#!/usr/bin/python
# coding: utf-8

# $ sudo  iw dev wlan0 interface add mon0 type monitor
# $ sudo ip link set dev mon0 up

interface = "mon0"

#######################################################
from scapy.all import *
import time

t_prev = None

def prn(p):
    global t_prev
    p.show()
    if p.haslayer(Dot11Beacon):
        if t_prev:
            print time.time() - t_prev[0], p.timestamp - t_prev[1]
        t_prev = [time.time(), p.timestamp]

sniff(iface=interface,prn=prn)