Wireless: The Next Generation
By Niall McKay in San Francisco, Tue Apr 16 00:00:00 GMT 2002

Approved for commercial use by the FCC last week, Ultra Wide Band technology promises to boost wireless networking to 500Mbps.

Last week, the Federal Communications Commission approved the commercial use of Ultra Wide Band (UWB) - a radar-based technology that, until now, was used mostly by the US military, police, and fire departments as a means of seeing through ground and walls

The ruling paves the way for UWB to be adapted into a high-speed wireless data networking solution that transfers full motion video between cameras, TVs, DVDs and personal computers over a short distance. Intel Research Labs, for example, is working on a version of the technology that will transfer data at rates up to 500 Mbps - some 45 times faster than today's wireless data offerings such as WiFi.

Wireless Firewire

"It is Firewire with out the wire," boasts Chris Fisher, vice president of XtremeSpectrum, a wireless company that designs $20 chips-sets that that can transfer data at 100 Mbps.

But UWB goes much further. It has some unique properties that enable the creation of highly accurate location tracking devices, low-cost automobile collision avoidance systems, and motion detectors that can see through walls. Until now, however, fears that FCC would ban the technology because it could interfere with Global Positioning Satellite, cell-phone and TV and radio signals delayed its commercial development.

FCC limits

And with good reason. Last week's ruling imposed severe restrictions on its power emissions and wavelengths positions so much so, in fact, that the range of location tracking devices used by US fire departments has been reduced from 150 feet to just 20 feet.

"Since there is no production of UWB equipment available, the commission chose... to err on the side of conservatism by setting emission limits when there were unresolved interference issues," an FCC statement says.

Radar technology

Unlike other wireless offerings, UWB uses radar rather than radio technology. With it, short pulses are pushed out over a wide section of the spectrum (between 3 and 6 GHz - hence the name Ultra Wide Band) rather than a single continuous stream of data occupying one or more bands, as with conventional radio-based technologies. This means that the signal can be triangulated so it can be used both as a radar - gauging the shape of objects underground or behind walls and as an accurate location device. In theory, at least, this gives it some significant advantages over competitive wireless technologies.

"It uses very little power (less than 200 mW for 100Mbps throughput) so this technology is ideal for battery operated devices such as laptop computers, PDA's and video cameras," says Jeff Ross, vice president for Time Domain, a company that designs UWB location tracking equipment for police and fire departments and wireless networking equipment for the consumer electronics industry.

Consumer electronics manufactures such as Sony, Sharp, Panasonic and Intel are also looking to UWB to provide a possible migration path to the next generation of short-range personal area networking products. Indeed, the technology is currently undergoing review by the IEEE's 802.15 committee as a possible future iteration of the home networking standard Bluetooth.

Market opportunity

Certainly, the demand for wireless products remains high despite the recent decline of consumer electronics sales. The home wireless networking market is set to grow from $2.5 billion in 2004 to $3.7 billion in 2006, according to a report by the US research firm Cahners In-Stat. If this steady growth is to continue, the report states, then faster and better wireless technologies will have to be released into the marketplace. Figures from the market research firm Frost and Sullivan predict that unit shipments of wireless LAN chip-sets will exceed 3 billion by 2005.

One explanation for the success of wireless home networking is that it is one of the few whistles and bells that is not only convenient but actually saves the customer money. For example, an investment in an 802.11 or WiFi access point means that many users can share a single DSL or Cable modem subscription. Similarly, high-speed wireless technologies that can handle full motion video such as UWB would enable a household share a single home entertainment system rather than have a bevy of DVD players, TVs and computers dotted around the household.

Problem looking for a solution

However, not everybody believes that UWB is the solution that is needed. Seamus McAteer, principle analyst with the San Francisco-based research firm the Zelos Group argues that as a networking technology UWB is a solution looking for a problem.

"There's disruptive technologies and then there's Ultra Wide Band," he says. "It not a question of how good the technology is but how much momentum it has in the market place and from where I am standing there is little momentum behind UWB."

Long military history

Like many so-called 'new' commercial technologies UWB has actually had a long military history. It has gone under many other monikers such as base-band, carrier free, time-domain, and Walsh waves since its invention in the 1950s. Until the mid 1980s, it was mostly under wraps in military research establishments but then mining companies started to use it to find underground mineral deposits and civil engineering companies started to use it to detect cracks in bridges and airport runways. In the early 1990s, Police, Fire departments and search and rescue crews started to use UWB solutions to relay back the exact location of personnel in a covered locations such as a burning building, where GPS equipment don't work. However, last week's ruling from FCC may put an end to such location-tracking schemes because the technologies range will be reduced significantly.

Ironically, UWB's biggest supporter and biggest opponent is the US military. It has been lobbying the FCC to ban the commercial use of the technology while at the same time pouring tens of millions of dollars into its development through the Defense Advanced Research Projects Agency (DARPA). Most likely, this is because it wants to keep its competitive advantage in the battlefield as well as prevent commercial versions from interfering with other crucial military technology such as GPS.

Despite its reservations, the US military has used UWB to build ground penetrating radar technology that can detect underground missile silos and caves. It has also built Low Probability of Detection and Interception (LPDI) communications equipment. The low-powered short pulses, spread over a wide section of the radio spectrum simply look like white or electrical noise to the casual observer so it can be an extremely secure method of communication.

To intercept the signal both the sender and the recipient need accurate timing devices (down to 10 Pico seconds) and the same mathematical algorithm to know exactly where and when to look for the signal. Commercial solutions, however, will probably share low-lever algorithms so that detection and interception will become easy and promote interoperability between equipment.

"The degree of accuracy needed at the chip level has made it unrealistic to use UWB as a commercial technology until recently," says Robert Fontana, president of Multispectral Solutions, a UWB provider. "It was simply too expensive to build the components."

Cheaper chips

Now high quality computer chips are easier and cheaper to obtain. So Multispectral, which for the past 13 years has been providing military technology, is looking to broaden its horizons and is designing low cost location devices such as automobile sensors and aviation altimeters.

However, Fontana says that his company is not interested in full motion video or high-speed data networking technology because of the intense competitive nature of the market. "I don't see any reason, at the moment, why future versions of 802.11 wouldn't provide the through-put needed for data networking applications."

Indeed, he may have a point. 802.11a provides up to 54 Mbps, which is adequate to support multiple steams of 10 Mbps DVD data in real time. 802.11b or WiFi supports up to 11 Mbps, Bluetooth is expected to provide 10 Mbps in the future and HiperLAN2 or Direct Mode provides up to 54Mbps.

XtremeSpectrum's Chris Fisher argues that all of these solutions except Bluetooth (which is currently too slow for real-time DVD data) are designed as data networking technologies. "They based on the medium access control (MAC) interface, use orthogonal frequency multiplexing, and do not support quality of service (QAS)," he says.

Furthermore, 802.11a consumes up to 2W of power, which makes it unsuitable for battery-operated devices while UWB uses less than 200 mW of power.

Either way, UWB has a long way to go before it can be deployed in the mass market. For one thing there are no commercial products available yet and for another, it has yet to gain widespread attention of the industry - let alone acceptance. Indeed, even with the support of dozens of consumer electronics, software and computer vendors Bluetooth, which made its commercial debut some four years ago, is only now making its way into products today. So UWB could take some time to reach primetime.

"Realistically, UWB is a 2005 technology not a 2002 technology," says Vince Coli, vice president of marketing for AetherWire and Locations Inc., a company that provides location tracking equipment for the fire, police and search and rescue crews.

Certainly, even if UWB is successful it is unlikely to take market share away from current offerings such as Bluetooth, 802.11 or Direct Mode. After all, today's computers ship with 56k modem, Ethernet, 802.11b, and Bluetooth. So it's likely that, if successful, UWB wont beat them it will simply join them.

Niall McKay is a freelance writer living in Silicon Valley. He can be reached at www.niall.org.