The Bluetooth Special Interest Group (SIG) has picked sides in the battle between two competing short-range, high-speed wireless technologies, choosing the Intel-backed WiMedia version of ultra-wideband.

Ultra-wideband (UWB) can provide up to 1 Gbit/s over short distances, and is expected to replace USB cables, as well as the current Bluetooth generation. However, the IEEE standards body failed to choose between two flavours, the Intel-backed WiMedia version, based on MB-OFDM (multiband orthogonal frequency division multiplexing), and Motorola's favourite, Freescale's DS-UWB (direct sequence)

The Bluetooth SIG has decided to base a future high-speed version of Bluetooth on WiMedia, said Michael Foley, executive director of the SIG in a news conference Tuesday. Last year, the SIG had endorsed UWB for future versions, but has only now chosen which technology.

"After speaking with our members, we have heard overwhelmingly that Wi-Media was the version of the technology they wanted to see enabled within the Bluetooth spec," Foley said. "There was not one thing in particular, it was a collection of features, or advantages, that made us choose."

The SIG plans to have an initial specification completed in the first quarter of 2007. After that it will enter a testing phase, with final completion of the specification expected in the third or fourth quarter of 2007. Devices with the new technology could start shipping in early 2008, Foley said.

This follows the selection of WiMedia for the official wireless version of USB - although Freescale is trying to get USB-compatible products out first.

After the Bluetooth rejection, Freescale will be concentrating on its USB-related efforts: "This announcement has no direct impact on Freescale’s continued focus on delivering Cable-Free USB solutions for consumer applications and leveraging the over 1 billion USB 2.0 devices in the market today," said Martin Rofheart, director of the UWB Operation at Freescale. "There are no high rate Bluetooth applications today nor are there any slated for the near term, which makes this an interesting technology to watch over the coming years, but does not present a near-term commercial opportunity. When there are well-defined applications that could benefit from our UWB technology in the Bluetooth arena, we will pursue them."

The SIG is targeting the high-speed version of Bluetooth for synchronizing and transferring large amounts of data and enabling high-quality video and audio applications for portable devices, multimedia projectors and television sets. Mobile devices such as high-end smart phones, that transfer large amounts of data are expected to be the first to incorporate UWB-based Bluetooth. Headsets and mice are expected to use existing Bluetooth specifications until costs and power consumption of UWB-based Bluetooth come down.

The SIG said it will work to ensure that future Bluetooth high-speed devices are backward compatible with existing devices.

Before finalising a specification, Foley acknowledged the SIG and the Wi-Media Alliance must first overcome regulatory and technological hurdles.

The two groups said they have decided to use the unlicensed radio spectrum above 6GHz for UWB-based Bluetooth. "We believe utilising a higher band, in the 6-9GHz spectrum, will give us a much better opportunity of getting global regulatory acceptance," Foley said.

On the technology side, Foley said that while initially costs will be higher and power consumption will be increased with UWB-based Bluetooth, the SIG will work hard to bring those in line with the current Bluetooth specification.

The cost of UWB-based Bluetooth will initially be about 10 to 15 times more than the current cost of Bluetooth, said Stephen Wood, president of the Wi-Media Alliance and technology strategist at Intel Corp. But Foley expects that price to eventually come down to the current costs of Bluetooth.

"Over time as we see much tighter integration into the solution, prices will come down. I expect the price curve will be similar to what you saw with the original Bluetooth radios. The original Bluetooth radios weren't at the price they are at today," Foley said.

Foley also expects that the optimal range for UWB-based Bluetooth will be similar to the existing Bluetooth technology.

"About 10 meters is what we're targeting," Foley said. "We think for many of the applications the sweet spot is around 100Mgbits/p/s at the 10 metre range."

Earlier this month, Bluetooth chip maker CSR chose WiMedia for its own fast Bluetooth products.

Peter Judge, Techworld, contributed to this report.