FreeBSD-8.0 802.11n support with ath/mwl

[Bernhard Schmidt]

On Sun, Feb 28, 2010 at 12:38:19PM -0500, Jim Pingle wrote:
> On 2/28/2010 7:54 AM, Rui Paulo wrote:
> > On 28 Feb 2010, at 03:22, Jim Pingle wrote:
> >>
> >> Are you aware if similar work ongoing for the mwl(4) based 802.11n
> >> cards? I picked up a couple cheap this past week and have them working
> >> with hostapd but, as with the OP in the thread, only with G rates.
> >>
> >> The ifconfig[1] output suggests that it is using 40MHz wide ht channels
> >> but devices only associate at 54Mbps[2].
> >>
> >> Jim
> >>
> >> [1] ifconfig mwl0_wlan1
> >> mwl0_wlan1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0
> >> mtu 1500
> >> ether 00:01:36:17:96:0e
> >> inet6 fe80::201:36ff:fe17:960e%mwl0_wlan1 prefixlen 64 scopeid 0x9
> >> inet 192.168.15.1 netmask 0xffffff00 broadcast 192.168.15.255
> >> nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
> >> media: IEEE 802.11 Wireless Ethernet autoselect mode 11na <hostap>
> >> status: running
> >> ssid WatchTower channel 100 (5500 MHz 11a ht/40+) bssid 00:01:36:17:96:0e
> >> regdomain DEBUG indoor authmode WPA2/802.11i privacy MIXED deftxkey 3
> >> AES-CCM 2:128-bit AES-CCM 3:128-bit txpower 14 scanvalid 60
> >> ampdulimit 64k ampdudensity 4 shortgi smps burst dtimperiod 1
> >>
> >>
> >> [2] ifconfig mwl0_wlan1 list sta (w/addr removed)
> >> AID CHAN RATE RSSI IDLE  TXSEQ  RXSEQ CAPS FLAG
> >> 1  120  54M 33.0    0   1537  25952 EP   A       RSN (rssi 68:20:20 nf
> >> 0:0:0)
> > 
> > mwl supports HT rates, but it looks like your AP is not sending HT rates to you.
> 
> Thanks for the quick clarification, that's very encouraging to find out!
> 
> In this case, the mwl card is the AP. The client line is from an
> associated Windows 7 laptop with an Intel 5100abgn card which does show
> the AP as 802.11n in the AP list. I'm connected and sending this message
> through it right now, actually.
> 
> Are there some other bits that need set in order to have clients
> associate with HT rates? Or some other prerequisite conditions such as
> number of attached antennae? I do only have one antenna attached as I
> didn't have a second pigtail for this test unit's case. The card
> actually has three connectors.
> 
> I didn't see hints in the mwl(4), wlan(4), hostapd(8), hostapd.conf(5),
> or ifconfig(8) man pages about troubleshooting rates. I see plenty of
> talk in ifconfig(8) about use and control of HT rates, but given what
> I'm seeing in ifconfig, it should be set to use them. I've tried several
> combinations of channels and standards (e.g. 11ng, 11na) but always end
> up with a 54Mbps link.
> 
> I'd appreciate any more pointers that you (or anyone else reading) may
> have. I'd like to write up something on the topic once I get it fully
> operational.

Did you measure the actual bandwidth you get? Changes are high that you
are actually using HT rates, the rate information is just no accurate.

-- 
Bernhard