Bluetooth Protocol Specifications

Bluetooth is an open specification for a radio frequency (RF) system that enables wireless voice and data communications over short distances. The Bluetooth protocol stack -- a group of programs, known as drivers -- is specified as several separate layers.

Physical Layer

The lowest level of the Bluetooth protocol stack is known as the physical layer. As the name suggests, this layer is, effectively, the physical communications interface. It deals with some of the basic aspects of RF communication, such as modulation, or the variation of amplitude or frequency of the signal.

Baseband

Layers known as the baseband and link control layer sit above the physical layers. In simple terms, they enable the physical RF link between Bluetooth devices to form a small network, known as a piconet.

Link Manager

Above these layers, the so-called link manager protocol is responsible for issues such as authentication and encryption during the establishment of Bluetooth links between devices. The link manager is written in software, but is often included as firmware -- permanently stored in read-only memory (ROM) -- for simplicity.

References

• The Wireless Directory: Bluetooth Specification
• "Dedicated Systems Magazine": Bluetooth Protocol Architecture