Hostapd and MCS rates

Huang, ChengcaiX chengcaix.huang at
Thu Jun 18 03:21:40 EDT 2015


If you use brcm chip, you can set the 11n mode rate MCS index with brcm "wl" config tool.

 root:/ # wlx nrate
mcs index 14 stf mode 3 auto
root:/ # wlx nrate -m 5                                            
root:/ # wlx nrate
mcs index 5 stf mode 1 fixed

Below is info. About the command:                                               
wl nrate: you need to set a legacy or mcs rate
nrate	"auto" to clear a rate override, or:
-r legacy rate (CCK, OFDM)
-m HT MCS index
-s stf mode (0=SISO,1=CDD,2=STBC,3=SDM)
-w Override MCS only to support STA's with/without STBC capability

-----Original Message-----
From: hostap-bounces at [mailto:hostap-bounces at] On Behalf Of Mathieu Slabbinck
Sent: Thursday, June 18, 2015 3:02 PM
To: Eduardo Abinader
Cc: hostap at
Subject: Re: Hostapd and MCS rates

Recompiled wpa_supplicant with CONFIG_HT_OVERRIDES but nothing changes.

using iw dev wlan0 set bitrates ht-mcs-5 2 sgi-5 or iw dev wlan0 set bitrates legacy-5 54 does not change the datarate of the packets.

Can I force it somehow to test if mcs rates are in fact able to be set?


On Wed, Jun 17, 2015 at 2:09 PM, Eduardo Abinader <eduardo.abinader at> wrote:
> I checked more in detail and noticed what Jouni has said previously:
> it is meant at the moment for wpa_supplicant only and for that you 
> need also CONFIG_HT_OVERRIDES=y in order wpa_set_htcap_mcs to be 
> called.
> Cheers.
> On Wed, Jun 17, 2015 at 2:48 AM, Mathieu Slabbinck 
> <matty.slabbinck at> wrote:
>> Hi,
>> Thanks for the info.
>> I'm using buildroot and checked the package. It states the following 
>> config options:
>>     CONFIG_ACS \
>>     CONFIG_HS20 \
>>     CONFIG_IEEE80211AC \
>>     CONFIG_IEEE80211N \
>>     CONFIG_IEEE80211R \
>>     CONFIG_LIBNL32 \
>> So that's checked.
>> Also, in my config file of hostapd states ieee80211n=1 So that should 
>> be fine to.
>> iw dev wlan0 station dump does not report anything...
>> On Tue, Jun 16, 2015 at 5:04 PM, Eduardo Abinader 
>> <eduardo.abinader at> wrote:
>>> Hi,
>>> I think you should enable at least CONFIG_IEEE80211N=y and 
>>> ieee80211n=1, so the HT rates are set as well as MCS rate info. Then 
>>> station dump with iw to check the MCS.
>>> Cheers.
>>> On Tue, Jun 16, 2015 at 5:41 AM, Mathieu Slabbinck 
>>> <matty.slabbinck at> wrote:
>>>> That's something I already tried but if I capture any packets they 
>>>> are not in any mcs rate.
>>>> Therefore I was wondering if hostapd provides any configuration to do this.
>>>> On Tue, Jun 16, 2015 at 11:31 AM, Avinash Patil <avinashapatil at> wrote:
>>>>> On Tue, Jun 16, 2015 at 2:53 PM, Mathieu Slabbinck 
>>>>> <matty.slabbinck at> wrote:
>>>>>> Hi,
>>>>>> I'm trying to force my AP into an mcs indexed bitrate but there's 
>>>>>> not to much information I can find around this.
>>>>>> Can anyone provide some information on how to force hostapd to 
>>>>>> set up an AP with an MCS rate?
>>>>> I think hostapd configures basic and extended rates only. If you 
>>>>> want to force using MCS rates your best bet is iw utility.
>>>>> "iw --help" yields this:
>>>>>     dev <devname> set bitrates [legacy-<2.4|5> <legacy rate in 
>>>>> Mbps>*] [ht-mcs-<2.4|5> <MCS index>*] [vht-mcs-<2.4|5> 
>>>>> <NSS:MCSx,MCSy... | NSS:MCSx-MCSy>*] [sgi-2.4|lgi-2.4] [sgi-5|lgi-5]
>>>>>         Sets up the specified rate masks.
>>>>>         Not passing any arguments would clear the existing mask (if any).
>>>>>> Kind regards
>>>>>> Mathieu
>>>>>> _______________________________________________
>>>>>> HostAP mailing list
>>>>>> HostAP at
>>>>> -Avinash
>>>> _______________________________________________
>>>> HostAP mailing list
>>>> HostAP at
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