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Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally unlicensed short-range radio frequency with a short range(power-class-dependent: 1 meter, 10 meters, 100 meters) based on low-cost transceiver microchips in each device.
Bluetooth was named after a late tenth century king, Harald Bluetooth King of Denmark and Norway. He is known for his unification of previously warring tribes from Denmark (including now Swedish Scania, where the Bluetooth technology was invented), and Norway. Bluetooth likewise was intended to unify different technologies, such as computers and mobile phones.
The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group(SIG). It is a privately held, not-for-profit trade association with headquarters in Bellevue, Washington. As of September 2007 the SIG is composed of over 9000 member companies that are leaders in the telecommunications, computing, automotive, music, apparel, industrial automation, network industrial and a small group of dedicated staff in Hong Kong, Sweden, and the USA.
The protocol operates in the license-free ISM band at 2.4-2.4835 GHz. The specification was developed in 1994 by Japp Haartsen and Sven Mattisson. It is based on frequency-hopping spread spectrum technology. To avoid interfering with other protocols that use the 2.45 GHz band, the Bluetooth protocol divides the band into 79 channels (each 1 MHz wide) and changes channels up to 1600 times per second.
Bluetooth exists in many products, such as phones, printers, modems and headsets. The technology is useful when transferring information between two or more devices that are near each other in low-bandwidth situation. Bluetooth is commonly used to transfer sound date with phones or byte data with hand-held computers.
Bluetooth simplifies the discovery and setup of services between devices. Bluetooth devices advertise all of the services they provide. This makes using services easier because there is no longer a need to setup network addresses or permissions as in many other net works.
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