Re: [BP] proposed channel model change
It the ripple spec that has the problem.
... Rich
-----Original Message-----
From: Charles Moore [mailto:charles.moore@avagotech.com]
Sent: Monday, December 05, 2005 2:48 PM
To: Mellitz, Richard; IEEE802.3ap
Subject: Re: [BP] proposed channel model change
rich,
I looked at how the proposed spec treated: 8 peters channels, 8 Molex
channels, and 7 Tyco channels,
all we currently have in the IEEE802.3ap data base. Only 1, Tyco Case3,
would fail the 1000BASE-KX
spec as i am proposing it. Could you re-check your figures?
charles
BTW: I have changed my email address, if you keep a file of addresses
you should update it.
Mellitz, Richard wrote:
> Hi All,
>
> When I talked to Charles I said this seemed to have promise because
> the Goergen line has as strong sqrt(f) dependence and low frequencies.
> It has basis in the skin loss physics. This would mostly affect KX
> which we really didn't spend much time on. After all we just changed
> the ICR fit line. However, I made these comments without really taking
> a close look at our data. Isn't theory grand... J
>
> Since then I did look at the data. I had Steve Krooswyk alter the
> spreadsheet s-parameter analysis tool (SCAT) to look at this new fit.
> What I discovered was that it actually makes many channels appear much
> worse. After further review of the data I think we could do much
> better by just changing the confidence region lines for KX only.
> However, I think the data needs to be presented and then we, as
> working group, can determine a plan of action.
>
> ...Rich Mellitz, Intel Corporation
>
> 803-216-2160 (o)
>
> 803-873-7343 (m)
>
> -----Original Message-----
> From: Charles Moore [mailto:charles_moore@agilent.com]
> Sent: Tuesday, November 29, 2005 1:11 PM
> To: STDS-802-3-BLADE@listserv.ieee.org
> Subject: [BP] proposed channel model change
>
> guys,
>
> Rich Mellitz and i have been discussing changing the channel model,
>
> to use a fit to Amax, as we are now doing for the interference
tolerance
>
> test channel (see moore_03_1105.pdf), instead of a fit to a straight
line.
>
> This would have several advantages:
>
> 1. It would use a common method for both the test channel and the
>
> working channel
>
> 2. It would allow us to replace three graphical tests:
>
> i. That the linear fit is better than Amax
>
> ii. That the insertion loss is always better than Amax + something
>
> iii. That the ripple is better than something
>
> with one numeric test, that mc < 1.0, and the graphical ripple
>
> test. We may need an additional limit on bc.
>
> 3. Since the fit to Amax will be substantially better than the fit
>
> to a straight line, the ripple will be smaller and more meaningful.
>
> This will reduce the number of false fails. We should be able
>
> to shrink the ripple bounds (Rich: will you figure out by how
>
> much?) which may also reduce false passes.
>
> 4. Since the fit will be especially improved at low frequency, we
>
> will be able to reduce f1, especially for 10GBASE-KR, which
>
> actually uses low frequencies more than either 1000BASE-KX or
>
> 10GBASE-KX4.
>
> Does anyone see any problems with this proposal?
>
> charles
>
> --
>
> |--------------------------------------------------------------------|
>
> | Charles Moore
>
> | Agilent Technologies
>
> | ASIC Products Division
>
> | charles_moore@agilent.com
>
> | (970) 288-4561
>
> |--------------------------------------------------------------------|
>
--
|--------------------------------------------------------------------|
| Charles Moore
| Avago Technologies
| ASIC Products Division
| charles_moore@agilent.com
| (970) 288-4561
|--------------------------------------------------------------------|