Bluetooth Quick Guide

Bluetooth technology is a great way to set up a simple wireless network in your office. It doesn't have the range of a Wi-Fi network, but it doesn't cost as much and it doesn't consume as much power. If you think of Wi-Fi as a wireless ethernet network, think of Bluetooth as a wireless USB port. It allows quick data transfer with a range of 10 meters (33 feet).

You may want to implement Bluetooth on your desktop, just to get rid of all the wires. A Bluetooth PC can be controlled by a Bluetooth mouse and a Bluetooth keyboard. You can even have a Bluetooth monitor and Bluetooth speakers Over on the other side of the office, you can have a Bluetooth printer.

Bluetooth devices are set up to work together in what's called a piconet. Up to 8 devices can work together with one device functioning as the master and the others as slaves. Any one of these devices can then communicate with a device or devices in another piconet if you like. This is called a scatternet.

It may sound complicated, but it's easy to set up. Bluetooth devices don't technically create a "network," they create sets of pairings. Choose your master device, a desktop PC in many cases. Now use the included software to pair that device with the next device you want to add via a simple handshaking procedure. Now the two devices form a piconet. You can add more devices in the same way. If two slave devices need to communicate with each other, they can do so by going through the master.

Bluetooth devices communicate with each other via radio signals in the 2.4 GHZ frequency range. They use frequency hopping technology to jump between 79 different 1 MHz channels within that range at a rate of 1600 hops per second. This minimizes interference and fading. Since each piconet's hop sequence is unique, piconets can exist side by side without stepping on each other's turf.

Bluetooth began its life with versions 1.0 and 1.0B. These versions have been discontinued due to compatibility and security issues. Bluetooth 1.1 is the earliest version that is still available. Bluetooth 1.2 improves over 1.1 by adding an anonymity mode, masking the hardware address of a device. It also allows adaptive frequency hopping to help the piconet cut down on interference from crowded frequencies. Bluetooth 2.0 is the most recent version and offers three times the connection speed of Bluetooth 1.2. Bluetooth 2.0 is backwards compatible with 1.2 and 1.1. Bluetooth 1.2 is backwards compatible with 1.1.

Since it's a wireless device, Bluetooth does have some security concerns. Most of these concerns can be addressed by standard safe computing practices. In general, you want to password protect your Bluetooth device rather than leaving it open to be used by anyone with a Bluetooth device that's nearby. More seriously, in 2004, a security flaw was discovered that made it possible to reverse engineer the PIN of a Bluetooth headset and listen in on the conversation. In general, though, the risk is slight. Since Bluetooth doesn't have a wide range, hackers need to be pretty close by to accomplish their dirty work.