Classic Bluetooth communication is based on point-to-point connections and point-to-multipoint connections. With Bluetooth, up to eight devices can communicate with each other in a piconet. Up to 10 piconets can be combined to form a communication network. Multiple piconets with overlapping radio ranges are referred to as a scatternet.
The Bluetooth network is controlled by a master. Within a piconet, one Bluetooth unit assumes the role of master, while the other units operate as slaves. In terms of active units, a piconet can comprise one master and a maximum of seven slaves. This keeps Bluetooth communication in a piconet to a maximum of eight units. In addition, up to 255 passive slaves can be logged into various standby modes.
The master uses a random generator to determine the sequence of frequency hops used by the participants in a piconet. Bluetooth works with point-to-point or point-to-multipoint connections. The first time a connection is established between two Bluetooth devices, the devices are paired so that they can recognize each other later. This device coupling is called pairing and is used to exchange identification data.
Other connection concepts known to Bluetooth are broadcasting and the mesh network introduced in Bluetooth Low Energy( BLE). The Bluetooth mesh is also called Smart Mesh. It is a mesh network in which all nodes are interconnected, increasing the range and reliability of the low- power Bluetooth protocol by bypassing blocked connections in the event of a link or node failure.