Ultrawideband renews high-speed wireless hopes

Ultrawideband (UWB) is shaping up as a high-speed wireless technology for the enterprise, but before its success can be assured, it must first navigate the complexities of industry working groups.

Specifications for UWB, including 802.15.3a, are being forged by a task group of the Wireless Personal Area Networking (WPAN) working group, a subset of the IEEE. The task group's charter carries a broad mandate that goes beyond streaming, encompassing all of what it calls "time-sensitive file transfers" such as media content.

Until now, UWB's main sphere of influence has been in consumer electronics, enabling applications to run multiple high-definition television video streams among several devices in a home or to instantly display camcorder output without cables, for example.

The technology’s capabilities, however, have since caught the eye of the enterprise.

Using extremely short and broad low-power pulses to convey information, this flavor of UWB would operate at speeds of 110Mbps at 10 meters and 480Mbps at 1 meter. At such rates, UWB could offer speeds equivalent to those of USB 2.0 or IEEE 1394/FireWire across short distances. Some analysts also speculate that UWB could develop into an alternative to Bluetooth in the future.

"We're really shooting for the size of a room," said Stephen Wood, strategic marketing manager at Intel's R&D unit in Santa Clara, Calif.

But even over distances of 100 meters, where speeds fall off to kilobits per second, UWB can increase Wi-Fi's efficiency by providing an access point with a user’s precise location, allowing a smart antenna to "electronically direct the radio energy in the direction of the actual clients or users," said Chris Fisher, vice president of marketing at Vienna, Va.-based XtremeSpectrum, a UWB pioneer and holder of patents on some of the fundamental technology.

In this context, UWB would most likely be a complement to higher-throughput 802.11 standards. Such standards, currently in the works, promise 100Mbps shared bandwidth over a large coverage area.

To capitalize on this promise, however, the enterprise will have to wait until UWB emerges from its working-group phase.

At the most recent working-group meeting in early August, the MultiBand OFDM (Orthogonal Frequency Division Multiplexing) Alliance proposal for 802.15.3a — backed by Texas Instruments and Intel, among others — received 60 percent of the vote and is viewed as the leading contender for standardization once a regulatory concern is addressed.

The group requires 75 percent approval to move a proposal on to the standardization phase.

The OFDM proposal encodes data with the same standard used for 802.11a and 802.11g and divides the available spectrum into several bands that can be used simultaneously to provide interference robustness, according to Intel's Wood.

XtremeSpectrum and Motorola are backing the other major 802.15.3a contender. This proposal offers a more traditional approach to UWB, making use of the entire frequency band with a notch taken out for the 5GHz range to avoid potential conflicts with military frequencies.