The basic concept of cellular phones began in 1947. Bell Laboratories introduced the idea of cellular communications in 1947 with the police car technology and Motorola was the first to incorporate the technology into portable device that was designed for use outside of an automobile. During that same year, AT&Tproposed that the Federal Communications Commission (FCC) allocate a large number of radio-spectrum frequencies so that widespread mobile telephone service would become feasible and AT&T would have an incentive to research the new technology. However, broadcasting and sending a radio or television message out over the airwaves would come under (FCC) regulation.
In 1968, the FCC changed its position by increasing, 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 was supposed to 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.
Dr Martin Cooper, a former general manager for the systems division at Motorola, is considered the inventor of the first modern portable handset and made the first call on a portable cell phone in April 1973 to his rival, Joel Engel, Bell Labs head of research. In 1977, AT&T and Bell Labs constructed a prototype cellular system and a year later, public trials of the new system were started in Chicago with over 2000 trial customers. Two years later in 1979 a different undertaking, the first commercial cellular telephone system began operation in Tokyo. The seventies held great promise for cell phones.
In 1981, Motorola and American Radio Telephone started a second U.S. cellular radio-telephone system test in the Washington/Baltimore area. By 1982, the slow-moving FCC finally authorized commercial cellular service for the USA. Despite the incredible demand, it took cellular phone service 37 years to become commercially available in the United States. Consumer demand quickly outstripped the 1982 system standards and by 1987, cellular telephone subscribers exceeded one million and the airways were crowded. To stimulate the growth of new technology, the FCC declared during that year that cellular licensees could employ alternative cellular technologies in the 800 MHz band. In 1988, another group, the Cellular Technology Industry Association (CTIA) was established to work with the cellular service operators and researchers to identify new technology requirements and set goals to introduce a new product by 1991. Shortly after, the Telecommunications Industry Association (TIA) created a standard specification based on the requirements the CTIA had recommended. The result was that wireless network divided them into time slots with each phone user having access to one time slot at regular intervals. These time slots will be discussed later in this unit.