Bicephale
join:2005-09-24
 ·TekSavvy Solutions..
| reply to Bicephale
Re: From the ground up!
GNet vs Siemens vs Thomson - DownStream SNR Margin & Rx CRC |
I wondered about this one for a long time. Something
told me my GNet could compare with my SpeedStream
in terms of noise but it's DownStream SNR Margin was
not expected to beat those of my Siemens SS4200 &
of my Thomson ST546 altogether. The mix of optimum
SNR Margin and of Noise performance may result from
lower Attenuation levels - which could relate with the
input stage design. Should it be true, the Attenuation
levels observed while evaluating different DSL MoDems
may happen to be an important parameter for persons
trying to decide which product to buy! There are other
criterias to consider than noise performance alone but
it seems possible Attenuation level variations between
products might be more significative than i suspected.
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| 
GNet GBB2060-Xi - Superposed vs Averaged Noise Curves |  GNet GBB2060···-2) .ZIP 638,724 bytes
GNet GBB2060-Xi Analysis (2009, Feb-16 to Mar-2) | | |
I had one large capture gathered this winter which
remained to be parsed... It's an interesting sample
for me because i've noticed a "bias" effect after my
record was separated into two sets: one which has
nicely aligned time-stamps and another where those
hour marks reveal some "jitter". See what happened
when i decided to superpose the curves instead of
averaging them as usual!... In my opinion, it's partly
due to the rejection of marginal "sparkle" events: it
defines/flattens a curve when those aren't allowed
to contaminate it. As a consequence, this suggests
i'll need to pay more attention to the duration of my
future tests (if i decide to go on) in order to make
sure that each curve undergoes a same amount of
filtering, hence removing the same amount of bias...
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Now lets put some curves on top of each other to ease comparisons...
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