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RE: Your 3PMD Proposal


These are the advantages of 1300nm WWDM:

1.  It is the only solution that will support 300 m on the installed base of

2.  It is widely acknowledged that in the short term, 1300 nm WWDM will be a
lower cost solution for 10km of SMF than the 1300-nm serial solution.  When
exactly the two approaches will cross in price is a subject for debate, but
it will be anywhere between 2 and 4 years.

3.  It is the one solution which will satisfy all MMF and SMF links from 1 m
to 10 km.  

Yes, it will probably cost more than 850-nm WWDM, but this will only cover
100m of installed MMF and is not compatible with SMF.

-Brian Lemoff
Agilent Technologies

> -----Original Message-----
> From: Larry Rennie [mailto:Larry.Rennie@xxxxxxx]
> Sent: Tuesday, June 13, 2000 5:15 PM
> To: piers_dawe@xxxxxxxxxxx; 'del.hansen@xxxxxxxxxxx'
> Cc: Stds-802-3-Hssg@xxxxxxxx
> Subject: Your 3PMD Proposal
> Del and Piers, your presentation 
> (
> _0500.pdfon) for 
> a proposed set of three PMD's includes 1310 WWDM, but not 850 
> WWDM.  According 
> to slide #6  "Comparison of PMD Technologies" in the 
> presentation by Jim Tatum 
> (
> 0500.pdf),  it 
> looks like the only advantage of 1300  WWDM over 850 WWDM is 
> that it can reach 
> lengths up to 300m, compared to 100m for 850 WWDM.  Also, 
> 1300 WWDM can operate 
> up to 10Km on SMF, but your proposed 1300 serial PMD looks 
> like a better 
> solution at 10Km because of its lower cost.
> According to the referenced slide, 850 WWDM is half the cost 
> of 1300 WWDM and 
> can reach lengths up to 550m on the new 50um fiber with a 
> bandwidth of 
> 2000MHz*km for 850nm.  Based on this information, it looks 
> like the only 
> advantage of using 1300 WWDM over 850 WWDM is that it can 
> reach 300m on 
> installed 62.5um fiber.
> Is this analysis correct and, if so, do you feel that the 
> extra length achieved 
> by 1300 WWDM on installed MMF is worth the extra cost?
> Thanks,
> Larry
> Lawrence J. Rennie
> National Semiconductor Corporation
> Calabasas, CA.
> larry.rennie@xxxxxxx
> 818 880 2720