5. Bluetooth

Bluetooth is a type of short range radio communication and networking protocol combined.

It was developed so devices close to one another could exchange data.

By close, we mean within about 10 metres of one another even if there is a wall in-between.

Advantages of Bluetooth

One advantage with Bluetooth working within a short range is that it only needs a tiny amount of radio power to work, less than a thousandth' of a Watt (a torch light uses about 1 Watt to light the bulb) so you can appreciate that this is a tiny amount of power. This means it is ideal for battery operated devices such as mobile phones.

Another advantage of Bluetooth is that it is completely automatic - every Bluetooth enabled device will sense the presence of another device within range. They can do this because they share a 'network protocol' that allows them to share data.

Another clever thing about the protocol is that it can reduce interference from other Bluetooth devices that are also exchanging data nearby. For example if Sam's mobile is exchanging data with Tom's mobile this will not interfere with Emma's mobile also exchanging data with Sophie's mobile nearby.

In terms of bandwidth, the first versions of the standard supported up to 1Mbps which is fine for laptop / mobile phone data transfers, then, as devices required higher speeds a later version of the standard was released (Version 2) offering 3Mbps for example a 3G mobile requiring a high speed internet connection. Version 3 of the standard offers 24 Mbps.

Examples of how it is used.

A Bluetooth enabled phone will detect phones nearby and provide you with a list of usernames. You can then send a message, photograph or movie sitting on your phone to any of the usernames. They, of course, have to accept the offer but the rest of it is automatic.

Another common use of Bluetooth is 'hand-free' operation of mobiles in the car. You wear a bluetooth headset that senses your mobile nearby. This allows you to talk using the mobile, but most importantly, keeping your hands on the steering wheel!

Bluetooth is also used to exchange files between a PDA and a desktop computer.

Further uses

• Hands-free mobile telephone calls
• Short range communication such as a PC and a nearby bluetooth enabled printer
• Transferring files, contact details and calendar appointments between devices
• Connection to measurement devices, medical equipment, GPS receivers, bar code scanners
• Connection to industrial and medical sensors