Infrared and Bluetooth Facts
Bluetooth
Bluetooth uses radio waves for communication. Bluetooth: -Uses ad hoc connections between devices to create personal are networks called piconets. A piconet can have up to 7 devices, and each device can participate in multiple piconets at the same time -Operates in the 2.4 GHz frequency range and uses adaptive frequency hopping (AFH). it automatically detects other devices in the area and avoids the frequencies used by those devices. It can switch between 79 channels to avoid interference. -Transmits at up to 3 Mbps. The maximum distance depends on the device class: *Class 3 devices transmit up to 1 meter *Class 2 devices transmit up to 10 meters *Class 1 devices transmit up to 100 meters Class 2 device as most common -Can be used for both voice and data signals -uses a 128-bit proprietary encryption mechanism to encrypt its signal
Other wireless communication methods
In addition to 802.11 specification for wireless networking, there are two additional wireless communication methods that can be used: Infrared (IrDA) and Bluetooth.
Infrared (IrDA)
Infrared uses invisible light waves for communication. Infrared: -is a line-of-sight medium. Objects cannot be in the path of communications. -Communicates at 9600 bps up to 4 Mbps and uses the resources of a COM port. -Works best for devices within 1 meter, but can operate up to 30 meters in areas without ambient light interference -Offers no security transmissions Infrared is typically used for remote control devices, of for sending data between two devices, such as two PDAs or from a PDA to a desktop/laptop computer
Common applications for Bluetooth
Of the two standards, Bluetooth is gaining is popularity due to its lower cost, greater bandwidth, and ability to transmit through objects. Common applications for Bluetooth include: -Connecting peripheral devices (such as keyboard and mouse) to a computer -Wireless headphones and headsets used with wireless phones. -Device to device connections (such as creating a simple network connection between devices of various types).
