Re: problem on ACS
From: Luis R. Rodriguez <hidden>
Date: 2011-07-27 20:25:23
On Tue, Jul 26, 2011 at 7:25 PM, MingAnn Ng [off-list ref] wrote:
Hi all, I had git the latest push by Luis, and make a quick test with it. the result is as below: 2412 MHz: 20.000000 2417 MHz: 7378697629483820665.500000 2422 MHz: 6456360425798343085.000000 2427 MHz: 7378697629483820668.000000 2432 MHz: 5534023222112865508.000000 2437 MHz: 922337203685477605.000000 2442 MHz: 4611686018427387922.500000 2447 MHz: 2767011611056432762.500000 2452 MHz: 2767011611056432763.250000 2457 MHz: 2767011611056432762.500000 2462 MHz: 3689348814741910340.000000 2467 MHz: 7378697629483820664.000000 2472 MHz: 8301034833169298245.500000 5180 MHz: 8.700000 5200 MHz: 9.900000 5220 MHz: 10.900000 5240 MHz: 10.500000 5260 MHz: 10.800000 5280 MHz: 12.000000 5300 MHz: 11.900000 5320 MHz: 10.900000 5500 MHz: 6.800000 5520 MHz: 8.000000 5540 MHz: 6.700000 5560 MHz: 6.800000 5580 MHz: 6.900000 5600 MHz: 2.100000 5620 MHz: 5.900000 5640 MHz: 6.000000 5660 MHz: 6.700000 5680 MHz: 6.900000 5700 MHz: 6.600000 Ideal freq: 5600 MHz The result is more convincing than the previous version without any -inf values.
Yay but yeah those really high values are a bit strange, can you try
compiling ACS with VERBOSE=1, you can do this as follows:
export CFLAGS=-DVERBOSE=1
make V=1
You should see DVERBOSE=1 in the cc lines.
As for the output, you will now see verbose details of each survey,
stuff that into a file and inspect it and see why the values for the
interference factor are so high. For example I get:
10 surveys for 5320 MHz:
Survey 1 from wlan0:
noise: -112 dBm
channel active time: 30 ms
channel busy time: 6 ms
channel receive time: 0 ms
channel transmit time: 0 ms
interference factor: 3.000000
Survey 2 from wlan0:
noise: -112 dBm
channel active time: 13 ms
channel busy time: 6 ms
channel receive time: 0 ms
channel transmit time: 0 ms
interference factor: 4.000000
Survey 3 from wlan0:
noise: -112 dBm
channel active time: 13 ms
channel busy time: 6 ms
channel receive time: 0 ms
channel transmit time: 0 ms
interference factor: 4.000000
... etc...
The above survey is made by the radio channel set to 2412MHz. When I do a survey when I'd set the channel to 5180MHz, The result is shown below: 2412 MHz: 17.000000 2417 MHz: 17.300000 2422 MHz: 15.200000 2427 MHz: 17.500000 2432 MHz: 17.800000 2437 MHz: 16.700000 2442 MHz: 15.800000 2447 MHz: 14.000000 2452 MHz: 15.500000 2457 MHz: 14.200000 2462 MHz: 14.100000 2467 MHz: 12.500000 2472 MHz: 15.500000 5180 MHz: 7.900000 5200 MHz: 9223372036854775814.000000 5220 MHz: 9223372036854775814.000000 5240 MHz: 9223372036854775815.000000 5260 MHz: 9223372036854775814.000000 5280 MHz: 7378697629483820653.500000 5300 MHz: 8301034833169298234.500000 5320 MHz: 7378697629483820653.500000 5500 MHz: 9223372036854775810.000000 5520 MHz: 9223372036854775809.000000 5540 MHz: 9223372036854775811.000000 5560 MHz: 9223372036854775809.000000 5580 MHz: 9223372036854775811.000000 5600 MHz: 9223372036854775811.000000 5620 MHz: 9223372036854775810.000000 5640 MHz: 9223372036854775811.000000 5660 MHz: 9223372036854775810.000000 5680 MHz: 9223372036854775811.000000 5700 MHz: 9223372036854775810.000000 Ideal freq: 5180 MHz the result for 5GHz band showing a much higher interference factor than the previous scan with channel set to 2412MHz, and the factor value for 2.4GHz is much lower.
Interesting -- the only explanation I have for this is the way the driver does calibration when on a channel, and this being affected somehow. More review of the actual survey details for each channel would help here. Try to inspect it and see why the values are so big. The different results based on what channel you are set should be corrected, just not sure yet how. If we use a passive scan I wonder if we'd get more consistent results -- likely not given that calibration would depend on your currently operating channel...
Is this a normal outcome since this is a off-channel survey?
Nope, for example, when I do the same thing you did, first with the card set to 2412 MHz: 2412 MHz: 11.100000 2417 MHz: 10.100000 2422 MHz: 10.000000 2427 MHz: 9.800000 2432 MHz: 10.000000 2437 MHz: 10.100000 2442 MHz: 8.800000 2447 MHz: 10.200000 2452 MHz: 9.000000 2457 MHz: 10.000000 2462 MHz: 9.600000 5180 MHz: 1.800000 5200 MHz: 1.700000 5220 MHz: 2.700000 5240 MHz: 2.700000 5260 MHz: 2.800000 5280 MHz: 3.900000 5300 MHz: 2.600000 5320 MHz: 3.800000 5745 MHz: -3.000000 5765 MHz: 0.300000 5785 MHz: 0.800000 5805 MHz: -0.200000 5825 MHz: -1.500000 Ideal freq: 5745 MHz And then if I tune it to 5745 MHz: 2412 MHz: 11.200000 2417 MHz: 9.900000 2422 MHz: 9.900000 2427 MHz: 9.600000 2432 MHz: 10.100000 2437 MHz: 10.100000 2442 MHz: 9.000000 2447 MHz: 9.800000 2452 MHz: 8.900000 2457 MHz: 10.000000 2462 MHz: 10.000000 5180 MHz: 1.800000 5200 MHz: 1.900000 5220 MHz: 2.900000 5240 MHz: 2.800000 5260 MHz: 2.700000 5280 MHz: 3.600000 5300 MHz: 2.600000 5320 MHz: 3.800000 5745 MHz: -3.000000 5765 MHz: 0.800000 5785 MHz: 0.700000 5805 MHz: 0.800000 5825 MHz: -1.100000 Ideal freq: 5745 MHz What 802.11 card do you have (dmesg | grep ath; and lspci output) ? I have an AR9280. I also know Felix has been telling me he has some enhancements to noise floor computation in his queue for ath9k, these might help here too. Luis