Goto Section: 25.102 | 25.104 | Table of Contents
Revised as of September 1, 2021
Goto Year:2020 |
§ 25.103 Definitions.
Terms with definitions including the “(RR)” designation are defined in
the same way in § 2.1 of this chapter and in the Radio Regulations of
the International Telecommunication Union.
1.5/1.6 GHz Mobile-Satellite Service. Mobile-Satellite Service provided
in any portion of the 1525-1559 MHz space-to-Earth band and the
1626.5-1660.5 MHz Earth-to-space band, which are referred to in this
rule part as the “1.5/1.6 GHz MSS bands.”
1.6/2.4 GHz Mobile-Satellite Service. A Mobile-Satellite Service that
operates in the 1610-1626.5 MHz and 2483.5-2500 MHz bands, or in any
2 GHz Mobile-Satellite Service. A Mobile-Satellite Service that
operates in the 2000-2020 MHz and 2180-2200 MHz bands, or in any
17/24 GHz Broadcasting-Satellite Service (17/24 GHz BSS). A
radiocommunication service involving transmission from one or more
feeder-link earth stations to other earth stations via geostationary
satellites, in the 17.3-17.7 GHz (space-to-Earth) (domestic
allocation), 17.3-17.8 GHz (space-to-Earth) (international allocation)
and 24.75-25.25 GHz (Earth-to-space) bands. For purposes of the
application processing provisions of this part, the 17/24 GHz BSS is a
GSO-like service. Unless specifically stated otherwise, 17/24 GHz BSS
systems are subject to the rules in this part applicable to FSS.
Ancillary Terrestrial Component (ATC). A terrestrial communications
network used in conjunction with a qualifying satellite network system
authorized pursuant to these rules and the conditions established in
the Orders issued in IB Docket No. 01-185, Flexibility for Delivery of
Communications by Mobile-Satellite Service Providers in the 2 GHz Band,
the L-Band, and the 1.6/2.4 GHz Band.
Ancillary Terrestrial Component (ATC) base station. A terrestrial fixed
facility used to transmit communications to or receive communications
from one or more ancillary terrestrial component mobile terminals.
Ancillary Terrestrial Component (ATC) mobile terminal. A terrestrial
mobile facility used to transmit communications to or receive
communications from an ancillary terrestrial component base station or
a space station.
Blanket license. A license for:
(1) Multiple earth stations in the FSS or MSS, or for SDARS terrestrial
repeaters, that may be operated anywhere within a geographic area
specified in the license; or
(2) For multiple space stations in non-geostationary-orbit.
Contiguous United States (CONUS). For purposes of subparts B and C of
this part, the contiguous United States consists of the contiguous 48
states and the District of Columbia as defined by Partial Economic
Areas Nos. 1-41, 43-211, 213-263, 265-297, 299-359, and 361-411, which
includes areas within 12 nautical miles of the U.S. Gulf coastline. In
this context, the rest of the United States includes the Honolulu,
Anchorage, Kodiak, Fairbanks, Juneau, Puerto Rico, Guam-Northern
Mariana Islands, U.S. Virgin Islands, American Samoa, and the Gulf of
Mexico PEAs (Nos. 42, 212, 264, 298, 360, 412-416). See § 27.6(m) of
Conventional C-band. The 3700-4200 MHz (space-to-Earth) and 5925-6425
MHz (Earth-to-space) FSS frequency bands.
Conventional Ka-band. The 18.3-18.8 GHz (space-to-Earth), 19.7-20.2 GHz
(space-to-Earth), 28.35-28.6 GHz (Earth-to-space), and 29.25-30.0 GHz
(Earth-to-space) frequency bands, which the Commission has designated
as primary for GSO FSS operation.
Conventional Ku-band. The 11.7-12.2 GHz (space-to-Earth) and 14.0-14.5
GHz (Earth-to-space) FSS frequency bands.
Coordination distance. When determining the need for coordination, the
distance on a given azimuth from an earth station sharing the same
frequency band with terrestrial stations, or from a transmitting earth
station sharing the same bidirectionally allocated frequency band with
receiving earth stations, beyond which the level of permissible
interference will not be exceeded and coordination is therefore not
Direct Broadcast Satellite (DBS) Service. A radiocommunication service
in which signals transmitted or retransmitted by Broadcasting-Satellite
Service space stations in the 12.2-12.7 GHz band are intended for
direct reception by subscribers or the general public. For the purposes
of this definition, the term direct reception includes individual
reception and community reception.
Earth station. A station located either on the Earth's surface or
within the major portion of the Earth's atmosphere intended for
(1) With one or more space stations; or
(2) With one or more stations of the same kind by means of one or more
reflecting satellites or other objects in space. (RR)
Earth Station Aboard Aircraft (ESAA). An earth station operating aboard
an aircraft that receives from and transmits to Fixed-Satellite Service
Earth Station in Motion (ESIM). A term that collectively designates
ESV, VMES and ESAA earth stations, as defined in this section.
Earth Station on Vessel (ESV). An earth station onboard a craft
designed for traveling on water, receiving from and transmitting to
Fixed-Satellite Service space stations.
Equivalent diameter. When circular aperture reflector antennas are
employed, the size of the antenna is generally expressed as the
diameter of the antenna's main reflector. When non-reflector or
non-circular-aperture antennas are employed, the equivalent diameter is
the diameter of a hypothetical circular-aperture antenna with the same
aperture area as the actual antenna. For example, an elliptical
aperture antenna with major axis a and minor axis b will have an
equivalent diameter of [a × b]1/2. A rectangular aperture antenna with
length l and width w will have an equivalent diameter of [4(l ×
Equivalent Power Flux Density (EPFD). The sum of the power flux
densities produced at a geostationary-orbit receive earth or space
station on the Earth's surface or in the geostationary orbit, as
appropriate, by all the transmit stations within a
non-geostationary-orbit Fixed-Satellite Service system, taking into
account the off-axis discrimination of a reference receiving antenna
assumed to be pointing in its nominal direction. The equivalent power
flux density, in dB(W/m2) in the reference bandwidth, is calculated
using the following formula:
eCFR graphic er12fe14.001.gif
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Na is the number of transmit stations in the non-geostationary orbit
system that are visible from the GSO receive station considered on the
Earth's surface or in the geostationary orbit, as appropriate;
i is the index of the transmit station considered in the
non-geostationary orbit system;
Pi is the RF power at the input of the antenna of the transmit station,
considered in the non-geostationary orbit system in dBW in the
θi is the off-axis angle between the boresight of the transmit station
considered in the non-geostationary orbit system and the direction of
the GSO receive station;
Gt(θi) is the transmit antenna gain (as a ratio) of the station
considered in the non-geostationary orbit system in the direction of
the GSO receive station;
di is the distance in meters between the transmit station considered in
the non-geostationary orbit system and the GSO receive station;
φi is the off-axis angle between the boresight of the antenna of the
GSO receive station and the direction of the ith transmit station
considered in the non-geostationary orbit system;
Gr(θi) is the receive antenna gain (as a ratio) of the GSO receive
station in the direction of the ith transmit station considered in the
non-geostationary orbit system;
Gr,max is the maximum gain (as a ratio) of the antenna of the GSO
Extended C-band. The 3600-3700 MHz (space-to-Earth), 5850-5925 MHz
(Earth-to-space), and 6425-6725 MHz (Earth-to-space) FSS frequency
Extended Ku-band. The 10.95-11.2 GHz (space-to-Earth), 11.45-11.7 GHz
(space-to-Earth), and 13.75-14.0 GHz bands (Earth-to-space) FSS
Feeder link. A radio link from a fixed earth station at a given
location to a space station, or vice versa, conveying information for a
space radiocommunication service other than the Fixed-Satellite
Service. The given location may be at a specified fixed point or at any
fixed point within specified areas. (RR)
Fixed earth station. An earth station intended to be used at a fixed
position. The position may be a specified fixed point or any fixed
point within a specified area.
Fixed-Satellite Service (FSS). A radiocommunication service between
earth stations at given positions, when one or more satellites are
used; the given position may be a specified fixed point or any fixed
point within specified areas; in some cases this service includes
satellite-to-satellite links, which may also be operated in the
inter-satellite service; the Fixed-Satellite Service may also include
feeder links of other space radiocommunication services. (RR)
Geostationary-orbit (GSO) satellite. A geosynchronous satellite whose
circular and direct orbit lies in the plane of the Earth's equator and
which thus remains fixed relative to the Earth; by extension, a
geosynchronous satellite which remains approximately fixed relative to
Inter-Satellite Service. A radiocommunication service providing links
between artificial earth satellites.
Ku band. In this rule part, the terms “Ku band” and “conventional Ku
band” refer to the 11.7-12.2 GHz (space-to-Earth) and 14.0-14.5 GHz
(Earth-to-space) bands. These paired bands are allocated to the
Fixed-Satellite Service and are also referred to as the 12/14 GHz
Land earth station. An earth station in the Fixed-Satellite Service or,
in some cases, in the Mobile-Satellite Service, located at a specified
fixed point or within a specified area on land to provide a feeder link
for the Mobile-Satellite Service. (RR)
Land Mobile Earth Station. A mobile earth station in the land
mobile-satellite service capable of surface movement within the
geographical limits of a country or continent. (RR)
Mobile Earth Station. An earth station in the Mobile-Satellite Service
intended to be used while in motion or during halts at unspecified
Mobile-Satellite Service (MSS). (1) A radiocommunication service:
(i) Between mobile earth stations and one or more space stations, or
between space stations used by this service; or
(ii) Between mobile earth stations, by means of one or more space
(2) This service may also include feeder links necessary for its
Network Control and Monitoring Center (NCMC). An NCMC, as used in Part
25, is a facility that has the capability to remotely control earth
stations operating as part of a satellite network or system.
NGSO. Non-geostationary orbit.
NGSO FSS gateway earth station. An earth station or complex of multiple
earth station antennas that supports the routing and switching
functions of an NGSO FSS system and that does not originate or
terminate communication traffic. An NGSO FSS gateway earth station may
also be used for telemetry, tracking, and command transmissions and is
not for the exclusive use of any customer.
Non-Voice, Non-Geostationary (NVNG) Mobile-Satellite Service. A
Mobile-Satellite Service reserved for use by non-geostationary
satellites in the provision of non-voice communications which may
include satellite links between land earth stations at fixed locations.
Permitted Space Station List. A list of all U.S.-licensed
geostationary-orbit space stations providing Fixed-Satellite Service in
the conventional C band, the conventional Ku band, or the 18.3-18.8
GHz, 19.7-20.2 GHz, 28.35-28.6 GHz, and 29.25-30.0 GHz bands, as well
as non-U.S.-licensed geostationary-orbit space stations approved for
U.S. market access to provide Fixed-Satellite Service in the
conventional C band, conventional Ku band, or 18.3-18.8 GHz, 19.7-20.2
GHz, 28.35-28.6 GHz, and 29.25-30.0 GHz bands.
Plane perpendicular to the GSO arc. The plane that is perpendicular to
the “plane tangent to the GSO arc,” as defined below, and includes a
line between the earth station in question and the GSO space station
that it is communicating with.
Plane tangent to the GSO arc. The plane defined by the location of an
earth station's transmitting antenna and a line in the equatorial plane
that is tangent to the GSO arc at the location of the GSO space station
that the earth station is communicating with.
Power flux density (PFD). The amount of power flow through a unit area
within a unit bandwidth. The units of power flux density are those of
power spectral density per unit area, namely watts per hertz per square
meter. These units are generally expressed in decibel form as
dB(W/Hz/m2), dB(W/m2) in a 4 kHz band, or dB(W/m2) in a 1 MHz band.
Power Spectral Density (PSD). The amount of an emission's transmitted
carrier power applied at the antenna input falling within the stated
bandwidth. The units of power spectral density are watts per hertz and
are generally expressed in decibel form as dB(W/Hz) when measured in a
1 Hz bandwidth, dB(W/4kHz) when measured in a 4 kHz bandwidth, or
dB(W/MHz) when measured in a 1 MHz bandwidth.
Protection areas. The geographic regions where U.S. Department of
Defense meteorological satellite systems or National Oceanic and
Atmospheric Administration meteorological satellite systems, or both
such systems, receive signals from low earth orbiting satellites. Also,
areas around NGSO MSS feeder-link earth stations in the 1.6/2.4 GHz
Mobile-Satellite Service determined in the manner specified in
Radiodetermination-Satellite Service. A radiocommunication service for
the purpose of radiodetermination involving the use of one of more
space stations. This service may also include feeder links necessary
for its own operation. (RR)
Routine processing or licensing. Expedited processing of unopposed
applications for earth stations in the FSS communicating with GSO space
stations that satisfy the criteria in § 25.211(d), § 25.212(c) through
(f), or § 25.218, include all required information, are consistent with
all Commission rules, and do not raise any policy issues. Some, but not
all, routine earth station applications are eligible for an autogrant
procedure under § 25.115(a)(3).
Satellite Digital Audio Radio Service (SDARS). A radiocommunication
service in which audio programming is digitally transmitted by one or
more space stations directly to fixed, mobile, and/or portable
stations, and which may involve complementary repeating terrestrial
transmitters and telemetry, tracking and command facilities.
Satellite system. A space system using one or more artificial earth
Selected assignment. A spectrum assignment voluntarily identified by a
2 GHz MSS licensee at the time that the licensee's first 2 GHz
Mobile-Satellite Service satellite reaches its intended orbit.
Shapeable antenna beam. A satellite transmit or receive antenna beam,
the gain pattern of which can be modified at any time without
physically repositioning a satellite antenna reflector.
Skew angle. The angle between the minor axis of an axially asymmetric
antenna beam and the plane tangent to the GSO arc.
Small satellite. An NGSO space station eligible for authorization under
the application process described in § 25.122.
Small spacecraft. An NGSO space station operating beyond Earth's orbit
that is eligible for authorization under the application process
described in § 25.123.
Space radiocommunication. Any radiocommunication involving the use of
one or more space stations or the use of one or more reflecting
satellites or other objects in space.
Space station. A station located on an object which is beyond, is
intended to go beyond, or has been beyond, the major portion of the
Earth's atmosphere. (RR)
Space system. Any group of cooperating earth stations and/or space
stations employing space radiocommunication for specific purposes. (RR)
Spacecraft. A man-made vehicle which is intended to go beyond the major
portion of the Earth's atmosphere. (RR)
Terrestrial radiocommunication. Any radiocommunication other than space
radiocommunication or radio astronomy. (RR)
Terrestrial station. A station effecting terrestrial
Two-degree-compliant space station. A GSO FSS space station operating
in the conventional or extended C-bands, the conventional or extended
Ku-bands, or the conventional Ka-band within the limits on downlink
EIRP density or PFD specified in § 25.140(a)(3) and communicating only
with earth stations operating in conformance with routine uplink
parameters specified in § 25.211(d), § 25.212(c), (d), (e), or (f), or
Vehicle-Mounted Earth Station (VMES). An earth station, operating from
a motorized vehicle that travels primarily on land, that receives from
and transmits to Fixed-Satellite Service space stations and operates
within the United States.
[ 79 FR 8311 , Feb. 12, 2014, as amended at 79 FR 26868 , May 12, 2014; 81 FR 55324 , Aug. 18, 2016; 83 FR 34489 , July 20, 2018; 84 FR 53651 , Oct.
8, 2019; 84 FR 66779 , Dec. 5, 2019; 85 FR 22864 , Apr. 23, 2020; 85 FR 44786 , July 24, 2020; 85 FR 43733 , July 20, 2020]
Goto Section: 25.102 | 25.104
Goto Year: 2020 |
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