ivate data net- ority, appointed by the President to regulate all inter- work for use by government departments.) state and international telecommunications.) Gross Domestic Product. (Measure of output from a Frame Check Sequence. (Field added to a trans- country.) mitted frame to check for errors.) Global European Network. (Joint venture between Fibre Distributed Digital Interface. (Standard for European PTOs to provide high speed leased line optical fibre transmission.) and switched services. Likely to be replaced by Facilities Data Link. (See EOC.) METRAN in mid 1990s.) Frequency Division Multiplexing. (Signal multi- Geodetic Earth Orbiting Satellite. plexing technique.) GigaHerts. (Measure of frequency. Equal to Frequency Division Multiple Access. (Multiple ac- 1000000000 cycles per second. See Hertz or Hz.) cess technique based on FDM.) Gaussian Minimum Shift Keying. (Modulation Full Duplex. (Transmission system in which the two technique, as used in GSM.) stations connected by a link can transmit and receive Government Network Management Profile. (Gov- simultaneously.) ernment procurement standard for network manage- Feedforward Error Correction. (Also called Forward ment, as part of GOSIP.) Error Correction. Technique for correcting errors Gross National Product. due to transmission.) Geostationary Operational Environmental Satellite. Far End Crosstalk. Grade of Service. (Measure of service performance Flat Fade Margin. (Used in microwave system de- as perceived by the user.) sign.) GOSIP Government OSI Profile. (Government procure- Fast Frequency Shift Keying. ment standard.) Frequency Hopping Spread Spectrum. Global Positioning System. (Usually refers to satel- First In First Out. (Technique for buffering data.) lite based vehicle positioning.) Federal Information Processing Standards. (De- Group Switching Centre. (Part of the hierarchy of veloped in US by NIST.) switching in BT's network. Also called the primary Fibre In The Loop. (Fibre optic cable access in the trunk switching centre by CCITT.) local 