSE@xxxxxxxxxxx
> Cc: Ali.Ghiasi@xxxxxxxxxxx
> Subject: RE: Equalization
>
>
>
> Hi Steve
>
> Steve Swanson wrote:
> >
> >
> > Walt,
> >
> > The right ones to include are:
> > 850 Serial
> > 850 CWDM
> > 1310 Serial
> > 1310 CWDM
> > 1550 Serial
>
> I am not sure Steve what criteria you are using to determine the right ones!
> Specially when you have left the lowest cost parallel optics out.
>
> I certainly can see if you want to support 300m at least on existing
> fiber for the backbone the choices would be:
>
> 1300CWDM
> 1310 Serial
> 1550 Serial
>
> In addition the standard should consider lower cost variants to support
> data center with maximum distance of 100m using standard fibers. A user
> can always implement high bandwidth fiber if he wishes. Below you will
> find suitable link choices for data centers:
>
> Serial 850 - difficult to reach 100m on standard fiber
> 850 CWDM - Too early to judge
> Parallel Optics - Lowest xcvr cost but long cables are expensive
>
> Thanks,
>
> Ali Ghiasi
> Sun Microsystems
>
>
> >
> > The standard could move forward very efficiently - no debate over
> objectives,
> no debate over band-aids, no debate over how many, etc. My recommendation to
> the
> committee is to support these PMDs in the standard. Individual companies and
> customers can then decide whether to support all of them, none of them, or
> some
> number in between. The standard sets expectations in the marketplace and
> encumbers noone. All of these PMDs have what I call "a critical level of
> support" on both sides - customers AND vendors. In this case, it is better
> at
> this point in time to include rather than exclude.
> >
> > Best regards,
> >
> > Steve
> >
> > > ----------
> > > From: Walter Thirion[SMTP:wthirion@xxxxxxxxxxxx]
> > > Sent: Saturday, July 22, 2000 12:35 AM
> > > To: stds-802-3-hssg@xxxxxxxx
> > > Subject: RE: Equalization
> > >
> > >
> > > I would really like for us to get away from the 3 PMD vs 5 PMD
> discussion
> > > and determine which PMDs are the right ones to include in the standard,
> > > whether it's 2, 3, 4, 5 or (hopefully not) "more than 5".
> > >
> > > Walt
> > >
> > >
> > > -----Original Message-----
> > > From: NetWorthTK@xxxxxxx [mailto:NetWorthTK@xxxxxxx]
> > > Sent: Friday, July 21, 2000 10:00 PM
> > > To: vipul.bhatt@xxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
> > > Subject: Re: Equalization
> > >
> > >
> > >
> > > Vipul:
> > >
> > > It is a good summary. They are all true.
> > >
> > > However, we know all these facts for quite a while, and they are not new
> to
> > > us.
> > > They are not simple problems to be resolved overnight. It will take
> > > systematic approach and time to solve. I do not expect a miracle in
> > > September to come out all answers -- rush, rush does not produce
> miracle.
> > >
> > > Be practical, solid and smart to approach any problem.
> > >
> > > What I do not understand is why some people have to limit to 3 PMD only.
> > > There is no justified reason at all to insist 3-PMDs; as a result, the
> 3-PMD
> > >
> > > is forcing us to produce a miracle. GIVE US A BREAK !! A successful
> > > project
> > > is always completed by practical approaches, but not by a miracle.
> > >
> > > We can vote 5 PMDs in, then we can concentrate next whole year to
> resolve
> > > all
> > > those issues -- this is practical, and doable.
> > >
> > >
> > > Regards,
> > >
> > > Ed Chang
> > > NetWorth Technologies, Inc
> > >
> > >
> > > Dear colleagues,
> > >
> > > Okay, so where are we? Let me review what I think I have heard so
> > > far.
> > >
> > > Yes, the idea of 10G Serial on installed MMF is interesting, but
> > > there are a couple of holes in the proposal, including bad timing.
> > > Here is the summary, followed by holes.
> > >
> > > 850 nm Serial solution:
> > > -----------------------
> > > - Will benefit from TIA FO 2.2 Encircled Flux and Restricted Mode
> > > Launch work.
> > > - Offset Launch jumper not required.
> > > - Start with 385 MHz-Km bandwidth assumption on installed MMF.
> > > - Add 6 dB equalization to support 100 meters operation, additional
> > > 9.54 dB to support 300 meters. Equalization has to be adaptive, in
> > > the sense that impulse response will be different for each link. It
> > > must overcome severe DMD in some cases. With Encircled Flux launch,
> > > for a given link, the impulse response will not vary significantly
> > > with time, so it can be assumed as time-invariant or very slowly
> > > varying in time.
> > > - Potentially, end up with a total of 3 PMDs that meet all 5
> > > Objectives.
> > >
> > > 1310 nm Serial solution:
> > > -----------------------
> > > - Will benefit from EMB work done with 802.3z.
> > > - Offset Launch jumper is required.
> > > - Start with 500 MHz-Km bandwidth assumption on installed MMF.
> > > - Add 4 dB equalization to support 100 meters operation, additional
> > > 9.54 dB to support 300 meters. Equalization has to be adaptive in
> > > the sense that impulse response will be different for each link. It
> > > must overcome severe DMD in some cases. With offset launch, for a
> > > given link, the impulse response will not vary significantly with
> > > time, so it can be assumed as time-invariant or very slowly varying>
> > > in time.
> > > - Potentially, end up with a total of 2 PMDs that meet all 5
> > > Objectives.
> > >
> > > List of holes:
> > > -------------
> > >
> > > 1. It hasn't been established that Encircled Flux over a randomly
> > > selected fiber from installed base will ensure 385 MHz-Km bandwidth
> > > (850 nm) with a high degree of statistical confidence. Gair's
> > > suggestion of tagging an RML-compliance condition is one possible
> > > solution. We need to know if that suggestion will be acceptable to
> > > 802.3ae end users and system integrators.
> > >
> > > 2. It hasn't been established that 10G equalization is feasible. By
> > > feasible, I mean something like - a demonstrable solution before the
> > > Working Group Ballot, capable of overcoming severe DMD, consuming
> > > less than 3 watts, with a cost comparable to that of other
> > > components, backed by technical presentations in September that
> > > instill a high degree of confidence in the 802.3ae members.
> > >
> > > 3. Perhaps it is too late. There is a high likelihood that at the
> > > September Interim, motions to adopt other PMDs that meet Objectives
> > > 1 and 2 will pass.
> > >
> > > Hole 1 can be bypassed by adopting a 1310 nm Serial solution. Hole 2
> > > can't be plugged until we have heard presentations from DSP experts
> > > in September. Hole 3 is the most regrettable. I don't know how to
> > > plug it. Jonathan, Walt, do you have any comments or suggestions?
> > >
> > > Thanks,
> > > Vipul >>
> > >
>