Personal area networks or PANs, as they are popularly known, can be defined as person centric networks intended to enable seamless inter connectivity of devices in a person's sphere of 10 meters radius. These networks could be wired, as most of today's networks are, or these could be wireless, as the emerging Wireless PANs (WPANs).

Bluetooth

Bluetooth, named after a tenth-century Danish king, is a royalty-free specification for short range RF based wireless connections among personal devices like PC, mouse, keyboard, printer, Personal Digital Assistant, mobile phones etc. Networks employing this standard use the unlicensed spectrum at 2.4 GHz and have a typical range of 330 feet.

The Bluetooth standard defines three different power classes:

The modulation scheme used is Gaussian Frequency Shift Keying (GFSK)

Bluetooth uses Frequency Hopping Spread Spectrum (FHSS) to hop from one radio channel (I MHz spaced) to another after the transmission of every few packets. This not only ensures full free spectrum utilization, it also offers interference immunity to the transmission.