Speed & Distance News in UWB

By Jeff Goldman

May 31, 2005

Long before ultrawideband is even in your hands, companies are finding ways to make it go farther and faster.

Last week at the Wireless USB Developers Conference in San Jose, Calif., Intel and Alereon demonstrated a Wireless USB media access controller (MAC) from Intel and a physical layer (PHY) from Alereon running at 480 Mbps—the maximum speed for wired USB.

According to Alereon CEO Eric Broockman, the level of interest in the first-ever Wireless USB Developers Conference was a good indication of the potential for Wireless USB, and for the WiMedia Alliance's MultiBand OFDM UWB standard upon which it is based.

"With 350 to 400 attendees, it was really an affirmation of the standard," he says.

The Alereon/Intel demonstration, Broockman says, used test software from LeCroy. "That obviously demonstrates that it's come a long way, when a test equipment vendor can write something to the spec which matches up to the prototype hardware that Intel had, and to our pre-production field silicon," he says.

That bodes well, Broockman says, for the WiMedia Alliance's chances at winning out over the competing DS-UWB standard backed by Freescale Semiconductor and others. "I think it's an important step forward to show that companies like Alereon can build WiMedia UWB that runs at the full rate, and that it's right there being compliant with the specification interface," he says.

Also last week, Freescale demonstrated its longest-range Direct Sequence Ultrawideband (DS-UWB) solution yet, transmitting video over a 20-meter (66-foot) distance at the Wireless Connectivity World conference in London. This demonstration, according to the company, greatly increases the number of potential applications for the technology.

Freescale's ability to increase the technology's range was a direct result of the FCC's March 2005 waiver ruling regarding UWB, according to Calvin Harrison, Marketing and Business Developer for Freescale's Ultrawideband Group.

"The FCC waiver helps us out not just in terms of range, but in terms of channel capacity and power," Harrison says.

The fact that the waiver involved a shift from an average power limit to a peak power limit, Harrison says, provides a key advantage for DS-UWB. "We can turn the radio off right after we transmit the data," he says. "That increases our battery life up to 30x, and we also get increased channel capacity in some applications up to 30x, because when the channel's not being used, another radio can broadcast."

It would be hard, Harrison suggests, for WiMedia's MultiBand OFDM technology to take advantage of the waiver in the same way. "OFDM is technically a high peak to average waveform," he says. "They don't get the benefit of getting on, getting the data out, and getting off like the Direct Sequence approach does."

The fact that this announcement focused on distance, Harrison says, doesn't mean that Freescale isn't focusing on speed as an issue as well—he says the company is still on track to demonstrate 660 Mbps this year, and 1 Gbps next year.

With greater speed and range for the technology, Harrison suggests, the applications under consideration are virtually limitless. "You're going to see ultrawideband in enterprise, you're going to see it in mobile handsets, you're going to see in the PC entertainment space, you're going to see it in wireless home theatres," he says. "It's going to be pervasive."



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