Mobile radio technologies could be categorised in dependency of their range. There are four types of networks: Personal Area Networks (PANs), Local Area Networks (LANs), Metropolitan Area Networks (MANs) and Wide Area Networks (WANs). Further these three main networks are categorised into wire and wireless networks. Wireless local area networks are also called ”wireless-LANs” (WLANs). PANs have only a range from about 10 meters. Bluetooth is a typical representative of such PANs and it is used for wireless communication between devices such as mobile phone with headset, personal digital assistants (PDAs) and printers. The idea of Bluetooth comprises three scenarios:

• substitution of wire and infrared technology
• data and voice transmission within a short distance
• access to personal networks

Further the Bluetooth technology persecutes the vision of an automatised synchronization with application or hardware such as email or headset. The Bluetooth technology is promoted by the Special Interest Group (SIG). SIG is a association of well-known and associated companies in the field of telecommunication, computing and network industries, for example Ericsson, IBM, Intel and Nokia [SIG 2000]. Bluetooth was founded 1998 for specification a low-cost and low-power consumption standard and based on the IEEE (Institute of Electrical and Electronical Engineers – eye-triple-e) 802.15 standard for wireless personal area networks (WPANs). Consequently the foundation was a further little step for ubiquitous computing. But in general it is limited to short distances such as within office.

The Bluetooth technology is qualified for peer-to-peer and ad-hoc networks. In a peer-to-peer network every system offers some resources to computers and the other way round it is possible to use the services of this computer. In opposite to a peer-to-peer network, an ad-hoc network means that as soon as some devices approach each other, there is a connection established to each other and services are exchanged and offered. Bluetooth systems use the 2.4 GHz ISM-Band (Industrial Scientific Medical) radio frequency which has been released without or buying a licensed by the International Telecommunications Union (ITU). The transmitting power comprises 1 mW which has a maximal range of 10m [Oki2000]. The elemental network of a Bluetooth topology is called ”piconet”. It comprises up to eight nodes in such a topolgy which can be synchronised with each other and it is a typically representative of a ad-hoc network. Every node within a piconet can be master or slave. One master node can be connected with maximal seven slave nodes. The direct communication between two slave-nodes is only possible about the master-node, i.e. there is no master-master or slave-slave communication. In that ad-hoc network it is possible, that a lot of devices enter or leave the topology after a certain time (dynamic networking). Several piconets can be combined to a ”scatternet” and implementing the communication between several piconets.

The Bluetooth specification supports a symmetric communication, a asymmetric communication and a channel which allows both (a asymmetric data and a symmetric voice transmission). Furthermore the symmetric data channel comprises up to three concurrent and synchronous voice channels. The symmetric communication offers a voice transfer rate of 64 kbit/s. In the opposite to the symmetric communication supports the asymmetric communication either a transmitter rate of 721 kbit/s or a receiver rate of 56 kbit/s. Or it allows a symmetric transmitter and a receiver rate of 432.6 kbit/s [Oki2000]. The technology of Bluetooth makes sure a high disturbance immunity against junks with the technique of frequency hopping¹. Furthermore Bluetooth supports different protocols or adapted well-known protocols such as TCP/IP and Wireless Application Protocol (WAP).