e2001 Your Digital Future - Bangkok Post Special Supplement

HOME NETWORKING

Wireless Bluetooth on the way

Standards will ease network difficulties

Tony Waltham

Today, getting one digital device to talk to another or to exchange data can be a messy tangle of a challenge that involves cables and ports.

But this will soon be history as a new home wireless networking standard initiated by Ericsson, IBM, Intel, Nokia and Toshiba just over two years ago is now beginning to appear in products.

It is called Bluetooth and it is named after a Scandinavian historical figure, King Harald Bluetooth, a Danish king of the 10th century who united Denmark and introduced Christianity to that country.

As such, the choice of name reflects how Scandinavia has been leading the world in mobile wireless data technologies.

Bluetooth will radically change the way that an increasing number of digital devices, MP3 players, mobile phones, PDAs or digital cameras communicate with one another, making this possible using radio waves.

It is an IEEE standard 802.15 that supports both voice and data. The voice channels support 64 Kbps, while there is an asymmetric data rate (one way) of 721 Kbps (while permitting 57.6 Kbps in the return direction); and symmetric rate of 432.6 Kbps is possible according to the Bluetooth specifications.

Transmissions will be secure in a business and home environment since Bluetooth has sufficient encryption and authentication techniques and is very secure in any environment.

A frequency-hopping scheme with 1600 hops/sec is also employed.

All this, along with an automatic power output adaptation that reduces range exactly to requirements, makes the system extremely difficult to eavesdrop.

Initially, Bluetooth is designed for very low power use, and the transmission range will only be 10 metres, or about 30 feet.

High-powered Bluetooth devices will enable ranges up to 100 metres (300 feet), but the original design concept will mean that 10 metres will be adequate for the purposes that it was originally intended for.

Because it uses the 2.4 GHz ISM (industrial-scientific-medical) frequency band, which is reserved for licence-free operation in most countries, no licensing will be required here in Thailand or elsewhere. (France, Spain and Japan have different regulations which cause slightly different frequency bands to be used.)

The technology is royalty-free, however companies who wish to develop Bluetooth products will have to sign a free licence agreement to comply with patent law.

Bluetooth is intended to replace wires in small, personal communication devices; and does not support many of the features that a fully-fledged wireless LAN technology as in the 802.11 specification requires in order to be used for corporate local area networks.

However, there have been concerns expressed about the possibility of interference stemming from the fact that wireless LANs, along with an alternative HomeRF networking specification, also share the same 2.4 GHz ISM frequency allocation.

Products are now being announced and leading companies expect that a total of 250 million Bluetooth-enabled devices, ranging from headsets to mobile and desktop computers, will be shipped in 2002.