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RE: [10GBASE-T] PAR and 5 critters

Yeah, the analog target specs look reasonable ...

For comparison, in my previous life (company) I did some
system simulations (and actual design) and came to the
conclusion that one could run 10 Gbps over cat-7 STP to
a distance of about 25 meters with a 7-bit effective ADC
at 625 Mbaud (PAM-5 modulation). At least, the 7-bit
effective ADC was achievable ...

Jaime E. Kardontchik, PhD
Mountain View, CA 94041

-----Original Message-----
From: Sreen Raghavan []
Sent: Tuesday, July 29, 2003 1:58 PM
To: 'DOVE,DANIEL J (HP-Roseville,ex1)';; 'Alan Flatman';
Kardontchik, Jaime
Cc: '[unknown]'; 'Sterling Vaden'
Subject: RE: [10GBASE-T] PAR and 5 critters


We are really referring to the theory (Shannon Capacity) when we say 10Gbps
cannot be achieved over CAT-5e or CAT-6 cabling. Theory shows that 10Gbps
can be achieved over CAT-7 cabling. Practical issues to accomplish 10Gbps
over CAT-7 cabling include (assuming PAM-10 modulation):

1. Building an 11-bit effective ADC at 833 MBaud,
2. Performing large number (x8 relative to 1000BaseT) of DSP calculations at
3. DDFSE critical path to be implemented in 1.2 ns
4. Building a linear transmit driver with an 833MGz bandwidth & 40 dB SNR

The above list by no means is exhaustive, but shows the implementation
issues that need to be considered.


-----Original Message-----
From: DOVE,DANIEL J (HP-Roseville,ex1) [] 
Sent: Tuesday, July 29, 2003 1:09 PM
To: ''; 'Alan Flatman'; 'Kardontchik, Jaime'
Cc: '[unknown]'; 'Sterling Vaden'
Subject: RE: [10GBASE-T] PAR and 5 critters

Hi Sreen,

One thing that occurs to me on this point is the difference between
theory and application. Specifically, how many process actions have to
take place within a baud time to close the loops on the DSP and what
process geometry would be required to make that timing closure?

I know that with 1000BASE-T, the theory was rock solid long before the
processes to implement it were reliable. 

HP ProCurve

> -----Original Message-----
> From: Sreen Raghavan []
> Sent: Tuesday, July 29, 2003 11:52 AM
> To: 'Alan Flatman'; 'Kardontchik, Jaime'
> Cc: '[unknown]'; 'Sterling Vaden'
> Subject: RE: [10GBASE-T] PAR and 5 critters
> Just to clarify, Vativ, Broadcom & Marvell presented capacity 
> calculations
> at the Portsmouth meeting and showed that worst-case CAT-7 
> (Class F) cabling
> had sufficient channel capacity to achieve 10Gbps throughput 
> at 100 meter
> distance. The reason for "may be possible" statement in the 
> conclusions was
> that the 3 PHY vendors felt that more work needed to be done 
> on practical
> implementation issues before the conclusion could be altered to a more
> definitive statement. 
> In addition, we proved conclusively that there was NOT 
> sufficient channel
> capacity on existing CAT-5e (Class D), or CAT-6 (Class E) 
> cables to achieve
> 10 Gbps throughput.
> Sreen Raghavan
> Vativ Technologies
> -----Original Message-----
> From:
> [] On Behalf 
> Of Alan Flatman
> Sent: Tuesday, July 29, 2003 9:51 AM
> To: Kardontchik, Jaime
> Cc: [unknown]; Sterling Vaden
> Subject: RE: [10GBASE-T] PAR and 5 critters
> Message text written by "Kardontchik, Jaime"
> >Was any reason given why it would not run on Class F ? Was it for
> technical reasons or for marketing reasons ?<
> The 3-PHY vendor presentation made in Portsmouth (sallaway_1_0503)
> calculated 49.36 Gbit/s capacity using unscaled Cat 7/Class F 
> cabling. This
> figure was reduced to 37.71 Gbit/s with worst case limits. Overall, I
> thought that this was a refreshingly realistic presentation and I
> interpreted the summary statement "Capacity calculations with 
> measured data
> indicate 10 Gigabit data transmission over 100m Cat 7 may be possible"
> (slide 16, bullet 3) as overly cautious engineering judgement.
> So, what has changed since the May interim? Not the laws of physics!
> Best regards,
> Alan Flatman
> Principal Consultant
> LAN Technologies