Notice of Test Plan for Determining Potential for Interference from Ultra-Wideband Devices (UWB) to Global Positioning System (GPS) Receivers; Review and Comment

AGENCY:

Office of the Secretary, Department of Transportation.

ACTION:

Notice.

SUMMARY:

Since the potential for interference from certain ultra-wideband (UWB) parameters has been determined through preliminary analyses and tests, the Department of Transportation has sponsored a more rigorous test to evaluate the potential for interference to Global Positioning System (GPS) receivers from UWB devices. The Department invites comments on this test plan.

DATES:

Comments should be submitted in written form July 24, 2000.

ADDRESS:

Send comments to: Department of Transportation, Office of the Secretary Radionavigation & Positioning Staff, P-7, Room 10315, 400 Seventh Street, SW., Washington, DC 20590 Attn: GPS-UWB Comments.

FOR FURTHER INFORMATION CONTACT:

Sally L. Frodge, (202) 366-4894.

SUPPLEMENTARY INFORMATION:

The Federal Communications Commission (FCC) is considering placing UWB devices under Part 15 of the FCC Regulations under Title 47 of the Code of Federal Regulations and modifying these rules accordingly. The FCC released on May 11, 2000, a Notice of Proposed Rule-Making (NPRM), “In the Matter of Revision of Part 15 of the Commission's Rules Regarding Ultra-Wideband Transmission Systems”. The FCC has proposed “* * * permitting the operation of ultra-wideband (UWB) technology on an unlicensed basis” citing “* * * enormous benefits for public safety, consumers and businesses” (http://www.fcc.gov/Bureaus/Engineering_Technology/News_Releases/2000/nret0006.html). The FCC has stated that test results are encouraged and can be submitted through October 30, 2000.

The term “ultra-wideband” by definition refers to any radiated waveform whose fractional bandwidth is greater than 25%. There are many technologies that fit this broad definition; of particular interest is a group of technologies known as “impulsive systems”. Such systems utilize short radio frequency (RF) pulses with pulse durations on the order of nanoseconds that result in bandwidths that can be on the order of several Gigahertz. Some current UWB impulsive system designs and devices have fractional bandwidths that can exceed 100%. Such systems could intentionally radiate energy into restricted bands (defined in Part 15) that include aeronautical safety-related systems, including GPS and other sensitive systems.

This test plan describes an initial phase of testing that selects the metric of accuracy performance and GPS signal reacquisition time. Aviation receivers meeting published specifications will be used in the accuracy measurement phase; a land receiver will be used for the reacquisition testing. A GPS simulator provides the GPS input and the UWB parameters are provided by a prototype UWB waveform generator where the various UWB waveform parameters can be varied independently in a controlled manner. These metrics were considered appropriate for the first phase of testing.

Obtaining a copy for comment. The Department will consider written comments for incorporation into the test plan. To obtain a copy of this test plan, contact Ms. Veronica Pannell at (202) 366-0353 or write to: Department of Transportation, Office of the Secretary Radionavigation & Positioning Staff, P-7, Room 10315, 400 Seventh Street SW, Washington, DC 20590.