PMD by cable vintage
Vipul,
Contrary to my previous statement about the lack of data on percentages of
cables by vintage, I believe there is some information that can be extracted
by combining the information from two plots. Looking at the cable vintage
data and the cumulative distribution data for all cables, I believe it is
possible to say that in this data set approximately 50% of the cables are
pre-1991. I arrived at this result by weighting the vintage data so that it
equates to the cumulative data.
Paul
----------
From: Kolesar, Paul F (Paul)
Sent: Tuesday, October 24, 2000 10:21 AM
To: Equalization Ad-Hoc Reflector; 'Vipul Bhatt'
Subject: RE: PMD data available
Vipul,
It is not possible to tell exactly where 99.99 percentile is due to
resolution of the plot. But it is at 99% around 3.6 ps/km^1/2. The
plot
flattens out at 100% above 4.6. So my best guess is 4.6. However, as
Henning
Bulow (in a subsequent email) and I both point out, this data set
does not
reflect the current statistics since much more low-PMD grade fiber
has been
installed since 1997. Unfortunately, the paper provides no
information on
the percentages of fiber of any vintage.
Regards,
Paul
----------
From: Vipul Bhatt [SMTP:vipul.bhatt@xxxxxxxxxxx]
Sent: Tuesday, October 24, 2000 12:44 AM
To: Equalization Ad-Hoc Reflector
Subject: RE: PMD data available
Paul,
This is useful; thanks. A couple of questions, in
anticipation of
what
the P802.3ae members may ask in the November meeting.
- In the cumulative distribution plots, what is the 99.99
percentile
value of PMD - the value below which 99.99% of the
population is?
It's
probably hard to figure out from the figures, but take a
shot.
- Does the paper say anything about what percentage of total
fiber
is
pre-1992?
Regards,
Vipul
==========================
> -----Original Message-----
> From: owner-stds-802-3-hssg-equal@xxxxxxxx
> [mailto:owner-stds-802-3-hssg-equal@xxxxxxxx]On Behalf Of
> Kolesar, Paul
> F (Paul)
> Sent: Monday, October 23, 2000 12:29 PM
> To: Equalization Ad-Hoc Reflector; 'Vipul Bhatt'
> Subject: PMD data available
>
>
>
> A Bellcore paper by J. Peters, A. Dori, and F. Kapron from
> NFOEC'97 entitled
> "BELLCORE'S FIBER MEASUREMENT AUDIT OF EXISTING CABLE
PLANT
> FOR USE WITH
> HIGH BANDWIDTH SYSTEMS" provides some field data about the
PMD
> characteristics.
>
> I found a number of points relevant to the IEEE, which I
> will summarize here
<snip>