Further UW2453 testing:

My tests were downloading a 36mb file over the internet from a fast host
(HTTP). When repeating the tests, I unloaded the module, replugged the
device, and loaded the module again inbetween each test. I made sure not
to change the location or orientation of the device, etc.

I measured the average transfer rate of the download using wget, and the
number of failed transmissions by counting the retry_failed interrupts.
It may sound odd to count failed transmissions in a download test but
keep reading anyway...

First comparison: zd1211rw vs vendor driver. In all cases the PLL locked
onto table 5, so table 6 was used for radio programming.

1. 120 fails, 773kb/sec
2. 313 fails, 593kb/sec
3. 659 fails, 602kb/sec

1. 1051 fails, 816kb/sec
2. 1799 fails, 643kb/sec
3. 2186 fails, 381kb/sec

There may be some heat-related issues here: all the numbers steadily
increase with time. Further testing showed that they decrease after a
while, then increase again, etc. I repeated the test from cold with the
vendor driver first, and found the opposite results (the vendor driver
from cold had a few hundred fails, then zd1211rw from warm had thousands
of fails).

Second comparison: calibrating the radio on channel 1 (the hard-coded
default) vs calibrating the radio on channel 11 (the channel where my
network is running).

All tests done with zd1211rw.

calibrated on channel 1 (PLL locked on table 5):
1. 120 fails, 773kb/sec
2. 313 fails, 593kb/sec
3. 659 fails, 602kb/sec

calibrated on channel 11 (PLL locked on table 4):
1. 2545 fails, 486kb/sec
2. 2572 fails, 487kb/sec
3. 2334 fails, 513kb/sec

The 2nd set of results were consistent even from cold -- calibrating the
radio on channel 11 produced ~2500 failures for each test. This is a
shame because one obvious way of attempting to fix calibration problems
would be to recalibrate the radio on the target channel, but this test
indicates it doesn't improve anything...

Third comparison: calibrating on channel 1 vs using autocal

autocal is used when the PLL doesn't lock on any RF configuration
tables. I though I'd try it as the other RFs work like this - a "one
size fits all" radio programming scheme. (I don't actually know that
autocal is designed to work like this, I'm just speculating based on its

Results were not pretty: couldn't test anything as when programmed with
autocal values, I get no scan results so can't even associate. Same
results with the vendor driver.

Conclusion: zd1211rw is no better/worse than vendor driver with the
UW2453 RF (they both perform badly), and my 2 initial guesses at finding
ways to improve reception/transmission success rate have failed miserably.


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