Tech Primer

What is Bluetooth?

Bluetooth is a short-range radio frequency technology that operates at 2.4 GHz and is capable of transmitting both voice and data. The effective range is around 32 feet with a transmission speed of 721 Kbps, which is enough to transmit voice, data, video and still images. The name ‘Bluetooth’ comes from Danish king, Harald Bluetooth Blaatand who merged (unified) territories of erstwhile Denmark and part of Norway. Bluetooth, too, is expected to ‘unify’ the telecom and computing industries.

What can it do?

Bluetooth is a popular option to connect devices— computers, cell phones and headphones—without the need for cables. Bluetooth chips can be integrated into devices by manufacturers. By embedding software into flash memory on chips, manufacturers can deliver wireless capabilities. Bluetooth devices that support similar software profiles can discover each other when they come within transmission range. For example, a Bluetooth-enabled mobile phone or PDA with a printer profile can automatically recognise the existence of a Bluetooth-enabled printer. Mobiles phones will be another big driver for Bluetooth. The Zelos Group, a research firm, reports that only 2.8 percent of handsets sold in the US in 2003 supported Bluetooth. This percentage increased to 9.4 percent in 2004. The group predicts that this will reach 81.8 percent by 2008.

Is there a special group that promotes and coordinates Bluetooth efforts?

To further Bluetooth’s interests, a Bluetooth Special Interest Group was founded in February 1998. Initially it consisted of five companies—Ericsson, Intel, Toshiba, Nokia and IBM. Today, more than 1,800 companies have joined the group to work on an open standard for Bluetooth. To avoid different interpretations of the Bluetooth standard regarding how a specific type of application should be mapped to the protocol. The group has defined a number of user models and protocol profiles. This process defines the criteria for Bluetooth product qualification to ensure that all the specifications are met.

Does the radio frequency of Bluetooth interfere with other devices?

Bluetooth uses a technique called spread-spectrum frequency-hopping. In this technique, transmitters change frequencies 1,600 times per second, which means that more devices can make full use of a limited slice of 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 minimises the risk that portable phones will disrupt Bluetooth devices, since any interference on a particular frequency will last only for a fraction of a second. One of the ways Bluetooth devices avoid interfering with other systems is by sending out very weak signals of 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 metres, bringing down the chances of interference between your computer system and a portable telephone or TV.

How secure is Bluetooth?

Bluetooth employs several layers of data encryption and user authentication techniques. All Bluetooth devices use a combination of a PIN (Personal Identification Number) and a Bluetooth address for identifying other devices. Additionally data encryption (128 bit) can be used to enhance Bluetooth security. As Bluetooth uses frequency-hopping techniques, it enables only synchronised receivers to pick up transmitted data.

For more information, please visit www.bluetooth.org