Monday, February 23, 2009

History of Cellular Phones

The basic concept of cellular phones began in 1947 when researchers looked at crude mobile (car) phones and realized that by using small cells (range of service area) with frequency reuse could increase the traffic capacity of mobile phones substantially, however, the technology to do it was nonexistent.
Anything to do with broadcasting and sending a radio or television message out over the airwaves comes under a Federal Communications Commission (FCC) regulation that a cellular phone is actually a type of two-way radio. In 1947, AT&T proposed that the FCC allocate a large number of radio spectrum frequencies so that wide-spread mobile phone service could become feasible and AT&T would have a incentive to research the new technology. We can partially blame the FCC for the gap between the concept of cellular phone service and it's availability to the public. Because of the FCC decision to limit the cellular phone frequencies in 1947, only twenty three cellular phone conversations could occur simultaneously in the same service area - not a market incentive for research.
The FCC reconsidered it's position in 1968, and stated "if the technology to build a better mobile phone service works, we will increase the cellular phone frequencies allocation, freeing the airwaves for more mobile phones." AT&T - Bell Labs proposed a cellular phone system to the FCC of many small, low-powered broadcast towers, each covering a 'cell' a few miles in radius, collectively covering a larger area. Each tower would use only a few of the total frequencies allocated to the cellular phone system, and as cars moved across the area their cellular phone calls would be passed from tower to tower. By 1977, AT&T Bell Labs constructed and operated a prototype cellular phone system. A year later, public trials of the new cellular phone system were started in Chicago, IL with over 2000 trial cellular phone customers. In 1979, the first commercial cellular phone system began operation in Tokyo. In 1981, Motorola and American Radio phone started a second U.S. cellular radio-phone system test in the Washington/Baltimore area. By 1982, the slow moving FCC finally authorized commercial cellular phone service for the USA. A year later, the first American commercial for analog cellular phone service or AMPS (Advanced Mobile Phone Service) was offered in Chicago, IL by Ameritech. Despite the incredible demand, it took cellular phone service 37 years to become commercially available in the United States.
Consumer demand quickly outstripped the cellular phone system's 1982 standards, by 1987, cellular phone subscribers exceeded one million, and the airways were crowded. Three ways of improving services existed:
one - increase cellular phone frequencies allocation
two - split existing cellular phone cells
three - improve the cellular phone technology
The FCC did not want to handout any more bandwidth and building/splitting cells would have been expensive and add bulk to the cellular phone network. To stimulate the growth of new cellular phone technology, the FCC declared in 1987 that cellular phone licensees may employ alternative cellular phone technologies in the 800 MHz band. The cellular phone industry began to research new transmission technology as an alternative.

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