【BLUETOOTH】 What is it, how it works, types, devices ▷ 2024

Do you know what bluetooth is? Since when can we use it? Why does it appear? How does it work? Although we have all used it on occasion, few know how to answer the previous questions.

This is, in summary, a technology that establishes a short-range communication protocol between two or more devices that include it, achieving the transmission of voice and data wirelessly .

However, you are interested in knowing much more about BT. For this reason we have designed this informative post where you will learn where it was born, when, what exactly, how Bluetooth works, what types exist, what are the dangers of its use and how it differs from WiFi , another wireless connection technology.

What is Bluetooth and what is it used for? Origin and evolution

Bluetooth is a short-range radio wave communication technology for low-power devices that appeared in 1994. This allows the transfer of information (both voice and data) between devices at distances short To do this, uses a radiofrequency link that occurs initially in the ISM band at 2.4 GHz.

With this it is intended to facilitate communication both between computers and between users, at zero cost (once we have our devices with the integrated technology) and without cables .

This specification is created by Bluetooth Special Interest Group, Inc ., a consortium of Ericsson, Toshiba, IBM, Intel, Nokia and Sony, who were interested in developing it.

According to your technical specifications, we have:

The communication channel that defines this technology is of 720 Mbit / s maximum , with a gross capacity of 1 Mbit / s.
The initial optimum range for the effective connection between devices is 10 meters . Of course, this expands over time, although it is still recommended for perfect communications.
The repeaters allow us to multiply this range by 10, reaching 100 meters.
The radio frequency used is between 2.4 and 2.48 GHz .
It can transmit at 1600 jumps per second .
These are up to 79 frequencies , with 1 MHz intervals.
An transmission output power is estimated from 1 mW to 10 meters and between 100 mW and 1 W in the case of long range.
Its baseband protocol includes packet switching and circuits that move in different jumps to that don’t get messy.
Synchronous channels transmit 432.6 kbit / s bidirectionally.
Asynchronous ones are faster in one direction (up to 721 kbit / s) but much slower in the opposite direction (up to 56 kbit / s).

How do Bluetooth connections work?

Communication between two or more devices that make up this communication protocol is given by radiofrequency, without the need for alignment of these.

The first thing that happens when we enable the BT connectivity option is that our device detects those that also have yours enabled .
So that the connection is possible analysis of the physical characteristics of the devices should be done, so that it is known if there is compatibility.
Similarly, it will be necessary that both share protocol communicative , it is the way in which the information can be interpreted correctly.
If necessary, define the data that you want to send as well as the time expected wait. This is done by the device itself when choosing the files to be sent.
The connection is made using the ISM 2.4GHz low power radio frequency standard . With this, the transmission speed is maintained, transferring the data quickly and consuming few resources.
So that the communication does not interfere tiny signals are sent, up to 1 mW ; This limits the range of action but respects communication, which cannot, as we say, be interfered.
It is not necessary that the devices are aligned as is the case with the infrared These can, in fact, be found in different rooms, separated by walls.

Bluetooth types and standards

It is the capacity of the channel that determines the different types of bluetooth we have had and currently have. To date we have found five official versions released to the market, which are v1.2, v2.o + EDR, v3.0 + HS, 4.0 and 5 . These have a bandwidth of 1, 3, 24, 32 and 50 Mbit / s respectively. Even so, it has worked with others, being able to highlight:

BT v1.0 and v1.kb

They brought more problems than solutions, so that the interoperability of products was often not allowed. These, by the way, should include the address of the device when transmitting , which meant a flagrant violation of privacy and anonymity.

BT v1.1

This one, launched in 2002 , solved many of the errors that were previously presented.
One of its main features is the addition of support for channels that were not encrypted .
The received signal indicator was also included.

BT v1.2

Launched in 2003 .
Offers support for the USB port v1.1.
The connection is significantly faster, with an ideal transmission of 721 Mbit / s .
Includes Discovery to detect other devices with BT.
The frequency hopping that occurs makes it give greater resistance to radio interference .
Extended synchronous connections are included that detect corrupt packets and eliminate them so that voice quality is better.

BT v2.0 + ERD

Launch in 2004.
Compatible with version 1.2 , so that “old” and “modern” devices coexist.
EDR is introduced , an improved, optional data rate, which accelerates data transfer, being the nominal one of 3 Mbit / s and the practice, of 2.1 Mbit / s and that requires a lower energy consumption in a reduced work cycle.

BT v2.1 + EDR

Appears publicly in 2007.
Secure Simple Pairing (SSP) is included, which allows for better pairing of the devices.
Also includes EIR , a broad research response, which gives more information to make more efficient filtering before connecting to them.

BT v3.0 + HS

Appears in 2009.
It has a theoretical or ideal speed of 24 Mbit / s between devices that include, all of them, this version.
The data transfer is not done with this connection but only with it the establishment; traffic happens to be done with an 802.11 link.
The novelty that highlights this version is AMP or Alternate MAC / PHY , which is precisely the addition of that link to high speed.

BT v4.0

Appeared in 2010.
It combines the three types of bluetooth known so far: high speed, classic and low consumption > (consumes 97% less).

BT v5.0

Launches in 2017.
Double the speed.
It’s more reliable.
Increase coverage range .
It is 8 times more capable than the previous version.

BT v5.1

It allows you to know the location of the devices with which we connect.

What range do wireless connections usually have for bluetooth?

Bluetooth, since its initial launch, has been described as an effective wireless technology up to 10 meters away between the devices involved. There are factors that can cause this to be reduced although it is not conventional.

With the different versions and the corresponding evolution this aspect has been improved and we find, today, devices with bluetooth class 1, whose ideal range is 100 meters , accompanied by a power 100 mW.

What are the differences between Wi-Fi and the technology of Bluetooth radio?

Both technologies are wireless, that is, they do not require cables to connect devices and share diverse information with each other and also work in bands. But otherwise, these are totally different.

First, we have the function:

WiFi is the technology designed to receive a network signal , that is, to connect to the internet. This option should be offered by the router to which the internet signal arrives. However, it is also essential that the device on which we want to enjoy the internet connection has a WiFi network detector ; this “reads” the waves and looks for the connections that are being emitted to try to connect to one of them.
In the case of bluetooth we see that this is used for connect devices that are at a similar level in terms of the information that is sent . For example, with a smartphone we launch an audio track to a soundbar or with a tablet we launch a game to watch it on TV while we play.

In addition, we have that the range of action is very different:

The bluetooth we have already seen that is short range , being useful up to about 10 meters away between devices always and when there are not too many obstacles.
WiFi , meanwhile, has a wider range of action , quadrupling the distance to which bluetooth works in cases where the router is in an enclosed space with obstacles and is up to eight times higher if it is in an open space .

Other different aspects but without major importance are that the connections by WiFi require previous configuration while the bluetooth allows us to connect with strangers quickly or that the output power of the WiFi is much greater.

List of most used devices using Bluetooth technology

If you are asked about a device that has this technology, the first mobile phone is the first one that comes to mind. However, there are many others, more and more, because in a technology society like the one we live in, the connection to the devices is mandatory.

Some of them are:

Mobile phone and tablet . The king of bluetooth (and his sister). When this technology became known, we were crazy going through polyphones with mobile phones. It is true that, a few years later, and after going out of fashion, many corporations chose not to include it in their new models. Although, the new possibilities and their lower current cost mean that, once again, we all enjoy this connectivity option in our smartphones.
Sound bars and towers . For convenience, technology is included, allowing us to comfortably launch audio tracks to play them instantly and without the need for cables, continuously changing the music we hear from the phone or tablet.
Stereo systems . Idem. We release the music without inserting CDs, tuning the radio, etc.
MP3 players . A simple way to pass the tracks without connecting the player to the computer.
Car radio equipment . We can do the same but to listen to the music of our devices through the radio of our vehicle.
Wireless speakers . Again, the function is the same, to launch music tracks to listen to them from a better device in terms of power and sound quality.
Printers . The bluetooth in the printers is born to prevent the startup and use of the intermediary: the computer. Being able to send the files to print from another device with this technology becomes unnecessary, making the process faster and lighter.
Scanners . The same goes for scanners, but vice versa. We scan a document on the machine and we can intercept it with our device.
Consoles . There are consoles that have been included to be able to use wireless controls.
Smart TVs . This allows us to play music on the TV, combining this with any other use, such as playing on the big screen. However, it also allows us to do many other things such as launching, for example, our phone notes, the drawings we make on the tablet, stored images and even our phone book.
TV Box The TV box is a box that includes the same thing that makes a television smart, so it is exactly the same as just explained.
Handsfree and headphones . Same concept: talk and listen without difficulty, sending the call signal to the device in question.
Laptops . Although it is not usual, many of them also include it, so that the connection with other devices is done wirelessly, what you want when we are working with a computer designed to move from one side to another: do not go with cables.
Peripherals . The best known are the mouse and keyboard, two input peripherals that, with cables, take up too much, affect space and make cleaning difficult.
Receivers and transmitters . Do not worry because if you need to use this and your devices do not have it there are receivers and transmitters that launch and capture the signals, so that we create our bluetooth space ourselves, being able to use it for whatever we want.

What are the dangers and vulnerabilities of the connections via Bluetooth and how to avoid them?

News and problems usually go hand in hand; a new resource is born to help the user and, with it, a misuse of this is also born to take advantage that is harmful to others.

Bluebugging

For this attack to occur there must be an error or bug when identifying the devices , which means that the attacker can end up taking control of yours. The motivation is diverse and includes espionage, viral infection, botnet networking …

Bluejacking

Bluejacking is the clear example of this in relation to the technology we are seeing today. This is nothing more than the sending of malicious and harmful messages that users do not want between computers that are interconnected and communicating in a bluetooth network .

Obviously, it is not something that affects us if we connect, in a meeting, with our friends, because, as we have already seen, the useful distance of use is limited. However, the fact that some devices include transmitters that amplify the signal is used; In this case we can be in danger .

Bluesnarfing

In principle, the activity is not intrusive , they simply send messages that the user does not want to receive. However, with the passage of time it has been possible to access the content of the devices (calendar, SMS …) and, unfortunately, its control , being able to even make calls or turn off the device and, of course, steal the information accessed. This process is known as bluesnarfing.

To be prevented and protected :

Ideally, disconnect the function as soon as we stop using it.
Choose devices with bluetooth with a type of secure protocol .
Perform the device configuration so that it remains hidden while we have the option active.
Set a password so that communication can be established from another device.
Includes PINS for those delicate operations that you do from your phone, so that even if another person takes control, they cannot guess them and, therefore, use them.