Bluetooth connectivity is already a classic. A connection present in many of the devices that we have at home, whether in headphones, televisions, audio equipment, computers, mobile phones … A blue and white logo appears on the box that identifies it and now we will try to differentiate between the different versions.
And it is that although it seems like it, not all Bluetooth connections are the same. Depending on the version, the performance of a connectivity that has evolved significantly over the years changes. That is why we have prepared a guide with the differences between each of them.
History of an evolution
And the first thing is to explain what Bluetooth is. It is a wireless communication protocol between devices. Without the need to use cables and by means of a radio frequency in the ISM band, an acronym for industrial, scientific and medical radio bands in English. This can be 1.2 GHz in the first connections to the current 2.4 GHz and with this system communication is achieved by sending weak signals of less than 1 milliwatt. Thus we can transmit both audio and image and data.
It is what we use when, for example, we want to connect headphones to the television or mobile phone or we want to transfer data from a mobile phone to a PC. In one case we can transmit audio and in the other data.
As you can imagine the number of devices that connect via Bluetooth is hugeFrom mice, keyboards, printers, digital cameras, headphones, televisions, mobile phones, all kinds of receivers … your car may even have a Bluetooth connection so that it connects to your mobile every time you use it.
Bluetooth and classes
And commented on what Bluetooth consists of, say that due to the way it works, sending weak signals of less than 1 milliwatt, this has an important limitation such as the scope. From one device to another there cannot be more than “X” meters if we do not want to find interferences or cuts. It does not matter if there is a wall in the middle or not, but what cannot be exceeded a certain number of meters.
And the distance of meters that a Bluetooth connection supports is determined by the “class”. Bluetooth devices are classified into different classes depending on their transmitting power, and its effective coverage. We thus find four different classes.
- Class 1: Offers a range of up to 100 meters with an average consumption of 100 mW.
- Class 2: Offers a range of up to 20 meters with an average consumption of 2.5 mW.
- Class 3: Offers a range of up to 1 meter with an average consumption of 1 mW.
- Class 4: Offers a range of up to 0.5 meters with an average consumption of 0.5 mW.
Here may arise the question of how two devices operate when they are of different class. In this case, the most powerful device prevails so that if we have a Class 1 device with a range of up to 100 meters and another Class 3 with a range of 1 meter, we can establish connections of more than 1 meter without any problem.
Scope | Average consumption | Power | dBm | |
---|---|---|---|---|
Bluetooth Class 1 | 100 meters | 100 mW | high | twenty |
Bluetooth Class 2 | 20 meters | 2.5 mW | Medium high | 4 |
Bluetooth Class 3 | 1 meter | 1 mW | Half | 0 |
Bluetooth Class 4 | 0.5 meter | 0.5 mW | Come down | -3 |
Bluetooth versions
The “class” is one of the classifications, but it is not the only one, much less the most important. And it is that the evolution of Bluetooth connectivity has brought with it an improvement in the benefits that is evident in different versions of Bluetooth that have been released. These are all we have known to date:
- Bluetooth 1.0: It is the first version we saw of Bluetooth. It hit the market in 1999 and is no longer in use today.
- Bluetooth 1.1: in 2002 the update of the previous one arrived. Bluetooth 1.0 allowed a transmission rate of around 721 kbps and solved the bugs present in Bluetooth 1.0.
- Bluetooth 1.2– This update came in 2003, improving the performance of Bluetooth 1.1 by minimizing interference.
- Bluetooth 2.0: in 2004 the first great evolution arrived. Bluetooth 2.0 brought us the Enhanced Data Rate (EDR) or improved data rate. From 721 kbps it jumped to a transmission rate of just over 2 Mbps.
- Bluetooth 2.1: in 2007 a revision of the previous one arrived with a groundbreaking characteristic. With it, it was no longer mandatory that we had to dial a code to add one device to another thanks to the Secure Simple Pairing (SSP) system that improved the pairing between Bluetooth devices. The speed did not change and was still just over 2 Mb / s.
- Bluetooth 3.0: this version arrived in 2009 and it did so with High Speed HS technology so that the transmission speed could reach 24 Mbps.
- Bluetooth 4.0: perhaps it is the most popular version and it arrived in 2010. In fact today and in 2021 it is used by a large number of devices, including new models that hit the market in the economic ranges. Bluetooth Low Energy technology premiered. It maintained the transfer speed of 24 Mb / s but thanks to the lower consumption it extended its presence in more types of devices. With it, the 2.4 GHz ISM band is released, achieving a range of 60 meters and a speed of up to 32 Mbps.
- Bluetooth 4.1: a revision of the previous one, aimed mainly at the Internet of Things (IoT). It arrived in 2013 and allowed the connection between small devices without intermediaries.
- Bluetooth 4.2: With this version, support for the IPv6 protocol is implemented to allow direct connection over the Internet. A version that arrived in 2014.
- Bluetooth 5.0: with all versions of Bluetooth 4.X the transfer speed was maintained, something that changed in 2016. With Bluetooth 5.0 the transfer rate reached 50 Mbps and the range became 100 meters.
- Bluetooth 5.1: Another renewal was coming in 2019. With this revision a device can know where a signal it is looking for comes from. In short, a device can know where another device is. The transfer rate remained at 50 Mbps but the range reached 200 meters.
Bluetooth 5.2 or Bluetooth LE Audio: the most current version of the blue connectivity, it still uses the 2.4 GHz ISM band but the range reaches 240 meters. A version that improves efficiency thanks to the Low Complexity Communication Codec (LC3). In this way data (audio, image, video …) can be transmitted while taking up less space. In addition, it allows the transfer of audio to several devices at the same time. It is a connection focused mainly on audio devices, which are the ones that can take better advantage of its improvements as it seeks to improve sound quality, data compression and energy efficiency. This happens to be the most interesting but it should be noted that it does not offer backward compatibility, so that to take advantage of it both the sending device and the receiver must have support for this technology.
Release date
Major improvements
Scope
Speed
Bluetooth 1.0
1999
721 kbps
Bluetooth 1.1
2002
General improvements
721 kbps
Bluetooth 1.2
2003
Minimize interference
721 kbps
Bluetooth 2.0
2004
Enhanced Data Rate (EDR) or enhanced data rate
50 meters
2 Mbps
Bluetooth 2.1
2007
Secure Simple Pairing (SSP) for easy pairing
50 meters
2 Mbps
Bluetooth 3.0
2009
High Speed HS that increases speed
50 meters
24 Mbps
Bluetooth 4.0
2010
Bluetooth Low Energy to consume less energy
Up to 100 meters
24 Mbps
Bluetooth 4.1
2013
Up to 100 meters
24 Mbps
Bluetooth 4.2
2014
IPv6 protocol support
Up to 100 meters
24 Mbps
Bluetooth 5.0
2016
Dual audio to pair two devices at the same time
Up to 100 meters
32 Mbps
Bluetooth 5.1
2019
Allows you to identify the direction from which a signal you are looking for is coming from
Up to 200 meters
50 Mbps
Bluetooth 5.2
2020
Low Complexity Communication Codec (LC3)
Enhanced Attribute Protocol (EATT)
LE Power Control (dynamic optimization of transmission power between devices)
Up to 240 meters
50 Mbps
At this point comes the doubt Can we pair devices with different versions of Bluetooth? Well, like almost everything in life, it depends. All versions prior to 4.0 with protocols are compatible so that we can use devices with different versions, but yes, only the basic functions are compatible with previous versions. This changes with the current versions and their more modern protocols (LCE, EATT, BLE, LE Power Control …) which are only compatible with each other.