Bluetooth - Wireless Technologies

An open wireless protocol used for the exchange of data over short distances is known as the Bluetooth. It uses short length radio waves for the exchange of data. Both fixed and mobile devices can exchange data through Bluotooth creating a Personal Area Network(PAN). Bluetooth can connect up to eight devices simultaneously. It was originally introduced as a wireless alternative to RS-232 data cables.

Bluetooth networking transmits data via really low-powered radio waves. The communication is done on a frequency of 2.45 GHz (between 2.402GHz and 2.480 GHz to be exact). This frequency band has been set aside for the use the use of industrial, scientific and medical devices(ISM) by an international agreement. Some other devices like baby monitors, garage door opens and the newest generation of cordless phones use this same radio frequency band. One of the ways Bluetooth devices avoid interference with these devices is by sending out very weak signals of about 1 milliwatt, while many powerful cell phones can generate a signal of 3 watts. This low power limits the range of a bluetooth device is normally about 10 meters which can go up to 100 meters depending upon the radios.

When devices capable of connecting through Bluetooth come within range of each other, it is determined through electronic conversion that whether they have data to share or one needs to control the other. In this way these devices form a network which is a Personal Area Network(PAN).

Here are some important facts about the Bluetooth technology.

Bluetooth was the name of a Danish king who unified Denmark and Norway. In the beginning Bluetooth was aimed at unifying the telecom and computing industries, thus the name Bluetooth.

It employs several layers of data encryption and user authentication, thus a network formed using Bluetooth technology is an extremely secure one.

Other radio frequency devices normally does not interfere with with Bluetooth devices because Bluetooth radios switch frequencies 1600 times per second (frequency hopping) and the data packets sent and received are too small.

Over the air data data rate is 1 to 3 Mbps.

Quite a few devices use Bluetooth and the number of these devices is increasing. Here are some:

GPS navigation receivers
Digital cameras and camcorders
Laptops
Cell Phones
Scanners
Printers
In-car handsfree kits
Keyboards and Mice
Headsets
PDAs
Home appliances (microwaves, refrigerators, driers etc.)

Frequency: 2.45 GHz(2.402 to 2.480 to be exact).

Cost: A very inexpensive technology as compared to other wireless technologies. Costs just about a third of Wi-Fi to implement.

Range: Normally 10 meters but can be increased up to 100 meters.

Power Consumption: Very low as compared to other wireless technologies like Wi-Fi and WiMAX.

Data Transfer: Normally 1 Mbps.

Bluetooth that consumes very low energy has been introduced and named as Wibree. Read more about Wibree.