Published on Jun 05, 2023


Blue tooth operates in the unlicensed ISM band at 2.4 GHZ frequency band and use frequency hopping spread spectrum technique. A typical Blue tooth device has a range of about 10 meters and can be extended to 100meters. Communication channels supports total bandwidth of 1 Mb / sec. A single connection supports a maximum asymmetric data transfer rate of 721 KBPS maximum of three channels.

Description of Bluetooth Based Smart Sensor Networks


In bluetooth, a Piconet is a collection of up to 8 devices that frequency hop together. Each Piconet has one master usually a device that initiated establishment of the Piconet, and up to 7 slave devices. Master's Blue tooth address is used for definition of the frequency hopping sequence. Slave devices use the master's clock to synchronize their clocks to be able to hop simultaneously.

Why Bluetooth?

In most of the communication systems wires are involved in transmission and receiving of data. For example, the wires are used to connect computer peripherals to pc, and the pc to the net. In this blue tooth technique wireless communication for transmitting and receiving of data is performed. The Blue tooth radio chip functions at 2.4 GHZ, which is in the unlicensed ISM (Industrial Scientific Medical) band. It can be transmitted over a range of 10m to 100m. The technology of Bluetooth centers a round a 9mmx9mm microchip, which functions as a low cost and a short-range radio link. It provides security for both stationery and mobile devices.

The communications capability of devices and continuous transparent information routes are indispensable components of future oriented automation concepts. Communication is increasing rapidly in industrial environment even at field level. In any industry the process can be realized through sensors and can be controlled through actuators. The process is monitored on the central control room by getting signals through a pair of wires from each field device in Distributed Control Systems (DCS). With advent in networking concept, the cost of wiring is saved by networking the field devices. But the latest trend is elimination of wires i.e., wireless networks.Wireless sensor networks - networks of small devices equipped with sensors, microprocessor and wireless communication interfaces.

In 1994, Ericsson Mobile communications, the global telecommunication company based in Sweden, initiated a study to investigate, the feasibility of a low power, low cost ratio interface, and to find a way to eliminate cables between devices. Finally, the engineers at the Ericsson named the new wireless technology as "Blue tooth" to honour the 10th century king if Denmark, Harald Blue tooth (940 to 985 A.D). The goals of blue tooth are unification and harmony as well, specifically enabling different devices to communicate through a commonly accepted standard for wire less connectivity.