Does 802.11 wireless card trigger any event upon data rate change?

Question

In 802.11 WLAN, there is data rate change of the connection as Dynamic rate scaling or Automatic Rate Selection is working. Is there any event triggered from the card so as to notify the OS (Linux Kernel event) about the same?

I know something about "iw events". Unfortunately it does give events like association, authentication etc but not of the data rate changes.

Please let me know if anyone aware of such functionality on any wireless card.

Thanks, Kedar

Answer 1

TX or RX rate?

It also depends on what kind of driver is used. If the rate control algorithm is implemented in the firmware then likely it's not possible. If the driver uses mac80211 then you can create a monitor interface and use e.g. tcpdump:

% sudo iw phy0 interface add mon0 type monitor
% sudo ifconfig mon0 up
% sudo tcpdump -ni mon0

Then you'll also get quite some information about the PHY for each packet.