What is Bluetooth and how does it work

Today, many of the users of wireless technologies not only do not bother to understand how Bluetooth works (or at least learn how this fast connection works), but generally have little idea, What does the name Bluetooth mean, do not know who the Danish king Harald Blatand, who united the warring Scandinavian tribes, gave the name to this technology, and how to turn on Bluetooth if it does not work automatically.

At the same time, many users are quite satisfied with a headset, speaker or Bluetooth mouse until problems arise. Well, if we are talking about replacing the battery, but there are problems and more serious. For example, failure of the main Bluetooth adapter in a laptop or stationary personal computer, PCMCIA, ExpressCard or PCI. If Bluetooth does not work, many questions arise: where to find the radio antenna, the power button, which drivers should be updated, where download Bluetooth for Windows 10 / 11, 8 / 8.1, 7, XP (64-bit and 32-bit), if the malfunction occurred as a result of a system failure? Let's start from the very beginning, let's figure out what Bluetooth is, how it works, how to make the most of this free channel for the secure transmission and reception of digital information and audio.

What is Bluetooth

Bluetooth seamlessly connects any smart device without wires. The word "any" in the previous sentence is not an exaggeration. The technology is so functional, reliable, convenient, inexpensive, energy efficient, safe that today almost every smart device has a built-in Bluetooth node (high-frequency transceiver).

The power consumption of a working Bluetooth module is often less than 30 mW, the most economical modes limit the power consumption of a node to 1 mW. And in terms of the cost of integration into any device, the Bluetooth chip or Wi-Fi / Bluetooth chip significantly outperforms all competitors. Fast wireless communication makes it easy to pair, connect the connected device, transfer a signal, file, document, photo, video clip, music, create Wireless networks, both peer-to-peer and with a dedicated server, organize an encrypted Internet access point and has many other functions.

What does the name Bluetooth mean

The word Bluetooth consists of two components: blue - blue and tooth - tooth. This word was born in the distant nineties of the twentieth century, when Ericsson's marketers decided to brand their cost-effective data and sound transmission technology. The prototype was King Harald Blatand, ruling in Denmark from 940 to 980, heir to the rulers of Denmark and England, who led the peaceful merger of Denmark and Norway in the 950s. He had one tooth of a bluish color, for which he received the nickname Blatand, which is translated into English from Danish as Blue-tooth, or Blue Tooth. The classic Bluetooth logo contains the initials Harald Blatand and the Hagall runes. It is understood that Bluetooth technology combines wireless communication protocols into a universal standard, as Harald Blatand did in the 10th century with his own and neighboring lands and peoples.

How this wireless technology was developed

Sweden in 1994 went down in history: Ericsson Corporation erected a symbolic stone to the glory of Bluetooth. In 1998, four more companies joined the development of this technology: Intel, IBM, Toshiba and Nokia, which formed the Special Interest Group - Bluetooth SIG.

Today, the Bluetooth SIG has several tens of thousands of members, including such corporations as: Intel, Microsoft, Hewlett-Packard, Sony, Samsung, Lenovo, Asus, Motorola, Xiaomi, Realtek, Logitech and many other famous companies. The best engineers are working to unify and innovate wireless technologies in a wide variety of smart devices.

Which devices use Bluetooth

The technology of replacing wires and cables allows a multitude of telecommunication devices of various levels of intelligence to interact through a single channel. On one side, there may be a modern personal computer or a powerful gaming smartphone, and on the other, a simple temperature sensor or a door lock. Moreover, device-to-device connection management and interaction scenarios can be arbitrarily complex.

This simple, cost-effective, and reliable short-range radio standard allows Bluetooth 5.0 and higher specification devices to communicate wirelessly and network within a range of up to 1.5 km (and up to 100 meters in specifications 2 to 4). Various devices such as desktops, laptops, tablets, smartphones, scanners, printers, multifunctional devices, photo and action cameras, mice, keyboards, microphones, headsets, portable speakers, powerful speakers, environmental sensors, smart door locks and many other devices. There are Bluetooth Serial Port Adapters for serial port equipment, adapters for Compact Flash and Sony Memory Stick, LAN and Internet servers. It should be noted that for Android and iOS there is no need to download anything from the Apple App Store and Google Play, but download Bluetooth for Windows XP, 7, 8.1, 10, 11 for free from the site https://www.bluetooth.today may be required or recommended to update.

Since many existing devices are equipped with a Bluetooth hardware module, this virtually free short-range radio communication is available everywhere.

Two types of links

Bluetooth has two types of communication: SCO (Synchronous Connection Oriented) and ACL (Asynchronous Connectionless). The first synchronous type of connection, SCO, creates a symmetrical point-to-point connection. The second, asynchronous, ACL, deals with packet data transmission, supporting symmetric and asymmetric point-to-multipoint connections. The modules interact in cycles of 625 µs. Each module in a cycle receives a certain frequency and the right to transmit or receive.

Bluetooth classes

Power (respectively, and range) depends on the Bluetooth class. The first class has 100 mW, which, in the absence of walls and other obstacles, provides a data transmission range of about 100 meters. The second class of 10 mW provides a data transmission range of about 50 meters. The third class at 1 mW provides a data transmission range of about 10 meters.

How Bluetooth works

When Bluetooth is activated, the radio transmitter and receiver of the radio signal are turned on in the device. Bluetooth technology is based on the radio waves of the ISM spectrum in the radio frequency range from 2.402 to 2.480 GHz. The radio transmitter periodically sends its coordinates and codes, and the receiver monitors all signals in this range from compatible devices in the vicinity. Other Bluetooth devices do the same. If the devices discover each other, communication becomes possible.

A synchronous SCO point-to-point connection is responsible for voice transmission. The transmission of data packets during a point-to-multipoint connection is handled by an ACL connection at speeds over 700 Kbps. If several independent smart devices communicate close to each other via Bluetooth, they do not interfere with their neighbors, since the frequencies and algorithms for switching between them are known only to those devices that are allowed to do this. Other Bluetooth devices do not have access to these frequencies and algorithms for reasons of security, reliability and resistance to interference.

Information is transmitted according to a pseudo-random algorithm that preserves confidentiality. A special FHSS algorithm ensures that the signal carrier frequency hops 1.6 thousand times every second. The frequencies and change sequence of each Bluetooth connection are available only to the transmitter and receiver, which ensures high security, reliable performance and resistance to interference. Several nearby working pairs of devices do not intersect with each other on radio waves. If individual data packets are lost, a retransmission is carried out, loss of audio signal is possible.

Bluetooth networks: Piconet and Scatternet

The connection occurs with the creation of a Bluetooth network called Piconet. One Bluetooth device acts as a master and generates clock signals. Other devices become slaves. A piconet can combine a master and up to seven slaves. Up to ten independent Piconets can be combined into a Scatternet Bluetooth network, while the Piconet must have at least one device that is a master in one and a slave in another Piconet. In Scatternet, 71 active devices can communicate, or 256 temporarily disabled backup devices (Passive Member Addresses).