Happy UNESCO World Radio Day! UNESCO is raising awareness about the radio—the medium with the largest audience worldwide. When we hear the word radio most of us think of a device for broadcasting music and news. In reality, the term radio more closely relates to wireless technology, and by extension, to Bluetooth® wireless technology.
Today the term “radio” refers to a specific device or medium, whereas “wireless” refers to transferring information between two or more points not physically connected. “Radio technology” refers to a wide range of wireless transmissions, including radio broadcasts. However, there is a whole group of “silent” radios that are just as impactful as the ones blaring out music!
A short history of radios and wireless technology
For most of our existence, humans have been using wireless technology—think about smoke, drum or flag signals. When humans started experimenting with electricity in the 18th century, the general opinion was that “Electricity is great, but the wires are just a fuss…”
And so, during the next century, famous scientists launched individual crusades against wires. Because science was not that advanced, experimentation came down to (dis)connecting wire and seeing what happened. Unsurprisingly, progress was slow and limited to short distances.
A major breakthrough came when German scientist, Heinrich Rudolf Hertz (1857-1894) proved the existence of radio waves and showed how to transmit, receive and manipulate them. Upon achieving this amazing feat, Hertz declared that: “It’s of no use whatsoever…” Wait, what?!
Heinrich “I honestly had no idea” Hertz (Source: Wikimedia Commons)
While Hertz did not see the potential of his discovery, Nikola Tesla (1856-1941), and later Gugliemo Marconi (1874-1937) did. Both men picked up where Hertz left off. They both invented wireless telegraphs that communicated over long distances, with Marconi’s device achieving the first transatlantic transmission in 1903.
Over the next 100 years, more and more wireless connections between devices appeared, eventually leading to the world as we know it. But it is clear that both radio broadcasts and Bluetooth technology originated from the experiments of Hertz, Tesla, Marconi and many other innovators.
How does radio and wireless technology work?
We are surrounded by electromagnetic energy. Some of the energy manifests itself as light while most of it remains invisible. Electromagnetic energy moves in waves and the distance from one wave to another is called frequency. The frequency is measured in Hertz (yes, it’s named after Heinirch. That’s the least we could do for the guy).
This graph gives a great overview of the electromagnetic spectrum.(Source: Wikimedia commons)
Radio waves are the part of this energy and have a frequency range between 3 kHz and 300 GHz, making them the longest wavelength in the electromagnetic spectrum. But how can we attach information to these waves?
Any wave can carry information in the form of energy. Sound waves, for example, carry energy through the air the same way actual waves do through water. Radio waves can carry energy and by varying the frequency or another characteristic of the wave, we can encode a message on it. This is why every connection using radio waves contains two key components:
- A modulator that attaches a message (comprised of any kind of data) to a radio wave when it’s sent out
- A decoder that receives the wave and interprets the message encoded on it
Obviously, a lot more can be said about this process, but in a nutshell, this is how it works.
What about Bluetooth technology?
In essence, Bluetooth technology is radio technology. It’s used for exchanging data over short distances in a highly secure way and with very little energy consumption. Bluetooth operates in the 2400 MHz-2480 MHz spectrum, well within the radio wave spectrum. So Bluetooth is a form of radio technology.
One of the fascinating things about Bluetooth is how it uses that radio spectrum. Rather than blasting information on one specific frequency and potentially colliding with other transmissions on the same frequency, Bluetooth uses Adaptive Frequency Hopping.
To avoid collisions, Bluetooth “hops” among 79 frequencies, and does so at an amazing rate. In fact, Bluetooth can hop from one frequency to the next 1,600 times in one second! Even more interesting, in the short time it takes for two Bluetooth devices to make their first connection, they figure out where to meet every time they hop. For users, hopping provides greater performance even when other radio technologies are being used nearby. A lot of engineering went into making Adaptive Frequency Hopping work, but you don’t need to worry. You just get a secure wireless connection that’s easy to use.
So once again, a very happy radio day to you all, but keep the silent radios—Bluetooth technology—in mind as well! If you have any additions, feel free to post them below or on our Facebook page!
