test on latest hostapd with acs

Wed Sep 18 04:20:02 EDT 2013

On 18 September 2013 09:49, Sarah Rumpel <Sarah.Rumpel at barco.com> wrote:
> Hi,
>

Hi Sarah,

> I did some tests on the latest hosapd with ACS (commit
> 50f4f2a066e60be7cc03e291635e9a0f953922bd 31 Aug 2013).
> I ran it without and with additionally generated continuous interference on
> channel 11, but I achieve for both cases more or less the same results.
> Does someone achieve similar results or have a solution?
> I attached my config file, perhaps there is a mistake in my configuration.
>
> Without interference:
>
> ACS: Survey analysis for channel 7 (2442 MHz)
> ACS: 1: min_nf=-99 interference_factor=0.447154 nf=-98 time=123 busy=55
> rx=38
> ACS: 2: min_nf=-99 interference_factor=0.633333 nf=-99 time=123 busy=79
> rx=62
> ACS: 3: min_nf=-99 interference_factor=0.585366 nf=-98 time=123 busy=72
> rx=64
> ACS: 4: min_nf=-99 interference_factor=0.634146 nf=-99 time=123 busy=78
> rx=70
> ACS: 5: min_nf=-99 interference_factor=0.672131 nf=-99 time=123 busy=83
> rx=69
> ACS:  * interference factor average: 0.594426
> ACS: Survey analysis for channel 8 (2447 MHz)
> ACS: 1: min_nf=-101 interference_factor=0.396694 nf=-98 time=123 busy=50
> rx=12
> ACS: 2: min_nf=-101 interference_factor=0.390244 nf=-98 time=123 busy=48
> rx=33
> ACS: 3: min_nf=-101 interference_factor=0.642202 nf=-99 time=123 busy=84
> rx=52
> ACS: 4: min_nf=-101 interference_factor=0.831776 nf=-101 time=123 busy=105
> rx=46
> ACS: 5: min_nf=-101 interference_factor=0.565574 nf=-98 time=123 busy=70
> rx=54
> ACS:  * interference factor average: 0.565298
> ACS: Survey analysis for channel 9 (2452 MHz)
> ACS: 1: min_nf=-99 interference_factor=0.528926 nf=-98 time=123 busy=66
> rx=14
> ACS: 2: min_nf=-99 interference_factor=0.57377 nf=-99 time=123 busy=71 rx=38
> ACS: 3: min_nf=-99 interference_factor=0.565574 nf=-98 time=123 busy=70
> rx=34
> ACS: 4: min_nf=-99 interference_factor=0.694444 nf=-98 time=123 busy=90
> rx=51
> ACS: 5: min_nf=-99 interference_factor=0.455285 nf=-98 time=123 busy=56
> rx=41
> ACS:  * interference factor average: 0.5636
> ACS: Survey analysis for channel 10 (2457 MHz)
> ACS: 1: min_nf=-104 interference_factor=0.256198 nf=-98 time=123 busy=33
> rx=27
> ACS: 2: min_nf=-104 interference_factor=0.349593 nf=-104 time=123 busy=43
> rx=36
> ACS: 3: min_nf=-104 interference_factor=0.577236 nf=-98 time=123 busy=71
> rx=65
> ACS: 4: min_nf=-104 interference_factor=0.38843 nf=-98 time=123 busy=49
> rx=41
> ACS: 5: min_nf=-104 interference_factor=0.393443 nf=-99 time=123 busy=49
> rx=44
> ACS:  * interference factor average: 0.39298
> ACS: Survey analysis for channel 11 (2462 MHz)
> ACS: 1: min_nf=-99 interference_factor=0.22622 nf=-98 time=37320 busy=9019
> rx=7361
> ACS: 2: min_nf=-99 interference_factor=0.226773 nf=-99 time=37470 busy=9074
> rx=7407
> ACS: 3: min_nf=-99 interference_factor=0.22749 nf=-98 time=37620 busy=9136
> rx=7462
> ACS: 4: min_nf=-99 interference_factor=0.227893 nf=-98 time=37770 busy=9192
> rx=7504
> ACS: 5: min_nf=-99 interference_factor=0.228157 nf=-99 time=37920 busy=9236
> rx=7541

This is an interesting bit. See the disparity between time spent on
channel 10 and 11?

If you calculate relative values you get the following for channel 11:

time=150 busy=55
time=150 busy=62
time=150 busy=56
time=150 busy=44

This seems to be close to channel 10, as expected.

> ACS:  * interference factor average: 0.227306
> ACS: Survey analysis for selected bandwidth 20 MHz
> ACS:  * channel 1: total interference = 1.6204
> ACS:  * channel 2: total interference = 2.09924
> ACS:  * channel 3: total interference = 2.57981
> ACS:  * channel 4: total interference = 2.71252
> ACS:  * channel 5: total interference = 2.80184
> ACS:  * channel 6: total interference = 2.82541
> ACS:  * channel 7: total interference = 2.91017
> ACS:  * channel 8: total interference = 2.82258
> ACS:  * channel 9: total interference = 2.34361
> ACS:  * channel 10: total interference = 1.74918
> ACS:  * channel 11: total interference = 1.18389
> ACS: Ideal channel is 11 (2462 MHz) with total interference factor of
> 1.18389
>
> With interference:
>
> ACS: Survey analysis for channel 7 (2442 MHz)
> ACS: 1: min_nf=-99 interference_factor=0.869919 nf=-99 time=123 busy=107
> rx=54
> ACS: 2: min_nf=-99 interference_factor=0.885246 nf=-99 time=123 busy=109
> rx=67
> ACS: 3: min_nf=-99 interference_factor=0.853659 nf=-99 time=123 busy=105
> rx=67
> ACS: 4: min_nf=-99 interference_factor=0.845528 nf=-99 time=123 busy=104
> rx=66
> ACS: 5: min_nf=-99 interference_factor=0.796748 nf=-99 time=123 busy=98
> rx=59
> ACS:  * interference factor average: 0.85022
> ACS: Survey analysis for channel 8 (2447 MHz)
> ACS: 1: min_nf=-98 interference_factor=0.98374 nf=-98 time=123 busy=121
> rx=84
> ACS: 2: min_nf=-98 interference_factor=0.98374 nf=-98 time=123 busy=121
> rx=82
> ACS: 3: min_nf=-98 interference_factor=0.95122 nf=-68 time=123 busy=117
> rx=77
> ACS: 4: min_nf=-98 interference_factor=0.98374 nf=-68 time=123 busy=121
> rx=80
> ACS: 5: min_nf=-98 interference_factor=0.957627 nf=-70 time=123 busy=118
> rx=76
> ACS:  * interference factor average: 0.972013
> ACS: Survey analysis for channel 9 (2452 MHz)
> ACS: 1: min_nf=-95 interference_factor=0.691057 nf=-60 time=123 busy=85
> rx=60
> ACS: 2: min_nf=-95 interference_factor=0.650407 nf=-62 time=123 busy=80
> rx=55
> ACS: 3: min_nf=-95 interference_factor=0.739838 nf=-61 time=123 busy=91
> rx=65
> ACS: 4: min_nf=-95 interference_factor=0.650407 nf=-62 time=123 busy=80
> rx=55
> ACS: 5: min_nf=-95 interference_factor=0.455285 nf=-95 time=123 busy=56
> rx=33
> ACS:  * interference factor average: 0.637399
> ACS: Survey analysis for channel 10 (2457 MHz)
> ACS: 1: min_nf=-95 interference_factor=0.390244 nf=-95 time=123 busy=48
> rx=26
> ACS: 2: min_nf=-95 interference_factor=0.373984 nf=-60 time=123 busy=46
> rx=25
> ACS: 3: min_nf=-95 interference_factor=0.439024 nf=-95 time=123 busy=54
> rx=32
> ACS: 4: min_nf=-95 interference_factor=0.422765 nf=-60 time=123 busy=52
> rx=30
> ACS: 5: min_nf=-95 interference_factor=0.382114 nf=-61 time=123 busy=47
> rx=25
> ACS:  * interference factor average: 0.401626
> ACS: Survey analysis for channel 11 (2462 MHz)
> ACS: 1: min_nf=-99 interference_factor=0.228277 nf=-99 time=38102 busy=9282
> rx=7578
> ACS: 2: min_nf=-99 interference_factor=0.228057 nf=-95 time=38252 busy=9308
> rx=7601
> ACS: 3: min_nf=-99 interference_factor=0.228001 nf=-95 time=38406 busy=9341
> rx=7631
> ACS: 4: min_nf=-99 interference_factor=0.227652 nf=-95 time=38556 busy=9362
> rx=7649
> ACS: 5: min_nf=-99 interference_factor=0.227331 nf=-95 time=38706 busy=9384
> rx=7668

Relative numbers for this would be:

time=150 busy=26
time=154 busy=33
time=150 busy=21
time=150 busy=22

Actually this reports less interference on channel 11.

> ACS:  * interference factor average: 0.227864
> ACS: Survey analysis for selected bandwidth 20 MHz
> ACS:  * channel 1: total interference = 1.59097
> ACS:  * channel 2: total interference = 2.10033
> ACS:  * channel 3: total interference = 2.71575
> ACS:  * channel 4: total interference = 2.743
> ACS:  * channel 5: total interference = 3.01982
> ACS:  * channel 6: total interference = 3.42506
> ACS:  * channel 7: total interference = 3.5531
> ACS:  * channel 8: total interference = 3.33931
> ACS:  * channel 9: total interference = 3.08912

It seems that channels 5/6/7/8/9 have increased interference here (in
comparison to the interference report for "without interference").

Either way it seems the driver/device doesn't reset the channel survey
information.

+ath9k-devel
Can someone from ath9k-devel confirm if ath9k doesn't reset survey
data after disassociation, etc? It looks to be the case here.

@Sarah: Can you reload the driver before you try each ACS run and see
if the issue persists, please?

Michał.