The Bluetooth connection is a system that uses short-range radio waves. Did you know that the name of the connection comes from a Viking king?
It has become irreplaceable and is present on any smartphone, even the data and less performing ones. We use it to make one device “communicate” with another or to exchange files with other smartphones. It is the Bluetooth technology. But what is it and above all how does it work?
Before moving on to the technical “stuff”, trying to understand how the Bluetooth connection works, it is useful to reconstruct a little of its history. Let’s start with the origin of the name. The creators, the technology was realized by Ericsson in the mid-90s, interested in developing a communication system between cell phones and other devices, alternative to infrared rays (IRDA), decided to call the wireless connection as Harald Blåtand, whose surname translated into English is precisely Bluetooth. Why was this decided? Harald Blåtand was a Viking king, who lived between 911 and 985-986, and who succeeded in uniting the Scandinavian peoples and introducing the Christian religion.
This probably led to the idea of using the Viking king, a symbol of cohesion, to name the Bluetooth network. Officially, the wireless connection came into “charge” when the SIG consortium, an acronym for Bluetooth Special Interest Group, was established. And you want to know something else? The classic icon of Bluetooth is formed by two Nordic runes, symbols of the Germanic alphabet and initials of Harald Blåtand.
Having done this due historical excursus, let’s move on to the technical stuff, as mentioned before. How does the Bluetooth connection work?
How does Bluetooth work
The connection system, which serves to unite two devices, uses short-range radio waves, which consume very little energy. Bluetooth technology uses the 2.45 gigahertz (Ghz) frequency range. It is in this radio “space” that the magic happens: two devices connected through this frequency can exchange data packets, i.e. transmit different information. In other words, with Bluetooth you can send and receive numerous files, such as images, videos and documents. And that’s not all. With Bluetooth, always making another example, you can connect your smartphone to a speaker and transmit music.
The radiated signal usually does not exceed 10 meters distance, although the latest devices can guarantee a coverage up to 50 meters. The Bluetooth network is not subject to frequency disturbances. The radio transmission system, in fact, uses a transmission technique known as frequency hopping spread spectrum, which basically expands the band. In other words, the band is broken down into 79 channels on which 1600 transmission changes per second are recorded.
How to connect two devices via Bluetooth
Now, let’s understand how the connection between two devices takes place. Once the Bluetooth network is activated, the signals emitted, for example by two smartphones, “cross” in this short-range frequency range. A device can connect up to a maximum of 7 other devices, although data transmission can only occur simultaneously between two Bluetooth objects.
The technology is based on the “master-slave” system: the first refers to the central device, the second to all the others connected with the “master”. Once this first meeting has taken place, to associate two devices the connection asks the “slave” to enter the code that identifies the master. At this point a Personal Area Network (PAN) is created, the private network that will allow, taking up the example above, the two smartphones to exchange data.