What Is Bluetooth – In-Depth Explanation

Bluetooth technology is used across a plethora of devices. Every single smartphone and tablet has it, most modern laptops have Bluetooth chips, and there are numerous wireless headphones that use Bluetooth as a way of receiving the signal from the master device ( a smartphone or tablet). Lately, the technology got quite popular as a mean of controlling your phone while in a car, driving. Also, many wireless keyboards, mice, and gamepads use Bluetooth to communicate with PCs; PlayStation uses Bluetooth wireless gamepads and let’s not forget millions of wireless speakers using Bluetooth, enabling you to make a party anywhere anytime.

The technology is basically a wireless communication protocol used today mostly for device-to-device transfers since it needs less power than Wi-Fi; Bluetooth is also much easier to set up, and today it became a standard for connecting various devices (speakers, keyboards, headphones, etc.) to your smartphone or a tablet.

The difference from Wi-Fi is that Wi-Fi’s better for making wider networks, usually based around one source of signal (a wireless router) while Bluetooth is better at creating a device-to-device connections, since it doesn’t require one main signal source, and since it uses much less power; an important feature because of battery limits smartphones and tablets have.

Did you know that even medical health sensors use Bluetooth to send data to various devices? Or that Bluetooth chips built in vehicles are used for predicting travel times and traffic congestions? All that is possible thanks to Bluetooth, the technology that arrived more than 20 years ago, but was not fulfilled its full potential until recently.


The history of Bluetooth

Bluetooth was the name of the king of Denmark, who ruled the country from 940 to 986. His name was Harald Blåtand, and his biggest success was converting Denmark into Christianity. His name is used for the technology that is one of the most used ways of transferring data and controlling devices in today’s world.

Since the tech was named after one of Denmark’s kings, it’s logical that one man coming from Denmark was the inventor of the technology. His name is Sven Mattisson; after getting his Ph.D. back in 1986 he worked on many different projects until he joined Ericsson Mobile Communications in 1995. There, he got involved in one experimental project that used MC Links (Multi-Communicator Links), wireless short-range radio links, trying to make mobile phones communicate each other without using cables (remember, that was 1995, and other than for phone calls and messages, mobile phones weren’t used for anything else).

Bluetooth USB Dongle

As Sven stated, “I was placed in a forward-looking project together with a Dutchman called Jaap Haartsen. We were to work on a concept involving short-range radio links with low output. The point was that mobile phones with this kind of radio link would be able to communicate with each other without having to be connected by cables. Initially, these were called MC Links, which stood for Multi-Communicator Links.”

Soon enough he realized the potential of the project and suggested Ericsson to find a partner company that could assist on the project. The company that saw the potential and decided to help Ericsson develop the tech was no other than Intel. Sven Mattisson got a new research partner, Jim Kardach, and two of them soon realized that the tech could be used not just on mobile phones technology, but for many other devices as well. Another conclusion is that Bluetooth could best be used as an open standard.

After Intel got into the Bluetooth wagon, and after some research has been made, allowing Bluetooth to function, other companies were invited in order to set up joint development of the new wireless standard. Those companies were Nokia, IBM, and Toshiba; all three hardware giants of the time.

Wireless Bluetooth Speaker
Wireless Bluetooth Speaker

The future was ready to be made. Although the first version of Bluetooth protocol could only transfer data at the rate of 721 kbps (Bluetooth 5.0 supports speed up to 50 Mbit/s), technology had a bright future, since it was easy to use, it used a tiny amounts of power and could work between two devices that had tens of meters between them (most today’s phones use ultra-low power Bluetooth chips, the reason why it can work at the range of around 10 meters. But some chips used in PCs can send and receive data with devices that are a hundred meters away.

Today, around 3000 companies from around the world adopted the Bluetooth standard.

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How Bluetooth Works

Bluetooth is a two-way communication protocol. All Bluetooth-equipped devices have a chip and an antenna used for two-way communication between devices. The technology uses Frequency-hopping spread spectrum (FHSS) for transmitting data. FHSS works by transmitting radio signals by rapidly switching frequencies, with chunks of data being transmitted on every frequency of the spectrum.

Frequencies used by Bluetooth devices are placed between 2402 and 2480 MHz. Although the band is not globally licensed it is regulated and is used for Industrial, Scientific, and Medical (ISM) purposes. AS we stated above, Bluetooth uses FHSS for transmitting data, with data being divided into packets, each packet being transmitted over one designated channel. There are 79 Bluetooth channels, with each channel having a bandwidth of 1 MHz. Recently developed Bluetooth low energy (used mostly by smartphones for sending audio to Bluetooth enabled headphones) standard uses 40 channels, with each channels using a 2 MHz bandwidth.

Bluetooth Chip
Bluetooth Chip

Bluetooth devices are capable of communicating in a small new comprised out of eight devices (one master and seven slave devices). The master device can be changed. For example, if you pair two smartphones in order to transfer data, both devices can receive (slave protocol) data as well as send it (master protocol).

All enabled devices (while Bluetooth protocol is turned on) send their discovery signal, enabling other devices to discover them; after a device discovers another, they can be paired, and after that, both devices are able to communicate over Bluetooth.

Devices can be set to be discoverable, or not. When in discoverable mode, other devices with an active connection can find them, and communicate with them. Some other devices, like Bluetooth speakers, cannot be hidden, since they usually function as slaves, controlled by other devices.

Bluetooth Standards Throughout The Years

There were many Bluetooth standards since the technology saw a rapid development since the Bluetooth SIG (Special Interest Group) which formalized the specifications was founded back in 1998.

Versions v1.0, v1.0B were extremely tough to incorporate into devices and made manufacturers sweat over a plethora of problems the first two versions faced. Since problems were there to stay, and a new version (v1.1) was developed, finally enabling easy implementation.

With version 2.0 which released in 2004, Bluetooth got an Enhanced Data Rate (EDR) protocol, enabling devices to send larger data packets (such as images, or sound recordings); EDR has a rate of 3 Mbit/s (with a practical rate being around 2.1 Mbit/s).

The next highly important version was v4.0 adopted in 2010. Bluetooth 4.0 brought low energy protocols, enabling devices to use much less energy while maintaining relatively fast data rate. The most important result of Bluetooth low energy protocols is enabling Bluetooth to be used for IoT (Internet of Things), since the new chips are much smaller, much more power efficient and are relatively cheap to manufacture, enabling Bluetooth to be implemented in practically any electric device.


Bluetooth v5 was recently announced (June 2016), and should bring even better specs. The efficient range on which devices can communicate should be quadrupled, the effective data transfer speed will double, and data broadcasting capacity of low energy Bluetooth-enabled devices should be much faster. Basically, Bluetooth v5 is targeted specifically for IoT devices.

Bluetooth will stay around since IoT devices will be featured more and more in the coming years, and since Bluetooth is much less power hungry than other types of wireless connections, it will continue to be upgraded.

The smart homes of the future will be filled with Bluetooth low energy chips, enabling smart communication on a completely different level.

Goran has a B.A in psychology, but never really went that road. He likes everything about video games, technology, Sci-Fi and science. Freelancing for almost a year, he tries to bring his readers something interesting and engaging every time.

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