Bad host-vased AP performace -- and qouple of questions about FreeBSD WiFi stack tuning

[Lev Serebryakov]

Hello, Adrian.
You wrote 9 августа 2011 г., 14:21:55:

>>> txpower 15 is actually 15dBm. Ie, try "ifconfig wlan0 txpower 1.5" :-)
>>  Bernhard Schmidt says, that iwn(4) uses half-dBm units and "txpower
>> 30" on iwn(4) means 15dBm physically.
> Right. I'll double-check with Bernhard as he's been knee deep in the
> iwn code. But I can tell you that the value passed from net80211 to
> ath is 2x the ifconfig power, as the ifconfig txpower is in 0.5 dBm
> units. So ifconfig wlanX txpower Y ends up storing a txpower value of
> 2*Y, and that's what ath gets. I bet iwn gets the same.
 What a mess. We have two "txpower" values -- command-line one and
 internal (2*cmd) one!

 BTW, ifconfig(8) uses very unclear wording:

 "The power argument is specified in .5 dBm units."

 It is not clear, what does it mean: that one txpower step means 0.5
 dBm and 1 on command line means 0.5 dBm, 2 means 1 dBm, and so on, up to 30
 on command line means 15dBm, OR (which seems to be true, but it is
 not clear!) it means, that you could set 0.5, 1, 1.5, and so on, and
 these numbers "true" dBm, but you cannot set 16.6, for example.

-- 
// Black Lion AKA Lev Serebryakov <lev at serebryakov.spb.ru>