The Short Story of Bluetooth

Everybody hates wires. They’re a nightmare to maintain, a pain to use, and they break easily. There was thus a need for an invention that could deliver us from the evil of the wired medium of communication: and its name was Bluetooth.

Today, we use Bluetooth for countless things, such as wireless headphones and smartwatches, wireless mice and keyboards. It is easy to take technology so seemingly simple like Bluetooth for granted. Especially if you don’t understand how it works.

What is Bluetooth?

Bluetooth is a wireless data transfer technology which uses radio waves to send communication signals.

The development of Bluetooth was started in 1989 by Nils Rydbeck, the CTO of Ericsson Mobile at the time. Jaap Haartsen and Sven Mattinson were the first developers of the technology. Haartsen was nominated by the European Patent Office for the European Inventor Award. 

Why is it Bluetooth called Bluetooth?

Funnily enough, the reason why it is called Bluetooth has nothing to do with teeth or the colour blue. 

In the 90s, there were large advances made in the development of wireless communication technology. Various companies were competing against each other, each having different communication protocols than the other. This served no purpose as only the devices which operated under the same communication protocols could communicate with each other.  So, there was a dire need for the unification of the different protocols for the sake of wireless communication technology. 

Developers had taken it upon themselves to make a new, universal wireless communication protocol, thereby unifying every old one.

The 10th century Viking king Herald “Bluetooth” Gormsson was famous for uniting the countries of Denmark and Norway into a single nation by converting Danish people to Christianity. The comparison was evident to the developers, and hence the name Bluetooth was born. The Bluetooth symbol is actually the initials of King Harald Bluetooth in Scandinavian runes.

How does Bluetooth Work?

Bluetooth uses signals of frequencies in the 2.4 GHz frequency band. This means that one vibration of this signal takes approximately 0.4 nanoseconds.

It uses a technique called frequency hopping where the signal alternates between different frequencies. This helps in avoiding interference by other radio signals. The standard is around 1600 hops per second. 

Bluetooth has a few categories based on its range and the power in the signal-

• Class 1– These signals have a range of distances up to 100m, and power up to 100mW.
• Class 2– These signals have a range of distances up to 10m, and power up to 2.5mW.
• Class 3– These signals have a range of distances up to 10cm, and power up to 1mW. 

When two or more devices are connected together via Bluetooth, it is called a piconet. Bluetooth follows a master-slave architecture. For example, let’s say that your phone is the master. This means that every other device connected to it, like your headphones, your smartwatch and stereo speakers become the slaves of the phone. A master can have up to 7 slaves. 

What are the security concerns of Bluetooth?

There are primarily two security risks in Bluetooth communication-

• Bluebugging– This refers to the activity of using Bluetooth to hijack an unsuspecting person’s phone to send text messages and place calls through it without the knowledge of that person.
• Bluejacking– it is the activity of sending a malicious message to a Bluetooth enabled device in the vicinity. 

Are there any health risks of Bluetooth?

A google search of “is Bluetooth harmful to health” would have you believe that it’s the worst thing mankind has invented since the atomic bomb. However, this isn’t the case. Not only do Bluetooth signals not have enough frequency to be considered harmful, cancer-causing radiation, but they also don’t have enough energy for the same either. Additionally, the energy of the signal obeys the inverse square law, meaning that if the distance from the emitter is doubled, the energy becomes 1/4th. 

In a nutshell

Bluetooth technology is probably one of the most commonplace in the world. However, for reasons unknown, it always gets taken for granted. Modern life would look very different without its invention, and we should respect it as such.

~Written by Rushil Dalal for MTTN

~Edited by Rahul Alvares