The highest altitude at which a land-based mobile phone call was successfully made is 8,848 m (29,029 ft), achieved by Rod Baber (UK) using a Motorola MOTO Z8 on the summit of Mt Everest, Nepal, at 12.52 am GMT on 21 May 2007.
Rod telephoned (local time 5.37 am) a voicemail account set up by Motorola which lasted for 1 min 48 sec and cost £2.39 ($4.72). It was able to happen, due to China building a mobile phone antenna in line of sight to the North Ridge.
Rod Haber and his team summitted via the North Col, North Face and the North East Ridge. He also holds the record for the highest text message.
The call became possible because of the China Telecom’s mobile phone tower set at the base camp on the north side of the mountain.