[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR101.105]
[Page 636-640]
TITLE 47--TELECOMMUNICATION
COMMISSION (CONTINUED)
PART 101_FIXED MICROWAVE SERVICES--Table of Contents
Subpart C_Technical Standards
Sec. 101.105 Interference protection criteria.
(a) The interference protection criteria for fixed stations subject
to this part are as follows:
(1) To long-haul analog systems, employing frequency modulated radio
and frequency division multiplexing to provide multiple voice channels,
the allowable interference level per exposure:
(i) Due to co-channel sideband-to-sideband interference must not
exceed 5 pwpO (Picowatts of absolute noise power psophometrically
weighted (pwpO), appearing in an equivalent voice band channel of 300-
3400 Hz); or
(ii) Due to co-channel carrier-beat interference must not exceed 50
pwpO.
(2) To short-haul analog systems employing frequency modulated radio
and frequency division multiplexing to provide multiple voice channels,
the allowable interference level per exposure:
(i) Due to co-channel sideband-to-sideband interference must not
exceed 25 pwpO except in the 952-960 MHz band interference into single
link fixed relay and control stations must not exceed 250 pwpO per
exposure; or
(ii) Due to co-channel carrier-beat interference must not exceed 50
pwpO except in the 952-960 MHz band interference into single link fixed
relay and control stations must not exceed 1000 pwpO per exposure.
(3) FM-TV. In analog systems employing frequency modulated radio
that is modulated by a standard, television (visual) signal, the
allowable interference level per exposure may not exceed the levels
which would apply to long-haul or short-haul FM-FDM systems, as outlined
in paragraphs (b) (1) and (2) of this section, having a 600-1200 voice
channel capacity.
(4) 12.2-12.7 GHz band. (i) To accommodate co-primary NGSO FSS earth
stations in the 12.2-12.7 GHz band, the PFD of an MVDDS transmitting
system must not exceed -135 dBW/m2 in any 4 kHz band at a
reference point at the surface of the earth at a distance greater than 3
kilometers from the MVDDS transmitting antenna.
(ii) To accommodate co-primary Direct Broadcast Satellite Service
earth stations, an MVDDS transmitting system must not exceed the EPFD
levels specified in paragraph (a)(4)(ii)(B) of this section at any DBS
subscriber location in accordance with the procedures listed in Sec.
101.1440 of this part.
(A) Definition of equivalent power flux density: The equivalent
power flux density (EPFD) is the power flux density produced at a direct
broadcast service (DBS) receive earth station, taking into account
shielding effects and the off-axis discrimination of the receiving
antenna assumed to be pointing at the appropriate DBS satellite(s) from
the transmitting antenna of a multichannel video distribution and data
service (MVDDS) transmit station. The EPFD in dBW/m2 in the
reference bandwidth is calculated using the following formula:
[GRAPHIC] [TIFF OMITTED] TR07JN04.000
Where:
Pout = Total output power of the MVDDS transmitter (watts)
into antenna
[[Page 637]]
Gm ([thetas]m,[phis]m = Gain of the MVDDS antenna
in the direction of the DBS earth station
Ge ([thetas]e,[phis]e = Gain of the
earth station in the direction of the MVDDS antenna
I = Interference scaling factor for the earth station (1 dB for MVDDS
transmitters employing the modulation discussed in Section 3.1.5 of the
MITRE Report (i.e., a QPSK modulated signal passed through a square-root
raised cosine filter). For other modulation and filtering schemes, the
interference scaling factor can be measured using the procedures
described in Appendix A of the MITRE Report available at http://
www.fcc.gov/oet/info/mitrereport/mitrereport--4--01.pdf).
Ge, max = Maximum gain of the DBS earth station
d = the distance between the MVDDS transmitting antenna and the DBS
earth station (meters)
(B) Regional equivalent power flux density levels:
(1) -168.4 dBW/m2/4kHz in the Eastern region consisting
of the District of Columbia and the following states: Maine, New
Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York,
New Jersey, Pennsylvania, Delaware, Maryland, Virginia, West Virginia,
Kentucky, Tennessee, North Carolina, South Carolina, Georgia, Alabama,
Mississippi, Louisiana, and Florida;
(2) -169.8 dBW/m2/4kHz in the Midwestern region
consisting of the following states: Ohio, Michigan, Indiana, Wisconsin,
Illinois, Minnesota, Iowa, Missouri, Arkansas, South Dakota, Nebraska,
Kansas, Oklahoma, and Texas;
(3) -171.0 dBW/m2/4kHz in the Southwestern region
consisting of the following states: Wyoming, Colorado, New Mexico, Utah,
Arizona, Nevada, and California (south of 37[deg] North Latitude);
(4) -172.1 dBW/m2/4kHz in the Northwestern region
consisting of the following states: Washington, Oregon, California
(north of 37[deg] North Latitude), Idaho, Montana, North Dakota, Alaska,
and Hawaii.
(iii) Except for public safety entities, harmful interference
protection from MVDDS stations to incumbent point-to-point 12 GHz fixed
stations is not required. Incumbent point-to-point private operational
fixed 12 GHz stations, except for public safety entities, are required
to protect MVDDS stations under the process described in Sec.
101.103(d) of this part.
(5) 71,000-76,000 MHz; 81,000-86,000 MHz. In these bands the
following interference criteria shall apply:
(i) For receivers employing digital modulation: based upon
manufacturer data and following TSB 10-F or other generally acceptable
good engineering practice, for each potential case of interference a
threshold-to-interference ratio (T/I) shall be determined that would
cause 1.0 dB of degradation to the static threshold of the protected
receiver. For the range of carrier power levels (C) between the clear-
air (unfaded) value and the fully-faded static threshold value, in no
case shall interference cause C/I to be less than the T/I so determined
unless it can be shown that the availability of the affected receiver
would still be acceptable despite the interference.
(ii) For receivers employing analog modulation: manufacturer data or
industry criteria will specify a baseband signal-to-noise requirement
(S/N) of the receiver that will result in acceptable signal quality for
continuous operation. Following TSB 10-F or other generally acceptable
good engineering practice, for each potential case of interference a C/I
objective shall be calculated to ensure that this S/N will not be
degraded by more than 1.0 dB. For the range of carrier power levels (C)
between the clear-air (unfaded) value and the fully-faded threshold
value, in no case shall interference cause the C/I to be less than the
objective so determined unless it can be shown that the signal quality
and availability of the affected receiver would still be acceptable
despite the interference.
(6) 92,000-94,000 MHz; 94,100-95,000 MHz. In these bands prior links
shall be protected to a threshold-to-interference ratio (T/I) level of
1.0 dB of degradation to the static threshold of the protected receiver.
Any new link shall not decrease a previous link's desired-to-undesired
(D/U) signal ratio below a minimum of 36 dB, unless the earlier link's
licensee agrees to accept a lower D/U.
(7) All stations operating under this part must protect the radio
quiet zones as required by Sec. 1.924 of this chapter. Stations
authorized by competitive
[[Page 638]]
bidding are cautioned that they must receive the appropriate approvals
directly from the relevant quiet zone entity prior to operating.
(b) In addition to the requirements of paragraph (a) of this section
the adjacent channel interference protection criteria to be afforded,
regardless of system length, or type of modulation, multiplexing, or
frequency band, must be such that the interfering signal does not
produce more than 1.0 dB degradation of the practical threshold of the
protected receiver. The ``practical threshold'' of the protected
receiver can be based upon the definition in TSB 10, referenced in
paragraph (c) of this section, or upon alternative generally acceptable
good engineering standards.
(c) Applying the criteria. (1) Guidelines for applying the
interference protection criteria for fixed stations subject to this part
are specified in the Telecommunications Industry Association's
Telecommunications Systems Bulletin TSB 10, ``Interference Criteria for
Microwave Systems'' (TSB 10). Other procedures that follow generally
acceptable good engineering practices are also acceptable to the
Commission.
(2) If TSB 10 guidelines cannot be used, the following interference
protection criteria may be used by calculating the ratio in dB between
the desired (carrier signal) and the undesired (interfering) signal (C/I
ratio) appearing at the input to the receiver under investigation
(victim receiver). Except as provided in Sec. 101.147 where the
applicant's proposed facilities are of a type not included in paragraphs
(a) and (b) of this section or where the development of the carrier-to-
interference (C/I) ratio is not covered by generally acceptable
procedures, or where the applicant does not wish to develop the carrier-
to-interference ratio, the applicant must, in the absence of criteria or
a developed C/I ratio, employ the following C/I protection ratios:
(i) Co-Channel Interference. Both side band and carrier-beat,
applicable to all bands; the existing or previously authorized system
must be afforded a carrier to interfering signal protection ratio of at
least 90 dB, except in the 952-960 MHz band where it must be 75dB, and
in the 71,000-76,000 MHz and 81,000-86,000 MHz bands where the criteria
in paragraph (a)(5) of this section applies, and in the 92,000-94,000
MHz and 94,100-95,000 MHz bands, where the criteria in paragraph (a)(6)
of this section applies; or
(ii) Adjacent Channel Interference. Applicable to all bands; the
existing or previously authorized system must be afforded a carrier to
interfering signal protection ratio of at least 56 dB, except in the
71,000-76,000 MHz and 81,000-86,000 MHz bands where the criteria in
paragraph (a)(5) of this section applies, and in the 92,000-94,000 MHz
and 94,100-95,000 MHz bands, where the criteria in paragraph (a)(6) of
this section applies.
(3) Applicants for frequencies listed in Sec. 101.147(b)(1) through
(4) must make the following showings that protection criteria have been
met over the entire service area of existing systems. Such showings may
be made by the applicant or may be satisfied by a statement from a
frequency coordinator.
(i) For site-based multiple address stations in the 928-929/952-960
MHz and the 932-932.5/941-941.5 MHz bands, a statement that the proposed
system complies with the following co-channel separations from all
existing stations and pending applications:
Fixed-to-fixed--145 km;
Fixed-to-mobile--113 km;
Mobile-to-mobile--81 km
Note to paragraph (c)(3)(i): Multiple address systems employing only
remote stations will be treated as mobile for the purposes of
determining the appropriate separation. For mobile operation, the
mileage is measured from the reference point specified on the license
application. For fixed operation on subfrequencies in accordance with
Sec. 101.147 the mileage also is measured from the reference point
specified on the license application.
(ii) In cases where the geographic separation standard in paragraph
(c)(3)(i) of this section is not followed, an engineering analysis must
be submitted to show the coordination of the proposed assignment with
existing systems located closer than those standards. The engineering
analyses will include:
(A) Specification of the interference criteria and system parameters
used in the interference study;
[[Page 639]]
(B) Nominal service areas of each system included in the
interference analysis;
(C) Modified service areas resulting from the proposed system. The
propagation models used to establish the service boundary limits must be
specified and any special terrain features considered in computing the
interference impact should be described; and
(D) A statement that all parties affected have agreed to the
engineering analysis and will accept the calculated levels of
interference.
(iii) MAS EA licensees shall provide protection in accordance with
Sec. 101.1333.
(4) Multiple address systems operating on subfrequencies in
accordance with Sec. 101.147 that propose to operate master stations at
unspecified locations must define the operating area by a radius about a
geographical coordinate and describe how interference to co-channel
users will be controlled.
(5) Multiple address frequencies in the 956.25-956.45 MHz bands may
be assigned for use by mobile master stations on a primary basis.
Multiple address frequencies in the 941.0-941.5 MHz bands that are
licensed on a site-by-site basis and the 952 MHz bands may be assigned
for use by primary mobile master stations on a case-by-case basis if the
956.25-956.45 MHz frequencies are unavailable. Multiple address mobile
(master and remote) operation is permitted on frequencies licensed by
geographic area subject to the interference protection criteria set
forth in Sec. 101.1333, i.e., adjacent channel site-based licensees and
co-channel operations in adjacent EAs. Mobile operation in the 959.85-
960 MHz band is not permitted.
(6) Each application for new or modified nodal station on channels
numbered 4A, 4B, 7, 9, and 19/20 in the 10.6 GHz band must demonstrate
that all existing co-channel stations are at least 56 kilometers from
the proposed nodal station site. Applicants for these channels must
certify that all licensees and applicants for stations on the adjacent
channels within 56 kilometers of the proposed nodal station have been
notified of the proposed station and do not object. Alternatively, or if
one of the affected adjacent channel interests does object, the
applicant may show that all affected adjacent channel parties are
provided a C/I protection ratio of 0 dB. An applicant proposing to
operate at an AAT greater than 91 meters must reduce its EIRP in
accordance with the following table; however, in no case may EIRP exceed
70 dBm on the 10.6 GHz channels:
------------------------------------------------------------------------
AAT (meters) EIRP dBm
------------------------------------------------------------------------
Above 300.................................................... +38
251 to 300................................................... 41
201 to 250................................................... 43
151 to 200................................................... 49
101 to 150................................................... 55
100 and below................................................ 85
------------------------------------------------------------------------
(7) Each application for new or modified nodal station on channels
numbered 21, 22, 23, and 24 in the 10.6 GHz band must include an
analysis of the potential for harmful interference to all other licensed
and previously applied for co-channel and adjacent channel stations
located within 80 kilometers of the location of the proposed station.
The criteria contained in Sec. 101.103(d)(2) must be used in this
analysis. Applicants must certify that copies of this analysis have been
served on all parties which might reasonably be expected to receive
interference above the levels set out in Sec. 101.103(d)(2) within 5
days of the date the subject application is filed with the Commission.
(8) If the potential interference will exceed the prescribed limits,
a statement shall be submitted with the application for new or modified
stations to the effect that all parties have agreed to accept the higher
level of interference.
(d) Effective August 1, 1985, when a fixed station that conforms to
the technical standards of this subpart (or, in the case of the 12,200-
12,700 MHz band, for an incumbent non-MVDDS station or a direct
broadcast satellite station) receives or will receive interference in
excess of the levels specified in this section as a result of an
existing licensee's use of non-conforming equipment authorized between
July 20, 1961 and July 1, 1976, and the interference would not result if
the interfering station's equipment complied with the current technical
standards, the licensee of the non-conforming station must take whatever
steps are necessary to correct the situation up to
[[Page 640]]
the point of installing equipment which fully conforms to the technical
standards of this subpart. In such cases, if the engineering analysis
demonstrates that:
(1) The conforming station would receive interference from a non-
conforming station in excess of the levels specified in this section;
and
(2) The interference would be eliminated if the non-conforming
equipment were replaced with equipment which complies with the standards
of this subpart, the licensee (or prospective licensee) of the station
which would receive interference must provide written notice of the
potential interference to both the non-conforming licensee and the
Commission's office in Gettysburg, PA. The non-conforming licensee must
make all required equipment changes within 180 days from the date of
official Commission notice informing the licensee that it must upgrade
its equipment, unless an alternative solution has been agreed to by all
parties involved in the interference situation. If a non-conforming
licensee fails to make all required changes within the specified period
of time, the Commission may require the licensee to suspend operation
until the changes are completed.
(e) Interference dispute resolution procedures. Should a licensee
licensed under this part receive harmful interference from another
licensee licensed under this chapter, the parties involved shall comply
with the dispute resolution procedures set forth herein:
(1) The licensee experiencing the harmful interference shall notify
the licensee believed to be causing the harmful interference and shall
supply information describing its problem and supporting its claim;
(2) Upon receipt of the harmful interference notice, the licensee
alleged to be causing the harmful interference shall respond immediately
and make every reasonable effort to identify and resolve the conflict;
and
(3) Licensees are encouraged to resolve the harmful interference
prior to contacting the Commission.
[61 FR 26677, May 28, 1996, as amended at 63 FR 68983, Dec. 14, 1998; 65
FR 17449, Apr. 3, 2000; 65 FR 38329, June 20, 2000; 65 FR 59358, Oct. 5,
2000; 66 FR 35110, July 3, 2001; 67 FR 43038, June 28, 2002; 69 FR
31746, June 7, 2004; 70 FR 29996, May 25, 2005]