That mode of operation in which communication between two terminals occurs in either direction but in only one direction at a time. Contrast with duplex or simplex operation. Note: Half-duplex operation may occur on half-duplex circuits or on duplex circuits, but it may not occur on simplex circuits.
Half-duplex operation Read More »
A circuit switched operational mode for transferring (transporting and switching) user information through a network. Contrast with packet switching mode.
A band of frequencies used for satellite and terrestrial communications. The range of frequencies from 4 to 6 gigaHertz (billion cycles per second) is used by most communications satellites.
Data represented by a physical quantity that is considered to be continuously variable and whose magnitude is made directly proportional to the data or to a suitable function of the data.
A method of accessing a satellite using time separation; sending simultaneous data streams interleaved using a clock to separate the various data packets.
Time Division Multiple Access (TDMA) Read More »
A satellite receiving antenna, also known as a downlink or a backyard dish
Television Receive Only (TVRO) Read More »
Digital transmission in which the time interval between any two similar significant instants in the overall bit stream is always an integral number of unit intervals. Note: Isochronous and anisochronous are characteristics, while synchronous and asynchronous are relationships.
Synchronous transmission Read More »
The focusing of energy from a satellite to the ground to concentrate the limited available effective radiated power (EIRP).
The process of interconnecting a number of individual networks to provide a path from a terminal or a host on one network to a terminal or a host on another network. The networks involved may be of the same type, or they may be of different types. However, each network is distinct, with its own
Decibel; an analog unit of measure of signal strength, volume, or signal loss due to resistance as expressed in logarithmic form.
A cryptographic algorithm for the protection of unclassified computer data, issued as Federal Information Processing Standard Publication 46-1.
Data Encryption Standard (DES) Read More »
Representation of facts, concepts, or instructions in a formalized manner suitable for communication, interpretation, or processing by humans or by automatic means.
A digital modulation scheme used in transmission communications.
Binary Phase Shift Keying (BPSK) Read More »
A unit measuring the rate of information flow, with five baud roughly equivalent to one alphanumeric character.
Point-to-point transmission from a remote site back to a central site for further distribution.
