| Feed | assembly at the focus of a reflector antenna, usually consisting of a feed horn and often other equipment such as an OMT and part of the tracking system (particularly in larger antennas) |
| Feed | transmission of video signals from a distribution centre |
| Feeder link | a transmission in the FSS band which will ultimately be retransmitted by another service, for example by the broadcasting satellite service |
| Feedhorn | a horn antenna normally placed at the focus of a parabolic antenna to radiate or collect RF signals |
| Filter | a device that allows only a predetermined range of frequencies to pass through |
| Finger | an individual digital channel of a rake receiver; also called a tine |
| Firmware | software programmed in a non-volatile memory |
| Fixed Assignment TDMA (FA-TDMA) | is a synchronised variant of TDMA in which transmissions only occur in exclusively allocated time slots |
| Fixed Satellite Service | the satellite radiocommunications service between fixed earth stations on the earth's surface |
| Flow control | any technique for governing the flow of information through a network |
| Fly-away terminal | transportable satellite news gathering terminal designed to be packed into several containers which can be shipped by commercial airliner |
| Footprint | the area on the Earth in which a satellite's signals can be received |
| Footprint | the contour map of received signal strength from a satellite |
| Forward Error Correction (FEC) | the addition of extra characters to blocks of a message to allow a receiver to detect errors and correct them without requiring the retransmission of the message |
| Fragment | a piece of a larger packet that has been broken down into smaller units |
| Fragmentation | the process of breaking a packet of data into smaller packets for transmission over a link which cannot support the original packet size |
| Frame | a set of bits that form an elementary block of data to be sent over a communications channel; usually a frame contains its own control information, including the transmission address and data for error correction |
| Frame check sequence | a CRC remainder transmitted at the end of a frame |
| Frame relay | a packet switched protocol for connecting devices on a wide area network (WAN) |
| Frequency coordination | the process by which the frequencies and power levels assigned to a satellite or earth station are chosen to reduce interference with other satellites to an acceptable level |
| Frequency Division Multiple Access (FDMA) | a technique in which several earth stations share a repeater by transmitting simultaneously at different frequencies |
| Frequency Division Multiplexing (FDM) | a technique in which the frequency range is divided into narrower bands, each of which is occupied by a separate channel |
| Frequency Modulation (FM) | a technique in which the frequency of a carrier wave is changed in proportion to the variations in strength of a baseband signal |
| Frequency reuse | the technique of using the same frequency simultaneously in a system for more than one transmission, for example in different beams from a satellite |
| Frequency Shift Keying (FSK) | an FM technique in which different states of the baseband signal are transmitted as different frequencies of the carrier wave |
| Full duplex | transmission in two directions in which the transmission is in both directions at the same time |
| Full time service | service offered on a continuous 24 hours per day basis |
