UWB is one of the most exciting technologies in the wireless world today, but it's
been fraught with controversy since its inception. On this page, we have a complete history
and current information on FCC rules concerning UWB, from 1998 to the present. Scroll down
the page, or jump to one of the topics listed below.
This table lists the complete contents of all three of our UWB pages. For information on
Ground Penetrating Radar, one of the interesting applications of UWB technology, see our
March 2003: FCC Issues UWB Memorandum Opinion and Order
On March 13, 2003, the FCC issued a Memorandum Opinion and Order and Further Notice
of Proposed Rulemaking on Ultra-wideband. This is an 89 page document accompanied by
separate statements from Chairman Powell and Commissioner Copps. Comments are being
accepted for 90 days, followed by an additional period for reply comments.
This Memorandum Opinion and Order (MO&O) amends Part 15 in response to 14 petitions filed after the
original Report and Order on UWB (February 2002, see below). While not making major changes
in the technical operating parameters for UWB devices, it does relax restrictions on operations
of through wall imaging systems and ground penetrating radar.
New rules are proposed to address issues raised regarding the operation of low pulse
repetition frequency UWB systems, including vehicular radars, in the 3.1-10.6 GHz band;
the operation of frequency hopping vehicular radars in the 22-29 GHz band as UWB devices;
the establishment of new peak power limits for wideband Part 15 devices that do not
operate as UWB devices; and the definition of a UWB device.
The FCC states its expectations that during the next 12-18 months, UWB devices will be
introduced and additional tests using such commercially available UWB devices will be
completed. At that time, FCC intends to continue reviewing the UWB standards to
determine whether further changes to the regulations are warranted.
On February 13, 2003, the FCC's Office of Engineering and Technology (OET) hosted a technology
demonstration of Ultra-wideband
devices at the FCC Commission Meeting Room, 445 12th Street, S.W., Washington, D. C. FCC senior
staff was available at the beginning of the event to address regulatory actions taken
by the Commission in this area. Six different companies presented UWB systems demonstrations.
See the full text of the press release (.doc file, 50K).
October 2002 NASA Report on UWB Aviation Interference
--by Jim Pearce, President, Pegasus Technologies, Inc.
A new report on a study of possible UWB interference to aircraft radio systems has just been released
by NASA. It is available for download from
NASA or from SSS Online's PDF archives.
The file is in PDF format and is 448K.
This report shows high interference potential to various radio systems such as the ILS and TCAS, but it seems
to me to have been written with a particular agenda in mind. My personal view after reading this report is
that the measurement technique is suspect, particularly with regard to the field strength of the UWB signal
that was interfering with the radios.
The test methodology consisted of connecting a UWB test signal generator to an antenna tuned to the frequency
of the particular radio service that was being investigated. For example, while looking for ILS interference
they connected the UWB signal generator to an antenna tuned to 108MHz. Of course, actual UWB products would
have antennas tuned to several GHz.
No accredited laboratory measurements were made of the actual emitted field strength of the UWB transmitter
in this configuration, so the EIRP that was used is not known.
The fact that one can coax interference out of an experimental UWB setup is not surprising to me. I
think it would be much more relevant, however, to configure the UWB transmitter with an antenna that is
more likely to be used in an actual UWB device, and to subject the setup to accredited lab emissions tests --
and then see if there is any detrimental interference.
"Ultra Wideband Interference Effects on an Amateur Radio Receiver,", by R.D. Wilson et al of
University of Southern California's UltRa Lab, is available for download from
NASA or from SSS Online's PDF archives. The file is in PDF format and
This paper illustrates the complexity of issues surrounding the accurate measurement
and interpretation of UWB interference effects in narrowband receivers.
On February 14, 2002, the FCC commissioners unanimously approved
limited uses of UWB, giving a real valentine to the wireless community. FCC has
promised to review the standards in the next 6-12 months
to explore the potential of more flexible standards and to address the operation of
additional types of UWB operations and technology. For now, UWB communications
devices will be restricted to intentional operation only between 3.1 and 10.6 GHz;
through-wall imaging and surveillance systems restricted between 1.99 and 10.6 GHz
(and used only for law enforcement, fire and rescue, and other designated organizations)
and automotive radars restricted to frequencies above 24.075 GHz. Initial communications
applications are further restricted to tethered operations indoor, or to lower
out-of-band emissions, outdoor hand-held use.
This technology has followed pretty much the same path as spread spectrum --
originally developed in secret for the military and classified for many years,
it has only come out of the closet in the last few years. There are many exciting
potential uses for this technology -- including finding people buried under rubble of
collapsed buildings, detecting cracks in critical structures, and for vehicle avoidance
systems -- but there is also much controversy over the best way to implement it.
The mud has really been flying over UWB since the FCC released its Notice of Proposed
Rule Making (NPRM) on May 10, 2000. This proposed a modification of the Part 15 Rules to allow
license-free use of UWB transmitters. A storm of controversy erupted over these proposed rules,
with more than 400 comments received and many months of behind the scenes negotiations among
The key issue in the controversy is the interference
potential of unfettered UWB use with traditional weak signal radio services, such as GPS.
This is because UWB, unlike other technologies which use narrow assigned frequencies to avoid
interference, uses a broad swath of the radio spectrum but in thousands or millions of
pulses of low-powered emissions per second. Some UWB proponents, most notably Time Domain
Corporation and Xtreme Spectrum, argued that very brief UWB pulses will not cause significant
interference. Others, such as Multispectral Solutions, Inc., held that some forms of UWB will
cause interference and believe that UWB emissions should not be allowed in any critical weak
signal frequency, mainly those below 3 GHz. Still others, including the US Department of Defense,
the airline industry, and companies such as Sprint that are heavily involved in other wireless
technologies, felt that UWB should not be allowed at all below 4.2 GHz, 6 GHz or even higher.
FCC's Complete Docket File on the Proposed Rulemaking
In the dialog box, enter
"98-153" in box 1, "Proceeding" and press the "Retrieve Document List"
button at the bottom of the screen. This will bring up a list of more than 500 documents, from the
first FCC Notice of Inquiry to the most recently received comments. You can scroll
through the list and view full text files from the FCC and a wide range of commenters including
individuals, labor unions, other government agencies, and numerous corporations --
The Department of Commerce's National Telecommunications and Information Administration (NTIA)
has issued a series of reports on UWB that address these issues. These reports have also been
filed with the FCC for inclusion in the public record in their
ongoing UWB proceeding, and have led to another series of comments from the public.
The reports are available in a variety of formats at the links below:
Fallout from FCC's Decision to Delay UWB Consideration,
December 2001-March 2002
The delay raised further protest from proponents of the
proposed rules, including several companies set to introduce new chip sets and other products
using the UWB technology. See links and articles below for some of the more interesting ones!
FCC set to expand
wireless frontier. This article from the January 2, 2002 issue of USAToday.com,
quotes a TimeDomain representative as implying that the delay is really a fear of competition
rather than interference.
On December 19, 2001, representatives of Intel, IBM, Texas Instruments, Sharp Labs and Siemens
wrote a .joint letter to the FCC Chairman Michael Powell protesting
FCC's removal of UWB from its December agenda. They write: "We are concerned that a short
delay could be extended, which in turn would be a substantial setback to the timely development
and deployment of UWB services. This could have a negative impact on current industry momentum
focused on building UWB technology and products. This proceeding is more than three years old
with almost 800 comments, notices, and technical studies on the docket. UWB proponents have
filed detailed technical analyses showing that operation of their devices will not cause harmful
interference to other users of the spectrum, both government and non-government. These analyses
also explain why studies that purport to show harmful interference gave incorrect results. It
is time to issue a decision."
FCC reschedules UWB Consideration for sixty days, December 2001
The FCC intended to consider a First Report and Order on UWB in its meeting
on December 12, 2001. However, in response to a November 20 letter from Deputy
Secretary of Defense Paul Wolfowitz, the discussion was postponed until the FCC's meeting
of February 14, 2002.
Another letter addressing this same subject
was dated November 19, from Badri A. Younes, Director of Spectrum Management for the Office of the Assistant Secretary
of Defense for Command, Control, Communications and Intelligence OASD(C3I) to William T. Hatch, Associate
Administrator, Office of Spectrum Management, NTIA. This letter stated that DOD wants
to prohibit intentional UWB emissions below 3.1 GHz, and preferably, below 4.2 GHz. OASD believes that
Ground Penetrating Radar (GPR) and imaging sensors should be excluded from this prohibition, but should be
licensed to conform to more restrictive emission limitations.