September 20, 2016

The History of Wireless Technology: Wireless or Radio? (Part 2 of 5)

Back in the latter half of the nineteenth century, uses for electricity were just being discovered. By 1880, Thomas Edison had improved his original light bulb to the point that it was a viable product, and early wiring of cities for power had begun. But scientists were discovering that there was a lot more to this new source of energy than first appeared.

In 1888, at the University of Karlsruhe in Germany, a young professor named Heinrich Hertz, proved what other scientists had only suspected; you could send electric "waves" through the air.

However, there hadn't been much work on the practical use of these waves at that point. So, the scientific and technical community just called them "Hertzian waves", since Hertz was the first to prove their existence. But it wasn't long before experimenters were looking at ways of using these new "waves" to do some useful work.

The wired telegraph had been around for a long time. In the United States, Samuel Morse created the first useful wired telegraph as early as 1844. Of course, to make it work, you had to string wires. That was time-consuming and expensive.

Some of the early pioneers of electrical science got the idea that maybe they could get rid of the wires by using these "waves" Hertz had already proven existed to send telegraph code instead. The scientific term that describes the sending of the waves is "radiation". You are "radiating" electricity when you create and send the waves. Once you do that, you have to have a way to "hear" them. The human ear can't hear these waves, so it was necessary to build something to do this. 

In 1890, Edouard Branly, a French physicist, developed a device that would do just that. He called it a "radio-conductuer", since it could receive waves that were being "radiated". However, not everyone used "radiation" or "radio" when discussing this new form of communication.

Gugelielmo Marconi, working in England between 1896 and 1898, showed that you could send signals through the air at considerable distances, and you could send Morse code on these signals.

Marconi called the company that he founded "The Wireless Telegraph and Signal Company" to make sure everyone knew that you didn't need any wires to send Morse code by this method. So, "wireless" became a common term for this new form of communication in England.

However, some technical people began to gravitate more towards using the term "radio" in place of the term "wireless". In the January 21, 1898 issue of The Electrician (London), a letter from a reader suggested that the term "radio-telegraphy" might be preferable to "wireless-telegraphy". 

In 1904, the British Post Office, which was the branch of the government that sent telegrams, specified that any telegram sent by an over-the-air method had to insure that "...the word "Radio"... is send in the Service Instructions". 

Meanwhile, in 1906, in Berlin, Germany, the Berlin Radiotelegraph Convention included a Service Regulation specifying that "Radiotelegrams shall show in the preamble that the service is 'Radio'", again to distinguish it from the use of wired telegraphs.

There were some holdouts on this, however. Electrical engineer William Maver, Jr., who, in the preface to his 1910 book "Wireless Telegraphy and Telephony", said that he intended to stay with the older term "wireless". Apparently, he was a traditionalist.

Between 1907 and 1920, "radio" and "wireless" were used to describe the new communication method interchangeably. In the United States, Lee de Forest, an early researcher who is credited with developing some of the first tubes used in receivers, called it "radio". This led to a general migration to the term "radio" in the United States. However, in England and Europe, "wireless" was still widely used.

It wasn't until the early years of broadcasting, around 1920, that the term "radio" began to become the more common term used everywhere. In 1923, the British Broadcasting Company (BBC) launched it's magazine devoted to broadcasting, called "Radio Times" (still in publication today). The BBC's decision to use "radio" pretty much put "wireless" aside. In most places around the world, "radios" became an understood term for over-the-air broadcasting and communications.

That is, until the rise of computer networks in the latter half of the 20th century.

Just like the early telegraph signals that were sent in the nineteenth century, early computer networking was done using wires, or, more properly, cables. Many times, the choice of cabling was either a coaxial cable or a twisted-pair cable. (Today, the bulk of the wired networking is done with twisted-pair cables.)

As computer networking evolved, it was easy to see that the need for over-the-air, un-cabled networks would provide a lot of convenience and solve a lot of problems. Just like what happened in the early 1900's with Morse code communications, scientists and technologists knew that, somehow, a way would be found to get rid of the cables.

Some early over-the-air computer communications with microwave systems was successful, due to the wide-band capability of these systems. Because of the bandwidth available at the higher microwave frequencies, these systems could transmit a large amount of data at a fast rate. Satellites, too, had this advantage due to the frequencies at which they operate. Uplinks and downlinks could replace terrestrial cable systems, including those that ran under oceans.

Finally, regulatory agencies created radio bands which were originally intended for use in "Industrial, Scientific and Medical" research, appropriately called ISM bands. Hardware designed to operate in these bands did not require users to obtain licenses. This opened the door to allow unwired computer networking systems to be implanted without users having to comply with complex regulatory filings.

And so, as these systems became more common, the term "wireless" arose again, due mainly to the fact that the use of these bands allowed elimination of the wires (or again, more properly, cables) needed to tie computer systems together.

So, now we're back to defining these systems as "wireless", just like in the early part of the last century. To quote baseball's Yogi Berra, "It's déjà vu, all over again".

Interestingly enough, today one major technical group defines wireless networking as: "Using radio, microwaves, etc. as opposed to cables to transmit computer networking signals". 

"Wireless" or "radio", the term used is less important than the ability to perform the work needed to get data across given distances. Call it what you will, it has revolutionized our ability to connect computers into a network and contributed greatly to the rise of the world-wide web.

Timeline: Radio vs Wireless

In part 3 of our series, we'll look at some of the requirements necessary to make radio/wireless systems capable of sending and receiving data without interfering with each other, as well as touch on the software systems that create these results.



Paul Black is a freelance writer and broadcast engineer in Northern California. He holds a Certified Professional Broadcast Engineer certification from the Society of Broadcast Engineers and an FCC Lifetime General Class Operator License. He is a licensed amateur radio operator (call sign N6BBZ) and has worked for several broadcast companies, including Bonneville Broadcasting, RKO General Broadcasting, and CBS Television. Visit his website at www.paulblackcopy.com



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