QCA9880 slow performance adhoc/IBSS mode

Ralph Houthoofdt ralph.houthoofdt at ugent.be
Tue Feb 28 10:02:08 PST 2017


Dear Ben,

I ran the same test again, this time running the iperf3 server on my laptop
and the client on the node. I could indeed see CPU usage rise to 40% on my
laptop, the node stayed at roughly 10%. The speeds remained roughly the
same. 215Mbit one way, 40Mbit the other.

As for the tx/rx rates I get these values:
tx bitrate:     234.0 MBit/s VHT-MCS 3 80MHz VHT-NSS 2
rx bitrate:     87.8 MBit/s VHT-MCS 2 80MHz VHT-NSS 1

I set the 4 antennas facing different directions approximately at 135 degree
angles relative to the device.

Thank you for your help so far. I will be leaving home for a few hours and
will be responding to any replies tomorrow morning.

Met vriendelijke groeten,
Ralph Houthoofdt
Student industriële wetenschappen informatica

-----Original Message-----
From: Ben Greear [mailto:greearb at candelatech.com] 
Sent: dinsdag 28 februari 2017 18:42
To: Ralph Houthoofdt <ralph.houthoofdt at ugent.be>
Cc: ath10k at lists.infradead.org
Subject: Re: QCA9880 slow performance adhoc/IBSS mode

Try UDP to make sure you are not hitting a TCP issue.

Try running iperf server on another laptop so that CPU of your nodes is less
important.

Check the tx/rx encoding rates to make sure you are getting good RF
behaviour.  'iw ... station dump'

Ensure antennas are not pointing all in the same direction so that you can
get some diversity working.

Thanks,
Ben

On 02/28/2017 09:36 AM, Ralph Houthoofdt wrote:
> Dear Ben,
>
> Thank you for your quick reply.
>
> My mesh is running on channel 36  using VHT80 and a TX power of 20 
> dbm, the maximum allowed according to my regulatory settings from iw 
> reg get. The hwmode is set as 11a.
> I have also enable the following ht_capabilities on my radio in
> /etc/config/wireless:
>
>         list ht_capab 'short_gi_80'
>         list ht_capab 'max-mpdu-11454'
>         list ht_capab 'TX-STBC-2BY1'
>         list ht_capab 'RX-STBC1'
>         list ht_capab 'RX-ANTENNA-PATTERN'
>         list ht_capab 'TX-ANTENNA-PATTERN'
>         list ht_capab 'MAX-A-MPDU-LEN-EXP7'
>
> I just finished running iperf3 from my laptop (2nd gen Core i7) to one 
> of my nodes. The results were indeed a bit different.
> Iperf server was running on my node and my laptop was the client.
> UDP:
> Normal: average result of 221Mbit, which is pretty normal I think.
> Reverse: average result of 41Mbit, which is better than the average 
> 20Mbit I got when running iperf3 using 2 nodes.
> TCP:
> Normal: average result of 49Mbit
> Reverse: average result of 35.4Mbit
>
> In terms of congestion, I'm not sure what you mean, but I'm in a low 
> populated area with few wireless access points. I disabled all my 5GHz 
> devices except for the mesh nodes. InSSIDer only shows my nodes in the 
> 5GHz range.
>
> Is there anything else I could try for you?
>
> Met vriendelijke groeten,
> Ralph Houthoofdt
> Student industriële wetenschappen informatica
>
> -----Original Message-----
> From: ath10k [mailto:ath10k-bounces at lists.infradead.org] On Behalf Of 
> Ben Greear
> Sent: dinsdag 28 februari 2017 17:56
> To: Ralph Houthoofdt <ralph at rora.be>; ath10k at lists.infradead.org
> Subject: Re: QCA9880 slow performance adhoc/IBSS mode
>
> Run iperf on a separate machine, as the apu2 have too weak of a CPU to 
> drive the wifi network at full speed.  And, publish what results you 
> do get, including RF information such as channel and how congested is 
> your test area.  Try udp as well as tcp.
>
> Thanks,
> Ben
>
> On 02/28/2017 08:51 AM, Ralph Houthoofdt wrote:
>> Dear all,
>>
>> I’m currently doing me masters thesis on the subject of Wireless Mesh 
>> Networks and how to optimize them for home use.
>> The devices I use are 5x PC Engine APU2c4 with 2x QCA9880 chip 
>> (Compex WLE900VX). All of them are running LEDE (OpenWRT fork).
>>
>> The problem I’m experiencing is the same as 
>> http://lists.infradead.org/pipermail/ath10k/2017-January/009075.html .
>> Using the tips mentioned I did not come to a better performance. I’m 
>> thinking it’s driver related..
>> When running iperf3 only one direction is running at a reasonable 
>> throughput. Since I am using adhoc mode primarily I decided to use 
>> these
>> packages:
>> -	Kmod-ath10k-ct
>> -	Ath10k-firmware-qca988x-ct
>> Some sources on the internet said that using the Candela Tech drivers 
>> should result in better support for adhoc/mesh networks.
>>
>> As suggested in the other issue linked above, I switched TCP 
>> congestion control to ‘Reno’ instead of the default ‘Cubic’.
>> I also did try the command “iw reg set BE” since I am from Belgium, 
>> but running “iw reg get” right after still gave me US as a result.
>>
>> Let me know what additional command info I should post. Any help 
>> would be greatly appreciated.
>>
>> Iwconfig:
>> adhoc0    IEEE 802.11  ESSID:"mesh"
>>           Mode:Ad-Hoc  Frequency:5.18 GHz  Cell: 02:CA:FE:CA:CA:40
>>           Tx-Power=20 dBm
>>           RTS thr:off   Fragment thr:off
>>           Encryption key:off
>>           Power Management:off
>>
>>
>> Iw reg get (I’m from Belgium):
>> global
>> country BE: DFS-ETSI
>>         (2402 - 2482 @ 40), (N/A, 20), (N/A)
>>         (5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
>>         (5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
>>         (5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS
>>         (57000 - 66000 @ 2160), (N/A, 40), (N/A)
>>
>> phy#1
>> country US: DFS-FCC
>>         (2402 - 2472 @ 40), (N/A, 30), (N/A)
>>         (5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
>>         (5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
>>         (5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
>>         (5735 - 5835 @ 80), (N/A, 30), (N/A)
>>         (57240 - 63720 @ 2160), (N/A, 40), (N/A)
>>
>> phy#0
>> country US: DFS-FCC
>>         (2402 - 2472 @ 40), (N/A, 30), (N/A)
>>         (5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
>>         (5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
>>         (5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
>>         (5735 - 5835 @ 80), (N/A, 30), (N/A)
>>         (57240 - 63720 @ 2160), (N/A, 40), (N/A)
>>
>>
>> Kind regards,
>> Met vriendelijke groeten,
>> Ralph Houthoofdt
>> Student industriële wetenschappen informatica
>>
>>
>> _______________________________________________
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>> ath10k at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/ath10k
>>
>
> --
> Ben Greear <greearb at candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com
>
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>

--
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com




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