Goto Section: 25.253 | 25.255 | Table of Contents
FCC 25.254
Revised as of October 2, 2015
Goto Year:2014 |
2016
§ 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 § 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 1.6/2.4 GHz Mobile-Satellite Service
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.
(d) To avoid interference to an adjacent channel licensee in the Broadband
Radio Service (BRS), the power of any ATC base station emission above 2495
MHz shall be attenuated below the transmitter power (P) measured in watts in
accordance with the standards below. If these measures do not resolve a
documented interference complaint received from the adjacent channel BRS
licensee, the provisions of § 25.255 shall apply.
(1) For base stations, the attenuation shall be not less than 43 + 10 log
(P) dB at the upper edge of the authorized ATC band, unless a documented
interference complaint is received from an adjacent channel licensee in the
BRS. Provided that a documented interference complaint cannot be mutually
resolved between the parties, the following additional attenuation
requirements set forth in subsections (2)-(5) shall apply:
(2) If a pre-existing BRS base station suffers harmful interference from
emissions caused by a new or modified ATC base station located 1.5 km or
more away, within 24 hours of the receipt of a documented interference
complaint the ATC licensee must attenuate its emissions by at least 67 + 10
log (P) dB measured at 3 megahertz above the edge of the authorized ATC
band, and shall immediately notify the complaining licensee upon
implementation of the additional attenuation.
(3) If a pre-existing BRS base station suffers harmful interference from
emissions caused by a new or modified ATC base station located less than 1.5
km away, within 24 hours of the receipt of a documented interference
complaint the ATC licensee must attenuate its emissions by at least 67 + 10
log (P) −20 log(Dkm/1.5) dB measured at 3 megahertz above the edge of the
authorized ATC band, or if both base stations are co-located, limit its
undesired signal level at the pre-existing BRS base station receiver(s) to
no more than −107 dBm measured in a 5.5 megahertz bandwidth and shall
immediately notify the complaining licensee upon such reduction in the
undesired signal level.
(4) If a new or modified BRS base station suffers harmful interference from
emissions caused by a pre-existing ATC base station located 1.5 km or more
away, within 60 days of receipt of a documented interference complaint the
licensee of the ATC base station must attenuate its base station emissions
by at least 67 + 10 log (P) dB measured at 3 megahertz above the edge of the
authorized ATC band.
(5) If a new or modified BRS base station suffers harmful interference from
emissions caused by a pre-existing ATC base station located less than 1.5 km
away, within 60 days of receipt of a documented interference complaint:
(i) the ATC licensee must attenuate its base station emissions by at least
67 + 10 log (P) −20 log(Dkm/1.5) dB measured 3 megahertz above the edge of
the authorized ATC band, or
(ii) if both base stations are co-located, the ATC licensee must limit its
undesired signal level at the new or modified BRS base station receiver(s)
to no more than −107 dBm measured in a 5.5 megahertz bandwidth.
(6) Compliance with these rules is based on the use of measurement
instrumentation employing a resolution bandwidth of 1 MHz or greater.
However, in the 1 MHz bands immediately above and adjacent to the 2495 MHz a
resolution bandwidth of at least one percent of the emission bandwidth of
the fundamental emission of the transmitter may be employed. A narrower
resolution bandwidth is permitted in all cases to improve measurement
accuracy, provided the measured power is integrated over the full required
measurement bandwidth (i.e., 1 MHz or 1 percent of emission bandwidth, as
specified). The emission bandwidth is defined as the width of the signal
between two points, one below the carrier center frequency and one above the
carrier center frequency, outside of which all emissions are attenuated at
least 26 dB below the transmitter power. When an emission outside of the
authorized bandwidth causes harmful interference, the Commission may, at its
discretion, require greater attenuation than specified in this section.
Note to § 25.254: The preceding rules of § 25.254 are based on cdma2000 and
IS-95 system architecture. To the extent that a 1.6/2.4 GHz Mobile-Satellite
Service licensee is able to demonstrate that the use of different system
architectures would produce no greater potential interference than would be
produced as a result of implementing the rules of this section, the licensee
may 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; 73 FR 25592 , May 5, 2008; 78 FR 8430 , Feb. 6, 2013]
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Goto Section: 25.253 | 25.255
Goto Year: 2014 |
2016
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