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Re: [802.3_10SPE] Objective - BER



Folks,

 

It seems to me that we have at least 3 clear use cases:

1.  Automotive Automation up to at least 15 m

2.  Industrial Automation up to at least 1000 m

3.  Building Automation up to at least N m where N is bigger than 15, maybe 300-500?

 

I think the Automotive Automation folks have been clear that they need 10^-10 for the 15 m reach. The other two cases are happy with 10^-9.

 

George proposed

Maintain a bit error ratio (BER) at the MAC/PLS service interface of less than or equal to:

10^-10 on link segments up to at least 15m, and

10^-9 on all link segments up to at least 1km

 

I read this as requiring 10^-10 on all link segments 15 m or less, and 10^-9 above this. To me it does not say anything about the number of PHYs the TF will define. I’d prefer to decide how many PHYs we need when we have the right technical data in the Task Force.

 

Regards

Peter

 

 

_______________________________________________

Peter Jones             Cisco Systems

Principal Engineer      560 McCarthy Blvd.

Campus Switching S/W    Milpitas, CA, 95035 USA

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Email:                  petejone at cisco.com

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From: Pat Thaler [mailto:000006d722d423ba-dmarc-request@xxxxxxxx]
Sent: Friday, October 28, 2016 2:55 PM
To: STDS-802-3-10SPE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_10SPE] Objective - BER

 

I don't see a difference in the implications of #1 and #2. In either case, the first part reads as requiring 10^-10 when the link segment is 15 m or less. #1 doesn't mention anything about which PHY so it says that even a PHY that can drive 1 km should 10^-10 or better BER when running on a 15 m link segment (and perhaps that would be true).

 

If then intent is that PHYs under proposed objective 9 support 10^-10 BER and those under proposed objective 10 support 10^-9 BER regardless of where in their distance range they are used, then that would need a different wording.

 

An editorial nit: we put a space between the number and the unit because IEEE style requires it.

 

On Fri, Oct 28, 2016 at 1:57 PM, Geoff Thompson <thompson@xxxxxxxx> wrote:

George-

 

I don't know.  I see two interpretations.

 

#1

Maintain a bit error ratio (BER) at the MAC/PLS service interface of less than or equal to 10^-10 on link segments up to at least 15m.
Maintain a bit error ratio (BER) at the MAC/PLS service interface of less than or equal to 10^-9 on all link segments up to at least 1km.

(which to my eyes would imply but not require two PHYs)

 

#2

Maintain a bit error ratio (BER) at the MAC/PLS service interface of less than or equal to:
10^-10 on link segments up to at least 15m, and
10^-9 on all link segments greater than 15m up to at least 1km

(which to my eyes would imply a single PHY)

 

...but would be clearer wording.

 

Which is it?

 

Geoff

 

 

On Oct 28, 2016, at 11:46 AMPDT, George Zimmerman <george@xxxxxxxxxxxxxxxxxxxx> wrote:

 

We have had some round-abouts on how to write the BER objective.  Ludwig had proposed a nice split, where the short-reach/automotive PHYs had a 10^-10 BER objective and the longer reach ones had a 10^-9 BER objective.  With that in mind, I propose the following objective for discussion:

 

Maintain a bit error ratio (BER) at the MAC/PLS service interface of less than or equal to:

10^-10 on link segments up to at least 15m, and

10^-9 on all link segments up to at least 1km

 

 

Do we have consensus?

 

George Zimmerman, Ph.D.

President & Principal

CME Consulting, Inc.

Experts in Advanced PHYsical Communications