Martin Cooper is the father of the mobile phone. And it’s all down to an event that took place on a pavement in midtown Manhattan on 3 April 30 years ago.

With the traffic whizzing by and New Yorkers bustling past, Marty stuck a kilo weight of plastic – housing all manner of wires and circuits – to his ear and started talking into it, becoming the first person to ever place a public call on a handheld cellular telephone.

BBC News Online tracked down this pioneer in the wireless industry at his day job in California’s Silicon Valley. Marty is the chairman, CEO and co-founder of ArrayComm, which makes software to help mobile phone carriers squeeze more calls on a network.