USRP timestamps

Hello!

I´ve got a code to write and need some help.
I´ve got gnuradio installed and the USRP up and running. I need to write
some python code that does the following:

  • it captures wlan traffic and tells me at which time a packet arrived
    and at which time the transmission of this packet ended.

I do not need to decode the packet and neither do I need to know what
kind
of packet that was, just the “timestamps” and the duration. So can
anybody
give me a hint or maybe a link with some material on how to do that?

I already successfully can run the usrp_fft.py and I can see that the
USRP
is working fine and I can see the device receiving signals if I set it
to
the correct frequency, so I know that it works, I just need a simple
code
that gives me an output of timestamps.

Thanks!"
tomek