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Re: [10GBT] FW: Contribution for May: Clause 55: Link Segment Spe cification

Title: Message

Chris, Brad, 802-3-10gbt,

Why are NEXT and MDNEXT calculations skewed in clause 55-Link Segment-release.pdf?

If I take the limits of cable NEXT and two connectors NEXTs and do a power summation I get 1.5 dB to 4.3 dB difference.  With MDNEXT the difference is 2 dB to 6 dB, worse at higher frequencies.

I notice the same thing happening in 568-B.2-1 equations (20) and (21).

It does not happen with 568-B.1 equations (5) or (6).

The 568-B.1/ASTM D4566 PSNEXT of equation (7) and the other expressions with factors of ten produces incorrect power summations as well.

It seems to me that all these expressions for power sums should be forming as root-sum-square.






Alan Thomas


Product Technology Development





-----Original Message-----
From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG]On Behalf Of Booth, Bradley
Sent: Tuesday, May 04, 2004 7:16 PM
Subject: [10GBT] FW: Contribution for May: Clause 55: Link Segment Specification


Dear Task Force members,


This will be posted on website in a couple of days, but here's a copy now for you to review.  Thanks to Chris for putting this together.





-----Original Message-----
From: []
Sent: Tuesday, May 04, 2004 8:50 PM
To: Booth, Bradley
Subject: Contribution for May: Clause 55: Link Segment Specification



Please find attached contribution D1.0 Clause 55 Link Segment specification for posting.




Chris DiMinico

editor: Clause 55.X Link Segment

MC Communications