title: how to find ap current channel when beacon frame is seen on multiple channel like 4,5,6 while sniffing
body: <p>I am trying to find answer for above question, but couldn't find  anything.
  Question is : i have three sniffer which are capturing packet on different channel like channel 4,5,6. On all three sniffer, i am getting beacon frame from same ap for same ssid. From this, how to find the ap current operating channel. whether there is any field in beacon frame to indicate this.</p>