QCA99XX with MU-MIMO and beamforming?

[Michal Kazior]

On 2 May 2016 at 19:59, Ben Greear <greearb at candelatech.com> wrote:
> On 04/26/2016 11:37 PM, Michal Kazior wrote:
>>
>> On 26 April 2016 at 16:35, Ben Greear <greearb at candelatech.com> wrote:
>>>
>>>
>>>
>>> On 04/25/2016 11:16 PM, Michal Kazior wrote:
>>>>
>>>>
>>>> On 25 April 2016 at 22:31, Ben Greear <greearb at candelatech.com> wrote:
>>>>>
>>>>>
>>>>> Has anyone tried this?  Looks like hostapd has the ability to set the
>>>>> feature flags, but I am not sure if it is really working in ath10k?
>>>>
>>>>
>>>>
>>>> Yes, it works. You need a few vht_capabs. I have mine like this:
>>>>
>>>>    >
>>>>
>>>> vht_capab=[RXLDPC][SHORT-GI-80][TX-STBC-2BY1][SU-BEAMFORMER][SU-BEAMFORMEE][MU-BEAMFORMER][RX-ANTENNA-PATTERN][TX-ANTENNA-PATTERN][BF-ANTENNA-4][MAX-MPDU-11454][RX-STBC-1][MAX-A-MPDU-LEN-EXP7]
>>>>
>>>> The SU-, MU- and BF- are the required part only I think.
>>>>
>>>>
>>>>>
>>>>> Do you actually need anything other than standard whip antenna to
>>>>> allow this to function properly?
>>>>
>>>>
>>>>
>>>> I don't think. FWIW Make sure the antennas are reasonably set
>>>> up/separated from each other. If you cram them too tight/randomly
>>>> beamforming won't work efficiently. I had problem with client antennas
>>>> being too close to each other and lying flat on a table (I than made a
>>>> foam-stand and put them a few cm apart) so the same thing must apply
>>>> to AP as well.
>>>>
>>>>
>>>>>
>>>>> What about station mode?
>>>>
>>>>
>>>>
>>>> Works as well. Both on QCA99XX and QCA9377.
>>>
>>>
>>>
>>> Thanks for the info.  How did you determine that it actually worked?
>>
>>
>> Empirically. If you get 600mbps UDP to two 1x1 clients it works :)
>>
>> Also, the rx bitrate on the receiving ath10k end will be kind of wierd
>> (there's currently no way to decode MU ratesets on Rx because group
>> ids are managed in firmware).
>
>
> So, I configured 3 systems:  1 is AP, two are acting as stations.
>
> All are 9980, but the two station systems are forced to act like
> 1x1.
>
> Single station download is about 270Mbps over-the-air.  But, when I
> add the second station, then total over-the-air stays at about 270Mbps.
>
> So, I guess mu-mimo is not actually working for me.
>
> My hostapd config looks like this (below).  Does it look right?  Do I need
> something
> special in wpa_supplicant config on the station side?

Nope.


[...]
> [TX-STBC][RX-STBC123][MAX-AMSDU-7935][DSSS_CCK-40][PSMP][LSIG-TXOP-PROT]
> ht_capab=[HT20][HT40+][SHORT-GI-40][SHORT-GI-20]
> vht_capab=[MAX-MPDU-11454][RXLDPC][TX-STBC-2BY1][RX-STBC-1][MAX-A-MPDU-LEN-EXP0][RX-ANTENNA-PATTERN][TX-ANTENNA-PATTERN][SU-BEAMFORMER][SU-BEAMFORMEE][MU-BEAMFORMER][SHORT-GI-80]

Are you sure you want to use EXP0? There was a bug in hostapd long
time ago that required that IIRC.. you should be setting EXP7 now, no?

FWIW you're missing BF-ANTENNA-4. Not sure if this is really necessary.

Other than that I guess you can look at debugs/traces (or add prints)
to see if vdev txbf param is set properly on both ap and clients and
if peer-assoc vht_caps include MU-.


Michał