Ultra-fast Bluetooth edges closer

Cambridge Silicon Radio is backing the WiMedia Alliance's ultra wideband technology

Chipmaker Cambridge Silicon Radio (CSR) has announced it is backing the WiMedia Alliance ultra wideband (UWB) technology. The move makes it more likely that this flavour of UWB will become the standard for high-speed data transfers in future Bluetooth products, which could ship as early as 2007.

Last year, the Bluetooth Special Interest Group (SIG) unveiled plans to support UWB as an optional physical layer (PHY) in Bluetooth products. However, the IEEE standards body failed to ratify either of the rival proposals as an approved UWB technology for high-speed short-range wireless, opting instead to let the market decide.

CSR said it is backing the WiMedia Alliance technology because it offers more flexibility for meeting regulatory approvals around the globe.

"Direct sequence UWB is regarded by many as 'true' wideband, while the MultiBand OFDM technology used by WiMedia is the same modulation seen in 802.11a and 802.11g wireless LANs. It can turn off any frequency bands where there is a conflict," said Eric Janson, vice president of sales and marketing at CSR.

However, a further compelling reason for choosing WiMedia is that it is backed by a number of companies including Intel and Texas Instruments, while DS UWB is proprietary to Freescale Semiconductor, Janson added.

The Bluetooth SIG has yet to decide which standard it will back, but Janson said there is a "very good chance" it will go with WiMedia. CSR itself is a member of the SIG and one of the leading Bluetooth chip makers.

UWB is not expected to replace the current Bluetooth radio, but will provide a secondary 'fat pipe' held in reserve for when a large volume of data needs moving, such as downloading images from a digital camera.

"UWB isn't a channel you would keep open all the time – that would chew up the battery life on the device," said Janson.

Bluetooth currently supports data speeds up to 2.1Mbit/s, while the first UWB chips due next year will be capable of 480Mbit/s over a distance of a few metres. The following chips will push this to 1Gbit/s, with the ultimate goal of reaching 5Gbit/s, according to Janson.