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Spectrum Is Critical to Aviation and Weapon Systems Superiority By Darrell E. Ernst The fierce competition for electromagnetic radio frequency spectrum affects the transformation of all kinds of communications, from commercial cell phones to military actions.
To accommodate the telecommunications industry, the government auctioned off some of the spectrum that was formerly used by the Department of Defense (DOD) for weapon support systems and high technology research and development. However, the same developments in information technology that are driving the consumer telecommunications market are also driving growth in the technical capabilities of aviation systems, military weapon systems, and weapons research and development (as well as many other critical communications systems). Just when the DOD—and other government agencies, such as the Federal Aviation Administration (FAA)—need additional spectrum to capitalize on these increased capabilities, they find themselves having to make do with less. Spectrum is vital for aeronautical testing—of both military and commercial aircraft. To safely test new designs, the aircraft industry employs telemetry. Aeronautical telemetry is the use of radio transmissions to remotely measure and analyze the systems and safety of aircraft. Monitoring such a wealth of data requires a healthy chunk of spectrum. A lack of adequate available spectrum will seriously curtail the use of telemetry, leading to increased costs, higher risks, test delays or cancellations, longer acquisition cycles and time-to-market impacts, and fewer test points, leading to reduction in test quality. Today, MITRE's Center for Advanced Aviation System Development is actively assisting the FAA in addressing its spectrum challenges. For example, we're providing the sponsor with technical solutions that would allow it to deploy a wireless airport network without interfering with commercial satellites and other users of the band within which the system would operate. For the DOD, MITRE is working on many different spectrum-related efforts, including the Joint Tactical Radio System program, the Air Force's Airborne Network concept, and the Army's Future Combat System. We are also providing technical policy support to the Office of the Secretary of Defense, the Defense Information Systems Agency's Defense Spectrum Office, and the Defense Test Resource Management Center. Spectrum decisions made today will determine how telemetry testing will be conducted in the future. Our economic impact studies on the DOD's need for more spectrum frequencies show that the amount of spectrum now allocated for telemetry is not sufficient to meet the growing requirements. The aeronautical weapons development community will run out of spectrum needed for development and testing of aeronautical vehicles in the near future. In seeking a solution to its sponsors' spectrum problems, MITRE has proposed a three-pronged strategy: (1) protect the sponsors' remaining spectrum against further encroachment, (2) develop new technologies for improving the efficiency of telemetry, (3) pursue initiatives to meet long-term growth in telemetry needs. MITRE established a watch program to support the first prong of the strategy. We will identify, analyze, and report to the sponsor potential threats to its bands of interest along with a recommended set of actions. We are supporting the second prong of the strategy by helping sponsors operate science and technology programs and by conducting assessments of candidate technologies. To address the third prong, we are projecting spectrum growth requirements, building an economic model showing the realistic consequences of inadequate spectrum access, and addressing the technical challenges of using spectrum frequencies above 3 GHz. For example, our analysis to date shows that serious consequences would probably occur if the DOD requirement for an additional 650 MHz of telemetry spectrum is not met. Currently, telemetry is conducted in specific frequency bands below 3 GHz. Spectrum below 3 GHz, however, is in great demand and fully allocated for various uses, so any additional bandwidth will need to be found at higher frequencies. MITRE has played a key role in the identification of technological requirements and limitations at frequencies above 3 GHz and in the assessment of technologies that could be used to facilitate the use of these bands. Many problems are encountered at higher frequencies. For example, increased atmospheric absorption reduces the effective range of telemetry links. It is more difficult to design practical small form-factor telemetry transmitters at higher frequencies because high-power transistors are not available above 15-16 GHz. Also, antenna beam widths narrow as frequency increases, which complicates acquisition and tracking of the vehicle under test. And fading effects become more complicated as frequencies increases. In our research, we have described the technological developments that are needed to overcome these potential problems and the limitations of both current technology and anticipated technology developments. This information will help sponsors scope out the portion of spectrum that should be sought for near-term use and help them establish science and technology programs to develop needed technologies. Our nation—and, indeed, the globe—faces the challenge of properly husbanding a limited resource so that all may profit from it. We are contributing our technical knowledge both to help the government wisely use the spectrum available and to discover creative methods of opening up more of the spectrum to use. MITRE's comprehensive spectrum stewardship strategy has led to a proposal before the International Telecommunications Union for a worldwide allocation of telemetry spectrum and a substantial research program to identify and develop needed technologies. It also proposes the establishment of a program to develop a net-centric test data communications system that will be capable of meeting the demand for ever-increasing quantities of data. If the entire strategy is adopted and successful, the United States' testing of new weapons systems will be able to keep up with the increasing capabilities of these systems. And the testing of new commercial aircraft will be able to keep up with demand. |
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| For more information, please contact Darrell Ernst using the employee directory. Page last updated: December 13, 2005 | Top of page |
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he
competition didn't begin until the late 1980s, when the telecommunications
industry introduced far-reaching strategic plans to make wireless data
communications an inexpensive consumer commodity. For its plans to come
to fruition, however, the industry needed more of the spectrum than it
was licensed to use. Since the spectrum is a finite public commodity,
the government has the responsibility to apportion its use to suit the
best interests of the public. The telecommunications industry successfully
convinced the government that the services it wanted to provide were important
enough to garner it a greater portion of the spectrum. 
MITRE
has a long history of working on spectrum issues for the DOD, FAA, and
other government agencies. We've advised the government and various multiagency
committees on ways to balance use of the spectrum and use it as efficiently
as possible. For example, we've been a leader within the International
Consortium for Telemetry Spectrum, a voluntary organization set up to
facilitate information exchange among interested parties, and have presented
our studies at numerous national and international forums to gain support
for worldwide telemetry spectrum augmentation.
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