Re: [802.3_ISAAC] Questions on "boyer_sharma-3dm_xx_05-14-25_2.pdf"
Rich - I think in order to make the judgement you ask, I would need to better understand the detail behind the failing cases presented.
I have repeatedly asked for validation behind the Zerna cases, because the curves shown look very much like those representing defects that would be unlikely to be suitable. The response I have gotten is that the data presented does not actually represent a case, but is a conglomeration of multiple simulated results - without anything to validate that the result is realistic or informative for any cable.
What we need to understand, in my opinion, is the yield of cable harnesses meeting these results - not simply whether one can simulate (or even measure) a failing harness. I have seen some analysis of yield that suggests that the cases cited are unrealistically pessimistic. Can you point me to other data to understand the yield (probability of passing) and the full transmission characteristics of such problematic links?
-george
Sent from my iPhone
On May 16, 2025, at 8:09 AM, Long, Richard J <0000451e32405de7-dmarc-request@xxxxxxxxxxxxxxxxx> wrote:
All,
The topologies presented in https://ieee802.org/3/dm/public/0325/boyer_sharma-3dm_xx_03-10-25_RevB.pdf not being suitable for evaluation of RL limits is agreeable to me.
If you take a look at some of the past contributions, such as presented here for RL limits, see slide 11, the limits presented by Rich and Rohit would not pass:
https://www.ieee802.org/3/dm/public/0724/Zerna_802.3dm_01b_240717_IL_RL_Limits.pdf
Here is another work with additional topologies presented that would not pass the limits proposed by Rich and Rohit:
https://www.ieee802.org/3/dm/public/0924/bergner_3dm_01a_18_09_24.pdf
Additionally keep in mind some of those topologies were created via simulation. So if you agree with those topologies, and the simulations, as being realistic then the RL limit should be relaxed. I would agree with something closer to what is presented by Zerna above.
Thanks.
-Rich Long
-----Original Message-----
From: Boyer, Rich <000012e205f410df-dmarc-request@xxxxxxxxxxxxxxxxx>
Sent: Thursday, May 15, 2025 2:06 PM
To: STDS-802-3-ISAAC@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_ISAAC] Questions on "boyer_sharma-3dm_xx_05-14-25_2.pdf"
[CAUTION] This email originates from outside of TE. Be cautious when clicking links, opening attachments and providing sensitive information.
Hello Conrad,
This email is from Both Rohit and Rich. We both worked on this reply.
The reason the IL changed is that we are working to a compromise in 802.3dm as a new asynchronous technology of what is feasible from the IC transceiver and what is doable by links. Our goal is to find out what is doable within reason so that is why we work and collaborate with as many people as want to work together for good balance in transceiver technology and what may come in the future of links.
For the RL, we have evaluated many different realistic topologies from measured links. What we mean by "realistic" is from our experience of implementing complete links into vehicles. We realize that there maybe cases that do not meet in the <400 MHz and those cases need to be examined as to applicability and what could be done to make them meet.
We will put together a presentation for the next 802.3dm meeting and show RL data from some link topologies.
Best Regards,
- Rohit and Rich
-----Original Message-----
From: Conrad Zerna <conrad@xxxxxxxxxxxxxx>
Sent: Wednesday, May 14, 2025 4:19 PM
To: STDS-802-3-ISAAC@xxxxxxxxxxxxxxxxx
Subject: [802.3_ISAAC] Questions on "boyer_sharma-3dm_xx_05-14-25_2.pdf"
CAUTION: This email comes from a non Aptiv email account Do not click links or open attachments unless you recognize the sender and know the content is safe.
Hi Rich, Rohit,
I was wondering about the specific reason, that the IL formula change from
Insertion loss(f) ≤ 0.0015 - 0.001325*f- 0.3785*√f - 1.1785/ √f (dB) in March to
Insertion loss(f) ≤ 0.0015 - 0.001325*f- 0.3645*√f - 1.1785/ √f (dB) now in May.
You said, it was due to "technology". What specific requirement/limitation of technology is that?
I also wanted to reiterate my comment from March, that the topologies in slides 3 here https://ieee802.org/3/dm/public/0325/boyer_sharma-3dm_xx_03-10-25_RevB.pdf
are not suitable to validate a proposed RL limit, especially in the lower frequency range.
If you have evaluated your new RL curve from May against other topology simulations?
Thanks,
Conrad
________________________________________________________________________
To unsubscribe from the STDS-802-3-ISAAC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-ISAAC&A=1
________________________________________________________________________
To unsubscribe from the STDS-802-3-ISAAC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-ISAAC&A=1
________________________________________________________________________
To unsubscribe from the STDS-802-3-ISAAC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-ISAAC&A=1
________________________________________________________________________
To unsubscribe from the STDS-802-3-ISAAC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-ISAAC&A=1