Q.What is Bluetooth?

Bluetooth is a wireless technology standard for exchanging data over short distances, using short-wavelength microwave transmissions in the ISM (Industrial, Scientific and Medical) band from 2400 MHz to 2480 MHz. It was developed as a cable replacement — originally to allow hands-free phone use by removing the wire between a cell phone and its headset — and it forms a Personal Area Network (PAN) by automatically setting up ad-hoc links between nearby devices.

Bluetooth works using two key techniques: Frequency Hopping Spread Spectrum (FHSS), in which the transmission rapidly hops among many frequencies so that interference on any one channel is only brief, and Frequency Shift Keying (FSK), the digital modulation that represents data by shifting the carrier frequency. The whole transceiver is available as a single chip, containing an embedded controller, that plugs into a device to make it part of the PAN; on that chip the RF transceiver, antenna, RF clock circuit, application processor and power supply work together. …