The Bluetooth Connection

In Bluetooth parlance, devices are categorized as either a slave or a master device. As the names imply, the master is responsible for setting up and controlling the communication between the two. The slave essentially does what it is told, receiving incoming signals and sending responses back to the master.

Communication between a master and slave requires three steps: pairing, connecting and talking. In the pairing process, the steps of which are device-specific, the two devices carry on an electronic communication to determine whether they are of a compatible type and have data to share. If these criteria are met, the two devices then must be connected, which makes them ready to communicate. This step, controlled by the master device, is analogous to plugging in a cable between the two. The devices must be reconnected whenever they lose their connection. For example, when one of them is turned off and back on, or when the two devices move out of and then back into their usable range, the connection is lost. Once paired and connected, the two devices are in standby mode. When a communication event takes place, either automatically or under the control of an operator, the two devices begin talking (exchanging data) over the established connection.

Bluetooth data transmission has far-reaching applications — between computers and their many peripheral devices, between a personal digital assistant and a computer, between a stereo amplifier and speakers, between machines and the instruments that monitor their performance, between mobile phones and Bluetooth headsets — which are growing daily.