How Bluetooth Works ?

Bluetooth, WiFi and WiMAX are wireless technologies which allow devices to inter-connect and communicate with each other. These technologies are radio frequencies. Similar to the analogue radio, or FM radio. Bluetooth works on 2.45GHz frequency. WiFi works in two frequency bands 2.4GHz and 5GHz. WiMAX works in two frequency bands, 2 - 11GHz and 10 - 66GHz.

BLUETOOTH

It is designed for short range communications with a range of about 10m. As a result, it consumes less power and are suited for very small battery powered devices and portable devices.  

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1. One of the ways Bluetooth devices avoid interfering with other systems is by sending out very weak signals of about 1 milliwatt. By comparison, the most powerful cell phones can transmit a signal of 3 watts. The low power limits the range of a Bluetooth device to about 10 meters (32 feet), cutting the chances of interference between your computer system and your portable telephone or television.
2. Bluetooth can connect up to eight devices simultaneously
3. Bluetooth uses a technique called spread-spectrum frequency hopping that makes it rare for more than one device to be transmitting on the same frequency at the same time. In this technique, a device will use 79 individual, randomly chosen frequencies within a designated range, changing from one to another on a regular basis. In the case of Bluetooth, the transmitters change frequencies 1,600 times every second, meaning that more devices can make full use of a limited slice of the radio spectrum. Since every Bluetooth transmitter uses spread-spectrum transmitting automatically, it’s unlikely that two transmitters will be on the same frequency at the same time. This same technique minimizes the risk that portable phones or baby monitors will disrupt Bluetooth devices, since any interference on a particular frequency will last only a tiny fraction of a second.