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The FCC's UWB Proceeding: An Examination of the Government's Spectrum Management Process
Subcommittee on Telecommunications and the Internet
Mr. Michael Gallagher
Chairman Upton, I would like to thank you and the members of the Subcommittee for inviting me to testify today about the National Telecommunications and Information Administration's (NTIA's) role in the development of rules to authorize ultrawideband (UWB) technology. I particularly want to commend the leadership of Chairman Michael Powell and the Federal Communications Commission (FCC), as well as the FCC staff, in the UWB authorization process. The process was long, the arguments were highly technical, and the record was voluminous. But, together, the FCC and NTIA were able to meet the challenge and develop a technically sound set of regulations for the safe and effective authorization of UWB technology while preserving public safety and national security. I am very pleased that new rules adopted by the FCC will ensure that UWB devices will soon be readily available in the marketplace. It is one of the most promising technologies of our time. UWB can perform a number of useful telecommunications functions that make them very appealing for both commercial and government applications. It can be used for communications devices such as wireless networks to transmit high-speed data with low battery drain, remote sensing or tracking, and ground penetrating radar (GPR). UWB through-the-wall imaging systems can also provide great assistance in locating survivors within collapsed buildings and provide situational awareness to law enforcement personnel. UWB technology can also be used for collision avoidance radars -- reducing deadly automobile accidents. With the number of invaluable applications of the technology that will soon be available, NTIA fully expects the U.S. Government to continue its role as the UWB industry's best customers. The regulatory challenge with UWB technology is, as its name implies, that it operates across very wide bandwidths of radio spectrum in which many other commercial and governmental communications systems operate. While most conventional communications technologies are authorized within specific frequency bands to avoid harmful interference to other devices, this traditional spectrum management technique was not an option given the wide bandwidths used by UWB devices. In many cases, their average power levels may have been low enough to be authorized under NTIA's and the FCC's respective rules for unlicensed devices. However, the bandwidths of UWB devices are so wide that some of the systems emit signals in bands in which such intentional transmissions have previously not been permitted because of the potential harmful effects on safety of life and other critical governmental systems. Finding a solution for authorizing UWB devices within the existing spectrum management regime was no small feat and required groundbreaking technical research and the dedication of the professional staffs of NTIA and the FCC. Admittedly, the outlook for UWB's authorization last fall was dim. The FCC had proposed rules that were strenuously and publicly opposed in writing by several agencies. The pressure from UWB companies was intense, and the FCC was pressing forward on a timeline to close the matter by the year's end. However, with engaged leadership, and a shared focus by NTIA and the FCC on the technical data in hand, we were able to authorize this new, world leading technology that will be sensitive to the needs of the congested U.S. spectrum environment and not imposed on us by the rest of the world. NTIA is fully aware that with an effort this broad in scope and its potential impacts, many challenges will continue to arise. We have already begun discussion with one group of GPR users who have been unintentionally excluded by the new rules from using GPRs to determine ways to help resolve their concerns. We are also working with the Department of Transportation to complete a study assessing the compatibility of UWB devices and aviation systems operating below 1 GHz. Background NTIA, like the FCC, has long been aware of UWB technology's earliest practical implementations as GPRs, which grew from research originally begun at some of the government laboratories. As early as 1994, NTIA made preliminary provisions for accommodating this developing technology within NTIA's systems review processes to encourage further developments. In 1997, a number of UWB developers, including TimeDomain, Fantasma, Multispectral Solutions, Inc., and XtremeSpectrum briefed NTIA spectrum managers and researchers on the rapid advances in the technology. These discussions heightened NTIA's awareness of the incredibly exciting opportunities the technology could present not just for commercial applications, but also for Federal agencies in their performance of critical services on behalf of the American people from law enforcement to roadbed construction. Moreover, from a spectrum management perspective, UWB technology, if properly managed could lead to a much-needed advance towards greater spectrum efficiency. NTIA identified the challenges and difficulties of analyzing the characteristics of this new technology and its interaction with critical spectrum-dependent public safety and national security systems, including aviation systems used for aircraft landings. These challenges were made greater by the expectation that these new UWB devices had the potential to become ubiquitous in American households and businesses, would be highly mobile, and would be offered on an unlicensed basis, making interference issues more difficult to resolve. The spectrum managers and researchers at NTIA, however, took very seriously the agency's dual charge to foster new technology and, to assure the Federal agencies' continued protection to the spectrum necessary to perform their critical missions. Thus, in 1998 when Time Domain Corporation, U. S. Radar and Zircon Corporation filed petitions to waive the FCC's rules for low power unlicensed transmitters, referred to as the Part 15 rules, to allow them to manufacture import and sell certain UWB devices, NTIA worked very closely with the FCC to accommodate the requests. In consultation with the Interdepartment Radio Advisory Committee (IRAC), NTIA was able to devise safeguards to protect public safety and critical government systems during the period of the waiver, which the FCC approved when it granted the Time Domain, U.S. Radar, and Zircon waiver requests in 1999. These waivers provided an opportunity for all interested stakeholders to develop a more thorough understanding of the potential impacts that this technology could have on other commercial and governmental systems operating in the bands. Since that date, NTIA has routinely approved requests for Special Temporary Authority from UWB companies seeking to demonstrate the technology's capabilities from commercial technology demonstrations to emergency assistance. In all cases the waiver requests were granted under conditions that did not present a risk to critical safety-of-life or national defense systems. For example, after the September 11th tragedy, NTIA, upon coordination with the potentially affected Federal agencies, and the FCC authorized the use of through-the-wall imaging systems for first responder use at the World Trade Center and Pentagon within 8 hours of the initial request for their use. NTIA began a significantly detailed measurement and analysis effort at its Institute for Telecommunication Sciences in Boulder, Colorado and within NTIA's Office of Spectrum Management here in Washington when the FCC issued its Notice of Proposed Rulemaking on UWB in May of 2000. These efforts first focused on determining the characteristics of UWB signals in the time and frequency domains. Once the UWB signals were characterized, the information to model the effect of receiver filters on received UWB signals was developed. Using this data with other information concerning interference thresholds, the impact of UWB signals on the critical receiving systems operated by the Federal government in the "restricted bands" was assessed. The restricted bands consist of 64 frequency bands between 90 kHz and 36.5 GHz (a span which covers over 96% of all spectrum use) and occupy a total of 13.283 GHz of spectrum protected by the FCC, NTIA, and international rules against intentional emissions because critical or sensitive receivers operate in them. Protected receivers include radio astronomy and satellite passive sensing and the systems used to land and control aircraft. NTIA focused only on the restricted bands in the 960 MHz to 6 GHz frequency range because of the high density of critical governmental use of those frequencies and the then-limitations of the UWB technology. NTIA obtained samples of 20 UWB devices for measurement and chose five of the 20 as fairly typical of the group for detailed measurements. NTIA then started two measurement programs to determine the potential effects UWB devices could have on conventional narrowband devices operating in the restricted bands. The documents outlining the two measurement programs were made available to the public and the FCC for comment. The first program examined the emissions from several UWB devices to determine how best to characterize the many types of UWB signals and to describe procedures and methods for measuring UWB signals for developing operable certification standards and criteria. These measurements determined the interference impact of UWB devices on several sensitive devices to determine permissible power levels and corresponding required separation distances and an assessment of the impact of aggregates of several UWB devices. As part of the first measurement and analysis program, NTIA identified relevant system characteristics and developed operational scenarios for conducting susceptibility studies on several systems that operate in restricted bands. The studies included devices as diverse as radars and other guidance devices used to navigate and safely land airplanes; receive signals from beacons transmitting from plane crash victims and mariners in distress and transmit them to rescue organizations; weather radars used in forecasting and alerting the public to severe weather and floods; and earth stations receiving signals from communication satellites and satellites gathering weather data and photographs. Recognizing the critical role the Global Positioning System (GPS) plays in the nation=s infrastructure, the second portion of NTIA's measurement and analysis program focused on an assessment of the compatibility between UWB devices and GPS receivers. GPS is a satellite navigation system developed by the military that provides accurate navigation signals to any location in the world. The military uses GPS on all land, air, sea, and space platforms and for precision-guided munitions. GPS will also be used in all urban warfare operations in support of homeland defense. GPS has become the preferred navigation system for the aviation community for en-route flight, precision and non-precision approach landings and for maritime navigation. Civilian use of GPS has risen dramatically due to enhanced coverage, improved accuracy, and rapidly decreasing user equipment cost. Some examples of existing and planned uses of GPS include: car navigation, consumer and recreational location, surveying, tracking and machine control, public services, public safety (Enhanced-911 position location) in mobile phones, timing, scientific research, environmental management, precision agriculture, open pit mining, and space navigation. Although these examples are not all inclusive, they illustrate the wide spread use of GPS signals, as well as GPS's ubiquitous availability. GPS has also proven to be a powerful enabling technology driving the creation of many new industries such as telematics and geographic information systems. A 2001 U.S. Department of Commerce Office of Space Commercialization report estimated that worldwide GPS hardware sales will exceed $9 billion in 2002. As part of the GPS modernization program two new navigation signals will be provided for civil use. Assisted GPS systems, which use local terrestrial stations to process location data, are also being developed to enhance position location inside buildings as well as in difficult propagation environments such as urban canyons. Once the analyses were completed, NTIA sought public comment on its measurement programs and provided the results in six reports made available to the FCC and placed on the public record in the UWB proceeding. These reports are available at the NTIA website http://www.ntia.doc.gov/osmhome/uwbreports/. The conclusions reached in these reports formed the technical basis of NTIA's understanding of the limits on UWB devices necessary for compatible operation with critical government systems and GPS receivers and were used as the technical baseline for UWB emissions by virtually all parties engaged in the UWB debate. The FCC's Amendment to the Part 15 RulesOn February 14, 2002, the FCC approved amendments to its Part 15 rules to permit UWB devices to operate on an unlicensed basis under conditions that are expected to protect existing radio systems operating in the environment. The First Report and Order for UWB devices establishes different technical standards and operating restrictions for different types of UWB devices based on their potential to cause interference. The different types of UWB devices are: 1) imaging systems including GPRs, wall, through-wall, and medical imaging systems; 2) surveillance devices; 3) vehicular radar systems; 4) communications and measurement systems; and 5) mobile hand-held systems. In all frequency ranges, the UWB devices are expected to meet or fall below the emission limits permitted for narrow band Part 15 devices. Narrow band refers to Part 15 devices that operate within a specific frequency band. In the range of frequencies between approximately 1 GHz and 10 GHz additional reduction in the UWB emission levels are required to protect the critical systems discussed above (see Exhibit A). In the bands used by GPS between 960 MHz and 1610 MHz the emission limits are between 12 to 34 dB below the emission limits permitted for unintentional emissions from narrowband devices in order to protect the critical applications of base station assisted GPS. In the 1.6 GHz to 10.6 GHz frequency range, the UWB emission limits are between 10 to 12 dB below the narrowband limits for unintentional emissions. Though these limits are conservative, they are based on NTIA's measurements and comments made on the public record, and reflect the effect of UWB signals on narrowband receivers. Most importantly, these measurements and analysis reflect NTIA's commitment in encouraging UWB technology while maintaining the utmost reliability and safety of our current radio services.[1] The new UWB rules also address the needs of automobile manufacturers seeking to deploy new short-range vehicular radar systems that could provide greater automotive safety. A 1999 report from the National Safety Council estimates that a death from vehicle crashes every 13 minutes resulting in 41,200 motor vehicle deaths per year. Statistics from the National Highway Transportation Safety Administration indicates that short-range radar systems could address 88 percent of all causes of rear-end collisions. The short-range radar systems are under development as a key component of the next generation of collision mitigation systems. For example, possible applications include braking automatically to avoid an impending collision with a car ahead that is unseen by the driver, or tightening seat belts or other restraint systems for optimal safety and deployment depending on the expected severity and position of impact. The automotive industry is seeking to develop these radar devices with their frequencies centered at 24.125 GHz with intentional emissions extending between 22.125 to 26.1252 GHz. The band 23.6-24 GHz is a restricted frequency band currently used by the Federal Government for satellite passive sensing operations because of its unique characteristics. The majority of the measurements using this band are performed over land and depends upon measurements of microwave energy naturally upwelling from the Earth=s surface. The atmospheric measurements derived from the satellite sensors operating in the 23.6-24 GHz frequency band are important to Department of Defense air combat mission planners and National Weather Service numerical forecast models. Since emissions from proposed vehicular short-range radar systems will extend into the 23.6-24 GHz band, NTIA recognized the possibility that these systems could cause interference to the Federal Government's passive satellite sensing operations. NTIA worked with representatives from the automobile industry representatives, the National Aeronautical and Space Administration (NASA), and the National Oceanic and Atmospheric Administration (NOAA) to perform an analysis examining under what conditions compatible operation would be possible. Based on this analysis, NTIA proposed to establish a time phased approach for emissions from vehicular short-range radar systems into the band, which would allow the technology to be deployed in a phase-in approach. The approach struck a balance between protecting critical Federal passive sensing operations and allowing the deployment of this potentially life-saving technology. I am pleased to note that the FCC adopted this compromise in its rules. Because of the worldwide nature of passive sensing operations, compatibility with UWB short-range radars is also being studied internationally. It is anticipated that the approach recommended by NTIA and adopted by the FCC will drive the standard worldwide. NTIA's Implementation of the New Part 15
Rules
NTIA has already begun to implement the new UWB rules. Our rules authorize Federal agencies to procure and use any device available in the marketplace that has been certified in accordance with the FCC's rules as being compliant with Part 15. When the FCC's new rules go into effect in July, government agencies may purchase and operate or contract for the operation of UWB systems that have been certified as being in conformance to those regulations with no further authorization from NTIA (See Part 7.8 of the NTIA Manual). Further, NTIA expects to incorporate appropriate portions of the new Part 15 text into its rules so that the government agencies may construct custom UWB devices that conform to these Rules with no further authorization by NTIA (See Part 7.9 of the NTIA Manual). NTIA expects that the vast majority of UWB applications used by the government will fall under either one or the other of these two cases. However, if an agency does need a UWB device that does not conform to the Part 15 Rules, it may seek spectrum support and frequency assignments through our Systems Review and Frequency Assignment processes. Operation of these latter devices will be closely controlled and coordinated with all nearby affected users. Next Steps
NTIA is quite aware that more testing and analysis is required on the impact of UWB devices on other radio systems. The FCC has indicated a desire to do additional measurements when more UWB devices are developed. We support the FCC's testing and the development of real world test data and will actively participate in these measurements. NTIA is pleased that the United States is now in a position to lead the evolution of UWB technology while protecting safety-of-life and national security systems. In summary, Mr. Chairman, NTIA works closely with the FCC and the Federal spectrum management community to balance the spectrum needs of the government agencies with those of the private sector. We look forward to continuing to work closely with them in the future. I thank you for this opportunity to share with you the views of NTIA on this important issue, and I look forward to answering any questions you may have. GLOSSARY FCC Federal Communications Commission GPR Ground Penetrating Radar GPS Global Positioning System GHz Gigahertz IRAC Interdepartment Radio Advisory Committee MHz Megahertz NASA National Aeronautics and Space Administration NOAA National Oceanic and Atmospheric Administration NOI Notice of Inquiry NPRM Notice of Proposed Rule Making NTIA National Telecommunications and Information Administration R&O Report and Order UWB Ultrawideband EXHIBIT A OVERVIEW OF SYSTEMS ANALYZED BY NTIA
[1] UWB technology can be based on very short pulses of radio energy. Its wide bandwidth yields low probability of intercept and excellent multipath immunity. For more information see the NTIA Institute For Telecommunication Sciences website http://www.its.bldrdoc.gov/home/programs/uwb/.
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