Mobile phone technology has come a long way since the first mobile phone call was made 40 years ago, but there is a lot more innovation to look forward to, according to one expert.
On April 3 1973 in America, Motorola employee Martin Cooper made the first ever call on a mobile phone - a triumph that lead to years of development, new inventions, and to what we know as the smartphone today.
People depend on phones for internet access, social networking, maps, morning alarms, games, apps and more - but an experimental phone call in 1973 is where it all began.
Dr Mike Short, an expert from the Institution of Engineering and Technology, said Mr Cooper's phone call is the first public call people recognise as being a cellular mobile call.
"He worked for Motorola. He had a lot of technology and research rivalry with a company called AT&T. He made a phone call from Motorola to AT&T saying 'I'm ringing you just to see if my call sounds good at your end', or something to that affect," he said.
Dr Short said the 10 years following that first call were "very much developmental", with research being carried out in laboratories before services were launched in 1981 in the US. The two most significant developments in mobile phone technology have been the widespread availability of devices and their ability to access the internet, according to Dr Short.
"In the early days of mobile, consumerisation was not considered. It was made for men in suits in business, whereas consumerisation followed much later.
"And then access to the internet followed much later again. The first smart phones weren't until about five years ago. So the pace of change has actually sped up over the 40 years, particularly in the last 15 to 18 years," he said.
Dr Short expects mobile technology to continue to evolve and said people can expect even more developments in future.
"More changes are expected. The early days of mobile were all about voice, whereas today it's much more about data."