Bluetooth: what is it, how does it works

Bluetooth: what is it, how does it works

Bluetooth is a WPAN (Wireless Personal Area Network) technology, which is in other words, a wireless network technology with the capacity to link devices without a physical connection. Unlike infrared technology, Bluetooth-enabled devices do not need a direct line to communicate, allowing flexibility and connectivity of multiple devices.

What is the history of Bluetooth?

The objective of Bluetooth is to allow data transfer between equipment which contains a circuit radio within a 32 to 328-foot radius with low power consumption.

Bluetooth is mainly intended to connect peripheral devices (i.e. printers, mobile phones, home appliances, wireless headsets, mice, keyboard, etc.), computers, or PDAs, without using a wired link. Bluetooth is also increasingly used in mobile phones to enable them to communicate with other devices, especially hands-free devices such as Bluetooth headsets. Bluetooth headsets can be used as an audio headset and often offer remote control capabilities.

Bluetooth was originally developed by Ericsson in 1994. In February 1998, an interest group called Bluetooth Special Interest Group (Bluetooth SIG), united over 2,000 companies, such as Agere, Ericsson, IBM, Intel, Microsoft, Motorola, Nokia and Toshiba, to produce the Bluetooth 1.0 specifications, published in July 1999.

What are the characteristics of Bluetooth?

Bluetooth allows bitrates of up to 1 Mbps, which corresponds to 1600 exchanges per second, with a range of about 328 feet with a class II transmitter and a little under 32 feet with a class I transmitter.

The Bluetooth standard is defined in three classes of emitters, which propose various rage capacities depending on the power of the signal:

Class Strength Range
I 100 mW (20 dBm) 328 feet
II 2,5 mW (4 dBm) 19-65 feet
III 1 mW (0 dBm) 33 feet

Unlike IrDA technology, the main competing technology using light rays for data transmission, Bluetooth uses radio waves (2.4 GHz frequency band) to communicate so devices do not have to be physically linked. Two Bluetooth devices can communicate even if located on opposite sides of a room and without any intervention once they are within range of one another.

What are the Bluetooth standards?

Below you will find the Bluetooth standards:

  • IEEE 802.15.1 sets the standard Bluetooth 1.x to achieve a bitrate of 1 Mbit / sec;
  • IEEE 802.15.2 uses of the 2.4 GHz frequency band (also used by WiFi). This standard is not yet validated;
  • IEEE 802.15.3 a standard currently under development that will offer broadband (20 Mbit/s) with Bluetooth technology;
  • IEEE 802.15.4 a standard currently under development for low-speed Bluetooth applications.

For more information, visit the official Bluetooth website.