The evolution that sparked a revolution
The term was first used around 1906, only a few years before the Radio Club of America was established, although the science and technology supporting radio dates back to at least 1873. The word radio embraces any form of electromagnetic communication. The history of radio is especially rich in colorful contributors and conflicting claims. The stories about the conception of the scientific principles behind radio and the evolution of the many industries it has spawned are dispersed into hundreds of books, articles and other documents. The original intent of this article was to illustrate the eclectic nature of radio, to demonstrate the importance of making the Radio Club of America an inclusive organization. But the richness of the history of radio is in the people who created and promoted the technologies that have had an enormous impact on all of our lives. I’ve tried to emphasize that aspect of radio as well. What follows is a tiny and incomplete snapshot of a rich and continuing industry.
Without an understanding of the underlying physics of electricity and magnetism there would have been no foundation for the creation of any kind of radio. As far back as 1820, Hans Christian Oerstad discovered the relationship between electricity and magnetism by demonstrating that a wire carrying current could deflect a magnetized compass pointer. Michael Faraday, in 1831, discovered electromagnetic induction and even suggested that these forces could extend into empty space. But James Clerk Maxwell put it all together. Among other things, he explained in 1873 the theoretical basis for the propagation of electric and magnetic waves. Even Thomas Edison dabbled in radio and patented, in 1885, a system of radio communication between ships.
Arguably the first transmission and reception of radio waves happened when, in 1878, David E. Hughes noticed that a laboratory balance produced noise into the receiver of his telephone, carrying on a tradition of accidental discoveries that included Newton’s apple — not to be confused with Steven Job’s Apple — and Alexander Graham Bell’s acid spill.
The foundation of wireless reception depended upon the invention, in 1884, of the coherer, a tube filled with iron filings that reacted to radio waves. Inventor Temistocle Calzechi-Onesti may have achieved an important position in history if he had been graced with a simpler name. But Heinrich Rudolph Hertz made the real theoretical breakthrough in the period 1886 to 1888, as he demonstrated the wave nature of electromagnetic radiation and created the mathematical equations that described this radiation. He was immortalized by the defining of “one cycle per second” as a Hertz. (Can you imagine talking about “a frequency of 2,000 Calzechi-Onesti?”)
An invention, however, requires a practical implementation, so now the fun starts. The four people most celebrated as inventors of radio were Nikola Tesla, Gugliemo Marconi, Alexander Popov, and Jagdish Chandra Bose. Each has reasonable credentials for celebration, so take your choice. It is likely, however, that Tesla actually achieved wireless radio communication first and demonstrated it in 1893. Marconi, being a far more effective promoter, received most of the historical credit, but the Russians insist that Popov was the inventor of radio and celebrate this event on their “Radio Day.” While Bose is comparably regarded in India. In all fairness, each of these remarkable men made sufficient contributions to the invention of radio, and thus deserve a place in history. The patent system has not clarified this conundrum (does it ever?) but the last U.S. patent action was in favor of Tesla.
All of this effort was directed at wireless telegraphy. It took Reginald Fessenden, in 1906, to transmit voice over the airwaves, thus giving him a rightful position as co-father of radio.
The commercialization of radio
The first commercial implementation of radio was wireless telegraphy. Marconi, by dint of enormous perseverance and an extraordinary ability to raise money, was most successful. The scientific community was understandably outraged by Marconi’s success in achieving long-range transmission since he had no real theoretical understanding of his results. His combination of brute force, persistence, and patient trial-and-error (not unlike Edison’s) made him the most successful of the pioneering radio entrepreneurs. He established a transatlantic wireless service in 1907. Tesla and Popov also created wireless telegraphy businesses with more limited success. The sinking of the Titanic stimulated universal wireless telegraphy on large ships.
While impressive for the time, wireless telegraphy pales when stacked against what was to unfold over the next 90 years, as evidenced by the following.
Broadcast radio: The first regular broadcasts were delivered in Morse code in 1916 and the first clear transmission of human speech occurred in 1919. In 1920, a station in Argentina provided the first regular wireless broadcasts of entertainment. And, the same year, Westinghouse launched the first commercial broadcasting station in the United States. It’s interesting to note that the early broadcasting stations ran the entire power of their transmitters through a carbon microphone. A “patent allies group” was formed that included General Electric, American Telephone and Telegraph, the Radio Corporation of America, and Westinghouse, with the intent of creating a monopoly in radio broadcasting. Fortunately for all of us, the group was foiled by clauses in the contracts defining their patent acquisitions that allowed “amateurs” to use the patents. Not surprisingly, there suddenly arose a large number of “amateurs” in the broadcasting business.
The growth of broadcasting into a consumer service was made possible by the invention of the vacuum tube by Lee DeForest and by work in amplitude modulation by DeForest and Fessenden.
Edwin Armstrong was an inventor who was inspired by Marconi to pursue wireless — first as a hobby, and then as a fundamental contributor to the body of radio technology. He invented the regenerative detector and when he accidentally drove the almost-oscillating detector into oscillation, Armstrong created the basis for continuous wave transmission. He also first applied the concept of superheterodyne conversion, and in 1933 invented FM radio. Although Armstrong earned millions from his inventions, he became embroiled in patent disputes that drove him to suicide, leaving his wife to enjoy a posthumous and monetarily rewarding vindication.
Although there were many amateur efforts at broadcasting both telegraph signals and voice, the early 1920s saw numerous radio stations come into existence, with KDKA in Pittsburgh arguably the first licensed broadcast station.
Television: Vladimir Zworkin invented the iconoscope in 1923 and the CRT in 1929, providing the basis for the generation of a television signal and the ability to display it. In 1930, Charles Jenkins broadcast the first TV commercial, while the BBC started broadcasting without commercials. As late as 1936, there were only 200 television sets in use in the world. David Sarnoff accumulated the work of Zworkin, Jenkins, and others to build RCA and to create NBC. This, along with the FCC’s issuance of the NTSC standard in 1941, stimulated the growth of television to 1 million homes in the United States alone by 1948, and to 1 billion TV sets worldwide by 1996.
Peter Goldmark invented color television in 1941, leading to an FCC standard for color TV in 1950. By 1965, color TV finally had achieved critical mass.
The combination of broadcast radio and television consumed more than half of the usable radio frequency spectrum into the 21st century. Only in recent years has it become evident that there is far greater value in using the RF spectrum for mobile applications and serving most of the television market via cable and satellite systems.
Satellites: Arthur C. Clark conceived the geosynchronous communications satellite in 1945 and Bell Lab’s John Pierce worked out the technical details in 1954, but the Russians actually launched the first man-made satellite to orbit the Earth in 1957. This was followed, in 1958, by the United States’ Explorer 1. Telstar, launched in 1963, was the first commercial satellite. It was followed by many others, including Relay, Syncom, and the Comsat Early Bird. Canada launched the first domestic satellite, Telesat, in 1972. At this writing, there are a few hundred satellites currently operational, out of the thousands of satellites that were launched by 50 countries using the capabilities of 10 nations. All of these satellites use some form of radio, from narrowband voice channels to broadband carriers carrying video and high-speed data.
Radio navigation and radar: While we tend to think of radio systems as carrying voice and other forms of information, a significant portion of the radio frequency spectrum is consumed by systems that allow location, navigation, and detection. An example is radar, which was first demonstrated in 1904 by Christian Huelsmeyer in Germany. However, it was not until World War II that the modern version of radar evolved.
VOR, an omnidirectional ranging system, was introduced in the 1950s and remained the primary aviation navigation tool, at least for small aircraft, until the advent of GPS (global positioning system). Andrew Alford invented the Alford Loop that was fundamental to the operation of VOR and other direction-finding systems, while Bradford Parkinson and Ivan Getting invented GPS, which became operational in 1993.
Digital technology: It is ironic that the first commercial uses of radio were digital, since that’s exactly what wireless telegraphy was, but for most of the 20th century all broadcast transmission was analog. For consumer applications, digital transmission offers distinct advantages, the most important of which is a sharp threshold of reception. When signals are above this threshold, the error rate is very low and there is minimal noise. Below the threshold, the signal is unusable. This coincides with a consumer preference to hear only high-quality signals or, alternatively, nothing. All television broadcasting in the U.S. is now digital, and both FM and AM radio are transitioning to digital technology.
Short-range computer communication, wireless LANs and Bluetooth: The convergence of radio and computers became complete with the introduction of the wireless LAN (local area network), a k a Wi-Fi, which was invented by Alex Hills, a Carnegie Mellon professor. Wi-Fi uses a broadband digital protocol that achieves spectral efficiency in short range applications that offer coverage in offices, homes and commercial “hot spots.” Most laptop computers are now equipped with Wi-FI. Attempts have been made to provide citywide coverage with wireless LANs; this misapplication of technology has been generally unsuccessful. Hatim Zaghoul is the inventor of OFDM, an enhancement of Wi-Fi also used in WiMAX and LTE. Several wireless air interfaces — including Bluetooth, Zigbee and UWB — use very short-range technology to interconnect devices with people and with other devices. Bluetooth, the most widely deployed, was invented by Jaap Haartsen and Sven Mattisson of Ericsson, who named it for a 10th century Danish king with a fondness for blueberries.
Land mobile, two-way radio, paging and cellular radio: Until the late 1990s, when cellular telephones became consumer products, the land mobile radio industry was a silent servant to the public, which benefitted enormously but was largely unaware of these efforts. Police departments were at the forefront of the industry’s beginnings and discovered that the improvements in timeliness, performance and productivity introduced by the use of LMR made the platform indispensable. This imperative spread to other emergency services and then to every business and government activity that involved people on the move. The boon to society was incalculable, but the industry remained virtually unknown. Even the introduction of citywide radio paging in the early 1970s did little to glamorize a mundane and utilitarian business. The advent of cellular telephony — which brought much lower service and device cost — introduced a new era in personal connectivity that has become revolutionary in scope.
In 1921, William P. Rutledge, a police commissioner in Detroit, charged his people with producing a robust one-way radio system. An engineer named Robert Batts, who later became a Motorola executive, produced the first police radios. Dan Noble, a college professor turned executive, joined Motorola and persuaded the industry to convert from AM to FM. Fred Link of Radio Club fame was a pioneer in the two-way radio manufacturing industry.
In the 1960s and 1970s the LMR industry divided into three distinct markets — two-way radio, radio paging and interconnected radiotelephone.
In two-way radio, continuing pressure to offer more service in limited RF spectrum led Raymond Spence at the FCC to support me, while I was working at Motorola, in creating the technology and spectrum allocations that transformed the two-way radio industry from one that operated on the premise of a single frequency at a time into one that embraced the more efficient trunked channel, or SMRS, paradigm. When cellular technology took root, Morgan O’Brien, a former FCC official, transformed much of the SMRS industry into cellular technology with the creation of Nextel.
The transition to portable communications was initiated by Paul Galvin, Motorola’s founder, when he observed, in the late 1930s, the preparations for war in Europe and led Motorola to become the largest producer of the SCR-300 field radio, a k a the “Walkie-Talkie.” When Orlando Wilson, police commissioner of Chicago, approached Motorola in the mid-‘60s to create a communications system that would allow his officers to communicate while walking their beats, I and my Motorola team responded with a cellular-like system, using only hand-held two-way radios.
Motorola then introduced the first high-capacity paging systems, pagers and terminals in 1971, but it took entrepreneurs like Homer Harris of ICS in California to adopt the technology and turn it into a productive business. Clayton Niles at Communications Industries moved the industry into a multi-city corporate mode and George Perrin created PageNet, which moved the industry further toward its peak of more than 60 million pagers — and provided the first large-scale commercial glimpse of how personal wireless communications could support the freedom to move.
The development of public radiotelephone in the U.S. was led by Bell Laboratories with its creation of IMTS and its introduction of the technology, in the United States, into fully automatic trunked systems, albeit with only 12 trunked channels at a time. Claude Davis at Bell Labs, Chandos Rypinski of Rydax, and I led the IMTS industry, which Motorola dominated until the advent of cellular communications in the early 1980s. Starting in the late 1960s, AT&T and Motorola sparred with each other to evolve the next generation of mobile telephony. Although Bell Labs created the concept of cellular communications — starting in 1947 with Douglas Ring and developed further by Amos Joel — the vision of AT&T was car telephones, while Motorola’s vision centered on personal portable telephones. Motorola, under the leadership of Bob Galvin, William Weisz, and John F. Mitchell, took on AT&T, which was then the largest company in the world. This battle culminated in 1973 with a phone call from me to Joel Engel, who, along with Richard Frenkiel, headed the AT&T program. During this call, I informed Engel that he was talking to someone who was using a “real cellular phone, a personal handheld cellphone.” The portable phone, conceived by me and designed by Rudy Krolopp, Don Linder and their teams, was demonstrated in New York and Washington. Later, with a personal demonstration by Bob Galvin to President Ronald Reagan, the 10-year FCC regulatory logjam was broken and cellular licenses started to flow to the top 30 markets in the United States. As a result of Motorola’s portable work, cellular systems were capable of personal communications from the outset, beginning in 1983.
More than half the people on Earth now use cell phones. Satellites, GPS, radio and television continue to make our lives more productive and safer, to educate and entertain us, and to make our social connections more robust. But this is only the beginning. Banking, health care and the ability of machines to “talk” to each other, provide a few examples of where the use of wireless technologies will revolutionize the coming years. So long as people yearn for the freedom that mobility offers, the technology of radio, in its many forms, will be a crucial and essential part of our lives.
Martin Cooper has made numerous contributions to wireless technology, including the conception of the handheld mobile phone.