re: A Belated Happy UWB Valentine's Day
<< As for UWB, 7.5GHz was a big Valentine >>
A Bitter-Sweet Offering
Tammy Parker
Mobile Communications International
Issue 89
01 March 2002
Ultra-wideband promises much, but at what price? The potential interference of UWB networks is causing plenty of debate in the US.
The Federal Communications Co-mmission's approval of a new technology that promises potential competition, not to mention possible radio interference, for mobile phone networks is raising hackles across the US wireless industry.
The FCC's First Report and Order approving ultra-wideband (UWB) for commercial use was a Valentine's Day gift for proponents, but a bitter blow to cellular and PCS operators as well as the host of government agencies that had fought the approval.
UWB is an unlicensed communications approach that would operate in the background of already-occupied spectrum ranges to provide new applications such as in-building radar and tracking, automobile collision avoidance systems, medical imaging, wireless broadband applications and more. The spread spectrum technology has many proponents in the United States, where it has been used for years in defence-related applications and has only been declassified in the past decade. The Institute of Electrical and Electronics Engineers (IEEE) is eyeing a UWB study group under the auspices of the wireless personal area networking (WPAN) task group 802.15. Supporters say a UWB Physical Layer draft spec could be completed by mid 2002. Among UWB's advocates are chipmaker Intel as well as consumer electronics manufacturer Sony.
UWB sends low-power (measured in microwatts) coded pulses across an ultra-wide swathe of spectrum. It doesn't require an assigned frequency or power amplifier. Proponents note that UWB's random, low-power signals rank as unintentional noise, much like the radio frequency emissions that escape from notebook computers or baby monitors. Because UWB signals can easily pass through non-metal walls, including those made of brick and cement, many support UWB as a foundation for wireless voice, data and video transmissions inside buildings, including personal area network applications, standard wireless local area network (WLAN) links and home networking.
A statement heralding the FCC decision from San Diego-based UWB developer PulseLINK noted: "Fundamentally different in operation than any existing form of wireless communications insomuch as it does not use a frequency carrier, UWB technology promises unmatched wireless data rates, better signal penetration through walls and obstacles and ultra-precise geographic positioning using extremely low power on relatively inexpensive architectures." Yet Alan Haase, president and CEO of antenna developer Skycross, cautions that the hubbub surrounding UWB may be nothing more than a common tendency to accord incredible powers and applications to new technologies undergoing development, only for them to be considerably less impressive when deployed in the real world.
Nonetheless, it appears UWB could be a strong competitor to Bluetooth as well as 802.11-based WLANs. UWB's success could disrupt many mobile phone network operators' plans to get involved with 802.11b-based hotspot WLAN deployments because UWB may prove to be a superior and less costly WLAN solution. Further, operators are also concerned because some pundits fear UWB networks might interfere with mobile phones being used nearby.
Because UWB would operate across unlicensed as well as licensed spectrum, many people object to the technology's commercial use. Though supporters claim UWB transmissions can share existing radio spectrum space without causing interference, numerous questions remain regarding potential interference from UWB networks. Opponents say Global Positioning System (GPS) devices will definitely not work correctly when in proximity to UWB networks.
This is a huge issue for US mobile phone networks, which are under federal pressure to provide accurate position determination for emergency calls to 911. Many of those networks are relying on GPS-based solutions to meet the federal E911 mandates.
Haase says he could make the UWB interference argument either way based on engineering principles. That, in fact, appears to be the biggest problem with UWB, which is largely untested outside its pockets of support.
The Pentagon, which oversees US defence, had said that UWB transmissions above the 4.2GHz band are acceptable. The US Department of Transportation and the National Aeronautical and Space Administration disagreed with that stance, saying any UWB use below 6GHz is unacceptable. None of those agencies got their wishes, however, as the FCC approved UWB for use between 3.1GHz and 10.6GHz. The Department of Defense subsequently acquiesced and gave the ruling its blessing after concluding that the FCC's operational restrictions on UWB were sufficient.
The commission repeatedly patted itself on the back for ostensibly taking an ultra-conservative approach by requiring strict operational conditions for UWB. The FCC's order "includes standards designed to ensure that existing and planned radio services, particularly safety services, are adequately protected." The commission also pledged to "act vigorously to enforce the rules and act quickly on any reports of interference." The FCC, which has conducted no-interference testing of UWB devices, also said it would consider relaxing those operational guidelines within a year.
After more than three years of contentious debates regarding UWB, the FCC appears to have bought into the international competitiveness argument offered by the handful of UWB developers. Because UWB is quite a home-grown technology, there is a strong desire on the part of both US business and government to maintain what is perceived as an early technological lead. That is also one reason the commission will likely revisit these initial UWB rules in mere months. FCC Commissioner Michael Copps said in a written statement: "Delay, even when advisable, still has costs.
If we find that our rules are too restrictive and we fail to correct them promptly, the price may be that the United States loses its leadership role in ultra-wideband. The technology could easily move overseas, where, I wager, would-be competitors are only too eager to get a step ahead of the USA."
The current focus on homeland security has also aided UWB's positioning, as the market is now larger than ever for precision radar products, such as those that can detect and image buried or hidden objects, and more secure wireless broadband links.
The wireless industry may not have to wait long to see UWB products. For instance, Huntsville, Al.-based Time Domain, which already has numerous government contracts for its UWB technology, has said its PulsON UWB chipsets and development modules will be available commercially later this year.
Even those not directly involved with UWB see huge promise for UWB-based products. "The potential of UWB's ubiquity and low costs could spark a wireless equipment boom that would dwarf the halcyon days of cellular in the 90s," observes Pat Kennedy, chairman and CEO of Cellport Systems, a producer of in-vehicle wireless communications and telematics systems.
Others are more wary of UWB's commercial prospects. "Even if the technology turns out to be the best thing since sliced bread, not interfere with anything and be good for our health, it will still need solid financial backing and promotion. And it remains to be seen whether the backers will be able to break through into established markets," observes Freda Benlamlih, director of services at UK consultancy ARC Group.
For sure, UWB has a strong place in radar and tracking applications, particularly those that require in-building coverage. The technology could be a potentially robust competitor to continued expansion of WLAN technologies such as 802.11, provided low-power UWB-based components can be made cheaply and diminutively enough for use in consumer devices.
But even more importantly, UWB's existence could threaten the very structure of the regulated, licensed wireless communications industry, meaning ongoing political battles are likely if UWB proves superior to existing approaches.
Cellport's Kennedy states: "A toll-free wireless broadband IP network (creating a community) coupled with ad hoc routing will warp today's paradigm of network carriers like DoCoMo and Verizon." Such a scenario could represent mobile phone operators' biggest fears.
Yet others see UWB as a complement rather than a threat. FCC commissioner Kevin Martin commented: "Ultra-wideband challenges the notion that use of particular frequencies or bands is necessarily mutually exclusive.
In defiance of our traditional allocation paradigm that often forces us to pick 'winners and losers' in the face of competing demands, this technology seems to allow more winners all around."
But in telecoms yin and yang, winners and losers go hand in hand. The concern of mobile phone network operators is that it's not yet clear who the UWB losers will be. <<
- Eric - |
