Thanks to the development of technology, now almost everyone owns a mobile phone, and telecommunication has become one of the most important means of communication in modern life. The advent of handsets has brought about the integration of telecommunication technology and the semiconductor industry. The first cellular phone call was made by Dr. Martin Cooper of Motorola in New York in a somewhat show-off manner to his rival, Joel Engel, at Bell Labs, AT&T. Through the years, mobile handset design has been continuously evolving with its physical size changed from “bulky” to “slim and handy”. Mobile phones not only serve as phones, but also serve as music players, cameras and internet navigation tools. In places like the Philippines and Estonia, mobile phones are even used to pay bills or public parking. They function like a bank/credit card. No one could have imagined the palm-sized gadget would become so versatile.
 

※Information source: http://en.wikipedia.org/wiki/Mobile_phone