RE: MMF PMD Selection
Dan,
The worst case 62.5-micron fiber is 160-MHz-km at 850-nm, but 500-MHz-km at
1310nm. This is why the 1300-nm WWDM PMD will support link distances up to
300m, while the 850-nm WWDM scheme will only support out to 100m.
-Brian Lemoff
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Brian E. Lemoff, Ph.D.
Project Manager
LAN/MAN Optical Technologies
Agilent Laboratories
3500 Deer Creek Rd., MS 26M-9
Palo Alto, CA 94304-1392
phone: (650) 485-8957
FAX: (650) 485-3626
email: brian_lemoff@xxxxxxxxxxx
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> -----Original Message-----
> From: daniel.draper@xxxxxxxxxxxx [mailto:daniel.draper@xxxxxxxxxxxx]
> Sent: Wednesday, July 19, 2000 1:19 PM
> To: David Martin
> Cc: stds-802-3-hssg
> Subject: Re: MMF PMD Selection
>
>
>
>
> Dear All,
>
> I thought I heard a comment during the PMD discussions last
> week that a
> large percentage of installed fiber was 62.5um 160 MHZ*km.
> While the 850nm
> CWDM and 1310nm WWDM PMDs presented support this fiber to
> 100m, it is not
> clear from any of the PMD presentations that they will support this
> installed base to 300m. Is this correct? I may have missed
> this, but what
> exactly is the modal bandwidth assumption when discussing "installed"
> fiber?
>
> Best Regards,
>
> Dan Draper
> ___________________________________
> Dan Draper
> Microcosm Communications
> A Division of Conexant Systems, Inc.
> 3000 NW Stucki Place Suite 220
> Hillsboro, OR 97124
> Phone: (503) 466-3002
> Fax: (503) 466-3050
> E-mail: daniel.draper@xxxxxxxxxxxx
>
>
>
>
>
> "David Martin"
>
> <dwmartin@nortelnetw To:
> stds-802-3-hssg <stds-802-3-hssg@xxxxxxxx>
> orks.com> cc:
>
> Sent by: Subject:
> MMF PMD Selection
> owner-stds-802-3-hss
>
> g@xxxxxxxx
>
>
>
>
>
> 07/19/00 10:41 AM
>
>
>
>
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>
>
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>
>
> All,
>
>
> In the interest of making progress on the MMF PMD selection, and in
> response to Bill's request for system vendor input, I'll
> paint a bright
> red target on myself. Here goes.
>
>
> Consider the following four distinct applications:
> 1. Dark fiber/SMF runs up to 40km & WAN interconnect (metro)
> 2. Dark fiber/SMF runs up to 10km & WAN interconnect (campus
> backbone)
> 3. MMF horizontal/vertical runs up to 100/300m (in-building)
> 4. New fiber (any type: ribbon, MMF, SMF) runs up to 300m
> (intra-office)
>
>
>
> It is easiest to explain to customers what to deploy when
> there is a PMD
> positioned to match each application (or ideally one that
> does all). I
> voted
> serial 1550 for app-1, serial 1310 for app-2, 1300 WWDM for app-3 and
> left app-4 for the OIF VSR work activity (as we don't have a
> general intra-
>
> office interconnect objective, but could adopt/adapt their
> results in a
> later
> effort).
>
>
> So why pick 1300 WWDM for app-3? My thinking:
> a. It is the only solution which addresses up to 300m for all
> installed base.
>
>
> That is really the end of the rationale. However,
> considering cost
> arguments:
> b. 1300 VCSELs are supposedly only 6 months away (or
> up to 6 years
>
>
> away depending on the source), which should make 1300 WWDM cost
> competitive with 850 VCSEL WWDM.
>
>
> Now I'll duck & cover.
>
>
> ...Dave
>
> David W. Martin
> Nortel Networks
> +1 613 765-2901
> +1 613 763-2388 (fax)
> dwmartin@xxxxxxxxxxxxxxxxxx
>
>
> ========================
>
>
> -----Original Message-----
> From: Bill Wiedemann [SMTP:billw@xxxxxxxxxxx]
> Sent: Monday, July 17, 2000 9:34 PM
> To: stds-802-3-hssg
> Subject: RE: what's next ?
>
>
>
>
>
> Jonathan, Thanks for your clarification on expectations for the
> interim
> meeting in September.
>
>
> I think it would be very helpful to have a discussion as to the
> "systems"
> vendors desires.
>
>
> For example their interest in the current candidates for
> the 100 meter
> and
> 300 meter objectives. 1300WWDM, 850CWDM, 850 serial.
>
>
> What they would "need" to see/understand for these to gain their
> support,
> and/or why they never will support one or all of these.
> My reason for
>
> initiating this is that it will be very difficult to get
> any of these
> approved unless we meet their expectations. I hope any
> of these aren't
>
> approved as the lesser of evils.
>
>
> Regarding 850CWDM we are planning to make first
> implementations with
> duplex
> SC moving to LC with small form factors. Our expectation is that
> small form
> factor with LC could be available a year from today.
> First size will
> be
> GBIC, electrical interface can be XGMII or XAUI for first
> implementations.
> Should we pursue equalization for 850CWDM to reach 300
> meters over
> legacy
> 62.5 um fiber?
>
>
>
>
>
> We have had initial discussions with Brad Booth and
> David Cunningham
> to be
> sure that the clauses for WDM implementations keep up
> with the current
>
> progress on serial clauses.
>
>
> Bill Wiedemann
> billw@xxxxxxxxxxx
> 925-560-1610 X169
>
>
>
>
>
>