What is Bluetooth ?

  Bluetooth is a wireless networking protocol (like WIFI) designed to quickly and automatically connect devices like printers, PDAs, Cameras to computers and to each other without wires.

Common Bluetooth applications are:

• Connecting mobile phones to each other to exchange pictures, ring tones, music etc
• Connecting computer peripherals like mice, keyboards, printers etc to a computer.
• Connecting headsets to mobile phones for hands free operation (Bluetooth car kits)

Bluetooth Versus WIFI

Because both technologies are associated with computers and mobile phones there is considerable confusion as to which one to use or which one should be used.

WIFI is the wireless equivalent of Ethernet making fast data transfer possible between computers. It is the choice for connecting computers together in a Home/Office environment.

Bluetooth can connect computers together but the data transfer rate between the computers is too slow to be off practical use. It is more commonly associated with connecting PDAs to computers for synchronization and for connecting other (low speed) peripheral devices like mice and keyboards.

Bluetooth Class and Standards

Bluetooth devices come in three classes 1-3. The device class determines the effective operating range/distance of the the device. Class 1 devices have a range up to 100m, class 2 devices up to 30 meters and class a device up to 10 meters.

Bluetooth is still being actively developed and the standard has already been through a number of versions. Each version is backwards compatible with the last making it possible to inter-operate devices with different version numbers.

 The current Bluetooth standard is at version 2.0, however most devices available in the market (April 2006) are at version 1.1 or 1.2. Wikipedia has more technical details on the different standards and the differences.

Bluetooth Pairing

Bluetooth devices can automatically discover other Bluetooth devices that are within range. However the discovery process takes time and the device connection must be approved. This is obviously not satisfactory for devices that must always be in contact with each other like a blue tooth keyboard and mouse or an in car hands free kit and the mobile phone.

Device pairing make an effective permanent connection between the two devices so that they  always connect without following the normal discovery process. The connection is made by assigning the devices a shared passkey (PIN) which they use to authenticate each other.

The process will vary slightly depending on the device but the general process for pairing two devices (Device A and B) is.

• Switch on both devices
• Device A should detect device B
• Select Pairing on device A and enter the PIN (passkey)
• Device B will ask the user for the PIN. Enter the same PIN (passkey)
• You should get confirmation that the devices are paired.

Related articles and resources:

• http://en.wikipedia.org/wiki/Bluetooth