Blue tooth of wireless electronics

The first mobile phones with Bluetooth technology appeared at the beginning of the 21st century. The new technology allowed for wireless data transmission. In addition, bluetooth made this task much easier. Previously, only an infrared port was used for this purpose, which entailed a lot of inconvenience. Pretty quickly, bluetooth has become one of the main technologies not only in mobile devices, but also in other devices and gadgets.

Headphones, keyboards, computer mice, and Bluetooth-enabled printers began to appear on store shelves. Every year the function gained distribution and new rounds of popularity. Perhaps every user has heard and encountered it, but not everyone knows why the technology got such a name and on what principle it works. These are the questions we will answer in this article.

Why the tooth is blue?

It should be more or less clear what bluetooth is. This is a wireless method of transferring data. The name of the function is point of interest. According to one of the theories, this name was given to bluetooth in honor of the Viking King Harald I Bluetooth. He ruled back in the 10th century on the territory of present-day Denmark and part of Norway. For Scandinavia, Harald I Bluetooth is an important historical figure: it was he who managed to unite the warring Danish tribes into one kingdom. The connection with Scandinavia is not accidental. Specialists and scientists of the Swedish company Ericsson worked on the creation of the technology. However, the developer of bluetooth is considered Jaap Haartsen from Holland. In 1994 he worked for Ericsson. It is believed that Bluetooth combines communication protocols into one universal standard. Based on this, the name was chosen in honor of the Danish king, who managed to unite the tribes.

The need for a "blue tooth" has been brewing for a long time, telecommunication cables RS-232, together with UHF waves, were distinguished by a short range. The developers themselves explained the name for consumer bluetooth as follows: “They decided to name the technology in honor of Harald Blatand, the Danish king. He loved blueberries and was known for successfully uniting the enemy tribes of Denmark, Norway and Sweden. Connecting different devices from different manufacturers such as Apple and Microsoft - that's what Bluetooth is - a technology at a low cost, low power consumption and reliable connection. " The logo deserves special attention. It represents a combination of Danish runes H (Hagalaz) and B (Berkana), corresponding to the initials of the king.

How it works?

The first official specification was introduced in 1999 and it was Bluetooth 1.0. After that, devices supporting the technology began to appear. Ericsson R520m and T36m were among the first mobile phones to support advanced wireless technology. These are the times when on the streets more and more people began to notice other people who seem to be talking to themselves. But in fact, this is how a wireless headset manifested itself.

And here is one of the main questions, how does bluetooth work? For its work, radio waves are used. The work takes place at a frequency of 2.4 GHz. Mobile communication works on it, Wi-Fi. Using the technology, the transmitted data is divided into packets, and then each packet is transmitted separately along one of the 79 designated channels. For transmission on two paired devices, there must be a special module. It works in both transmitter and sender modes. The adapters are connected using the protocols - LMP, L2CAP and SDP. After establishing a connection between the devices, "communication" begins. Profiles or standards provide this. The most popular A2DP profile.

Specifications and limitations

It is obvious that the first version could not avoid mistakes and miscalculations. Among the main problems are persistently weak signal and intermittent connection drops. Also, there was no compatibility in the full understanding of the meaning of this term. The manufacturer could claim that two specific devices are compatible, but in practice it was often missing. That is, there was practically no confidence among users that bluetooth would work. In the future, bluetooth was constantly improved. The most significant improvement is considered to be version 2.0, which featured an enhanced data transfer rate - EDR. But the maximum that could be squeezed out of it was 2.0-2.1 Mb / s.

Other innovations include:

  • a slight decrease in the energy consumption indicator;

  • added bandwidth for synchronous connection of multiple devices;

  • increased data transfer rate.

Already in 2009, a new standard was approved - Bluetooth 3.0. As in previous times, the main efforts of the developers were aimed at increasing the transfer speed. In theory, it reached 24 Mbps. Moreover, this version of bluetooth included two versions of the radio system - standard up to 3 Mb / s and high-speed up to 24 Mb / s, compatible with 802.11. But this improvement in technology is not over.

Even later, Bluetooth 4.0 was released, and in 2016, Bluetooth 5.0 appeared. The first received a range of up to 100 meters and, in order to improve the energy efficiency, the transmission speed was left at 1 Mb / s. Bluetooth 5.0 differs in reduced power consumption in comparison with Wi-Fi, plus the developer has once again increased the transmission speed - in comparison with version 4.2, it has increased four times. If you go to the official website of the bluetooth developer, you can try a special calculator that calculates the signal range. Also here the user will be able to get acquainted with the main differences between the "classic" protocol from LE - Low Energy.

The main difference lies in the energy efficiency indicator. By developing Bluetooth LE, experts have achieved a decrease in connection delay (5-30 ms instead of 100 ms), the frequency and range remained the same. The only thing that had to be sacrificed was the data transfer speed.

As for the limitations, the average range of the technology is 10 meters. This rule is true for phones, headphones, laptops. It should be said here that, in theory, the signal range can be either 100 meters or 1 meter. Therefore, it is extremely difficult to say, at what distance the devices will "see" each other. Usually we take into account:

  • frequency and wavelength;

  • receiver sensitivity;

  • transmitter power;

  • antenna;

  • natural losses in the environment.

From the physics course, we remember that the higher the frequency, the shorter the wavelength, and the worse the wave passes through obstacles. Since the operating frequency of Bluetooth is 2.4 GHz, it was initially not designed to transmit a signal over hundreds of meters.

Alternatives. Bluetooth and Wi-Fi

How is bluetooth different from Wi-Fi? Another question often asked by users. There are several main differences:

  • bluetooth is designed to connect devices to each other, wi-fi - to connect devices to the Internet;

  • different power, range and data transfer speed - Wi-Fi wins in all these indicators.

Wi-Fi is a wireless communication protocol designed to replace a wired connection, primarily Ethernet. It usually requires a wireless router to work. Also, the device connected to the router must be equipped with a Wi-Fi wireless data transmission module.

From the technical specifications, it can be seen that Wi-Fi and Bluetooth can operate at the same frequency - 2.4 GHz. This leads to the appearance of mutual interference, which in turn degrades the stability of the connection and slows down the operating speed. To prevent this, it is worth dividing the technologies into different frequencies. Most often, Wi-Fi is transferred to 5 GHz - this is the best option. So, what is better to use - bluetooth or Wi-Fi?

Depends on the situation. For streaming high-definition video, using a GoPro camera is better suited Wi-Fi. But to establish a connection between a smart watch and a mobile device is easier using the "blue tooth".


Despite the emergence of Wi-Fi and partial replacement of Bluetooth, the “blue tooth” technology remains in demand as before. It is especially useful when connecting two portable devices. Bluetooth works well in establishing a connection between devices with a simple configuration - a smartphone and a headset, a smart watch. Therefore, in the future, it is only worth waiting for continuous development of bluetooth and its improvement.

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