[Federal Register Volume 61, Number 67 (Friday, April 5, 1996)]
[Proposed Rules]
[Pages 15206-15208]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8386]



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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Parts 2 and 15

[ET Docket No. 96-8; FCC 96-36]


Spread Spectrum Transmitters

AGENCY: Federal Communications Commission.

ACTION: Proposed rule.

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SUMMARY: By this Notice of Proposed Rule Making (``NPRM''), the 
Commission proposes to amend its rules regarding the operation of 
spread spectrum transmission systems in the 902-928 MHz, 2400-2483.5 
MHz and 5725-5850 MHz bands. For simplicity, these bands will be 
referenced in this proposal as 915 MHz, 2450 MHz and 5800 MHz, 
respectively. The Commission proposes to eliminate the limit on 
directional gain antennas for spread spectrum transmitters operating in 
the 5800 MHz band. We are also proposing to reduce, from 50 to 25, the 
minimum number of channels required for frequency hopping spread 
spectrum systems operating in the 915 MHZ band. These proposals are in 
response to Petitions for Rule Making filed by Western Multiplex 
Corporation (WMC) and Spectralink Corporation (Spectralink). We are 
also denying a Petition for Rule Making from Symbol Technologies, Inc. 
(Symbol). Further, the Commission on its own motion proposes a number 
of amendments to the spread spectrum regulations to clarify the 
existing regulations, to codify existing policies into the rules, and 
to update the current definitions. These changes will expand the 
ability of equipment manufacturers to develop spread spectrum systems 
for unlicensed use.

DATES: Comments must be filed on or before June 19, 1996, and reply 
comments must be filed on or before July 19, 1996.


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

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

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Notice 
of Proposed Rule Making, ET Docket No. 96-8, FCC 96-36, adopted January 
30, 1996, and released February 5, 1996. The full text of this 
Commission decision 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 duplication contractor, International Transcription 
Service, (202) 857-3800, 2100 M Street, N.W., Suite 140, Washington 
D.C. 20037.

Summary of Notice

    1. The Commission is proposing to amend Parts 2 and 15 of the rules 
regarding the operation of spread spectrum transmission systems in the 
915 MHz, 2450 MHz and 5800 MHz bands. The spread spectrum rules, as 
originally adopted, did not specify a limit on antenna gain. At that 
time there were few other operators in these bands and little potential 
that interference would be caused to other users. Further, we wished to 
offer an incentive to spur the development of spread spectrum systems. 
These bands, especially the 915 MHz and the 2450 MHz bands, are now 
becoming more crowded, particularly with mobile units, increasing the 
potential that spread spectrum systems using high gain antennas will 
cause harmful interference. In addition to the licensed radio services, 
wireless computer local area network systems and various consumer 
products, such as cordless telephones, are being used under Part 15 in 
the 915 MHz and 2450 MHz bands.
    2. Since there are few operators in the 5800 MHz band, the 
potential that harmful interference will occur from the use of 
directional antennas is much lower. There are also fewer mobile users 
in the 5800 MHz band. It is easier to engineer a fixed, point-to-point 
system to operate without causing harmful interference problems if the 
other stations in that band are fixed in location. Further, the 5800 
MHz band is ideal for fixed, point-to-point wideband microwave 
operations, the type of applications desired by WMC. Accordingly, the 
Commission believes the limit on directional antenna gain should only 
be eliminated for spread spectrum systems operating in the 5800 MHz 
band. We request comment on this proposal. While we are not inclined to 
provide a similar relaxation for the 2450 MHz band, we also ask for 
comment on whether we should eliminate the 6 dB limit on directional 
antenna gain in this band.
    3. The Commission further believes that if spread spectrum 
transmitters employing high gain antennas were made available to the 
general public, it would be difficult to ensure that these systems are 
used only for fixed, point-to-point applications. In addition, high 
gain directional antenna systems, because of their narrow transmission 
beamwidth and the problems associated with aligning the transmitter 
with the receiver site, are not products that would normally be 
employed by the general public. Accordingly, we believe that the 
marketing of spread spectrum systems employing high gain antennas 
should be limited to commercial or industrial operators and exclude 
sales to the general public. The Commission further proposes to hold 
the operator of a spread spectrum system responsible for ensuring that 
the system is operated in a compliant manner. In addition, we propose 
to require that the manual supplied with the spread spectrum 
transmitter contain language in the installation instructions notifying 
the operator of this responsibility.
    4. In addition, absent controls regarding the locations and manner 
in which spread spectrum transmitters may be used, systems employing 
high gain directional antennas could expose the public to potentially 
harmful signal levels that exceed the radio frequency exposure limits 
in our rules and recommended by various standards-setting 
organizations. In order to meet our obligation under the National 
Environmental Policy Act, we propose to hold the holder of the grant of 
certification for the transmitter, the grantee, responsible for 
ensuring that the equipment is designed to minimize exposure of the 
public to excessive radio frequency (RF) signal levels. Comments are 
requested concerning possible biological hazards from the high 
effective radiated power levels that could be emitted from these 
systems, any additional methods that can be employed to prevent 
unnecessary exposure of the public, and whether we should prescribe the 
use of specific means for preventing such exposure.
    5. The Commission also seeks comments in two additional areas 
regarding the technical standards for spread spectrum transmission 
systems operating without a limit on directional antenna gain. The 
first of these concerns a reduction in the output power of the 
transmitter based on the amount that the increase in directional 
antenna gain exceeds the current limit of 6 dBi. We propose that the 
output power of a transmitter would need to be decreased by 1 dB for 
every 3 dB that the antenna gain exceeds 6 dBi in order to maintain an 
``equivalent'' area of interference, i.e., the geographic area over 
which interference could result with a directional antenna as compared 
to the area obtained with an omnidirectional antenna. See the proposed 
new Section 15.274(b)(4) in Appendix B of the NPRM. We are also seeking 
comments on whether the rules should specify limits on the horizontal 
and vertical beamwidths of antennas used with point-to-point systems. 
Certain antenna designs, e.g., a horizontally polarized yagi antenna, 
concentrate the signal strength in azimuth (horizontal) but not in 
elevation (vertical). A fixed, point-to-point system employing an 
antenna with a wide elevation beamwidth that is pointed towards an 
office building with multiple floors could result in severe 
interference problems to any party in that building who is in line with 
the system and is operating in the same band. Several antenna designs 
concentrate the radiated signals in both azimuth and elevation, e.g., 
circular dish antennas and stacked yagi antennas. The Commission 
believes that any interference problems resulting from excessive 
vertical emissions could be resolved if the 3 dB beamwidths, in both 
the vertical and the horizontal planes, of the high gain directional 
antennas employed with these fixed, point-to-point systems differ by no 
more than a factor of two and are proposing such a limit.
    6. As SpectraLink observes in its petition, there could be mutual 
interference problems between wideband, multilateration LMS systems and 
Part 15 frequency hopping spread spectrum systems, and it would be 
beneficial if these two operations could avoid sharing the same 
spectrum. The modification sought by SpectraLink would appear to 
promote frequency sharing within this band. Therefore, the Commission 
proposes to amend the rules to permit frequency hopping spread spectrum 
systems in the 915 MHz band to use only 25 hopping channels, provided 
that those systems employ hopping channel bandwidths of at least 250 
kHz and the transmitters operate at a reduced power level. Hopping 
systems using channel bandwidths less than 250 kHz already can avoid 
operating in the bands used by broadband multilateration LMS systems 
and require no decrease in the

[[Page 15208]]
minimum number of hopping channels. For frequency hopping systems 
employing channel bandwidths of 250 kHz or greater, we propose to 
reduce the minimum number of hopping channels to 25. Consistent with 
this plan, we are also proposing to modify the maximum average time of 
occupancy on any hopping frequency to 0.4 seconds in any 10 second 
period to correspond to the reduction in the number of hopping 
channels. Comments are also requested as to whether the rules should 
specify a formula for the minimum number of hopping channels based on 
the amount by which the bandwidth of the hopping channel exceeds 250 
kHz.
    7. Further, in order to reduce the potential for interference due 
to the smaller number of hopping channels, we propose to require that 
frequency hopping spread spectrum systems in the 915 MHz band that use 
fewer than 50 hopping channels operate with a maximum peak transmitter 
output power of 500 mW.
    8. We are also denying the Petition for Rule Making from Symbol to 
reduce the minimum number of hopping channels for frequency hopping 
spread spectrum systems operating in the 2450 MHz or 5800 MHz bands.
    9. There are also several additional regulations concerning Part 15 
spread spectrum transmission systems that need to be clarified, 
codified or amended. They are Spectral power density, Short duration 
transmissions, Measurement of processing gain, Limits on unwanted 
emissions, Frequency hopping coordination, External radio frequency 
power amplifiers, Transition provisions, Definition of direct sequence 
and Pseudorandom sequence and frequency hopping systems. These are 
discussed in more detail in the full text of the Commission's NPRM, ET 
Docket 96-8.

Initial Regulatory Flexibility Analysis

    1. Reason for Action: This rule making proceeding is initiated to 
obtain comment regarding proposed changes to the regulations for non-
licensed spread spectrum transmitters.
    2. Objectives: The Commission seeks to determine if the standards 
should be amended as sought in Petitions for Rule Making filed by WMC, 
Symbol and SpectraLink. Additional amendments are also proposed to 
clarify the existing regulations and to codify existing policies into 
the rules.
    3. Legal Basis: The proposed action is authorized under Sections 
4(i), 301, 302, 303(e), 303(f), 303(r), 304 and 307 of the 
Communications Act of 1934, as amended, 47 U.S.C. Sections 154(i), 301, 
302, 303(e), 303(f), 303(r), 304 and 307.
    4. Reporting, Recordkeeping and Other Compliance Requirements: Part 
15 spread spectrum transmitters are already required to be authorized 
under the Commission's certification procedure as a prerequisite to 
marketing and importation. The changes proposed in this proceeding 
would not change any of the current reporting or recordkeeping 
requirements. Further, the proposed regulations add permissible methods 
of operation and would not require the modification of any existing 
products.
    5. Federal Rules Which Overlap, Duplicate or Conflict With These 
Rules: None.
    6. Description, Potential Impact and Number of Small Entities 
Involved: The actions proposed in this proceeding add permissible 
methods of operation and will not require the modification of any 
existing products. Accordingly, there should be no mandatory impact on 
any small entities.
    7. Any Significant Alternatives Minimizing the Impact on Small 
Entities Consistent with Stated Objectives: None.

List of Subjects

47 CFR Part 2

    Communications equipment, Radio.

47 CFR Part 15

    Communications equipment, Radio.

Federal Commications Commission.
William F. Caton,
Acting Secretary.
[FR Doc. 96-8386 Filed 4-4-96; 8:45 am]
BILLING CODE 6712-01-P