How Bluetooth Actually Works
Bluetooth has been around for over 20 years now; and it’s a technology you may use several times a day; whether it’s the wireless mouse on your computer or the true wireless earbuds connected to your mobile. But what is Bluetooth, where did it come from, and how does it work?
Simply, Bluetooth is a radio signal that transfers data over a short distance. Your phone, tablet or laptop does the hard work converting whatever media or signal you want to transmit into a format that’s easy to transmit, then passes this signal to the transmitter. Like all radio signals, a transmitter vibrates electrons and creates a radio wave. This wave travels (at lightspeed!) to a receiver - in the headphone - and the information is decoded and turned into an analogue audio signal, ready for the audio driver.
Bluetooth is a fairly low-powered radio signal, which is optimal for portable equipment with limited battery capacity - such as your phone. Additionally, it’s nature as a radio wave means it doesn’t need line-of-sight to connect and broadcast; it bends round corners and can pass through some objects.
Long before this tech appeared in our hands it was making waves in Hollywood, California.
It’s the 1940s and Oscar nominated actress Hedy Lamarr is gracing the silver screen with her presence. However, behind the scenes, Lamarr has a passion for inventing and, compelled to assist in the unfolding world war, turns her attention to radio-controlled torpedoes. Recognising that these signals could easily be jammed, rendering the projectile useless, she creates an evasive frequency-hopping radio signal with the help of composer and pianist George Antheil. However, this technology did lay down the foundations for modern Wi-Fi and Bluetooth signals - in addition to confusing torpedos, the frequency-hopping pattern helps combat interference.
Bluetooth was designed so that one device is designated as the ‘master’. This device coordinates all synced equipment to broadcast and skip between 79 available frequencies - 1600 times every second - which minimises the risk that two different connections will interfere with each other. This doesn't require an input from you - when you pair devices, what you’re doing is establishing a relationship between your two objects so that these connections match. For true wireless earbuds this relationship is a little more complicated: your phone broadcasts to just one earbud - usually the right - which acts as the 'master' to the left earbud; effectively broadcasting your signal twice in succession.
The short-range radio signal that would become known as Bluetooth took shape in 1989 inside Ericsson Mobile in Lund, Sweden. The name was inspired by historic Danish and Norwegian king Harald Gormsson. Reigning from c. 958 to c. 986, King Harald is remembered for two things:
Uniting the dissonant tribes of Denmark into a single kingdom and
Poor dental health.
A prominent dead tooth, with a bluish-grey hue, earned King Harald the nickname “Bluetooth”. And, as a tribute to his unification of Denmark, leading engineer Jaap Haartsen named this new type of connection Bluetooth. The ‘Bluetooth’ symbol that we all know today is a combination of the Scandinavian runes ᚼ and ᛒ; King Harald Gromsson’s initials.
Bluetooth technology has taken a long journey to achieve a short connection. But, now it’s hard to imagine going a day without interacting with it. So, next time you pair to a speaker, press play on our Bluetooth playlist, filled with famous songs from Sweden and Denmark, you can find it here: