Interview with mobile phone inventor Marty Cooper
3 April 2013 Last updated at 17:26 BST
The first mobile phone call was made 40 years ago today, on 3 April 1973.
Martin Cooper, a senior engineer at Motorola, called a rival colleague at another telecoms company and announced he was speaking from "a 'real' cell telephone".
Mr Cooper, aged 85, is now renowned as the "father" of the mobile phone.
In an interview with BBC Click's Richard Taylor, Mr Cooper recounted the story and shared his thoughts on why he thinks the industry has innovated in the wrong direction.