Spectrum Management
Better Knowledge Needed to Take Advantage of Technologies That May Improve Spectrum Efficiency Gao ID: GAO-04-666 May 28, 2004Recent advances in technologies that rely on the use of the radiofrequency spectrum have turned science fiction of the past into reality. Cellular telephones, wireless computer networks, global positioning system receivers, and other spectrum-dependent technologies are quickly becoming as common to everyday life as radios and televisions. Further, these technologies have become critical to a variety of government missions, including homeland security and strategic warfare. However, with the increased demand, the radio-frequency spectrum--a resource that once seemed unlimited--has become crowded and, in the future, may no longer be able to accommodate all users' needs. As a result, there has been a growing debate among spectrum policy leaders about how to use spectrum more efficiently. To help inform these debates, GAO was asked to look at agencies' investments in spectrum efficient technologies and how the nation's spectrum management system may affect the development and adoption of these technologies.
The nine federal agencies that GAO reviewed--which are among the largest users and investors in technologies and systems impacting spectrum use--have made some investments in technologies that provide improved spectrum efficiency. However, these investments have tended to occur when agencies needed to make greater use of available spectrum to meet a mission requirement--not by an underlying, systematic consideration of spectrum efficiency. For example, as a result of growing spectrum constraints, the Department of Defense (DOD), the Federal Aviation Administration, and the National Aeronautics and Space Administration began investing in technologies that would increase the throughput of information while using smaller segments of their available spectrum. However, agencies also consider other factors--including cost and technical and operational concerns--that may dissuade them from investing in spectrum efficient technologies. For example, DOD may need to use more spectrum to meet an operational requirement to field a jam-proof and accurate radar for military aircraft. The current structure and management of spectrum use in the United States does not encourage the development and use of some spectrum efficient technologies. Because the spectrum allocation framework largely compartmentalizes spectrum by types of services (such as aeronautical radio navigation) and users (federal, nonfederal, and shared), the capability of emerging technologies designed to use spectrum in different ways is often diminished. For example, software-defined cognitive radios--radios that adapt their use of the spectrum to the real-time conditions of their operating environments--could be used to sense unused frequencies, or "white spaces," and automatically make use of those frequencies. It may also be possible to use software-defined cognitive radios to exploit "gray spaces" in the spectrum--areas where emissions exist yet could still accommodate additional users without creating a level of interference that is unacceptable to incumbent users--to increase spectrum efficiency. Currently, however, the spectrum allocation system may not provide the freedom needed for these technologies to operate across existing spectrum designations, and defining new rules requires knowledge about spectrum that spectrum leaders do not have. At the same time, there are few federal regulatory requirements and incentives to use spectrum more efficiently. While the National Telecommunications and Information Administration (NTIA) is responsible for managing the federal government's use of spectrum and ensuring spectrum efficiency, NTIA primarily relies on individual agencies to ensure that the systems they develop are as spectrum efficient as possible. Agencies' guidance and policies, however, do not require systematic consideration of spectrum efficiency in their acquisitions. The lack of economic consequence associated with the manner in which spectrum is used has also provided little incentive to agencies to pursue opportunities proactively to develop and use technologies that would improve spectrum efficiency governmentwide.
RecommendationsOur recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.
Director: Team: Phone:GAO-04-666, Spectrum Management: Better Knowledge Needed to Take Advantage of Technologies That May Improve Spectrum Efficiency
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Report to Congressional Requesters:
United States General Accounting Office:
GAO:
May 2004:
SPECTRUM MANAGEMENT:
Better Knowledge Needed to Take Advantage of Technologies That May
Improve Spectrum Efficiency:
GAO-04-666:
GAO Highlights:
Highlights of GAO-04-666, a report to congressional requesters
Why GAO Did This Study:
Recent advances in technologies that rely on the use of the radio-
frequency spectrum have turned science fiction of the past into
reality. Cellular telephones, wireless computer networks, global
positioning system receivers, and other spectrum-dependent technologies
are quickly becoming as common to everyday life as radios and
televisions. Further, these technologies have become critical to a
variety of government missions, including homeland security and
strategic warfare.
However, with the increased demand, the radio-frequency spectrum”a
resource that once seemed unlimited”has become crowded and, in the
future, may no longer be able to accommodate all users‘ needs. As a
result, there has been a growing debate among spectrum policy leaders
about how to use spectrum more efficiently. To help inform these
debates, GAO was asked to look at agencies‘ investments in spectrum
efficient technologies and how the nation‘s spectrum management system
may affect the development and adoption of these technologies.
What GAO Found:
The nine federal agencies that GAO reviewed”which are among the
largest users and investors in technologies and systems impacting
spectrum use”have made some investments in technologies that provide
improved spectrum efficiency. However, these investments have tended
to occur when agencies needed to make greater use of available spectrum
to meet a mission requirement”not by an underlying, systematic
consideration of spectrum efficiency. For example, as a result of
growing spectrum constraints, the Department of Defense (DOD), the
Federal Aviation Administration, and the National Aeronautics and Space
Administration began investing in technologies that would increase the
throughput of information while using smaller segments of their
available spectrum. However, agencies also consider other factors”
including cost and technical and operational concerns”that may dissuade
them from investing in spectrum efficient technologies. For example,
DOD may need to use more spectrum to meet an operational requirement to
field a jam-proof and accurate radar for military aircraft.
The current structure and management of spectrum use in the United
States does not encourage the development and use of some spectrum
efficient technologies. Because the spectrum allocation framework
largely compartmentalizes spectrum by types of services (such as
aeronautical radio navigation) and users (federal, nonfederal, and
shared), the capability of emerging technologies designed to use
spectrum in different ways is often diminished. For example, software-
defined cognitive radios”radios that adapt their use of the spectrum to
the real-time conditions of their operating environments”could be used
to sense unused frequencies, or ’white spaces,“ and automatically make
use of those frequencies. It may also be possible to use software-
defined cognitive radios to exploit ’gray spaces“ in the spectrum”areas
where emissions exist yet could still accommodate additional users
without creating a level of interference that is unacceptable to
incumbent users”to increase spectrum efficiency. Currently, however,
the spectrum allocation system may not provide the freedom needed for
these technologies to operate across existing spectrum designations,
and defining new rules requires knowledge about spectrum that spectrum
leaders do not have. At the same time, there are few federal regulatory
requirements and incentives to use spectrum more efficiently. While
the National Telecommunications and Information Administration (NTIA)
is responsible for managing the federal government‘s use of spectrum
and ensuring spectrum efficiency, NTIA primarily relies on individual
agencies to ensure that the systems they develop are as spectrum
efficient as possible. Agencies‘ guidance and policies, however, do
not require systematic consideration of spectrum efficiency in their
acquisitions. The lack of economic consequence associated with the
manner in which spectrum is used has also provided little incentive to
agencies to pursue opportunities proactively to develop and use
technologies that would improve spectrum efficiency governmentwide.
What GAO Recommends:
GAO is making six recommendations intended to facilitate greater
investment by federal agencies in spectrum efficient technologies.
Overall, the agencies indicated their commitment to promoting greater
flexibility and more efficient use of radio spectrum.
www.gao.gov/cgi-bin/getrpt?GAO-04-666.
To view the full product, including the scope and methodology, click on
the link above. For more information, contact Katherine V. Schinasi at
(202) 512-4841 or schinasik@gao.gov.
[End of section]
Contents:
Letter:
Results in Brief:
Background:
Agencies' Decisions to Invest in New Technologies Are Generally Driven
by Factors Other Than Achieving Spectrum Efficiency:
Federal Spectrum Management System May Limit the Development and
Adoption of Spectrum Efficient Technologies:
Conclusions:
Recommendations for Executive Action:
Agency Comments and Our Evaluation:
Appendix I: Comments from the Department of Commerce:
Appendix II: Comments from the Federal Communications Commission:
Appendix III: Comments from the Department of Homeland Security:
Tables:
Table 1: Five Steps Associated with the Command-and-Control Approach to
Spectrum Management:
Table 2: Descriptions and Key Examples of Existing or Emerging
Technologies That Can Improve Spectrum Utilization:
Table 3: Agency Research and Development Investments in Technologies
That May Improve Spectrum Efficiency:
Figure:
Figure 1: NTIA's Spectrum Measurement Van:
Abbreviations:
AGILE: Advanced Generation of Interoperability for Law Enforcement:
DARPA: Defense Advanced Research Projects Agency:
DHS: Department of Homeland Security:
DOJ: Department of Justice:
FAA: Federal Aviation Administration:
FCC: Federal Communications Commission:
FCS: Future Combat Systems:
GHz: gigahertz:
IWN: Integrated Wireless Network:
JTRS: Joint Tactical Radio System:
KHz: kilohertz:
NSF: National Science Foundation:
NTIA: National Telecommunications and Information Administration:
NEXCOM: Next Generation Air/Ground Communications:
OMB: Office of Management and Budget:
TTNT: Tactical Targeting Network Technology:
TSAT: Transformational Satellite:
UWB: ultra-wideband:
United States General Accounting Office:
Washington, DC 20548:
May 28, 2004:
The Honorable Tom Davis:
Chairman, Committee on Government Reform:
House of Representatives:
The Honorable Adam Putnam:
Chairman, Subcommittee on Technology, Information Policy,
Intergovernmental Relations, and the Census:
Committee on Government Reform:
House of Representatives:
Over the past several decades, the development and use of
telecommunications and information technology has expanded
dramatically, greatly increasing the use of the radio-frequency
spectrum. Cellular telephones, wireless computer networks, and global-
positioning-system receivers are quickly becoming as common to everyday
life as radios and televisions. Wireless communications have become
critical to private industry and a variety of government missions--
ranging from scientific research and public safety to homeland security
and strategic warfare. As a result, the radio-frequency spectrum, which
once seemed unlimited, has become crowded and, in the future, may no
longer be able to accommodate all users' needs.
Because of the growing demand for spectrum, there has been increased
attention in spectrum management policy debates on ways to improve the
efficient and effective use of spectrum. This has led to a growing
interest in technologies that can provide more efficient use of
spectrum. Therefore, you asked us to (1) determine whether federal
agencies are investing in developing spectrum efficient technologies
and the key factors they consider in making these investments and (2)
determine the extent to which the nation's system for managing
government and private sector use of spectrum facilitates the
development and adoption of these technologies.
Our review focused on federal agencies that are among the largest users
of technologies and systems impacting spectrum use--the Department of
Defense (DOD), the Federal Aviation Administration (FAA) within the
Department of Transportation, the Department of Homeland Security
(DHS), the Department of Justice (DOJ), and the National Aeronautics
and Space Administration (NASA)--as well as the National Science
Foundation (NSF), which funds research on spectrum-related
technologies. To determine whether agencies were investing in
technologies that might improve spectrum efficiency, we reviewed agency
budget and investment planning documents and sought additional
information from agency officials on specific programs and projects. To
assess the key factors that influenced agency investment decisions, we
interviewed agency officials and reviewed various documents and
studies.
To determine the extent to which the nation's spectrum management
system facilitates the development and adoption of these technologies,
we interviewed officials at the two agencies responsible for spectrum
management in the United States--the Federal Communications Commission
(FCC) and the Department of Commerce's National Telecommunications and
Information Administration (NTIA)--and reviewed these agencies'
spectrum management policies and procedures. We reviewed processes
established by the federal spectrum management system and individual
agencies for addressing new technologies. We also met with officials at
the agencies we reviewed to discuss the challenges of developing and
adopting new technologies under the current spectrum management system.
In addition, we interviewed experts and reviewed studies from private
sector organizations that are examining spectrum policies and
technologies--including the Center for Strategic and International
Studies and the National Academy of Sciences--and attended several
private-and government-sponsored conferences and forums on national
spectrum management issues and new spectrum technologies.
We performed our work from June 2003 through May 2004 in accordance
with generally accepted government auditing standards.
Results in Brief:
The agencies that we reviewed have made some investments in
technologies that provide improved spectrum efficiency. However, these
investments have been primarily driven by the imperatives of their
individual missions--not by an underlying, systematic consideration of
spectrum efficiency. For example, as a result of growing spectrum
constraints, DOD, FAA, and NASA began investing in technologies that
would increase the throughput of information while using smaller
segments of their available spectrum. These investments were needed to
meet mission-specific requirements and goals, such as DOD's need for
enhanced communications capabilities to meet its goal of information
superiority and network-centric war-fighting, and FAA's need to meet
growing demands for air traffic control communications. In addition to
mission requirements, agencies consider other factors and tradeoffs--
including cost and technical and operational concerns when making
investment decisions. However, some of these considerations may
dissuade agencies from investing in spectrum efficient technologies.
For example, to meet an operational requirement to field jam-proof and
accurate radar for military aircraft, DOD may need to use more
spectrum.
The current structure and management of spectrum use in the United
States may limit the development and use of some spectrum efficient
technologies. Because the spectrum allocation structure largely
compartmentalizes spectrum by types of services (such as aeronautical
radio navigation) and users (federal, nonfederal, and shared), the
capability of emerging technologies that are designed to use spectrum
in different ways is often diminished. For example, technologies like
software-defined cognitive radios can be adapted to operate in
virtually any segment of spectrum and, in the future, may be able to
adapt to real-time conditions and make use of underutilized spectrum in
a given location and time. Currently the spectrum allocation system,
however, may not provide the freedom needed for these technologies to
operate across existing spectrum designations. Moreover, defining new
rules to accommodate these emerging technologies requires knowledge
about spectrum use that is not currently available. For example, NTIA
and FCC do not have a sufficient understanding of the spectrum
environment, including how and how much spectrum is used, and lack
agreed-upon models to assess spectrum efficient technologies. At the
same time, there are few federal regulatory requirements and incentives
for agencies to use spectrum more efficiently. While NTIA is
responsible for managing the federal government's use of spectrum and
ensuring spectrum efficiency,[Footnote 1] NTIA primarily relies on
individual agencies to ensure that the systems they develop make as
efficient use of the spectrum as possible. Agencies' guidance and
policies, however, do not require systematic consideration of spectrum
efficiency in their acquisitions. The lack of economic consequence
associated with the manner in which spectrum is used has also provided
little incentive to agencies to pursue opportunities proactively to
develop and use technologies that would improve spectrum efficiency
governmentwide.
We are making six recommendations to help facilitate greater
consideration and investment by federal agencies in spectrum efficient
technologies. Specifically, we are recommending that the NTIA
Administrator and the FCC Chairman jointly take actions to build more
flexibility into the spectrum allocation system where feasible and gain
a better understanding of the current spectrum environment and spectrum
efficient technologies to increase the use of these technologies. We
are also recommending that the NTIA Administrator take actions to
encourage agencies to use spectrum more efficiently. In commenting on
the draft report, FCC supported our recommendations. The Department of
Commerce also commented on the draft, though it did not specifically
address our recommendations.
Background:
The radio-frequency spectrum supports a vast array of government and
commercial services, including radio and television broadcasts,
personal communications services, satellite communications, wireless
local area networks, public safety communications, air traffic control,
scientific research, and radar-based weather forecasting. The radio
spectrum spans a range of frequencies within the electromagnetic
spectrum from about 3 kilohertz (kHz) to 300 gigahertz (GHz), but most
of its use is concentrated in the lowest 1 percent of these
frequencies--sometimes referred to as the "beachfront property" of the
radio spectrum.[Footnote 2] Advances in technology have greatly
expanded the usable portions of the radio-frequency spectrum and have
led to more efficient means of using the available spectrum.
Simultaneously, these advances have created opportunities to provide
new spectrum-dependent services, which have led to even greater demand
on the limited available spectrum.[Footnote 3]
The spectrum is managed to maximize the benefits derived from this
limited resource, while mitigating interference among various
users.[Footnote 4] Within the United States, the spectrum is managed
jointly by the NTIA, within the Department of Commerce, and the FCC.
NTIA is principally responsible for developing and articulating
domestic and international telecommunications policy[Footnote 5] and
for managing the federal government's use of the radio spectrum. FCC
has authority over all nonfederal spectrum use, including the use of
the spectrum by state and local governments.
In managing the spectrum, FCC and NTIA have largely used a "command-
and-control" approach, which dictates how each segment of the radio
spectrum can be used and who can use it. This approach generally
involves five steps: allocation, adoption of service rules or technical
standards, certification, assignment, and enforcement. Table 1
describes each step.
Table 1: Five Steps Associated with the Command-and-Control Approach to
Spectrum Management:
Step: Allocation;
Actions taken by FCC and NTIA: Particular segments, or "bands," of the
radio spectrum are designated for specific types of services--for
example aeronautical radio navigation--with bands of varying widths.
Step: Adoption of service rules or technical standards;
Actions taken by FCC and NTIA: Rules and standards specify the required
technical and operational characteristics of the radios (or other radio-
frequency devices) that will use the allocated band, such as radiated
power limits, channel bandwidth and location, levels of acceptable
interference, and other service-specific or band-specific rules.
Step: Certification;
Actions taken by FCC and NTIA: Major federal systems that directly use
the radio-frequency spectrum must be certified by NTIA, as required by
the Office of Management and Budget (OMB) Circular A-11, to be assigned
a bandwidth. An agency first determines if the system it proposes to
field is "major"--that is, the system could cause significant impact on
the radio-frequency spectrum- -then conducts the necessary technical
studies of the proposed system, selects potential frequency bands,
coordinates with other agencies involved, and prepares and files a
certification application to NTIA for review. FCC similarly certifies
nonfederal systems.
Step: Assignment[A];
Actions taken by FCC and NTIA: Once service rules and technical
standards have been established, portions of the allocated band are
assigned--typically, to individual users or service providers operating
within a certain geographic area through a variety of mechanisms.
Step: Enforcement;
Actions taken by FCC and NTIA: Spectrum monitoring, interference
reporting, and other regulatory mechanisms are used to enforce
allocations, technical standards and service rules, and unique
geography-based assignments.
Source: GAO.
[A] Not all spectrum use requires an assignment. For example, many
familiar "unlicensed" wireless devices--such as cordless phones, baby
monitors, garage door openers, and wireless Internet access devices--
are allowed to operate within certain spectrum bands provided they do
not cause harm to assigned users and accept any interference received.
[End of table]
NTIA and FCC implement the command-and-control approach differently
because of differences in their missions. For example, NTIA assigns
spectrum resources through an administrative process that emphasizes
interdepartmental advice and coordination among federal agencies, while
FCC has used a number of administrative processes including comparative
hearings and lotteries as well as its authority to assign spectrum
through auctions.[Footnote 6] However, because so much of the spectrum
is shared between federal and nonfederal users, FCC and NTIA must
coordinate their management of spectrum.[Footnote 7]
For many decades, command-and-control has been the most commonly used
approach for managing the spectrum. However, as both the usage of and
demand for spectrum have exploded over the past decade, the
disadvantages of the command-and-control approach have become
increasingly apparent. For example, in October 2001, the FCC Chairman
noted that it is becoming difficult for government officials to
determine the best use for spectrum and to repeatedly adjust
allocations and assignments of spectrum to accommodate new spectrum
needs and new services. The President has similarly noted that the
existing legal and policy framework for spectrum management has not
kept pace with the dramatic changes in technology and spectrum use and
can discourage the introduction of new technologies.
In June 2002, the FCC Chairman established a Spectrum Policy Task Force
to help identify and evaluate changes in spectrum management policy and
to provide specific recommendations to FCC for ways to evolve from the
current command-and-control approach to a more integrated, market-
oriented approach. In November 2002, the Task Force reported its
findings and recommendations to FCC.[Footnote 8] While noting that no
single regulatory model should be applied to all spectrum, the Task
Force recommended that FCC pursue a spectrum management policy that
includes both exclusive spectrum usage rights granted through market-
based mechanisms and creates open access to spectrum "commons," with
command-and-control regulation used in limited circumstances. In
January 2003, we issued a report recommending a commission be
established to conduct a comprehensive examination of current U.S.
spectrum policy. [Footnote 9] In May 2003, the President signed an
executive memorandum establishing the federal government's "Spectrum
Policy Initiative" to develop recommendations for improving spectrum
management policies and procedures for the federal government and to
address state, local, and private spectrum use.[Footnote 10]
Although work under the President's initiative is ongoing, the
initiative recognizes, along with the findings of the 2002 FCC Task
Force, that existing and emerging technologies create the potential for
future radios and other radio-frequency devices and systems to use
spectrum more efficiently.[Footnote 11] Efficiency may be accomplished
through improvements to a broad set of technologies and applications.
Table 2 provides descriptions and key examples of such technologies and
applications that can improve the utilization of spectrum.
Table 2: Descriptions and Key Examples of Existing or Emerging
Technologies That Can Improve Spectrum Utilization:
Technology: Radio frequency component-level;
Description: Encompasses a broad set of radio-frequency components--
transmitters, receivers, and antennas (and their enabling
technologies)--that can improve spectrum utilization;
Key examples:
* "Smart" antennas that can selectively amplify desired signals while
canceling out competing signals;
* Modulation and channel coding can also influence how much spectrum
is needed to transfer encoded voice data.
Technology: Other component-level;
Description: Encompasses a broad set of other (non-radio frequency)
radio components including digital processors and associated algorithms
to compress data, and batteries for handheld devices;
Key examples:
* More advanced algorithms to encode and digitally compress a human
voice can greatly reduce the radio's data transfer requirements;
* Improving the efficiency of a handheld radio's battery can allow it
to accomplish more sophisticated data compression, modulation and
coding, and thus indirectly, influence the radio's ability to use
spectrum more efficiently.
Technology: Network-level;
Description: Technologies and related network or spectrum management
practices that can significantly improve information transfer and
spectrum efficiency as well as mission effectiveness;
Key examples:
* Improvements to an ad-hoc network's routing strategies can enable
more efficient use of available network resources, including spectrum
resources;
* Advanced quality of service algorithms may enable a diverse set of
network users with very different requirements and mission-driven
priorities, to operate on a single network and share the spectrum
resources of the entire network; these algorithms can grant high
priority to the rapid transmission of critical communications and lower
priority to routine message traffic.
Technology: Other enabling technologies;
Description: Includes investments in various technologies that may
yield improvements to spectrum utilization and efficiency;
Key examples:
* Advancements in microelectronics and semiconductors have enabled
greater processing power in smaller lighter weight packages. These
advancements continue with the development of semiconductor
technologies that may greatly improve upon the performance of today's
radio-frequency components;
* Research directed toward improving models of the ionosphere can lead
to more efficient use of some frequency bands.
Technology: Off-loading technologies;
Description: Technologies that are being developed, which would
facilitate "off-loading"--that is, relocating certain communications
requirements from highly congested radio-frequency spectrum to higher
radio-frequency bands and non-radio- frequency portions of the
electromagnetic spectrum;
Key examples:
* Research is under way to further the use of lasers to communicate at
very high data rates.
Source: GAO.
[End of table]
Many spectrum efficient technologies have both component-level and
network-level attributes. For example, some "smart" antennas can
pinpoint the source signal and selectively amplify it while canceling
out competing signals. In addition, because smart antennas direct
transmitted power toward desired receivers, the level of interference
experienced by other spectrum users is reduced. This adaptive behavior
may be controlled by local sensors but may also be cued by information
provided through the radio's network. Similarly, software-defined
radios, unlike traditional radios, have operating parameters (such as
the operational frequency and modulation type) that are determined by
software, meaning they can be programmed to transmit and receive on
many frequencies and to use any desired modulation or transmission
format within the limits of their hardware designs; as with smart
antennas, the programmed operating parameters of the radio may be
controlled internally or may be cued through the radio's network.
FCC and NTIA are both charged with promoting the efficient and
effective use of the radio spectrum. NTIA has told us that ensuring
efficient use of the spectrum is a major NTIA goal reflected throughout
most of its spectrum management processes, which include:
* setting standards for equipment that use the radio spectrum,
* certifying that proposed new systems conform with existing spectrum
allocations and associated standards, and:
* requiring justification of frequency assignment requests and
continuous review of existing frequency assignments.
Additionally, NTIA is responsible for conducting spectrum analyses and
research to keep abreast of the latest spectrum efficient technologies
that are appropriate for government use and for developing and adopting
automated information systems that support the spectrum management
processes and facilitate appropriate spectrum conservation measures.
Agencies' Decisions to Invest in New Technologies Are Generally Driven
by Factors Other Than Achieving Spectrum Efficiency:
Federal agencies have made some investments in technologies that may
provide improved spectrum efficiency. However, their decisions to
invest in those technologies are primarily driven by their individual
missions--not by an underlying, systematic consideration of spectrum
efficiency. Agencies generally do not identify spectrum efficiency as a
distinct category of technology investment. Other considerations that
influence agencies' technology decisions include technical and
operational concerns and costs that may make spectrum efficient
technologies impracticable.
Agency Mission Is a Key Factor in Determining Investments in New
Technologies:
Determining investments that may improve spectrum efficiency is
difficult because agencies do not clearly identify spectrum-related
investments in their budgets. However, using published budget and other
information provided to us by each of the nine agencies, we identified
projects that might result in improved spectrum efficiency and spoke
with agency officials about their technology investments. Based on this
review, we identified 335 fiscal year 2004 federally funded projects
that potentially included funding for spectrum efficient
technologies.[Footnote 12] Funding for these projects totaled
approximately $1.8 billion.[Footnote 13] These investments cover a wide
range of technologies that can affect spectrum use, including the
compression of raw source data, advanced radios, and network
improvements. The military services and Defense Advanced Research
Projects Agency (DARPA) combined are by far the largest federal
investors in new technologies that use the spectrum. In contrast, the
Departments of Justice and Homeland Security have small research and
development budgets and tend to rely on technologies that are
commercially available. Table 3 provides the total fiscal-year-2004
funding identified for each agency's projects related to spectrum
efficiency and highlights major areas of investment.
Table 3: Agency Research and Development Investments in Technologies
That May Improve Spectrum Efficiency:
Agency: DARPA;
Areas of major investment related to spectrum efficiency: Antenna
technologies, laser communications, transistor technologies, and
cognitive communications;
Total funding for fiscal year 2004: $339.7.
Agency: U.S. Air Force;
Areas of major investment related to spectrum efficiency: Software
defined radio/laser communications;
Total funding for fiscal year 2004: $649.4.
Agency: U.S. Army;
Areas of major investment related to spectrum efficiency: Software
defined radio;
Total funding for fiscal year 2004: $381.9.
Agency: U.S. Navy/Marine Corps;
Areas of major investment related to spectrum efficiency: Software
defined radios;
Total funding for fiscal year 2004: $172.4.
Agency: NASA;
Areas of major investment related to spectrum efficiency: Optical
(laser) communications;
Total funding for fiscal year 2004: $41.8.
Agency: DOJ;
Total funding for fiscal year 2004: 0[A].
Agency: DHS;
Total funding for fiscal year 2004: 0[B].
Agency: FAA;
Areas of major investment related to spectrum efficiency: Air traffic
control communications and digital radar;
Total funding for fiscal year 2004: $165.8.
Agency: NSF;
Areas of major investment related to spectrum efficiency: Interference
avoidance and measurement, networking, antenna technologies, data
compression, error correction, and cognitive radio research;
Total funding for fiscal year 2004: $14.8[C].
Source: GAO.
[NOTE:] Investments include amounts invested in projects undertaken
with a stated goal of improving radio-frequency spectrum and projects
where spectrum efficiency is not a stated goal but a possible outcome
(including enabling technologies like software defined radios). These
investments also include projects to off-load/achieve communications in
non-radio portions of the electromagnetic spectrum, for example, laser
communications. Because of the difficulty identifying relevant projects
and quantifying relevant investments in projects where spectrum
efficiency may be only a small component, actual investment numbers may
be higher or lower.
[A] DOJ focuses on the acquisition of commercial-off-the-shelf
equipment.
[B] While DHS is not currently funding research and development into
technologies to provide improved spectrum efficiency, it expects to in
the future.
[C] NSF grants funded in fiscal year 2003. According to agency
officials, NSF has recently initiated a number of spectrum efficiency
projects, including a study of programmable wireless networking, on
which it plans to allocate at least $8 million per year.
[End of table]
Agency investments in technologies that provide greater spectrum
efficiency have tended to occur when agencies need to make greater use
of available spectrum to meet a mission requirement and the additional
spectrum is not readily available, as is the case with DOD.
Specifically, DOD systems are requiring greater bandwidth to transmit
intelligence and surveillance information, facilitate enhanced
communications capabilities, and conduct electronic warfare--which DOD
considers essential to meeting its key strategic goal of information
superiority. As a result, DOD has made significant investments in new
systems that, in part, address problems related to insufficient
spectrum, as the following examples illustrate:
* Joint Tactical Radio System (JTRS): To address key communications
shortfalls and significantly improve military capabilities, DOD has
begun to make significant investments in software-defined radios, which
offer the potential of more efficient spectrum use in the future
without the need for expensive and complex hardware changes. In 1997,
DOD initiated the JTRS program to develop and apply this technology and
to bring together separate service-led programs into a joint software-
defined radio development effort. JTRS radios are intended both to
interoperate with existing radio systems and to provide military users
with more flexible communications capabilities in the future.
* Air Force's Transformational Satellite (TSAT) Program: The Air Force
is exploring new technologies that enable communications in higher
radio-frequency bands, which are much less congested, and in non-radio-
frequency portions of the electromagnetic spectrum. Non-radio-
frequency technologies will enable next-generation military satellites
to communicate at very high data rates using lasers. As a result,
information can be transferred without relying on the radio-frequency
spectrum.
* DARPA's Tactical Targeting Network Technology (TTNT) Program: TTNT
program aims to demonstrate a high-capacity sensor data system that
could enable networks of strike aircraft to accomplish their missions.
In particular, certain missions require the rapid sharing of targeting
sensor data among a large ad-hoc network of strike aircraft. Currently,
the U.S. military's airborne tactical data links cannot support a large
network of aircraft simultaneously due to spectrum constraints. TTNT is
expected to provide a data rate 10 to 25 times higher than the current
airborne tactical data link in an equivalent amount of spectrum.
Other agencies have made some investments in spectrum efficient
technologies, and like DOD, these investments were largely driven by
agency mission, as in the following examples:
* NASA's Mars Laser Communications Demonstration Project: NASA
anticipates a significant increase in the near future in demand for
long-haul communications services from deep space to Earth. As a
result, it has undertaken the Mars Laser Communications Demonstration
Project--a joint project with the Massachusetts Institute of
Technology's Lincoln Laboratory--to develop a laser-based
communications system that would transfer information without relying
on the radio-frequency spectrum. Such a system would facilitate
bandwidth-hungry instruments, such as imaging systems and radar to be
used in deep space exploration.
* Federal Aviation Administration's Next Generation Air/Ground
Communications (NEXCOM) Initiative: In 1990, FAA began the NEXCOM
initiative in response to growing demands for air-to-ground air traffic
control communications. By replacing current analog radios with digital
radios, the program is expected to achieve greater spectrum capacity
using the same spectrum currently allocated for air traffic control
communications. Each of NEXCOM's 25 kHz channels will support four
voice circuits, instead of the one circuit supported by the current
system.
* DOJ's Integrated Wireless Network (IWN) System: While Justice is not
investing directly in research and development into technologies to
improve spectrum efficiency, it has undertaken a joint effort--the IWN
system--with the Departments of Homeland Security and Treasury to
provide improved interoperability of communications within the federal
law-enforcement community. New equipment being acquired under the IWN
system, such as new land mobile radios, will significantly increase
spectrum efficiency.
Other Factors That Influence Agencies' Investment Decisions:
Besides mission objectives, several other factors, such as technical
and operational considerations and cost-effectiveness, influence
agencies' technology investments. In considering these factors,
agencies may determine that using more spectrum efficient technologies
is impractical.
If an agency developed a system solely to minimize spectrum usage or
optimize spectrum efficiency, the system may also include other less
desirable or unacceptable operational characteristics--that is,
characteristics that are incompatible with accomplishing an agency
mission. For example, the Army's Future Combat Systems (FCS)[Footnote
14]--the centerpiece of the Army's plan to transform to a lighter, more
agile, and more capable force--will rely on superior information to see
and hit the enemy first. Future Combat Systems' capabilities depend, in
part, on the ability of the Army's network to collect, process, and
deliver vast amounts of information such as imagery and communications
that will require much higher spectrum usage. Operational
considerations also can affect radar aboard military aircraft. Such
radars must operate in unfriendly and stressed conditions, including
exposure to enemy jamming capabilities and flight speeds of up to 1800
to 2000 kilometers per hour. Aircraft radars must also function while
the aircraft is conducting evasive maneuvers to avoid threats such as
enemy missiles. According to DOD officials, the bandwidth used by
aircraft radars is directly related to the radar's accuracy. As a
result, limiting the radar's bandwidth could result in the aircraft
engaging a wrong target or other unwanted consequences. Also, some
federal agencies that intend to operate spectrum-dependent systems
outside of the United States may have to compromise the application of
more efficient technologies in order to acquire spectrum access in
other countries. For example, in developing communications and radio
navigation systems for aircraft, FAA is largely limited to using
globally allocated bands that are designated for aeronautical services.
In addition, agencies need to make tradeoffs between spectrum
efficiency and cost. For example, a new type of smart antenna, called
an adaptive array, can extend the range of communications systems and
minimize interference. Although more efficient in its use of spectrum,
this new technology is generally more expensive than traditional
antenna technology, and, as a result, these technologies may not be
considered or developed unless justified by mission needs. Similarly,
the Department of Justice's Advanced Generation of Interoperability for
Law Enforcement (AGILE) program is coordinating the efforts of federal,
local, state, and regional public safety organizations to achieve
interoperable communications. However, local, state, and regional
organizations may lack funding to replace their legacy radio systems
and radio infrastructure with the most efficient systems available. As
a result, these interoperability and funding concerns may dictate what
technologies can be selected for use in new federal systems and may
limit the degree of spectrum efficiency achieved.
Agencies' Technology Planning Processes Do Not Identify Spectrum
Efficiency as an Investment Area:
To help manage their investment decisions, some agencies have
established science and technology planning processes to identify long-
term technological needs, establish research and technology priorities,
and coordinate research activities. These processes enable policy
makers and implementers to adjust the allocation of agency resources to
meet changing requirements for fulfilling agency missions. However, the
agencies' science and technology planning processes that we reviewed do
not specify spectrum efficient technologies as an investment area. For
example, FAA's research and development strategy does not focus
specifically on achieving spectrum efficiency; rather, it emphasizes
improving the overall efficiency of the nation's air traffic control
systems--which may require making better use of the spectrum.
Similarly, the military services' science and technology planning
processes emphasize achieving overall operational efficiency and
effectiveness, which may or may not result in improved spectrum
efficiency. A DOD official within the Office of the Assistant Secretary
of Defense for Networks and Information Integration acknowledged that
spectrum efficiency does not receive the same level of attention as
science and technology efforts to improve more conventional weapons
systems' performance requirements such as lethality and survivability.
However, DOD has taken initial steps to consider spectrum efficiency by
revising its policy and guidance on spectrum management. Specifically,
DOD's Electromagnetic Spectrum Management Strategic Plan--which was
issued in December 2002 --has five core principles, including one that
recognizes the need to invest in new spectrum efficient technologies.
In addition, the strategic plan established a goal to improve spectrum
utilization through technological innovation. As part of developing a
strategy for DOD, the Defense Spectrum Office[Footnote 15] has begun to
study emerging technologies and future war fighter requirements. In
addition, DOD convened a group of technologists last year to discuss
spectrum technologies and how to link them more directly to DOD's
science and technology planning process. Because these efforts are in
their early stages, they have not yet resulted in policy changes or
modifications to investment plans. Similarly, NASA is working on an
electromagnetic spectrum management strategy, which is in the final
stages of review before release.
Federal Spectrum Management System May Limit the Development and
Adoption of Spectrum Efficient Technologies:
The current structure and management of spectrum in the United States-
-allocating bands of spectrum to certain users for specific uses--may
limit the development and adoption of some emerging technologies that
promise improved spectrum efficiency. However, redefining this
structure and management of spectrum to take full advantage of future
opportunities to improve spectrum efficiency could be difficult due, in
part, to the lack of flexibility in the spectrum allocation system,
policy makers' limited knowledge about spectrum use and new and
emerging technologies, as well as a lack of agreed-upon models to
assess these technologies. At the same time, there are few regulatory
requirements and incentives to encourage agencies to develop and use
spectrum more efficiently. The current federal regulatory framework and
system certification process tend to focus only on major systems that
directly use the radio spectrum and their compliance with existing
standards to avoid interference--not on spectrum efficiency. A lack of
incentives to achieve spectrum efficiency also limits agencies'
consideration of spectrum efficient technologies in the acquisition of
systems. However, providing such incentives is challenging, in part,
because financial considerations must be balanced with mission needs.
Current Spectrum Structure and Management Could Constrain Efforts to
Use Spectrum More Efficiently:
To manage the use of the radio-frequency spectrum in the United States,
FCC and NTIA allocated the spectrum into federal, nonfederal, and
shared bands and designated specific bands for specific uses, such as
broadcast radio and television. Historically, this structure has served
a valuable function. In addition to seeking to avoid interference among
users, the structure has enabled spectrum leaders to balance government
and commercial interests, provide stability and design certainty for
equipment manufacturers, and accommodate a certain level of increased
demand by apportioning spectrum for future uses. However, the current
allocation structure has proven effective largely because technologies
operated within a fairly narrow range of spectrum. While emerging
technologies that use wider segments of spectrum or move across
segments of spectrum may be able to operate within current
demarcations, greater efficiencies may be achievable if these
technologies were allowed to operate in an environment that provides
more operational freedom than the current structure.
With nearly all of the spectrum allocated and access rights granted to
users, such freedom tends to require increased "sharing" of the
spectrum[Footnote 16]--that is, allowing more than one user to transmit
radio signals on the same frequency band.[Footnote 17] In working to
increase spectrum sharing, spectrum leaders will need to carefully
consider the impacts on incumbent users' operations and define
appropriate rules to mitigate those impacts.
However, attaining agreement on such rules may be difficult and could
result in operational constraints that reduce the promise of increased
spectrum efficiency. For example, radios that are largely defined by
their software components could provide greater efficiencies if
software enabled them to operate in a shared environment--as DOD hopes
to do with JTRS. Currently, DOD is developing 34 waveforms[Footnote 18]
for use in JTRS radios. Of these, 33 waveforms are to be operationally
identical to their respective, already fielded, traditional radio
counterparts and, consequently, will be able to operate in the current
spectrum structure. However, these waveforms will be no more efficient
than their existing radio counterparts. While the remaining waveform
promises to achieve greater spectrum efficiency in providing voice,
video, and data services, it requires access to a wider swath of the
spectrum, which JTRS program officials believe will challenge the
current spectrum structure and certification process because it could
impact other users' operations. JTRS program officials stated that for
the near term, some of the concerns associated with the new waveform
could be addressed by using software "lockouts" to ensure that
sensitive bands are protected. However, to achieve greater efficiency,
JTRS program officials believe that spectrum sharing issues will need
to be worked out, and spectrum policies and rules will need to be
adjusted.
As software-defined radios become more sophisticated, the challenge in
employing them will become even greater. For example, software-defined
cognitive radios--radios that adapt their use of the spectrum to the
real-time conditions of their operating environments--could be used to
sense unused frequencies, or "white spaces," and automatically make use
of those frequencies. According to FCC, many portions of the radio
spectrum are not in use for significant periods of time and that
tapping into these white spaces--both temporal and geographic--could
significantly increase spectrum available for use.[Footnote 19] It may
also be possible to use software-defined cognitive radios to exploit
"gray spaces" in the spectrum--areas where emissions exist but that
could accommodate additional users without raising the overall noise
level in a band to a level unacceptable to incumbent users--to increase
spectrum efficiency.[Footnote 20]
However, employing the technologies needed to exploit these spaces
could present significant problems of interference. Currently, FCC is
exploring a new approach to cognitive radios and interference control
and management[Footnote 21] based on the concept of measuring
"interference temperature."[Footnote 22] Under this concept, the
interference temperature in a given band would be measured, and devices
receiving these measurements would restrict their operations in order
to maintain the interference temperature at or below a prescribed limit
for that band. In the simplest case, the entire process would take
place within an individual device, such as a software-defined cognitive
radio capable of measuring the interference temperature at its location
and making a decision to transmit or not transmit based on this
measurement plus its own contribution of radio-frequency energy.
However, the interference temperature concept is controversial and in
the view of many has yet to be successfully demonstrated in a practical
context. NTIA believes that more study is needed to determine what
might be the "correct" tool for quantitatively controlling interference
between mobile and unlicensed transmitting devices that share spectrum
with existing telecommunication facilities.
Lack of Knowledge and Varying Perspectives about Spectrum May Further
Constrain the Use of More Spectrum Efficient Technologies:
The extent to which emerging and future technologies, such as those
that would exploit white and gray spaces, could be utilized to increase
spectrum efficiency is dependent on the degree of freedom these
technologies would be provided to operate across the spectrum. While
unconstrained operation may not be realistic--given the sensitivity of
certain uses of spectrum--it may be possible to develop policy-based
rules to maintain some constraints, such as blocking the use of certain
frequency bands, while allowing greater freedom in other areas of
spectrum. Defining such rules, however, requires a level of
understanding of the spectrum environment--including how and how much
spectrum is used--and spectrum efficient technologies that NTIA and FCC
do not currently have. For example, in 2002, the FCC's Spectrum Policy
Task Force noted that in order to define rules for the implementation
of the interference temperature concept, additional knowledge--
including the need to acquire data on the current ambient noise levels
for different frequency bands and geographic regions--would be
required.[Footnote 23] To that end, the Task Force recommended a
systematic study of the spectrum environment.
Currently, NTIA has the capability to capture knowledge needed to
better understand the radio spectrum environment through a radio
spectrum measurement program, which it established in 1973 to assess
whether spectrum is being used in accordance with applicable
regulations and to provide information to prevent or resolve
interference problems involving federal government systems.[Footnote
24] However, the measurement program is limited to measuring and
recording radio signals between 10 kHz and 20 GHz at selected sites
through equipment housed in a single van (see fig. 1)[Footnote 25] and
in portable suitcases. As such, the van has been used primarily to help
reach consensus on difficult or unusual interference and spectrum
sharing problems having a high national importance. For example, such
measurements have assisted in reaching some consensus on the use of
ultra-wideband (UWB) devices, expanded 5 GHz unlicensed device
operation, and broadband over power lines. According to NTIA, all of
these activities directly support the Administration's goals related to
facilitating emerging technologies. However, the last compliance-type
measurements were conducted in the mid-1980s. According to NTIA, these
measurements were discontinued because of a lack of resources and
generally low benefits provided to national spectrum management. NTIA
has also discontinued its broadband spectrum surveys--which covered the
spectrum from about 100 MHz to 20 GHz.[Footnote 26] The last broadband
survey measurements were made in the San Francisco area in 1995 with
results reported in 1999.
Figure 1: NTIA's Spectrum Measurement Van:
[See PDF for image]
[End of figure]
In addition, NTIA lacks sufficient information to more accurately model
and test the impact of emerging technologies to determine their likely
operational characteristics. For example, NTIA must typically rely on
federal agencies to provide information on the technical
characteristics of their radio communication systems. According to NTIA
officials, this information has been insufficient to perform detailed
analyses of some technologies. Furthermore, since NTIA and FCC have
different spectrum management responsibilities--federal and
nonfederal, respectively--they have different perspectives on spectrum
use. NTIA tends to focus on protecting the federal government's use of
the spectrum from harmful interference--especially in areas critical to
national security and safety--while FCC tends to focus on maximizing
public access to and use of the spectrum. As a result, NTIA and FCC
have different perspectives on the assumptions and operational
scenarios that should be used to assess potential interference from new
technologies. This divergence can lead to difficulties in establishing
agreed-upon service rules and technical standards, resulting in delays
in accommodating new technologies.
The effect of limited knowledge and varying perspectives on defining
policy-based rules is demonstrated in the government's recent efforts
to accommodate commercially developed low-power UWB devices,[Footnote
27] which offer greater utilization of the spectrum in a shared
environment. Potential uses include radar imaging of objects buried
underground or behind walls and short-range, high-speed data
transmissions. Because UWB devices transmit over large swaths of
spectrum and emit into spectrum used by both federal and nonfederal
users, NTIA and FCC have shared responsibilities in their use. However,
there has been considerable debate over how much interference UWB
devices would cause to other spectrum users--with particular concern
for protecting the Global Positioning System and public safety systems.
For example, NTIA was concerned that allowing UWB systems to emit
intentionally into certain bands would cause potential interference to
vital federal government services. To assess the potential impact of
introducing UWB devices into the spectrum environment, NTIA had to make
assumptions about the devices' characteristics and simulate their
transmissions because commercial UWB devices were not available for
testing.
In February 2002--after substantial debate among NTIA, FCC, and other
interested parties--FCC established rules to allow the development and
marketing of unlicensed, low-power UWB devices in a limited frequency
range and with power limitations, based in large measure on standards
recommended by NTIA.[Footnote 28] However, FCC has expressed its intent
to revisit the adopted standards eventually because of its concern that
the standards may be overly stringent--reflecting technical analyses of
"worst case" scenarios, not real-life operating conditions--and could
unnecessarily constrain development of UWB technology.[Footnote 29]
Conversely, some federal agencies remain concerned that not enough is
known about how UWB interacts with existing systems, including the
aggregate effect of large numbers of UWB devices. According to FCC
officials, UWB device manufacturers expressed concerns that their
investments in components that comply with the adopted standards would
be lost if a less restrictive order is adopted too soon. In February
2003, FCC made minor changes to UWB regulations but opted not to make
any significant changes to the existing UWB technical parameters,
citing the lack of experience with UWB devices and concerns that any
major changes to the rules for existing UWB product categories would be
disruptive to current industry product development efforts.
Federal Requirements to Invest in Spectrum Efficient Technologies Are
Limited:
NTIA is responsible for promoting the efficient and effective use of
spectrum that has been assigned to federal users. However, the current
regulatory framework and system certification process for federal
spectrum use tend to focus on compliance with existing standards to
avoid interference, not on spectrum efficiency. Furthermore, agency
regulations do not systematically require the consideration of spectrum
efficiency in the development and acquisition of systems.
While NTIA's certification process helps avoid interference, it does
not directly consider whether the fielded system would use too much
spectrum or could incorporate other technologies to improve spectrum
efficiency. In general, NTIA's certification process focuses on
maintaining the integrity of the current spectrum structure by ensuring
that:
* fielded systems operate in a frequency band allocated for the type of
service they provide, such as maritime mobile radio;
* frequency assignments are available for systems to operate in their
intended operational environment; and:
* the technical characteristics of fielded systems are compatible with
the operation of other systems, that is, they will not significantly
interfere with others.
NTIA's ability to influence spectrum use is also somewhat limited
because it only receives and reviews spectrum certifications for
"major" federal systems that directly use the radio-frequency spectrum-
-that is, systems that could have significant impact on other users of
the radio spectrum--with each agency determining which of its systems
are major. In addition, systems that utilize spectrum, but are not
direct transmitters or receivers of radio waves, such as network
routing strategies, are not subject to the certification process and
therefore not within NTIA's influence. Finally, NTIA officials told us
that in general, individual agencies have not identified and reported
their long-term requirements for spectrum. These officials also
indicated that telecommunication investments are not easily
identifiable because agency budget submissions do not break out or
otherwise provide the ability to readily identify investments for
systems that require spectrum. Although agencies must obtain spectrum
certification prior to submitting budget proposals to OMB for approval,
as required by OMB Circular A-11, NTIA officials told us that OMB does
not routinely receive this information from NTIA nor systematically
review and coordinate intended spectrum use during its review of agency
budget submissions. Because agency investment in radio spectrum
dependent systems cannot be readily identified, NTIA officials also
stated that NTIA has generally had to react to spectrum demands as they
become apparent through the certification process as opposed to
planning for future spectrum use.
NTIA has generally relied on agencies to ensure that their systems are
as spectrally efficient as possible.[Footnote 30] However, the
acquisition guidance and policies of the agencies we reviewed do not
require the systematic consideration of spectrum efficiency in the
design and development of systems. Similar to NTIA's certification
process, these agencies' internal certification procedures tend to
focus on avoiding significant interference among systems. For example,
FAA's policy for the use of radio spectrum identifies spectrum
efficiency as a broad objective, but its certification process focuses
mainly on equipment characteristics and compliance with NTIA standards
and national and international spectrum allocation rules. While DOD's
acquisition policies and procedures require system developers and
acquirers to consider spectrum supportability, they do not specifically
require consideration of spectrum efficiency. Ensuring spectrum
supportability could ultimately result in some spectrum efficiencies.
However, we have previously reported that DOD's weapons programs often
failed to obtain, consider, or act on spectrum supportability knowledge
during the early stages of acquisition,[Footnote 31] as required by DOD
policy. Several weaknesses underlie this failure, including program
managers' lack of awareness of spectrum certification requirements,
out-of-date and unclear spectrum management publications, competing
demands of program mangers, and a lack of effective enforcement
mechanisms for existing spectrum certification requirements.[Footnote
32]
Creating Incentives to Encourage the Development and Use of Spectrum
Efficient Technologies Is Challenging:
The fact that spectrum is virtually cost free may influence whether
agencies consider spectrum efficiency and invest in spectrum efficient
technologies. Currently, agencies have little or no economic incentive
to use the radio-frequency spectrum more efficiently because they pay
only small administrative fees for its use. Once it is allocated and
users gain access to the spectrum, there are generally no financial
incentives for them to consider accommodating other users, or in many
cases, even to move to more efficient technologies. Incentives--both
governmentwide and agencywide--could theoretically go a long way in
encouraging agencies to proactively develop and use spectrum efficient
technologies. However, incentives may not be appropriate, desirable, or
feasible in all circumstances.
In the private sector, the goals of maximizing profits can be a strong
incentive to increase efficiency and utilization of the spectrum. For
example, firms offering cell phone service may use various
technologies, such as modulation techniques, to increase the number of
cell phone users in a particular band. While market-based incentives
promote efficiency, this model is not easy to apply to the federal
sector--largely because government agencies need to balance their
missions of providing public benefit with achieving economies and the
difficulty of finding ways to apply these economies.
For more than a decade, NTIA and others have considered the use of
market-based incentives to promote spectrum efficiency in the federal
government. In its 1991 report U.S. Spectrum Management Policy: Agenda
for the Future, NTIA suggests exploring with FCC various fee proposals
that would invoke the forces of supply and demand to create market-
based mechanisms for spectrum management. Following this report, NTIA
imposed agency fees to cover its administrative costs, which amount to
about $55 per assignment. In November 2002, FCC's Spectrum Policy Task
Force Report also discussed the use of fees to improve spectrum
efficiency in the public sector where market forces may be inadequate
to spur efficiency. In October 2003, the Center for Strategic and
International Studies reported that market approaches such as licenses
that can be traded or sold would allow the market to determine the most
efficient use of the spectrum.[Footnote 33] The President's Spectrum
Policy Initiative, chaired by the Secretary of Commerce, is currently
examining issues of spectrum efficiency. Adopting market-based
incentives to encourage spectrum efficiency is not limited to the
United States. To varying degrees, Australia, Canada, and the United
Kingdom have put in place mechanisms to reflect the opportunity costs
associated with government spectrum use. These mechanisms include
auctions and incentive-based fees, more flexible licenses, and
secondary markets. The three countries have reported more flexibility
in reassigning and allocating spectrum to its most efficient use.
However, creating viable economic incentives to achieve spectrum
efficiency in the U.S. federal government may be difficult. As we have
previously reported,[Footnote 34] NTIA could face several challenges if
it decides to use such incentives. First, implementing a market-based
approach may be difficult for some agency functions that are critical
and unique, such as public safety and national defense. Second,
incentives that would require greater flexibility among license holders
of spectrum may ultimately result in problems of interference. Although
flexibilities have resulted in improved spectrum efficiency in other
countries, these flexibilities may not apply to the United States
because of the unique and worldwide missions of the U.S. military and
the divided structure and missions of the U.S. spectrum management
system. Third, it is unclear whether licensees would have the right to
buy and sell spectrum, and what rights would be conferred and under
what circumstances rights would be granted. Finally, while it may be
possible to impose fees on federal agencies' use of assigned spectrum,
it is far from obvious how such fees or other economic incentives could
be applied to agencies' opportunistic use of white and gray spaces in
the spectrum--as would be the case with software-defined cognitive
radios, which adapt their use of the spectrum in real time. In its 2002
report, FCC also acknowledged that there are instances where
regulation, as opposed to a market-oriented approach, is more
appropriate.
Conclusions:
With the rapid advances in telecommunications technology and the
increasing demand--both public and private--for radio-frequency
spectrum, NTIA and FCC are faced with the daunting task of achieving
greater spectrum efficiency while maintaining the level of services
that users have come to expect. Further development and use of spectrum
efficient technologies may provide an answer to this dilemma without
negatively affecting the ability of agencies to carry out their
missions; however, users have not actively pursued these technologies
because there are few regulatory requirements or incentives to do so
and because factors associated with the nation's current spectrum
management system may not encourage the use of these technologies. To
ensure the most efficient use of spectrum, it will be necessary to
rethink the current environment in which spectrum is managed, define
requirements, and examine the requirements and incentives needed to
encourage agencies to promote new and emerging technologies for
achieving spectrum efficiency. Efforts currently under way at the
national level, such as the President's Spectrum Policy Initiative,
provide an opportunity to establish appropriate policies and
mechanisms, including incentives, to facilitate greater consideration
of spectrum efficiency and create a more flexible, adaptable spectrum
management environment that allows emerging technologies to fulfill
their potential of spectrum efficiency. Without greater flexibility and
incentives, efficiency may remain an unmet promise, and the growing
demand for spectrum may soon threaten agencies' ability to meet their
missions.
Recommendations for Executive Action:
We are making six recommendations to help increase the development and
adoption of spectrum efficient technologies. Specifically, we recommend
that the NTIA Administrator and the FCC Chairman jointly:
* assess and determine the feasibility of redefining the spectrum
allocation system to build in greater flexibility where appropriate to
facilitate emerging technologies;
* develop and implement plans to gain a more thorough and on-going
understanding of the current spectrum environment; and:
* strengthen efforts to develop jointly accepted models and
methodologies to assess the impact of new technologies on overall
spectrum use and increase opportunities to permit testing of those
technologies.
To better ensure federal agencies consider and invest in spectrum
efficient technologies, we further recommend that the NTIA
Administrator:
* establish guidance for agencies to determine and report their future
spectrum requirements;
* strengthen NTIA's spectrum certification process to more directly
address spectrum efficiency; and:
* determine approaches, where appropriate, for providing incentives to
agencies to use spectrum more efficiently and then pilot and measure
the effectiveness of those approaches.
Agency Comments and Our Evaluation:
We provided a draft of this report to the agencies that we reviewed.
The Department of Commerce, FCC, and DHS provided written comments
(reprinted as appendixes I, II, and III, respectively), and DOD, DOT,
NASA, and NSF provided oral comments. DOJ did not have comments.
FCC in commenting on the draft report supported our recommendations and
indicated it would work with NTIA to incorporate the report's findings
and recommendations in future work. FCC also emphasized a number of
actions it has taken to encourage and facilitate new technologies that
might improve spectrum efficiency. The Department of Commerce did not
comment on our recommendations but noted that NTIA and FCC "have met
regularly to explore areas of common focus in spectrum management."
While we agree that meeting regularly is an important step toward
building a more cohesive spectrum management process, it is not clear
that these discussions have addressed or will address our
recommendations to improve spectrum efficiency. Continued difficulty in
reaching consensus between NTIA and FCC will hinder opportunities to
accommodate new technologies and users and improve spectrum efficiency.
Several of the agencies' comments indicated their commitment to
promoting greater flexibility and more efficient use of radio spectrum.
Overall, the comments from agencies, other than NTIA and FCC, were
generally technical in nature and were incorporated where appropriate.
In addition, the agencies provided a few comments relating to our
findings and recommendations. Most notably as follows:
* NSF observed that future use of spectrum through software-defined
cognitive radios could adversely affect the operation of sensitive
radio telescopes that NSF supports. We agree that this is a valid
concern because these systems are "passive"--or receive only--and their
use of spectrum could go unnoticed. As noted in this report, when
seeking to increase spectrum sharing, spectrum leaders will need to
carefully consider incumbent users operations and define appropriate
rules to obviate those impacts.
* NSF, as well as DHS, also commented on our recommendations directed
to the NTIA Administrator. Specifically, NSF noted that incorporating
spectrum efficiency measures into the certification process of major
systems could prove difficult and suggested either deleting or
modifying the recommendation to focus on incentives. However, our
recommendation does not call for the creation of measures but rather
emphasizes the need for NTIA to focus on efficiency when considering
certification. But in doing so, NTIA may determine that measures are an
appropriate means to help increase spectrum efficiency and may be
applicable in some cases. Further, we have recommended that NTIA take
action to determine appropriate incentives for agencies to use spectrum
more efficiently. Therefore, we did not modify our recommendations.
Contrary to NSF, DHS stated that incentives do not apply to the
government. While we recognized that incentives may not be applicable
or desirable in all circumstances, we believe that there may be
opportunities to use incentives to promote consideration of spectrum
efficiency, and therefore recommended that such opportunities be
explored.
We are sending copies of this report to the Acting Assistant Secretary
of Commerce for Communications and Information and Administrator of the
NTIA, the Chairman of the Federal Communications Commission, the other
agencies we reviewed, and interested congressional committees. We will
also make copies available to others upon request. In addition, the
report will be available at no charge on the GAO Web site at http://
www.gao.gov.
If you or your staffs have any questions about this report, please
contact me at (202) 512-4841 or John Oppenheim at (202) 512-3111. Other
individuals making key contributions to this report are Bruce Thomas,
Jay Tallon, Gary Middleton, Karen Sloan, and Allison Bawden.
Signed by:
Katherine V. Schinasi:
Managing Director, Acquisition and Sourcing Management:
[End of section]
Appendix I: Comments from the Department of Commerce:
May 18, 2004:
THE SECRETARY OF COMMERCE
Washington, 0.C. 20230:
Ms. Katherine V. Schinasi:
Managing Director, Acquisition and Sourcing Management:
United States General Accounting Office:
Washington, DC 20548:
Dear Ms. Schinasi:
Thank you for providing the Department of Commerce with an opportunity
to comment on the General Accounting Office's (GAO) draft report
entitled "Spectrum Management: Better Knowledge Needed to Take
Advantage of Technologies That May Improve Spectrum Efficiency."
I commend GAO for its efforts to examine the complex public policy
issues surrounding our Nation's spectrum management procedures. As you
are aware, the Department of Commerce is also addressing spectrum
efficiency at the direction of President Bush as part of his Spectrum
Policy Initiative. The President's initiative defines two courses of
action: first, the establishment of a Federal Government Spectrum Task
Force to focus on improving spectrum management policies to stimulate
more efficient use of Federal Government spectrum; and second, to
conduct broad outreach to encourage the public to express its views on
improvements to our spectrum management policies. These initiatives are
complete, and I will soon be forwarding t the President two reports
outlining recommendations for improving the management of both Federal
Government and non-Federal Government spectrum.
With respect t the draft GAO report, I note that it is recommended that
the NTIA Administrator and the FCC Chairman "jointly" work t improve
spectrum management procedures. It should be noted that the NTIA
Administrator and the FCC Chairman are directed by statute to meet
biannually to conduct joint spectrum:
planning with respect to, among other things, "actions necessary to
promote the efficient use of the spectrum, including spectrum
management techniques to promote increased shared use of the spectrum
that does not cause harmful interference as a means of increasing
commercial access."[NOTE 1] During this Administration, the NTIA
Administrator and the FCC Chairman have met regularly to explore areas
of common focus in spectrum management, particularly spectrum
efficiency. NTIA and the FCC, as co-managers of the radio frequency
spectrum, will continue to work together on important spectrum
management issues.
I hope this information is helpful. If you have any additional
questions concerning the Department of Commerce's comments on the
report or any issue involving spectrum management, please contact
Acting Assistant Secretary for Communications and Information Michael
D. Gallagher at (202) 482-1830.
Signed by:
Donald L. Evans:
NOTE:
[1] See 47 U.S.C § 922.
[End of section]
Appendix II: Comments from the Federal Communications Commission:
Federal Communications Commission
Washington, D.C. 20554:
May 21, 2004:
Ms. Katherine V. Schinasi
Managing Director, Acquisition and Sourcing Management:
U.S. General Accounting Office
Washington, DC 20548:
Dear Ms. Schinasi:
Thank you for sharing the General Accounting Office's ("GAO's") draft
report, entitled "Spectrum Management: Better Knowledge Needed to Take
Advantage of Technologies That May Improve Spectrum Efficiency."
Chairman Powell has asked me to provide comments on the draft report. I
will focus on your recommendations in response to the second of the two
requests GAO received to explore possible steps to facilitate
consideration and investment by federal agencies as well as others in
spectrum-efficient technologies. In particular, GAO's draft report sets
out three recommendations for joint action by the Administrator of the
Department of Commerce's National Telecommunications and Information
Administration ("NTIA") and the Chairman of the Federal Communications
Commission ("FCC"). We value GAO's analysis as a way to build upon our
existing work and cooperative efforts already underway with the NTIA.
Under Titles I and III of the Communications Act, the FCC is charged,
among other things, with adopting policies for non-federal spectrum use
that make wireless communication services available to all Americans,
that provide for national defense, and that promote the safety of life
and property. In fulfilling these responsibilities, the FCC has been
undertaking various groundbreaking steps to encourage the use of new,
more spectrum-efficient technologies. As the GAO draft report
recognizes, in 2002 FCC Chairman Powell established a Spectrum Policy
Task Force ("SPTF") staffed by senior agency personnel to identify
outmoded procedures and policies, and evaluate changes in spectrum
policy, that could increase the public benefits derived from the use of
the radio spectrum. The SPTF's work resulted in a report published in
November of that year setting out many new recommendations for spectrum
policy reform.
GAO's draft report specifically notes the SPTF's recommendation that
the Commission should adopt, where feasible, a more quantitative
approach to interference management based on the concept of the
"interference temperature." Under this approach, a "cognitive" or
"smart" radio would sense the use of a given frequency band in a
particular location. The radio then would utilize the band only to the
extent possible without exceeding the "interference temperature" limit
prescribed for that band. In that way, a radio could use spectrum that
would otherwise have to lie fallow before the advent of such
technologies. The SPTF Report recognized that the FCC required better
information about actual use of different bands before it could set
"interference temperature" limits for specific bands and, as a result,
recommended that the Commission
undertake a systematic study of the radiofrequency ("RF") noise floor.
Since the issuance of that SPTF Report, the Commission has adopted a
Notice of Proposed Rulemaking that seeks further comment on the
"interference temperature" concept, on how best to obtain more
systematic data on the RF noise floor, and on two proposals for rule
changes that would facilitate deployment of such technologies in two
satellite bands.
As the draft report recognizes, we also have worked closely with the
NTIA in the FCC's consideration and reform of its rules to allow the
use of ultra-wideband ("UWB") unlicensed devices. UWB devices are able
to use sophisticated processing capabilities to provide communications
at very low power across wide swaths of spectrum without causing
interference to current spectrum licensees - federal and non-federal -
that are authorized to use those spectrum bands at much higher power
levels. UWB technology is another example of new cutting-edge
technologies that allow use of spectrum for communications.
I wanted to note as well that the FCC has been aggressively adopting
and considering other changes to its rules to facilitate the use of the
latest technologies to encourage more efficient spectrum use. The use
of "software-defined radios" and "cognitive radios," for instance, is
not limited to situations in which the "interference temperature"
metric can be employed. As one example, the FCC late last year adopted
rules that allow the more efficient use of spectrum in the 5 GHz band
by unlicensed devices with cognitive features. These devices do not
have to comply with an "interference temperature" limit, but only have
to avoid using a frequency in real time whenever a licensee is using
that frequency. Similarly, the FCC is seeking comment on other
proposals that do not require setting specific "interference
temperature" limits, but would allow radios with certain cognitive
features to use currently unutilized or underutilized spectrum: (1) in
rural areas, (2) in the 3650-3700 MHz band, and (3) in the "white
spaces" in the TV bands. As yet another example, the FCC has sought
comment on possible reforms of its rules that would facilitate the use
of "smart radio" features by licensees to enable more opportunities for
part-time leasing of spectrum. The goal of all these proposals is to
facilitate the use of more spectrum-efficient technologies while we are
continuing to pursue the "interference temperature" construct. Finally,
we are working with our Technological Advisory Committee and in other
forums to explore other approaches for assessing and increasing the
deployment of spectrum-efficient technologies.
As the draft reports rightly notes, these and other new technologies
potentially enable new approaches for the sharing of spectrum between
federal and non-federal users. For instance, new technologies now allow
the use of "millimeter wave" spectrum at 70/80/90 GHz. In close
consultation with NTIA, the FCC has adopted an innovative regulatory
approach providing for the registration of individual links in federal
and non-federal databases. This approach should permit a speedier and
more efficient sharing of spectrum by both federal and non-federal
users than would otherwise be possible.
There undoubtedly is other spectrum not being used today, or being
underutilized, that could be more efficiently used if new spectrum-
efficient technologies were deployed
and if more flexible approaches to spectrum allocations were used. I
would note, however, that the Communications Act of 1934, as amended,
specifically provides that the FCC licenses non-federal radio stations.
In contrast, radio stations owned or operated by the Federal Government
obtain their frequency designations from the President, or his
designate. Therefore, in response to your first recommendation for
joint NTIA-FCC collaboration, the FCC will be happy to work with NTIA
within those statutory limits to explore approaches for facilitating
the use of new technologies to permit non-federal users to use spectrum
formally allocated to federal users, as well as federal users to use
spectrum formally allocated to non-federal use. And we will continue our
recent policy of generally adopting flexible allocations for non-
federal spectrum to help facilitate the use of spectrum-efficient
technologies.
We also are supportive of your second recommendation for joint FCC-NTIA
activity-developing and implementing plans to gain a more thorough
understanding of the current spectrum environment. A greater
understanding of spectrum use holds the potential of allowing even more
efficient use of spectrum than is possible with greater use of new
spectrum-efficient technologies alone.
Finally, we will continue ongoing efforts with the NTIA to develop
jointly accepted models and methodologies to assess and test the impact
of new technologies. Successful development of such models and
methodologies can only expedite the consideration and approval of new
spectrum-efficient technologies.
I commend you and your staff for your hard work in helping to develop
ideas for improving U.S. spectrum management policies in a manner that
ensures that the radio resource will be effectively and efficiently
employed for the benefit of the American people. We support any effort
to continue to improve our policies in this area, and will work with
our colleagues at NTIA to assess how best to incorporate the report's
findings and recommendations in our future work.
Sincerely,
Edmond J. Thomas,
Chief:
Office of Engineering and Technology:
[End of section]
Appendix III: Comments from the Department of Homeland Security:
U.S. Department of Homeland Security
Washington, DC 20528:
Homeland Security:
May 18, 2004:
Ms. Katherine V. Schinasi
Managing Director, Acquisition and Sourcing Management
U.S. General Accounting Office
Washington, DC 20548:
Re: SPECTRUM MANAGEMENT - Better Knowledge Needed to Take Advantage of
Technologies That May Improve Spectrum Efficiency," GAO-04-666, May
2004; GAO Case 120254:
Dear Ms. Schinasi:
The Department of Homeland Security (DHS) appreciates the opportunity
to review and comment on the General Accounting Office (GAO) draft
report to the Honorable Tom Davis and the Honorable Adam H. Putnam,
Committee on Government Reform, House of Representatives, entitled
"SPECTRUM MANAGEMENT - Better Knowledge Needed to Take Advantage of
Technologies That May Improve Spectrum Efficiency," GAO-04-666, May
2004.
The draft report does not include any specific recommendations
regarding DHS. However, we submit the following comments for your
consideration:
The Department applauds the ongoing and continuing research into
advanced technologies that will expand the better utilization of scarce
spectrum allocations and recommends an active role by both the National
Telecommunications and Information Agency (NTIA) and the Federal
Communications Commission (FCC) in encouraging migration to spectrum
efficient technologies, particularly research being conducted by the
Department of Defense. We furthermore consider such actions as positive
in respect to the goals of the President's Spectrum Policy Initiative.
We recommend that the NTIA and FCC proceed with caution and closely
monitor the development of the Software-Defined Cognitive Radio (SDCR)
and the determination of spectrum utilizations by licensees within the
spectrum. Furthermore, we recommend that the FCC conduct an in-depth
study into the interference temperature concept that is considered
controversial and will be used as a potential baseline in the
establishment of a noise floor. Protection must be in place for
incumbent users. The terms "white spaces" and "gray spaces" as they
pertain to SDCR technologies must be well defined. We also recommend
that all spectrum assigned to public safety first responders be
restricted and protected from SDCR devices by use of spectrum lockout
capabilities or other suitable solution.
* In regard to the current structure and management of spectrum used
within the United States, we recommend that both the NTIA and FCC
identify spectrum that can be set aside and protected for future
technology testing and evaluation.
* With the ongoing interference temperature initiative within the FCC,
we recommend that the enforcement avenues within the FCC be expanded to
allow for the identification of sources of interference and the
enforcement aspect of protecting incumbent licensees or users.
* The use of incentives to encourage agencies to develop and use
spectrum more efficiently does not apply at the federal government
level. The use of incentives may have some functionality in other
environments, but does not apply to the government. A more appropriate
means for governmental spectrum efficiency is a mandated migration
process similar to the ongoing wide-band to narrow-band transition in
the VHF and UHF federal bands.
* We recommend that the FCC and the NTIA work more closely and
proactively in all issues surrounding spectrum management.
Thank you again for the opportunity to comment on this draft report. If
you have questions or need clarification regarding our comments, please
contact Mr. Thomas Krones, (202) 401-5861, or e-mail:
Thomas.krones@dhs.gov.
Sincerely,
Signed by:
Anna F. Dixon:
Director, Bankcard Programs and GAO/OIG Liaison:
[End of section]
FOOTNOTES
[1] FCC has authority over all nonfederal spectrum use, including the
use of spectrum by state and local governments.
[2] Radio waves are a form of electromagnetic energy, propagating
through space at the speed of light. The number of waves that pass a
given point per second defines the frequency of a radio wave in cycles
per second, or hertz. Kilohertz (kHz), megahertz (MHz), and gigahertz
(GHz) describe frequencies of thousands, millions, and billions of
hertz, respectively. The radio spectrum above 100 MHz and below 3 GHz
has propagation characteristics that are well suited for services such
as mobile phones, radio and television broadcasting, some satellite
communication systems, radars, and aeronautical telemetry systems.
[3] Nearly 30 years ago, GAO reported that technology was creating
demands for spectrum faster than it was creating methods to meet those
demands. See U.S. General Accounting Office, Information on Management
and Use of the Radio Frequency Spectrum--A Little-Understood Resource,
B-159895 (Washington, D.C.: Sept. 13, 1974).
[4] Interference occurs when two or more radio signals interact in a
manner that disrupts or degrades the ability of these signals to convey
information successfully to their intended receivers. However, the
extent and impact of interference depends on the technologies used both
to transmit and receive radio signals, and the types of services and
applications supported.
[5] Each country makes its own allocations of spectrum use; therefore,
allocation decisions may differ in other regions of the world and in
other countries. However, because radio wave propagation obeys the laws
of physics and cannot be forced to respect national borders, spectrum
management decisions (particularly allocation decisions) generally
have been coordinated internationally. The International
Telecommunication Union (ITU), a specialized agency of the United
Nations, holds World Radiocommunication Conferences every 3 to 4 years
to coordinate spectrum decisions and address other pressing
international spectrum management issues.
[6] 47 USC § 309(j).
[7] For more information on how spectrum is managed, see U.S. General
Accounting Office, Telecommunications: Better Coordination and
Enhanced Accountability Needed to Improve Spectrum Management,
GAO-02-906 (Washington, D.C.: Sept. 30, 2002).
[8] Federal Communications Commission, Spectrum Policy Task Force
Report; ET Docket No. 02-135 (Washington, D.C.: Nov. 2002).
[9] U.S. General Accounting Office, Telecommunications: Comprehensive
Review of U.S. Spectrum Management with Broad Stakeholder Involvement
Is Needed, GAO-03-277 (Washington, D.C.: Jan. 31, 2003).
[10] The initiative consists of two courses of spectrum-related
activity: (1) an interagency task force to focus on improving spectrum
management policies and procedures to stimulate more efficient and
beneficial use of government spectrum and (2) a series of public
meetings that will assist the Department of Commerce in developing a
detailed set of recommendations for improving policies and procedures
for use of spectrum by state and local governments and the private
sector, as well as the spectrum management process as a whole.
[11] In addition, the NSF is currently sponsoring a study at the
National Academy of Sciences on wireless technology advances and
associated implications for spectrum management policy.
[12] Amounts included for NSF are based on funds provided grantees in
2003.
[13] We did not verify the reliability of the funding information,
however, it comes from published agency budget documents and program
officials.
[14] FCS is an information network linking a suite of 18 new manned and
unmanned ground vehicles, air vehicles, sensors, and munitions.
[15] The Defense Spectrum Office has the responsibility within DOD for
supporting the Assistant Secretary of Defense for Networks and
Information Integration in establishing national and international
strategies for new technologies that may affect how spectrum is used,
occupied, or managed by the department.
[16] Greater freedom could also be achieved through "band clearing"--
moving incumbent users to other parts of the spectrum. Because this
reallocation could take significant time and funding to accomplish,
band clearing is difficult to implement.
[17] In a shared spectrum allocation, "primary" users have priority
over the use of a frequency and "secondary" users must defer to the
primary user. Users may also be designated as "co-primary," in which
the first operator to obtain authority to use the spectrum has priority
to use the frequency over another primary operator.
[18] A waveform is the representation of a signal that includes the
frequency, modulation type, message format, and/or transmission system.
In general usage, the term waveform refers to a known set of
characteristics, for example, frequency bands (VHF, HF, UHF),
modulation techniques (FM, AM), message standards, and transmission
systems. In JTRS, the term waveform is used to describe the entire set
of radio functions that occur from the user input to the radio-
frequency output and vice versa. A JTRS waveform is implemented as a
re-useable, portable, executable software application that is
independent of the JTRS operating system, middleware, and hardware.
[19] FCC Spectrum Policy Task Force Report; ET Docket No. 02-135
(Washington, D.C.: Nov. 2002).
[20] DOD's DARPA has a major effort under way (the Next Generation
Communications Program) to develop enabling technologies and system
concepts to dynamically use the spectrum through real-time sensing of
the spectrum environment and adjustment of radio operations to take
advantage of white and gray space opportunities. Its goal is to
increase spectrum access by a factor of 10.
[21] FCC Notice of Proposed Rulemaking and Order In the Matter of
Facilitating Opportunities for Flexible, Efficient, and Reliable
Spectrum Use Employing Cognitive Radio Technologies; FCC 03-322 (Dec.
30, 2003); FCC Notice of Inquiry and Notice of Proposed Rulemaking in
the Matter of Establishment of an Interference Temperature Metric to
Quantify and Manage Interference and to Expand Available Unlicensed
Operation in Certain Fixed, Mobile and Satellite Frequency Bands; FCC
03-289 (Nov. 28, 2003).
[22] "Temperature" refers to a measure of the undesired radio-frequency
power in a particular band and location. FCC's Spectrum Policy Task
Force developed the concept of an interference temperature to
characterize and quantify undesired (interfering) transmitters'
contributions to radio-frequency energy at a receiver's location.
[23] Under the proposed approach, an interference temperature metric
would establish maximum permissible levels of interference, thus
characterizing the "worst case" environment in which a receiver would
be expected to operate. Different threshold levels would then be set
for each band, geographic region or service based on an understanding
of the radio frequency environment.
[24] FCC and FAA also have spectrum-monitoring capabilities.
[25] In fiscal year 2002, NTIA received $2.1 million to replace the
van. The replacement van was used for the first time in the summer of
2003.
[26] The term "broadband" used in this context refers to a survey of
multiple radio frequency bands. The use of the term here does not refer
to technologies that encompass all evolving high-speed digital
technologies that provide consumers integrated access to voice, high-
speed data, video-on-demand, and interactive delivery services.
[27] UWB devices employ very narrow or short duration pulses to create
wideband transmissions.
[28] NTIA has also established similar rules governing federal use of
low-power UWB devices.
[29] The lack of technologies capable of providing users with real-time
knowledge of spectrum environments has required an approach to spectrum
management based on worst-case assumptions to minimize interference.
[30] A few NTIA policies and technical standards do specifically
require federal agencies to improve efficiency in a few portions of the
spectrum. For example, in 1992, the Congress directed NTIA to adopt and
implement a plan for federal agencies with existing mobile radio
systems to use more spectrum efficient technologies. In response, NTIA
required all federal agencies to upgrade their land-based mobile
systems through narrowbanding, a process for reducing the amount of
spectrum needed to transmit a voice signal, by 2008. NTIA also
established a trunking program for land mobile systems in certain areas
of the country. The trunking technique allows systems to share a common
set of voice radio channels to conserve spectrum. For more information
on NTIA's efforts to promote efficiency through its narrowbanding and
trunking policies for land mobile radios, see GAO-02-906.
[31] U.S. General Accounting Office, Spectrum Management in Defense
Acquisitions, GAO-03-617R (Washington, D.C.: Apr. 30, 2003).
[32] In our April 30, 2003, report, we made several recommendations
aimed at addressing these weaknesses.
[33] Center for Strategic and International Studies, Spectrum
Management for the 21st Century: A Report of the CSIS Commission on
Spectrum Management, (Washington, D.C.: Oct. 2003).
[34] GA0-03-277.
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