Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz) from fixed and mobile devices, and building personal area networks (PANs). Invented by telecom vendor Ericsson in 1994, it was originally conceived as a wireless alternative to RS-232 data cables. It can connect up to seven devices, overcoming problems that older technologies had when attempting to connect to each other.
Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which has more than 30,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The IEEE standardized Bluetooth as IEEE 802.15.1, but no longer maintains the standard. The Bluetooth SIG oversees development of the specification, manages the qualification program, and protects the trademarks. A manufacturer must meet Bluetooth SIG standards to market it as a Bluetooth device. A network of patents apply to the technology, which are licensed to individual qualifying devices.
The development of the "short-link" radio technology, later named Bluetooth, was initiated in 1989 by Nils Rydbeck, CTO at Ericsson Mobile in Lund, Sweden, and by Johan Ullman. The purpose was to develop wireless headsets, according to two inventions by Johan Ullman, SE 8902098-6, issued 1989-06-12 and SE 9202239, issued 1992-07-24 . Nils Rydbeck tasked Tord Wingren with specifying and Jaap Haartsen and Sven Mattisson with developing. Both were working for Ericsson in Lund. The specification is based on frequency-hopping spread spectrum technology.
| Class |
Max. permitted power |
Typ. range
(m) |
| (mW) |
(dBm) |
| 1 |
100 |
20 |
~100 |
| 2 |
2.5 |
4 |
~10 |
| 3 |
1 |
0 |
~1 |
| 4 |
0.5 |
-3 |
~0.5 |
| Bluetooth version |
Maximum speed |
Maximum range |
| 3.0 |
25 Mbit/s |
|
| 4.0 |
25 Mbit/s |
200 feet (60 m) |
| 5 |
50 Mbit/s |
800 feet (240 m) |
...
Wikipedia
