Bluetooth is a standardized technology that is used to create temporary (ad-hoc) short-range wireless communication systems. These Bluetooth wireless personal area networks (WPANs) are used to connect personal accessories such as headsets, keyboards and portable devices to communications equipment and networks. The Bluetooth system can dynamically discover and connect to other nearby devices. To setup a Bluetooth system, one of the devices is designated as a master (controlling) and the other devices are setup as slaves (responding to the commands of the master). When a small Bluetooth system has been setup, it is called a Piconet.
Bluetooth is a wireless personal area network (WPAN) communication system standard that allows for wireless data connections to be dynamically added and removed between nearby devices. Each Bluetooth wireless network can contain up to 8 active devices and is called a Piconet. Piconets can be linked to form Scatternets.
The system control for Bluetooth requires one device to operate as the coordinating device (a master) and all the other devices are slaves. This is very similar to the structure of a universal serial bus (USB) system that is commonly used in personal computers and devices such as digital cameras. However, unlike USB connections, most Bluetooth devices can operate as either a master (coordinator) or slave and Bluetooth devices can reverse their roles if necessary.
This diagram shows the basic radio transmission process used in the Bluetooth system. This diagram shows that the frequency range of the Bluetooth system ranges from 2.4 GHz to 2.483 GHz and that the basic radio transmission packet time slot is 625 usec. It also shows that one device in a Bluetooth piconet is the master (controller) and other devices are slaves to the master. Each radio packet contains a local area piconet ID, device ID, and logical channel identifier. This diagram also shows that the hopping sequence is normally determined by the master's Bluetooth device address. However, when a device is not under control of the master, it does not know what hopping sequence to use to it listens for inquiries on a standard hopping sequence and then listens for pages using its own Bluetooth device address.