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By the Commission: Federal Communications Commission FCC 00-163


Before the
Federal Communications Commission
Washington, D.C. 20554

In the Matter of )
)
Revision of Part 15 of the Commissions Rules )
Regarding Ultra-Wideband Transmission ) ET Docket 98-153
Systems )


NOTICE OF PROPOSED RULE MAKING

Adopted: May 10, 2000 Released: May 11, 2000


Comment date:
[insert date 90 days from publication in Federal Register]
Reply comment date:
[insert date 120 days from publication in Federal Register]

By the Commission:

SUMMARY

1.
By this Notice of Proposed Rule Making ("Notice"), we propose to amend Part 15 of the
Commissions rules to pave the way for new types of products incorporating ultra-wideband ("UWB")
technology. UWB devices may have the capability to provide for significant benefits for public safety,
businesses and consumers. While comprehensive tests have not been completed, UWB devices appear to be
able to operate on spectrum already occupied by existing radio services without causing interference, which
would permit scarce spectrum resources to be used more efficiently. We are moving forward with this
Notice to begin the process of identifying potential rule changes and alternatives necessary for the
deployment of UWB technology. The proposals in this Notice are designed to ensure that existing and
planned radio services, particularly safety services, are adequately protected. UWB technology is relatively
new. Further testing and analysis is needed before the risks of interference are completely understood.
Such testing is already being planned by a number of organizations. We will provide ample opportunity to
complete these tests and ensure that analyses of the test results are submitted in the record for public
comment before adopting any final rules in this proceeding. We invite broad comment on this Notice so
that the Commission may ultimately provide for the introduction of this new and exciting technology.


BACKGROUND

2.
The Commission, on its own motion, issued a Notice of Inquiry (NOI) in this proceeding to
investigate the possibility of permitting the operation of UWB devices on an unlicensed basis under Part
15 of the FCC rules.
1
Part 15 of the Commission's regulations permits the operation of RF devices
without a license from the Commission or the need for frequency coordination.
2
The technical standards
contained in Part 15 are designed to ensure that there is a low probability that these devices will cause


1
See Notice of Inquiry in ET Docket No. 98-153, 63 Fed. Reg. 50184, September 21, 1998,
http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/fedreg/63/50184.pdf
.

2
See 47 C.F.R. §§ 15.1 et seq.
Federal Communications Commission
FCC 00-163





2
harmful interference to other users of the radio spectrum.
3
Intentional radiators, i.e., transmitters, are
permitted to operate under a set of general emission limits
4
or under provisions that allow higher
emission levels in certain frequency bands.
5
Intentional radiators generally are not permitted to operate
in certain sensitive
6
or safety-related frequency bands, designated as restricted bands,
7
or in the frequency
bands allocated for television (TV) broadcasting.

3.
The NOI observed that recent advances have enabled the development of UWB technology for
a variety of applications. UWB devices can be used for precise measurement of distances or locations and
for obtaining the images of objects buried under ground or behind surfaces. UWB devices can also be used
for wireless communications, particularly for short-range high-speed data transmissions suitable for
broadband access to the Internet. UWB radio systems typically employ pulse modulation whereby
extremely narrow pulses are modulated and emitted to convey or receive information. The emission
bandwidths generally exceed one gigahertz.
8
In some cases, impulse transmitters are employed where the
pulses do not modulate a carrier. Instead, the radio frequency emissions generated by the pulses are applied
to an antenna, the resonant frequency of which determines the center frequency
9
of the radiated emission.
The bandwidth characteristics of the antenna will act as a low-pass filter, further affecting the shape of the
radiated signal.



3
The primary operating conditions under Part 15 are that the operator must accept whatever interference is
received and must correct whatever interference is caused. Should harmful interference occur, the operator is
required to immediately correct the interference problem, even if correction of the problem requires ceasing
operation of the Part 15 system causing the interference. See 47 C.F.R. § 15.5.

4
See 47 C.F.R. § 15.209.

5
See 47 C.F.R. §§ 15.215-15.407. In some cases, operation at the higher emission levels within these
designated frequency bands is limited to specific applications.

6
The sensitive bands referenced here are bands employed by radio services that must function, as a nature of
their operation, using extremely low received signal levels. These systems may be passive, such as radio astronomy,
or active, such as satellite down links and wildlife tracking systems.

7
See 47 C.F.R. § 15.205.

8
Typical pulse widths currently are on the order of 2-0.1 nanoseconds, or less, in width. The emission
spectrum appears as a fundamental lobe with adjacent side lobes that can decrease slowly in amplitude. Annex J of
Chapter 5 of the National Telecommunications and Information Administrations Manual of Regulations and
Procedures for Federal Frequency Management contains a procedure to

calculate the 20 dB bandwidth of a non-FM
pulsed radar using the equation B = 1.79/ ( r ) or 6.36/ , whichever is less, where B is the bandwidth in megahertz, is the emitted pulse duration, in microseconds, at the 50% amplitude (voltage) points and r
is the emitted pulse rise
time in microseconds from the 10% to the 90% amplitude points on the leading edge. As an example, for a pulse
with = 1.0 nS, ignoring rise time, the 20 dB bandwidth of the emission is calculated to be 6.36 gigahertz. The
spectrum produced by a pulsed emission consists of a line spectrum with the spectral lines separated by 1/T where T
is the time, in seconds, of the pulse spacing.
9
A definition of center frequency is proposed in paragraph 21 of this Notice.
Federal Communications Commission
FCC 00-163





3
4.
The NOI observed that the current Part 15 rules pose two primary obstacles to the
implementation of UWB technology. First, the wide bandwidth that is intrinsic to the operation of UWB
devices can result in transmission of the fundamental emission
10
into restricted frequency bands or into the
television (TV) broadcast frequency bands, which is prohibited under the Part 15 rules. Second, the
current emission measurement procedures specified in our Part 15 rules were developed for narrowband
systems and may be inappropriate for, and pose unnecessary restrictions to, UWB technology, particularly
impulse systems. For example, Part 15 measurement procedures require the application of a pulse
desensitization correction factor.
11
The application of this correction factor can cause UWB systems to
exceed the peak emission limits currently specified under the Part 15 rules.
12


5.
The NOI requested comment on the potential applications for UWB devices and their
technical characteristics, such as frequency ranges of operation, bandwidths, power levels, and operating
distances. In addition, the NOI requested comments concerning what regulatory treatment would be most
appropriate for UWB devices, including whether they should be regulated under Part 15 or some other
rule part. The NOI asked how the Commission should define UWB devices. Further, the NOI sought
comments on whether UWB devices should be prohibited from operating in the restricted frequency
bands and TV broadcast frequency bands or if there are certain restricted frequency bands where the
Commission should permit UWB operation. Comments were sought concerning what emission limits
and measurement procedures would be appropriate for UWB devices. The NOI invited comments on any
other matters or issues that may be pertinent to the operation of UWB systems. In response to the NOI, 42
parties filed comments and 37 parties filed reply comments.
13
The list of the commenting parties is
shown in Appendix B.

6.
In the NOI the Commission noted that three requests for waivers of the Part 15 rules were
filed to permit the operation of UWB systems.
14
U.S. Radar Inc. filed a Petition for Waiver to permit the
operation of a ground penetrating radar system that could be used to detect buried objects.
15
Time


10
The fundamental emission, as used herein for pulsed UWB emission systems, consists of the main lobe
when viewed on a spectrum analy