|
Martin Cooper and invention of cell phone
The first automatic analog cellular phone was made in the 1960's. Commercial models were introduced in Japan by NTT on December 3, 1979. They were introduced in Scandinavia in 1981, in Chicago, USA, on October 13, 1983 (by Motorola), and in Europe in the late 1980's. Early mobile FM (frequency modulation radio was invented by Edwin H. Armstrong in 1935) radio telephones had been in use in the USA since 1946, but since the number of radio frequencies are very limited in any area, the number of phone calls was also very limited. Only a dozen or two calls could be made at the same time in an area. To solve this problem, there could be many small areas (called cells) which share the same frequencies. But when users moved from one area to another while calling, the call would have to be switched over automatically without losing the call. In this system, a small number of radio frequencies could accommodate a huge number of calls. This cellular phone concept was devised by a team of researchers at Bell Labs in 1947, but there were no computers available to do the switching. As small inexpensive computers were developed, cell phones could be produced. Motorola holds the US patents for the cell phone. Henry Taylor Sampson and George H. Miley hold a 1968 patent (US patent #3,591,860) on a "gamma electric cell," which is not a component 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 they could increase the traffic capacity of mobile phones substantially. However at that time, the technology to do so was nonexistent.
Anything to do with broadcasting and sending a radio or television message out over the airwaves comes under Federal Communications Commission (FCC) regulation. A cell phone is a type of two-way radio. In 1947, AT&T proposed that the FCC allocate a large number of radio-spectrum frequencies so that widespread mobile telephone service would 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 initial concept of cellular service and its availability to the public. The FCC decided to limit the amount of frequencies available in 1947, the limits made only twenty-three phone conversations possible simultaneously in the same service area - not a market incentive for research.
The FCC reconsidered its position in 1968, stating "if the technology to build a better mobile service works, we will increase the frequencies allocation, freeing the airwaves for more mobile phones." AT&T and Bell Labs proposed a cellular system to the FCC of many small, low-powered, broadcast towers, each covering a 'cell' a few miles in radius and collectively covering a larger area. Each tower would use only a few of the total frequencies allocated to the system. As the phones traveled across the area, calls would be passed from tower to tower.
|
