[10GBT] Total EMI Penalty
Hi All,
The frequency range of interest for our transmit PSDs is <0.25fs, as far as
emissions is concerned. In this frequency range, the transmit PSD of PAM12
will be at least 0.8dB higher than PAM8, even by Jose's calculations. Now,
recall that during the July plenary, Dr.Ungerboeck had recommended to the
task force that the transmit PSD for 10GBASE-T should have a spectral NULL
at 0.5fs? If we follow his advice, please ask yourself how much energy will
be left at 0.4fs? Besides, in any case, the FCC limits for emissions
increases in the neighborhood of 220MHz, thereby rendering Jose's emissions
contentions completely irrelevant.
The total EMI penalty for PAM12 over PAM8 is still between 4.0dB and 4.4dB
in the 0-55m range of Cat6 cabling (existing cabling infrastructure). It
varies between 2.6dB and 4.0dB in the 55m-100m range of Cat6 cabling (new
cabling). Therefore, there is not a single line length range of UTP cabling
in which I can recommend PAM12 over PAM8 to this task force, without
abrogating my technical responsibilities.
Regards,
Sailesh Rao.
srao@phyten.com
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