Mobiles Biography:
The mobile phone was launched in the UK in 1985 and now, there are statistically more mobile phones in the country than people. There is no question that the mobile phone has had a tremendous and lasting impact on our lives. In many ways, more so than any other form of telecommunications technology. Can you imagine life without your smart phone that allows you to browse the web, download apps, send text messages, check your email, take photographs, play music, find out where you are using the built-in GPS receiver and, by the way, also make telephone calls? But how did it all begin and how has the mobile phone evolved from those early days of 1985 when a mobile phone was exactly that, a device for making telephone calls whilst outside? This section will trace that evolution from the walkie talkie to high performance smart phones.
A cellular phone, in actuality is really a radio, a very sophisticated one at that, but a radio nonetheless. A cellular phone system can be compared to a CB radio system. A CB radio uses the same frequency for transmitting and receiving, therefore only one person can speak at a time and the other has to listen (the practice of saying 'over' is to inform the other person that the speaking person has finished speaking). A communication device using single frequency is categorized as a simplex device. A cell phone on the other hand is a duplex device; i.e. it uses one frequency for transmitting and a second, separate frequency for receiving. Cell phones operate within cells that is the system uses many base stations to divide a service area into multiple 'cells'. Cellular calls are transferred from one station (transmitting tower) to another as the phone moves from cell to cell. This switching mechanism allows cellular phones to have virtually unlimited ranges.
The concept of cellular phones first came to light in 1947, when researchers realized that by dividing service areas into small cells, and reusing frequencies the Car phone traffic could be immensely increased. The only problem was the lack of technology, which hampered the realization of this concept.
Since a cell phone is actually a type of two-way radio, AT&T proposed that the Federal Communications Commission (FCC) allot a large number of radio frequencies so that wide-spread mobile telephone service could become feasible and communication giants could enter the field. This would not only create a bigger market but also provide incentive to research the new technologies. The FCC adopting a conservative approach allocated very few frequencies thus allowing only twenty-three phone conversations to occur simultaneously in the same service area. This was highly inefficient and uneconomical considering the huge investment the companies would have to pump into equipment and research and development. The FCC revised its decision and allowed more frequencies on the condition that a better more sophisticated mobile network be established. AT&T - Bell Labs, again at the forefront of innovation and development, proposed a cellular system based on small, low-powered broadcasting towers, each covering a 'cell' a few kilometers in radius, jointly covering a larger area. Each tower would service the mobiles present in its coverage areas and pass them onto the next tower as they moved out of its coverage area, thus at any particular moment very few frequencies would be required.
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Nokia Mobile Phones Of The Future (1)
The Mobiles
