Cell Phone Development - Motorola Solutions USA
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Cell Phone Development

1973 - 1983: Making History: Developing the Portable Cellular System

In the communications world, the Motorola brand brings to mind innovation. Years of experience engineering portable two-way radio systems led to Motorola's vision of personal, portable communications. The result was the world's first commercial portable cellular phone in 1983. Motorola's DynaTAC 8000X phone and the cellular system behind it changed how the world communicates.

Building the foundation
Motorola's success in cellular had its roots in the company's earlier research. Born as the Galvin Manufacturing Corporation in Chicago in 1928, the company was a radio communications pioneer. The company produced its first Motorola-branded car radio in 1930, followed soon after by radios for public safety officers. In 1940 Motorola developed its first handheld radio, the Handie-Talkieā„¢ portable two-way radio, designed for the U.S. military. More two-way radios for public safety and businesses, and entertainment radios for consumers -- many of them portable -- were among the products the company made during the 1940s through the 1960s. Motorola had a mobility mindset dedicated to making communications available where and how people needed them.

Welcoming cellular technology
The car radiotelephone industry provided a new opportunity for Motorola to help people communicate. Beginning in 1946 when radiotelephone service began in the U.S., the company produced mobile telephones in cars or "car phones," as they came to be called. Radiotelephones essentially were two-way radios connected to the landline telephone system.

However, problems with car radiotelephone systems emerged as their popularity grew. Due to the limited number of available frequencies, car phone systems allowed only a few calls at one time. Frustrated callers often experienced long waits. In addition, radio channels could not be reused in nearby areas because of interference from the high-powered base stations.

In 1968, the U.S. Federal Communications Commission (FCC) proposed to allocate frequencies in the 800-900 MHz range for a new technology to solve these problems. Cellular technology, conceptualized by Bell Laboratories (AT&T) years earlier, was a possible solution. Geographical areas would be broken into small adjacent cells and many more car phones could be used at one time. A network of cell sites would be supported by a call-switching infrastructure that tracked users as they moved through the network and automatically switched their calls as their location changed. By the early 1970s, AT&T and Motorola both announced plans for high-capacity mobile telephone systems based on cellular technology.


Motorola's portable cellular concept
While AT&T developed a system based on mobile (car) phones, Motorola decided to apply its decades of radio expertise and compete with AT&T for access to the proposed new radio frequencies.

When Motorola engineers began researching cellular technology, they soon recognized its potential. But their vision went far beyond car-based phone technology. "When you park your car and leave, you can't use your mobile [car phone] but you can take your portable with you," stated Martin Cooper, who was one of the leaders in early cellular development at Motorola. The company's idea was a big one: It would involve not only creating a portable wireless phone, but also building the system and infrastructure to support it. The Motorola team would have to prove to the FCC that a cellular system compatible with portable phones would work. They did not have much time.

Creating the first wireless portable cell phone in the world was an enormous challenge. No one had ever seen one before, so there was nothing to compare it to. Cooper called on Motorola's industrial design director, Rudy Krolopp, and his team to design the shape of the phone. A three-dimensional model needed to be built within days in order to have a working prototype for the FCC meeting in six weeks.

After several days of continual work, Krolopp's team gathered for dinner at a nearby restaurant to present their concepts. Hours later, they emerged with a winning design. "We called it a shoe phone, because it sort of looked a little bit like a boot," recalled Krolopp.

The design and engineering teams began to work together at a fast pace to meet the impending deadline. The engineers' challenge now was to make the electronics small enough to fit in the handset that Krolopp's team designed. Fortunately, because of Motorola's two-way radio and semiconductor experience, the company already held patents on, and manufactured, much of the basic electronics needed for a portable phone system.

By February of 1973, Motorola had produced a working DynaTAC (DYNamic Adaptive Total Area Coverage) portable phone prototype. They presented the DynaTAC prototype phone and system concept to the FCC, which soon announced that it would hold new hearings on allocating spectrum for cellular service. It was an incredible achievement for the Motorola team. But they now faced another challenge: designing a commercial large area system that would enable their portable phone to operate.


Designing a portable system
The DynaTAC cellular system required phone calls to be switched from cell to cell as users traveled. Making that happen without a high rate of dropped calls required innovative engineering. And foremost, Motorola had to create a high capacity system that worked with both portable phones and mobile car phones.

The Motorola engineering team's concept involved designing a large number of overlapping cells in a geographic area. Low powered transmitters in each cell allowed frequencies to be reused in cells farther away. Computerized network equipment tracked the moving caller through the system and automatically switched the call to a new cell and frequency as the caller changed locations (a process known as "hand-off"). The system automatically adjusted the phone's transmitting power so it would not interfere with neighboring cell sites and linked the call with the wireline telephone network. Specialized directional antennas focused the radio signal where it was needed. As more people subscribed to cellular services, the system could be expanded by splitting cells and making many smaller cells within the same geographic area. Because the radio channels used a narrower bandwidth than the older car radiotelephone system, hundreds more available channels meant more people could share the same radio spectrum.

To test their concept Motorola engineers spent many hours in Chicago, New York City and Washington, D.C., deploying experimental equipment, taking measurements and testing radio signals. The prototype system now was ready for a market trial with paying subscribers. When the F.C.C. granted a developmental license for the Baltimore-Washington, D.C., area in 1977, Motorola supplied DynaTAC cellular equipment. One user summarized the new experience, "My business calls are automatically forwarded to my DynaTAC portable and I'm always in touch!"

The DynaTAC cellular radiophone system's unique features created a complete system tailored to the needs of both car and portable phones. While Motorola worked with U.S. government agencies to receive regulatory approval, the team continued to test and refine the technology. Meanwhile, the cellular concept was spreading through other parts of the world. Motorola began supplying systems and phones to other countries.

Achieving A World First
On September 21, 1983, Motorola made history when the FCC approved the DynaTAC 8000X phone, the world's first commercial portable cell phone. After more than 10 years and a US$100 million investment, Motorola's commitment produced an innovative portable technology that revolutionized the communications industry and changed the lives of people around the world.



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