Bluetooth technology is designed to transmit data to a small (no more than 100m for latest versions) distances. This is explained by the principle of action, based on radio communication in ISM-band.
The speed at which Bluetooth transmits data is significantly lower than that of Wi-Fi, but it uses less battery power and allows you to quickly connect devices to each other. In addition, the Bluetooth connection is resistant to all sorts of broadband noise and bluetooth enabled devices are normally less expensive to implement.
Bluetooth 1.0 was published in 1998 and was able to transfer data at a distance of several meters. It was characterized by poor compatibility between products from different manufacturers, and was impossible to implement an anonymous connection at the protocol level. This version is no longer used.
Versions 1.1 and 1.2
These updates administered support for unencrypted channel mapping for incoming power signals, and accelerated the process of detecting and connecting devices. Noise was increased and transmission speed increased (721 kbps) and network implementation was anonymous. This version allows you to send longer voice messages, and use stereo audio transmission. Currently, some Chinese manufacturers will be able to sell you a cheap phone with the update 1.2.
Versions 2.0 and 2.1
Update 2.0 was released in 2004, 2.1 in 2007. The difference between them lies in the greater energy efficiencies of the latest version. The main feature of Bluetooth 2.0 – the introduction of EDR technology, the speed increases to a theoretical 3 mbps (in practice it was more like 1.5-2 mbps). Today you can buy an inexpensive smartphone that supports this technology.
Version 2.1 was the most popular update to Bluetooth. It is compatible with virtually all devices represented in the mobile market.
Energy consumption in version 2.1 decreased by almost 10 times. There is additional bandwidth, and the update to 2.1 made it easier to use multiple connections simultaneously.
Bluetooth 3.0 was published in 2009 and pioneered the use of high-speed data broadcasting. Its speed increased to 24 mbps. The speed increase was due to the installation of two modules: Bluetooth 2.1 + EDR module as well as the wifi 802.11 module. This module provides a bump in speeds but does not provide Wi-Fi-compatibility. You would be able to transfer a small amount of files with version 3.0.
The disadvantage of this solution is the increased power consumption. This version is supported by almost all smartphones.
Versions 4.0 and 4.1
Update 4.0 was released in 2010. It fixed the main drawbacks of high speed – excessive energy consumption. The 4.0 specification included the traditional Bluetooth module and also a high-speed module based on a wifi protocol. It added the Bluetooth protocol with minimal power consumption. This version is mainly used in electronic sensors, particularly mini sensors in healthcare.
Connectivity time was reduced to 5 ms, and the transmission distance increased to 100m. Permission AES-encryption for data protection was implemented. This version is implemented in new models of major manufacturers.
Update 4.1 was introduced in 2013. Its major improvements relate to the joint operation of Bluetooth and the LTE-standard. Data packets are automatically coordinated to not interfere with each other.
This new version came out in 2017. Bluetooth 5 is faster than 4.0, and more importantly, it allows you to connect devices at a greater distance. Bluetooth v. 5.0 -enabled smartphones are able to maintain the connection at a distance of over 100 meters. In addition, you can connect a large number of devices, not to worry about the safety and energy consumption. Bluetooth version 5.0 has improved data transfer speeds, and opens up new possibilities for lovers of quality sound. In the near future there will be a lot of smartphones with support for Bluetooth 5 and the compatible accessories will also increase. We will write an extensive review of Bluetooth 5 in later articles.