We know that when someone is speaking on the radio with ATC, he tells his call sign. But is there any other system that verifies the identity of the person speaking besides
![Listen LIVE to Bankstown Airport Control Tower Frequencies =============================================================================== Listen LIVE to Bankstown Airport Control Tower Frequencies ===============================================================================](http://www.grahamswebdesign.com/bankstownrunways.jpg)
Listen LIVE to Bankstown Airport Control Tower Frequencies ===============================================================================
![BBC Radio 5 Live on Twitter: "Heathrow Airport is pushing ahead with its £14bn plan for a third runway. Their expansion director Emma Gilthorpe says it will benefit all of us by BBC Radio 5 Live on Twitter: "Heathrow Airport is pushing ahead with its £14bn plan for a third runway. Their expansion director Emma Gilthorpe says it will benefit all of us by](https://pbs.twimg.com/media/D9U8TDYXUAEJ9SF.jpg)