Bluetooth

Bluetooth is an Industrial Specification for Wireless PANs first developed by Ericsson, later formalized by the Bluetooth SIG. The system is named after a Danish king Harald Blåtand, otherwise known as Harold Bluetooth. It is a radio standard primarily designed for low power consumption with a reach of up to 10 meters (30 ft). It can be used to wirelessly connect periphery like printers or keyboards to computers, or to have personal digital assistants (PDA's) communicate with other nearby PDA's or computers. Cell phones with integrated Bluetooth technology have also been released, that can connect to computer, PDAs and, very specially, to handsfree. However, the standard also includes support for more powerful longer-range devices suitable for constructing a Wireless LAN.

The protocol operates in the license-free ISM band at 2.45 GHz. It reaches speeds of 723.3 kbps downstream with a simultaneous 57.6 kbps upstream. In order to avoid interfering with other protocols which may use the 2.45 GHz band, the Bluetooth protocol divides the band into 79 channels and changes channels up to 1600 times per second.

Every Bluetooth device can simultaneously maintain up to 7 connections. Every device can be configured to constantly announce its presence to nearby devices, in order to establish a connection. It is also possible to password protect a connection between two devices, so that no others can listen in.

Bluetooth should be compared to WiFi, a faster protocol requiring more expensive hardware that covers bigger distances and uses the same frequency range.

See definition from Personal Telco Wiki, http://www.personaltelco.net/index.cgi/BlueTooth

External links

• http://www.howstuffworks.com/bluetooth.htm

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See also Harold Bluetooth, king of Denmark.