Incorrect Atheros txpower output

[JoaoBR]

On Tuesday 29 July 2008 17:38:57 Sam Leffler wrote:
> M. Warner Losh wrote:
> > In message: <6fe7c62a0807291226x15ef59bcn334c97562f3399b8 at mail.gmail.com>
> >
> >             "Mohammad Ikram" <ikram at wideband.com.pk> writes:
> > : Hi !
> > :
> > : I am using FreeBSD 7.0 and recently installed a Engines EPI-3601S card.
> > : The card has an Atheros chip with a 27dBm output power rating. I am
> > : using it as hostap. FreeBSD detects it fine, but the trouble is FreeBSD
> > : does not takes the power level up. The max i was able to set is was
> > : 16dBm. (ifconfig ath0 txpower xx). I tried it on linux with madwifi but
> > : same results, so i started having a few doubts with this card, a friend
> > : of mine suggested that i should try the router OS (www.mikrotik.com) i
> > : did, and it worked perfectly.
> > :
> > : can any one tell me why can't i change the power level ? (i did changed
> > : country codes, to no avail)  i read some where it is the problem with
> > : the driver ? so is there any patch ?
> >
> > Did you measure the output power directly?  Many cards have a final
> > stage amplifier that kicks things up a few dB...  Maybe router OS
> > knows about this card's quirks and copes...
>
> The external PA's you're thinking of are not controllable by the host;
> they are always present.  The original post doesn't explain how mikrotik
> "worked perfectly" while freebsd did not.  I have measured many high
> power cards with a power meter and SA under FreeBSD and have never seen
> a power cap other than that imposed by regulatory or vendor mis-claims.
>

certainly the poster has reason here, follows an ifconfig from a machine with 
a DLINK AG530 (ath1) which has 60mW I think and a genius 400mW card (ath0), 
both show with same power values

but clients connected to each card (and switching them between both ssid) show 
that they get a far better RSSI on the stronger card, something about 20-25%

also on client site you can see a clearly stronger signal what on a FreeBSD 
ath client shows up with  30% more RSSI when connected to the 400mW

I do not believe that this card really has 400mW, if then the signal or RSSI 
should be far stronger but is not, I compare to a test I run with an 0.5W 
amplifier I sticked onto the Dlink card which than gives a really signal 
boost

I also have no comparism to other OS with this cards and I am not so worried 
about what ifconfig tells because at the end the signal is stronger

I use this ath_hal: 0.10.5.6  but the former hal gave same results




ath0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 
1500
        ether 00:02:6f:4a:a6:29
        media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11b <hostap>
        status: associated
        ssid LUCENET-CW channel 6 (2437 Mhz 11b) bssid 00:02:6f:4a:a6:29

        wepkey 4:40-bit powersavemode OFF powersavesleep 100 txpower 31.5
        txpowmax 18.0 rtsthreshold 2346 fragthreshold 2346 bmiss 7
        scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi11a 7
        roam:rate11a 12 roam:rssi11b 7 roam:rate11b 1 roam:rssi11g 7
        roam:rate11g 5 -pureg protmode CTS -ht -htcompat -ampdu ampdulimit 8k
        ampdudensity - -amsdu -shortgi htprotmode RTSCTS -puren -wme burst -ff
        -dturbo hidessid -apbridge dtimperiod 1 doth inact bintval 100

ath1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 
1500
        ether 00:19:5b:cf:26:78
        media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11b <hostap>
        status: associated
        ssid LUCENET-CS channel 1 (2412 Mhz 11b) bssid 00:19:5b:cf:26:78

        wepkey 4:40-bit powersavemode OFF powersavesleep 100 txpower 31.5
        txpowmax 18.0 rtsthreshold 2346 fragthreshold 2346 bmiss 7
        scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi11a 7
        roam:rate11a 12 roam:rssi11b 7 roam:rate11b 1 roam:rssi11g 7
        roam:rate11g 5 -pureg protmode CTS -ht -htcompat -ampdu ampdulimit 8k
        ampdudensity - -amsdu -shortgi htprotmode RTSCTS -puren -wme burst -ff
        -dturbo hidessid -apbridge dtimperiod 1 doth inact bintval 100





-- 

João







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