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Tom:
Legacy 62.5 um fiber attenuation was specified as 3.75 dB/km at 850 nm as
defined in TIA-568 Rev A. TIA-568 has recently been updated (2001) as
Rev. B that modified the 850 nm attenuation to 3.5 dB/km for 62.5 um fiber.
Also, TIA-568 Rev B now includes 50 um multimode fiber with an attenuation
of 3.5 dB/km at 850 nm.
Hope this helps.
Doug
"Lindsay, Tom"
<tlindsay@xxxxxxxxxxxxxxxxxxxx> To: "802.3ae Serial reflector (E-mail)"
Sent by: <stds-802-3-hssg-serialpmd@xxxxxxxx>
owner-stds-802-3-hssg-serialpmd@majordom cc: "Doug Coleman (E-mail)" <doug.coleman@xxxxxxxxxxx>
o.ieee.org Subject: [802.3ae_Serial] Cable plant values?
05/17/02 12:07 PM
Questions
1. Table 52-25 quotes 3.5 dB/km max attenuation at 850nm, whereas the
spreadsheet uses 3.75. 10GFC also quotes 3.75 in its documentation. Which
value is correct? ll 3 sources agree on 3.5 dB for 50 micron fiber.
2. Table 52-24 shows channel insertion losses. Can someone explain where
the values come from for the 850 nm variants? Except for 2000 MHz-km, I
get significantly different values. The values in the table are not
consistent with the model nor with the budget tables for the PMDs.
Thanks, Tom
Stratos NW
(425) 672-8035 x105
(See attached file: Tom Lindsay @ work.vcf)
=?iso-8859-1?Q?Tom_Lindsay_@xxxxxxxxx?=