Designed as a wireless alternative to data cables, Bluetooth operates in the UHF band of frequencies from 2.400 to 2.485 GHz. The idea of short-link radio technology was first devised in 1989 with the first commercial application coming ten years later in the form of a hands-free headset for a mobile phone. The range of a Bluetooth device depends on its class. The following is a table of these classes. The ranges are approximate:
|
Class |
Transmission Power |
Range |
|
1 |
100 mW |
100 meters |
|
2 |
2.5 mW |
10 meters |
|
3 |
1 mW |
1 meter |