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/m^2 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/m^2 in the reference bandwidth is calculated using
   the following formula:
   [MATH:  :MATH]

   Where:

   P[out]= Total output power of the MVDDS transmitter (watts) into antenna

   Gm ( Θ [m], φ [m]= Gain of the MVDDS antenna in the direction of the DBS
   earth station

   G[e]( Θ [e], φ [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 ).

   G[e,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/m^2 /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/m^2 /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/m^2 /4kHz in the Southwestern region consisting of the
   following states: Wyoming, Colorado, New Mexico, Utah, Arizona, Nevada, and
   California (south of 37 ° North Latitude);

   ( 4 ) −172.1 dBW/m^2 /4kHz in the Northwestern region consisting of the
   following  states:  Washington, Oregon, California (north of 37 ° 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 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;

   (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 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]