Glossary Terms Beginning F

0-9 : A : B : C : D : E : F : G : H : I : J : K : L : M

N : O : P : Q : R : S : T : U : V : W : X : Y : Z

Fade margin: The difference between the calculated or actual performance of a link and the threshold of operation; see Threshold margin.
FDMA: Frequency division multiple access: refers to the use of multiple carriers within the same transponder where each uplink has been assigned a frequency slot and bandwidth, usually employed in conjunction with frequency modulation.
FEC: Forward error correction: data correction signal added at the uplink to enhance concealment of errors that occur on the passage of the signal via the satellite to the downlink.
Feed: Generic term for the feedhorn, or the feedhorn and the antenna; a generic term for a transmission.
Feeder link: Backbone Earth-satellite links in contribution and distribution networks.
Feedhorn: In SNG, the assembly on the end of the arm extending out from the antenna from which signals are transmitted into the focus of the antenna.
Fibre-optic: Transmission process using mono-frequency sources of light modulated with a signal or group of signals transmitted through a glass fibre.
Field: Partial scan of a frame; there are two fields in a single TV frame.
Figure of merit: G/T: a measure of the performance of a downlink station expressed in units of dB/K, depending on the receive antenna and low noise amplifier combination G (in dBi), and the amount of receiving system noise T expressed as a temperature in kelvin (K). The higher the G/T number, the better the system.
Firewire: IEEE 1394: data transfer standard for consumer and semi-professional audio-visual devices.
Flange power: The output power of the HPA delivered to the output port for delivery to the uplink antenna.
Flight-case: Electronics transit case built for ruggedness, typically made from aluminium alloy or polypropylene, with internal shockproofing, to withstand the rigours of shipping by air.
Flux-gate compass: Electronic compass.
Flyaway: Transportable earth station used for SNG which can be broken down and transported in cases to location.
FM: Frequency modulation.
Footprint: Arrangement of satellite coverage beams to cover a particular area; a map of the signal strength of a satellite transponder showing the EIRP contours of equal signal strengths as they cover the Earth's surface.
Forward error correction: FEC: inner convolutional coding that adds unique codes to the digital signal at the source so errors can be detected and corrected at the destination.
fps: Frames per second.
Frame: A single TV picture is referred to as a 'frame' and there are two 'fields' in every frame.
Frequency: The number of times that an electromagnetic wave goes through a complete cycle in one second. One cycle per second is referred to as 1 Hertz (Hz) and is the basic measurement of frequency.
Frequency band: Specific span of electromagnetic spectrum.
Frequency co-ordination: Process to analyse and eliminate frequency interference between different satellite systems or between terrestrial microwave systems and satellites.
Frequency modulation: Process whereby a carrier signal is shifted up and down in frequency ('deviates') from its 'at rest' (centre) frequency in direct relationship to the amplitude of the baseband signal.
FSS: Fixed-Satellite Service: ITU designation.