Sec.  25.254   Special requirements for ancillary terrestrial components operating
in the 1610–1626.5 MHz/2483.5–2500 MHz bands.

   (a) An applicant for an ancillary terrestrial component in these bands must
   demonstrate that ATC base stations shall:

   (1) Not exceed a peak EIRP of 32 dBW in 1.25 MHz;

   (2) Not cause unacceptable interference to systems identified in paragraph
   (c) of this section and, in any case, shall not exceed out-of-channel
   emissions of −44.1 dBW/30 kHz at the edge of the MSS licensee's authorized
   frequency assignment;

   (3) At the time of application, that it has taken, or will take steps
   necessary to avoid causing interference to other services sharing the use of
   the 2450–2500 MHz band through frequency coordination; and

   (4) Base stations operating in frequencies above 2483.5 MHz shall not
   generate EIRP density, averaged over any two-millisecond active transmission
   interval, greater than −70 dBW/MHz in the 1559–1610 MHz band. The EIRP,
   averaged over any two-millisecond active transmission interval, of discrete
   out-of-band emissions of less than 700 Hz bandwidth from such base stations
   shall not exceed −80 dBW in the 1559–1610 MHz band. A root-mean-square
   detector function with a resolution bandwidth of one megahertz or equivalent
   and no less video bandwidth shall be used to measure wideband EIRP density
   for purposes of this rule, and narrowband EIRP shall be measured with a
   root-mean-square detector function with a resolution bandwidth of one
   kilohertz or equivalent.

   (b) An applicant for an ancillary terrestrial component in these bands must
   demonstrate that mobile terminals shall:

   (1) Meet the requirements contained in  Sec. 25.213 to protect radio astronomy
   service (RAS) observations in the 1610.6–1613.8 MHz band from unacceptable
   interference;

   (2) Observe a peak EIRP limit of 1.0 dBW in 1.25 MHz;

   (3) Observe an out-of-channel EIRP limit of −57.1 dBW/30 kHz at the edge of
   the licensed MSS frequency assignment.

   (4) ATC mobile terminals operating in assigned frequencies in the
   1610–1626.5 MHz band shall not generate EIRP density, averaged over any
   two-millisecond active transmission interval, greater than -70 dBW/MHz in
   the 1559–1605 MHz band or greater than a level determined by linear
   interpolation in the 1605–1610 MHz band, from −70 dBW/MHz at 1605 MHz to −10
   dBW/MHz at 1610 MHz. The EIRP, averaged over any two-millisecond active
   transmission interval, of discrete out-of-band emissions of less than 700 Hz
   bandwidth from such mobile terminals shall not exceed −80 dBW in the
   1559–1605 MHz band or exceed a level determined by linear interpolation in
   the 1605–1610 MHz band, from −80 dBW at 1605 MHz to −20 dBW at 1610 MHz. The
   EIRP density of carrier-off-state emissions from such mobile terminals shall
   not exceed −80 dBW/MHz in the 1559–1610 MHz band, averaged over a
   two-millisecond interval. A root-mean-square detector function with a
   resolution bandwidth of one megahertz or equivalent and no less video
   bandwidth shall be used to measure wideband EIRP density for purposes of
   this rule, and narrowband EIRP shall be measured with a root-mean-square
   detector function with a resolution bandwidth of one kilohertz or
   equivalent.

   (c) Applicants for an ancillary terrestrial component to be used in
   conjunction with a mobile-satellite service system using CDMA technology
   shall coordinate the use of the Big LEO MSS spectrum designated for CDMA
   systems using the framework established by the ITU in Recommendation ITU-R
   M.1186 “Technical Considerations for the Coordination Between Mobile
   Satellite Service (MSS) Networks Utilizing Code Division Multiple Access
   (CDMA) and Other Spread Spectrum Techniques in the 1–3 GHz Band” (1995).
   Recommendation ITU-R M.1186 is incorporated by reference. The Director of
   the Federal Register approves this incorporation by reference in accordance
   with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this standard can be
   inspected at the Federal Communications Commission, 445 12th Street, SW.,
   Washington, DC (Reference Information Center) or at the National Archives
   and Records Administration (NARA). For information on the availability of
   this material at NARA, call 202–741–6030, or go to:
   http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_loc
   ations.html. The ITU-R Recommendations can also be purchased from the
   International Telecommunication Union (ITU), Place des Nations, CH–1211
   Geneva 20, Switzerland.

   Note to  Sec. 25.254: The preceding rules of  Sec. 25.254 are based on cdma2000 and
   IS–95 system architecture. To the extent that a Big LEO MSS licensee is able
   to demonstrate that the use of different system architectures would produce
   no greater potential interference than that produced as a result of
   implementing the rules of this section, an MSS licensee is permitted to
   apply for ATC authorization based on another system architecture.

   [ 68 FR 33653 , June 5, 2003, as amended at  69 FR 18803 , Apr. 9, 2004;  70 FR 19320 , Apr. 13, 2005]