Via ElectronicsWeekly.com

Bluetooth is buzzing because demand for wireless headsets on mobile phones is driving the technology forward. But how will the technology create new applications to sustain that growth?

After a protracted and less than smooth birthing period, Bluetooth is expected to ship around 270 million units during 2005, thanks in large part to wireless headsets for mobile phones. With that figure set to increase by 200 million next year, it is now safe to describe it as an established technology.

But wireless headsets are one thing – their uptake has been driven in Europe by legislation to outlaw driving while clutching a handset. How is Bluetooth going to create new applications?

Cambridge Bluetooth developer CSR says the mono headset market is now maturing, with products designed to match the styling of particular phones, or to target different age groups. The devices no longer have quite the geeky image they once had, but still CSR expects the volume market to be woken up by high quality stereo headphones.

“With people like Nokia and Sony Ericsson [producing phones intended for music playback], it seems pretty clear that, after a lot of speculation, music on mobile phones will take off in the next year,” says Luke D’Arcy, product marketing manager at CSR.

“All of these stereo devices will also need to handle voice, and it’s quite hard technically to get good quality voice in headphones that people will actually want to wear. Geekiness is not really where we want to be as far as getting mass market adoption of wireless headphones is concerned.”
EW.com

In its BlueCore5 MultiMedia device, released last month, CSR has included native support for various audio compression standards, to tackle issues with power consumption that accompanied earlier Bluetoothparts using the built-in sub-band coding (SBC).

Using SBC for audio playback involves transcoding from whatever format the source file is in, a computationally onerous task that D’Arcy says can occupy 80 per cent of the Mips of the phone. “You can get very, very short battery life and it’s a big problem. Native support is the answer,” he says.

“We are incorporating some common phone features onto a more sophisticated Bluetooth chip like BlueCore5 MultiMedia, for use in a phone,” continues D’Arcy. “That way the Bluetooth device can take over some of the more processor-intensive tasks. I think that’s a growing trend now. Elements of the phone’s baseband are going into the Bluetooth chip, rather than the other way around.”

BlueCore5 meets the v2.0 EDR (extended data rate, 3Mbit/s) version of the Bluetooth spec. It is expected that a v2.1 will appear next year, with improved ease of device pairing and better security. And in 2007, CSR says the spec will evolve into a 200Mbit/s version, using an ultra wideband (UWB) PHY.

In the meantime, CSR has included an FM radio on one version of its latest silicon. “Putting [FM radio and Bluetooth] on the same piece of silicon we can reduce costs and help our customers add features at lower price, which is great for driving Bluetooth into lower-end phones,” says D’Arcy.

Reducing costs will be a priority if and when a UWB physical layer is adopted. At the moment the majority of UWB systems – being developed for Wireless USB and in-home streaming of high bandwidth video – use an exotic SiGe or SiGe:C process, which in all likelihood will preclude them from low end phone specs.

However, US start-up Staccato Communications, which has been touting an all-CMOS approach for several years, says its single-chip CMOS device is now working. What is more, Mark Bowles, founder and v-p of business development at Staccato, says the WiMedia Alliance specification can satisfy the requirement for ‘detect and avoid’ interference mitigation technology.

What is as yet unknown is whether the Bluetooth SIG will choose the WiMedia technology, or that of its competitor the UWB Forum, and how UWB Bluetooth will exist alongside Wireless USB.

“If you watch the day to day activity, there’s really no way to tell which they will choose,” says Bowles. “If you look at the strategic viewpoints of the board, it is quite heavy with WiMedia supporters. Also, the SIG is set up so that it needs a unanimous vote to get anything like this done. When you have democracy, unanimous is a hard thing.”

Assuming the SIG does eventually pick one, and does it within a reasonable space of time, Bowles expects UWB Bluetooth to find applications where Bluetooth already has a foothold, leaving Wireless USB to play a role in USB-type applications. However, the fact that many devices already feature both could make things intriguing.