The following definitions are issued: Active satellite. An earth satellite carrying a station intended to transmit or re-transmit radiocommunication signals.

Aeronautical advisory station. An aeronautical station used for advisory and civil defense communications with private aircraft stations.

Aeronautical fixed service. A fixed service intended for the transmission of information relating to air navigation preparation for and safety of flight.

Aeronautical fixed station. A station in the aeronautical fixed service.

Aeronautical mobile service. A mobile service between aeronautical stations and aircraft stations, or between aircraft stations, in which survival craft stations may also participate.

Aeronautical multicom land station. An aeronautical station operating in the aeronautical multicom service.

Aeronautical multicom mobile station. A mobile station operating in the aeronautical multicom service.

Aeronautical multicom service. A mobile service not open to public correspondence, used to provide communi

cations essential to conduct of activities being performed by or directed from private aircraft.

Aeronautical radionavigation service. A radionavigation service intended for the benefit of aircraft.

Aeronautical search and rescue mobile station. A mobile station used for communication with aircraft engaged in search and rescue operations.

Aeronautical station. A land station in the aeronautical mobile service. In certain instances an aeronautical station may be placed on board a ship or an earth satellite.

Aeronautical telemetering land station. A telemetering land station used in the flight testing of manned or unmanned aircraft, missiles, or major components thereof.

Aeronautical telemetering mobile station. A telemetering mobile station used in the flight testing of manned or unmanned aircraft, missiles, or major components thereof.

Aeronautical utility land station. A land station located at airdrome control towers and used for control of ground vehicles and aircraft on the ground at airdromes.

Aeronautical utility mobile station. A mobile station used for communication, at airdromes, with the aeronautical utility land station, ground vehicles, and aircraft on the ground.

Aircarrier aircraft station. An aircraft station aboard an aircraft engaged in, or essential to, transportation of passengers or cargo for hire.

Aircraft station. A mobile station in the aeronautical mobile service on board an aircraft or an air-space vehicle.

Airdrome control station. An aeronautical station providing communication between an airdrome control tower and aircraft.

Amateur service. A service of selftraining, intercommunication and technical investigations carried on by amateurs, that is, by duly authorized persons interested in radio technique solely with a personal aim and without pecuniary interest.

Amateur station. A station in the amateur service.

Aural broadcast STL station. A fixed station utilizing telephony for the transmission of aural program material between a studio and the transmitter of a broadcasting station other than an international broadcasting station, for simultaneous or delayed broadcast.

Aural broadcast intercity relay station. A fixed station utilizing telephony for the transmission of aural program material between broadcasting stations other than international broadcasting stations, for simultaneous or delayed broadcast.

Authorized frequency. The frequency assigned to a station by the Commission and specified in the instrument of authorization.

Authorized power. The power assigned to a radio station by the Commission and specified in the instrument of authorization. The authorized power does not necessarily correspond to the power used by the Commission for purposes of its Master Frequency Record MFR) and notification to the International Telecommunication Union.

Aviation instructional station. A land or mobile station in the aeronautical mobile service used for radiocommunications pertaining to instructions to students or pilots while actually operating aircraft or engaged in soaring activities.

Aviation services. Aviation services are primarily for the safe, expeditious and economical operation of aircraft. They include the aeronautical fixed service, aeronautical mobile service, aeronautical radionavigation service, and secondarily, the handling of public correspondence to and from aircraft.

Baseband. In the process of modulation, the baseband is the frequency band occupied by the aggregate of the modulating signals when first used to moduate a carrier.

Base station. A land station in the and mobile service carrying on a service with land mobile stations.

Broadcasting service. A radiocommunication service in which the trans

tions are intended for direct recep. by the general public. This service ay include sound transmissions, telen transmissions or other types of transmissions.

Broadcasting station. A station in the br.adcasting service.

Carrier. In a frequency stabilized stem, the sinusoidal component of a modulated wave whose frequency is inpendent of the modulating wave; or the output of a transmitter when the adulating wave is made zero; or a wave arcerated at a point in the transmitting

stem and subsequently modulated by

-between earth stations, when using active or passive satellites for the exchange of communications of the fixed or mobile service, or -between an earth station and stations on active satellites for the exchange of communications of the mobile service, with a view to their re-transmission to or from stations in the mobile service.

Communication-satellite space station. A space station in the communication-satellite service, on an earth satellite.

Community antenna relay service. A fixed service, the stations of which are used for the transmission of television and related audio signals, and signals of standard and FM broadcasting stations, to a terminal point from which the signals are distributed to the public by cable.

Community antenna relay station. A fixed station in the community antenna relay service.

Deep space. Space at distances from the earth equal to or greater than the distance between the earth and the moon.

Disaster communications service. A service of fixed, land, and mobile stations licensed or authorized to provide essential communications incident to or in connection with disaster or other incidents which involve loss of communications facilities normally available or which require the temporary establishment of communications facilities beyond those normally available.

Domestic fixed public service. A fixed service, the stations of which are open to public correspondence, for radiocommunications originating and terminating solely at points all of which lie within: (a) the State of Alaska, or (b) the State of Hawaii, or (c) the contiguous 48 states and the District of Columbia, or (d) a single possession of the United States. Generally, in cases where service is afforded on frequencies above 72 Mc/s, radiocommunications between the contiguous 48 States (including the District of Columbia) and Canada or Mexico, or radiocommunications between the State of Alaska and Canada, are deemed to be in the domestic fixed public service.

Domestic fixed public station. A fixed station in the domestic fixed public service.

Domestic public radiocommunication services. The land mobile and domestic fixed public services the stations of which are open to public correspondence. Duplex operation. Operating method in which transmission is possible simultaneously in both directions.

Earth station. A station in the space service located either on the earth's surface, including on board a ship, or on board an aircraft.

Experimental station. A station utilizing radio waves in experiments with a view to the development of science or technique. This definition does not include amateur stations.

Facsimile. A system of telecommunication for the transmission of fixed images, with or without half-tones, with a view to their reproduction in a permanent form.

Facsimile broadcasting station. A broadcasting station utilizing facsimile primarily.

Fixed earth station. An earth station intended to be used at a specified fixed point.

Fixed public control service. A fixed service carried on for the purpose of transmitting intelligence between transmitting or receiving stations in the public radiocommunication services and the message centers or control points associated therewith.

Fixed service. A service of radiocommunication between specified fixed points.

Fixed station. A station in the fixed service.

Flight test station. An aeronautical station used for the transmission of essential communications in connection with the testing of aircraft or major components of aircraft: Provided, however, flight test stations, when operating on the frequency 3281 kc/s, are designated as land stations, only with respect. to operation on the frequency 3281 kc/s.

FM broadcasting station. A broadcasting station utilizing telephony by means of frequency modulation, and when authorized under a Subsidiary Communications Authorization (SCA), utilizing F9 emissions.

Gc/s (gigacycle per second). A gigacycle per second (Gc/s) means one thousand megacycles.

Harmful interference.

Any emission,

radiation or induction which endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs, or repeatedly interrupts a radiocommunication service operating in accordance with this chapter.

Industrial radio services. Any service of radiocommunication essential to, operated by, and for the sole use of, those enterprises which for purposes of safety or other necessity require radiocommunication in order to function efficiently, the radio transmitting facilities of which are defined as fixed, land, mobile or radiolocation stations.

Industrial, scientific and medical equipment (ISM equipment). Devices which use radio waves for industrial, scientific, medical, or any other purposes including the transfer of energy by radio and which are neither used nor intended to be used for radiocommunication.

Instructional television fixed station. A fixed station operated by an educational organization and used primarily for the transmission of visual and aural instructional, cultural and other types of educational material to one or more fixed: receiving locations.

Instrument landing system. A radionavigation system which provides aircraft with horizontal and vertical guidance just before and during landing and, at certain fixed points, indicates the distance to the reference point of landing. Instrument landing system glide path. A system of vertical guidance embodied in the instrument landing system which indicates the vertical deviation of the aircraft from its optimum path of descent.

Instrument landing system localizer. A system of horizontal guidance embodied in the instrument landing system which indicates the horizontal deviation of the aircraft from its optimum path of descent along the axis of the runway.

International broadcasting station. A broadcasting station employing frequences allocated to the broadcasting service between 5950 kc/s and 26100 kc/s, whose transmissions are intended to be received directly by the general public in foreign

countries.

International control station. A fixed station in the fixed public control service associated directly with the international fixed public radiocommunication service. International fixed public radio servce A fixed service, the stations of which are open to public correspondence and which, in general, is intended to provide radiocommunication between any one of the contiguous 48 states (including the District of Columbia) and the State of Alaska, or the State of Hawaii, or any U.S. possession or any foreign point; or between any U.S. possession and any other point; or between the State of Alaska and any other point; or between the State of Hawaii and any other point. In addition, radiocommunications within the contiguous 48 states (including the District of Columbua in connection with the relaying of International traffic between stations which provide the above service, are also deemed to be in the international fixed public radiocommunication service; proVaded, however, that communications

ely between Alaska, or any one of the contiguous 48 states (including the District of Columbia), and either Canada or Mexico are not deemed to be in the international fixed public radiocommunication service when such radiocommunications are transmitted on frequencies above 72 Mc/s.

International fixed public station. A fixed station in the international fixed Public radio service.

Interzone station. A fixed station in the public safety (police) radio service using radiotelegraphy (A1 emission) for communication with zone stations within the zone and with interzone stations in other zones.

Ionospheric scatter. The propagation of radio waves by scattering as a result of irregularities or discontinuities in the ionization of the ionosphere.

Kc/s (kilocycle per second). A kilocycle per second (kc/s) means one thousand cycles per second.

Land mobile service. A mobile service between base stations and land mobile stations, or between land mobile stations.

Land mobile station. A mobile station in the land mobile service capable of surface movement within the geographical limits of a country or continent.

Land station. A station in the mobile service not intended to be used while in motion.

Land transportation radio service. Any private service of radiocommunication essential to the conduct of certain land transportation activities and operated for the use of persons engaged in those activities, the transmitting facilities of which are defined as fixed, land, mobile or radiolocation stations.

Localizer station. A radionavigation land station in the aeronautical radionavigation service which provides signals for the lateral guidance of aircraft with respect to a runway centerline.

Loran station. A long distance radionavigation land station transmitting synchronized pulses. Hyperbolic lines of position are determined by the measurement of the difference in the time of arrival of these pulses.

Marine radiobeacon station. A radionavigation land station, the emissions of which are intended to enable a ship station to determine its bearing or its direction in relation to the marine radiobeacon station.

Maritime mobile service. A mobile service between coast stations and ship stations, or between ship stations, in which survival craft stations may also participate.

Maritime radionavigation service. A radionavigation service intended for the benefit of ships.

Marker beacon. A transmitter in the aeronautical radionavigation service which radiates vertically a distinctive pattern for providing position information to aircraft.

Mc/s (megacycle per second). A megacycle per second (Mc/s) means one thousand kilocycles.

Meteorological aids service. A radiocommunication service used for meteorological, including hydrological, observations and exploration.

Meteorological-satellite earth station. An earth station in the meteorologicalsatellite service.

A

Meteorological-satellite service. space service in which the results of meteorological observations, made by instruments on earth satellites, are transmitted to earth stations by space stations on these satellites.

Meteorological-satellite space station. A space station in the meteorologicalsatellite service, on an earth satellite. Mobile earth station. An earth station intended to be used while in motion or during halts at unspecified points.

Mobile, except television pickup, station. Any mobile station other than a television pickup station.

Mobile service. A service of radio communication between mobile and land stations, or between mobile stations.

Mobile station. A station in the mobile service intended to be used while in motion or during halts at unspecified points.

Modulation. The process of producing a wave some characteristic of which varies as a function of the instantaneous value of another wave, called the modulating wave.

Omni-directional range station. A radionavigation land station in the aeronautical radionavigation service providing direct indication of the bearing (omni-bearing) of that station from an aircraft.

Operational fixed station. A fixed station, not open to public correspondence, operated by and for the sole use of those agencies operating their own radiocommunication facilities in the public safety, industrial, land transportation, marine, or aviation service.

Operational land station. A land station, excluding aeronautical stations, not open to public correspondence, operated by and for the sole use of those agencies operating their own radiocommunication facilities in the public safety, industrial, land transportation, marine, or aviation services.

Operational mobile station, A mobile station, excluding aircraft stations, not open to public correspondens, operated

by and for the sole use of those agencies operating their own radiocommunication facilities in the public safety, industrial, land transportation, marine, or aviation services.

Passive satellite. An earth satellite intended to transmit radiocommunication signals by reflection.

Port operations. Communications in or near a port, or in locks or waterways, between coast stations and ship stations, or between ship stations, in which messages are restricted to those relating to the movement and safety of ships and, in emergency, to the safety of persons.

Primary standard of frequency. The primary standard of frequency for radio frequency measurements shall be the national standard of frequency maintained by the National Bureau of Standards, Department of Commerce, Washington, D.C. The operating frequency of all radio stations will be determined by comparison with this standard or the standard signals of station WWV of the National Bureau of Standards.

Private aircraft station. An aircraft station on board an aircraft not operated as an air carrier.

Public correspondence. Any telecommunication which the offices and stations must, by reason of their being at the disposal of the public, accept for transmission.

Public safety radio service. Any service of radiocommunication essential either to the discharge of non-Federal governmental functions or the alleviation of an emergency endangering life or property, the radio transmitting facilities of which are defined as fixed, land, mobile, or radiolocation stations.

Racon. A radionavigation system transmitting, automatically or in response to a predetermined received signal, a pulsed radio signal with specific characteristics.

Racon station. A radionavigation land station which employs a racon.

Radar. A radiodetermination system based on comparison of reference signals with radio signals reflected, or retransmitted, from the position to be determined.

Radio. A general term applied to the use of radio waves.

Radio altimeter. A radionavigation equipment, on board an aircraft, which makes use of the reflection of radio waves from the ground to determine the height of the aircraft above the ground.