Phones

The inventor of the first mobile phone was Martin Cooper, an employee of Motorola on April 3, 1973, although many cited the inventor of a mobile phone is a team from one of the divisions of Motorola (the division where Cooper works) with the first model is DynaTAC. The idea coined by Cooper is a small, flexible travel-carrying instrument. Cooper and his team face the challenge of how to incorporate all the electronic materials into the small tool for the first time. But finally a first mobile phone successfully completed with a total weight of two kilograms. To produce it, Motorola costs equivalent to US $ 1 million. "In 1983, portable mobile phones cost US $ 4 thousand (Rp36 million) equivalent to US $ 10 thousand (Rp90 million). Having succeeded in producing mobile phones, the next biggest challenge is to adapt the infrastructure to support the mobile phone's communications system by creating a network system that requires only 3 MHz spectrum, equivalent to five channel TV channels across the globe. Another character who is known to be very meritorious in the world of cellular communication is Amos Joel Jr. who was born in Philadelphia, March 12, 1918, he is indeed recognized as a world expert in the field of switching. He received a bachelor's degree (1940) and master (1942) in electronic engineering from MIT. Not long after the study, he began his career for 43 years (from July 1940-March 1983) at Bell Telephone Laboratories, where he received over 70 US patents in telecommunications, particularly in the field of switching. Amos E Joel Jr., establishes a mobile phone switching system from one cell region to another. This switching should work when mobile phone users move or move from one cell to another so that the conversation is not interrupted. Because of Amos Joel's invention the use of mobile phones is convenient.