Table of Contents:
Bluetooth protocol comprises of a number of protocols which can be divided into four categories. Each of these protocols is responsible for specific type of task and stands on its own. In the previous Bluetooth article we talked about the basic terms, the specific values of power, frequency, range and many more. The concept of master, slaves, Pico nets and scatter net forming ad-hoc network. This part of Bluetooth will deal with the protocols responsible for the working of Bluetooth technology. The four categories in which these protocols are divided are shown below:
Bluetooth Core Protocols
The baseband enable the radio frequency link between Bluetooth devices to form a Pico-net. Information is exchanged in packets in Bluetooth. A packet is a binary data unit that carries information required by the user which can be routed through a computer network. Both circuit switching and packet switching is used to transfer the packets in the network. Packet-switched networks move data in separate, small blocks -- packets -- based on the destination address in each packet. When received, packets are reassembled in the proper sequence to make up the message. Circuit-switched networks require dedicated point-to-point connections during calls and generally used in telephone lines for exchange.
The Link Manager Protocol
The link manager protocol is responsible for setting a link between two Bluetooth devices. This protocol layer is responsible for security issues like authentication, encryption, exchanging and checking the link and encryption keys.
Logical Link Control and Adaptation - Layer (L2CAP)
The Bluetooth logical link control and adaptation layer supports higher level multiplexing, segmentation and reassembly of packets and quality of service communication and groups. This layer is not responsible for reliability and uses ARQ to ensure it.
Service Discovery Protocol (SDP)
SDP is the basis for discovery of services on all Bluetooth devices. This is essential for all Bluetooth models because with SDP device information, services and the characteristics of the services can be queried and after that connection between two or more Bluetooth devices may be established .Other service discovery protocols such as Jini,UpnP etc. maybe used in conjunction with the Bluetooth SDP protocol.