frequency range of bluetooth

Bluetooth operates in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band. The frequency range used by Bluetooth is divided into 79 channels, each 1 MHz wide. These channels start from 2.402 GHz and go up to 2.480 GHz, spaced 1 MHz apart. The standard frequency hopping scheme used by Bluetooth is designed to minimize interference with other devices operating in the same frequency band.

Bluetooth uses a spread spectrum frequency hopping (FHSS) technique to transmit data. In FHSS, the transmitter and receiver rapidly switch among the available channels in a synchronized manner. This helps to reduce the impact of interference and improve the overall reliability of the communication.

The frequency hopping pattern is determined by the master device in a Bluetooth network, and all the connected devices synchronize their hopping to this master. The hopping sequence is pseudo-random, and it changes rapidly, making it difficult for external devices to interfere consistently with Bluetooth communication.

The 2.4 GHz ISM band is a shared frequency band used by various wireless technologies, including Wi-Fi, Zigbee, and microwave ovens. To mitigate interference, Bluetooth devices dynamically adjust their hopping patterns to avoid channels with high interference levels.

It's worth noting that Bluetooth Low Energy (Bluetooth LE or BLE), which is commonly used in modern Bluetooth devices, also operates in the 2.4 GHz ISM band. BLE uses a narrower bandwidth and has a simpler modulation scheme compared to classic Bluetooth, making it well-suited for low-power applications such as wearable devices and sensors.

The frequency range of Bluetooth is from 2.402 GHz to 2.480 GHz, divided into 79 channels, each 1 MHz wide, and it uses a frequency hopping spread spectrum technique to transmit data while minimizing interference.