With Bluetooth up to eight units may be wirelessly connected in a micro network. The range is usually up to 10 meters (33 ft). This version is called Pico-Bluetooth and only takes up to 1 mW. Also Mega-Bluetooth with a range of up to 100 meters (330 ft) and a sending power of up to 100  mW is possible. The wireless standard uses the licence free 2,4GHz band an does not need to have a direct view between the units in contrary to infrared. The utilized hardware is very small - the chip only measures 9 mm² (0.014 in²) - and consumes very few energy, ideal premises for PDAs and cellular phones. Other common devices of our everyday life will support this standard, too. The refridgerator tells the PDA that there is no more milk for example. The communication is build up on a voice and a data channel. The voice channel supports with 64 Kbit/s ISDN speed and the data channel receives a maximum of 721 Kbit/s and sends up to 56,6Kbit/s. Thus the cellular phone may rest in the jacket or suitcase while using it.

To get two Bluetooth units to understand each other they both have to support the same profile which can be different for different applications. Here you will find a complete Overview of all Bluetooth profiles.

The name of this technology was taken from king Harald Blåtand which unified Danmark and Norway in the 10th Century.

The Ericsson T39m and T520m were the first phones which featured build in bluetooth technology thus providing short distance wireless connections. A selection of Bluetooth add-ons to extend the functions of these and other Bluetooth enabled cellular phones shows the following table.

Overview

Back to main page