
Baber was sponsored by Motorola to make the attempt and managed to make the call from 29,035 feet above sea level in temperatures of -30 degrees. The call can be heard here.
"Everest symbolises the greatest challenge to any climber. To reach the summit and achieve world records with Motorola is a once-in-a-lifetime opportunity," said Baber from Everest Base Camp.
The call involved a number of technical challenges. The Chinese government had to set up a base station within line of sight of the summit, and the phone's batteries had to be taped to Baber's body to keep them warm enough to function.
The climber made two calls, one for publicity purposes and another to let his wife and children know he was OK. The calls had to be kept short to stop Baber passing out from lack of oxygen. He also sent one text message.