On my Raspberry Pi 3 running Raspbian
iwconifg produces the following output:
wlan0 IEEE 802.11bgn ESSID:"ssid of my network" Mode:Managed Frequency:2.452 GHz Access Point:******* Bit Rate=72 Mb/s Tx-Power=1496 dBm Retry short limit:7 RTS thr:off Fragment thr:off Power Management:on Link Quality=39/70 Signal level=-71 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 lo no wireless extensions. eth0 no wireless extensions.
According to the definition of dBm (see https://en.wikipedia.org/wiki/DBm) such a high tx power is not possible due to energy conservation :-).
Thus I have the following questions:
* What do I have to do, to see the right tx-power?
* Is it a bug of iwconfig or the broadcom kernel driver?
The Raspberry Pi uses for wlan the BCM43438 (see www.raspberrypi.org/magpi-issues/MagPi43.pdf, page 10 of pdf). I see exactly the same tx power on a Raspberry Pi 1 running ArchLinux ARM with the official Raspberry Pi Wifi Dongle (www.raspberrypi.org/products/usb-wifi-dongle/), which has the BCM43143 chipset. Also other users with the same hardware seem to have this problem: Does BCM43438 Wireless chip in Raspberry Pi 3 support ad-hoc networking?