Hi Adrian,
We have a high end spectrum analyzer. So we are sure there is no
background interference
We run our experiments in the 5 GHZ spectrum. The channel conditions can
still vary due to
the movement of the people in the vicinity of the experiment setup. We
select a rate that
experiences at least 20% error on average. Since if the error is 100% or
0% it's not interesting
for us.
My point is if the channel conditions change the distribution of failed
packets should be uniform.
The first and second half of the packets have the same chance to be
received successfully.
Thanks,
Ali
On 25/10/2014 11:19 AM, Adrian Chadd wrote:
On 24 October 2014 13:42, Ali Abedi <a2abedi@xxxxxxxxxxxx> wrote:
We don't use a rate adaptation at this moment (i.e., fixed rate) and the
setup
is stationary. So we expect to see relatively stable channel conditions.
Even if the channel
conditions change during the aggregated frame. The first half of the MPDUs
have the same chance of experiencing worse channel conditions.
How do you /know/ you have stable channel conditions?
There are a lot of things that could be going on inside the devices
you're testing on. It doesn't have to be channel noise coming in an
antenna. For example, your computer could be generating rapidly
changing noise spurs from some clocking sources.
Try firing up the spectral scan mode on the NIC and plot the data. See
if there are any abnormal peaks going on over time.
And a large / long A-MPDU could be measured in milliseconds of length.
the original poster didn't say which rate(s) they are trying with and
how much margin (SNR) the receiver is seeing. Pulling out EVM from the
received A-MPDU frames would also be helpful.
Thanks,
-adrian
-adrian
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