wifiway:~# iwpriv wlan1 highpower 1
wifiway:~# iwconfig wlan1 txpower 35
wifiway:~# iwconfig wlan1
wlan1 802.11b/g Mode:Monitor Channel=1 Bit Rate=11 Mb/s
Tx-Power=35 dBm
Retry:on Fragment thr:off
Link Quality=82/100 Signal level=20 dBm Noise level=18 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

por defecto esta a Tx-Power=14 dBm