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

[[Page 650]]

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
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) 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 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

[[Page 651]]

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 sideband 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 75 dB; 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.
    (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;
    (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

[[Page 652]]

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 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

[[Page 653]]

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]