Re: [10GBT] Validity of comparing PSDs to determine electromagnetic emissions
Were you assuming any power back-off mechanism for the 0m calculation or
was this assuming the same launch power that would be used for 100m?
From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
Behalf Of sailesh rao
Sent: Monday, September 06, 2004 12:37 PM
Subject: Re: [10GBT] Validity of comparing PSDs to determine
The total EMI advantage I computed for PAM8 over PAM12 (2.6dB to 3.8dB)
over the agreed upon Models, 1, 2 and 3, which include worst-case Alien
NEXT. i included the 0m calculation (4.5dB) as a basis that cannot be
There are enough EMI challenges in 10GBASE-T (~6dB higher emissions than
1000BASE-T, ~7dB lower susceptibility than 1000BASE-T, for a total of
worse EMI performance than 1000BASE-T) for us to begin by throwing away
>From: Hugh Barrass <hbarrass@CISCO.COM>
>Reply-To: "IEEE P802.3an" <STDS-802-3-10GBT@listserv.ieee.org>
>Subject: Re: [10GBT] Validity of comparing PSDs to determine
>Date: Mon, 6 Sep 2004 07:35:13 -0700
>The tests are generally conducted under "worst case" conditions. That
>is, conditions where emissions are highest for EMC testing, or where
>equipment is most susceptible for immunity testing.
>For current equipment there is no consideration of alien NEXT
>environment as this is assumed to be unrelated to the emissions or
>susceptibility of the equipment. If the alien NEXT environment of 10GBT
>does effect the EMI performance then that will have to be taken into
>account when the test guidelines for that type of equipment are
>As the standard develops we will have to keep this in mind.
>sailesh rao wrote:
>>Regulatory EMI tests are not conducted with worst-case alien NEXT
>>environments set up in the range.
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