[Federal Register Volume 63, Number 182 (Monday, September 21, 1998)]
[Proposed Rules]
[Pages 50184-50185]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-25113]



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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Part 15

[ET Docket No. 98-153; FCC 98-208]


Revision of the Rules Regarding Ultra-Wideband Transmission 
Systems

AGENCY: Federal Communications Commission.

ACTION: Proposed rule.

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SUMMARY: By this Notice of Inquiry, the Commission is initiating a 
proceeding to investigate the possibility of permitting the operation 
of ultra-wideband (UWB) radio systems on an unlicensed basis under its 
rules. Comments are requested on the standards and operating 
requirements that should be applied to UWB systems to prevent 
interference to other radio services.

DATES: Comments are due December 7, 1998, reply comments are due 
January 4, 1999.

ADDRESSES: Federal Communications Commission, 1919 M Street, N.W., 
Washington, D.C. 20554.

FOR FURTHER INFORMATION CONTACT: John A. Reed, Office of Engineering 
and Technology, (202) 418-2455.

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Notice 
of Inquiry in ET Docket No. 98-153, adopted August 20, 1998, and 
released September 1, 1998. The complete text of this Notice of Inquiry 
is available for inspection and copying during normal business hours in 
the FCC Reference Center (Room 239), 1919 M Street, N.W., Washington, 
D.C., and also may be purchased from the Commission's copy contractor, 
International Transcription Services, Inc., (202) 857-3800, 2100 M 
Street, NW, Suite 140, Washington, D.C. 20037.

Summary of the Notice of Inquiry

    1. The Commission is initiating this inquiry on its own motion to 
investigate the possibility of permitting the operation of ultra-
wideband (UWB) radio systems on an unlicensed basis under part 15 of 
its rules. Through this inquiry, we are seeking input to help us 
evaluate UWB technology and to determine what standards and operating 
requirements are necessary to prevent interference to other users of 
the radio spectrum. Upon review of the responses to this inquiry, we 
will determine whether to propose any changes to the rules.
    2. UWB radio systems typically use extremely narrow pulse (impulse) 
modulation or swept frequency modulation that employs a fast sweep over 
a wide bandwidth. Because of the type of modulation employed, the 
emission bandwidths of UWB devices generally exceed one gigahertz and 
may be greater than ten gigahertz. In some cases, these 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 of the radiated emission.
    3. UWB systems could provide an improved method for providing radar 
applications where precise distance resolution is required and for 
providing covert voice or data communications that overcome multipath 
problems. Radar systems are currently being developed to detect buried 
objects such as plastic gas pipes or hidden flaws in airport runways or 
highways. Other radar systems would be used as fluid level sensors in 
difficult-to-measure situations such as oil refinery tanks and other 
storage tanks. Public safety personnel have expressed a desire for 
radar systems that can detect people hidden behind walls or covered 
with debris, such as from an earthquake. Public safety personnel also 
have expressed a need for UWB communications systems that can operate 
covertly. These communications systems could also be employed by heavy 
industrial manufacturers to overcome multipath and machinery-generated 
radio noise.
    4. Applications and general characteristics. What types of UWB 
devices can we expect to be developed? What are the frequency ranges 
and bandwidths expected to be used by UWB devices? What are the 
expected total power levels and spectral power densities, peak and 
average, of UWB devices? What are the expected or desired operating 
distances?
    5. Regulatory treatment. We understand that UWB systems will 
operate at very low spectral power densities, producing noise-like 
signals. Further, it appears that UWB systems will operate over very 
short distances. Because of this, it appears appropriate to provide for 
UWB technologies under part 15 of the rules. We invite comments on 
whether it would be appropriate to apply our part 15 rules to UWB 
technologies. Are there certain types of UWB devices or applications 
that should be regulated on a licensed basis under some other rule 
part? If so, which rule parts? If provisions are made for UWB 
technology under part 15, how should we define UWB technology?
    6. TV broadcast and restricted bands. Part 15 designates certain 
sensitive and safety-related frequency bands as restricted bands. Only 
spurious emissions not exceeding the general emission limits are 
permitted within these restricted bands or, with few exceptions, within 
the frequency bands allocated for TV broadcasting. However, it is 
difficult, if not impossible, for UWB systems to avoid placing 
fundamental emissions within the restricted bands or the TV broadcast 
bands. Accordingly, comments are requested on whether the Commission 
should eliminate the requirement that only spurious emissions be 
permitted to fall within the restricted bands and the TV broadcast 
bands. Should the rules generally continue to prohibit operation of UWB 
systems within the restricted bands and the TV broadcast bands? Are 
there certain restricted bands where operation could be permitted, but 
not others? If so which bands and what is the justification? If certain 
restricted bands were retained, what impact would this have on the 
viability of UWB technology?
    7. Emission limits. The current part 15 rules are based on the 
equivalent of a spectral power density, i.e., a field strength limit is 
specified along with a measurement bandwidth. In most cases, emissions 
at or below 1000 MHz are based on the use of a quasi-peak detector 
which employs a designated measurement bandwidth. Above 1000 MHz, 
emissions are based on average field strength limits with a minimum 
measurement bandwidth of one megahertz. Where an average limit applies, 
there is also a limit on peak emission levels. Are the existing general 
emission limits sufficient to protect other users of the spectrum, 
especially radio operations in the restricted bands, from harmful 
interference? Should different limits be applied to UWB systems? Should 
we specify a different standard for UWB devices based on spectral power 
density? Should these standards be designed to ensure that the 
emissions appear to be broadband noise? What is the potential for 
harmful interference due to the cumulative impact of emissions if there 
is a large proliferation of UWB devices? Could the cumulative impact 
result in an unacceptably high increase in the background noise level? 
Should the Commission limit proliferation by restricting the types of 
products or should the rules permit manufacturers to design products 
for any application as long as the equipment meets the standards? 
Should a limit on the total peak level apply to UWB devices? Can 
emissions below or above a certain frequency range be further filtered 
to reduce the potential for interference to

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other users of the radio spectrum without affecting the performance of 
the UWB systems? Are the existing limits on the amount of energy 
permitted to be conducted back onto the AC power lines appropriate for 
UWB devices? What operational restrictions, if any, should be required 
to protect existing users? Is the use of UWB modulation techniques 
necessary for certain types of communication systems; if so, for what 
purposes?
    8. Measurements. Part 15 references the specific measurement 
procedure to be employed, the frequency range over which measurements 
are to be made, and the measurement detector functions and bandwidths 
to be employed. Comments are requested on whether the peak output level 
continues to be indicative of the interference potential of a UWB 
system. Is a pulse desensitization correction factor appropriate for 
measuring emissions from a UWB device? Should any modifications be made 
to this measurement procedure for UWB devices? Would another 
measurement procedure that does not apply a pulse desensitization 
correction factor be more appropriate for determining the interference 
potential of an UWB device? The frequency range over which measurements 
are required to be made depends on the frequency of the fundamental 
emission. Is the frequency of the fundamental emission readily 
discernible for UWB devices? Are the current frequency measurement 
ranges specified in the rules appropriate for UWB devices or should 
these ranges be modified? Are the measurement detector functions and 
bandwidths appropriate for UWB devices? Should these standards be 
modified and, if so, how? Are there any other changes to the 
measurement procedures that should be applied to UWB devices?
    9. Other matters. There is a prohibition in the rules against the 
use of a Class B, damped wave emission. This prohibition stems from a 
similar International Telecommunication Union regulation and is a 
throwback to the days when spark gap transmitters were employed. There 
is no longer a clear definition of a Class B, damped wave emission. 
Should the prohibition against Class B, damped wave emissions apply to 
UWB systems or is the prohibition irrelevant, especially in light of 
the relatively low power levels employed by UWB devices? Comments are 
invited on any other matters or issues that may be pertinent to the 
operation of UWB systems.
    10. This is a non-restricted notice and comment rule making 
proceeding. Ex parte presentations are permitted, except during the 
Sunshine Agenda period, provided they are disclosed as provided in the 
Commission's rules. See generally 47 CFR 1.1202, 1.1203, and 1.2306(a).
    11. Comments may be filed using the Commission's Electronic Comment 
Filing System (ECFS) or by filing paper copies. See Electronic Filing 
of Documents in Rulemaking Proceedings, 63 FR 24121 (1998). Comments 
filed through the ECFS can be sent as an electronic file via the 
Internet to <http://www.fcc.gov/e-file/ecfs.html<. Generally, only one 
copy of an electronic submission must be filed. If multiple docket or 
rule making numbers appear in the cation of this proceeding, however, 
commenters must transmit one electronic copy of the comments to each 
docket or rule making number referenced in the caption. In completing 
the transmittal screen, commenters should include their full name, 
Postal Service mailing address, and the applicable docket or rule 
making number. Parties may also submit an electronic comment by 
Internet e-mail. To get filing instructions for e-mail comments, 
commenters should send an e-mail to [email protected], and should including 
the following words in the body of the message, ``get form