rotation, 9/5 ionosphere signals, 6/21-2 European Parliament, EEC, 22/15 Faraday's law of electromagnetic surface waves, 6/24 EUTELSAT satellite, 51/3, 51/18 induction, 6/3 Filtering, minimising EMC, 23/20-4 EWOS (European Workshop on open FAS (Frame Alignment Signal), Filters, systems), 16/8, 22/14, 22/22-3 error detection, 61/11 active, 19/13 Exchanges see Telephone exchanges; TDM, 21/9-10 anti-aliasing, 19/13 Telephone switching systems Fast Fourier transform see FFT mains, safety problems, 23/8 Exclusive telephone service, 31/6 Fast packet switching, matched, impulse response, 19/6-7 Exhaustive transmission, multiple access, Cell Relay, 55/3, 55/6-10 media, 33/5 13/18 Frame Relay, 55/3-6 switched capacitor, 19/13 Expanders, 4/12 in SDH, 42/26 Finite schemes, entropy of, 4/5 Expert systems, 25/7 Fault management, 16/5 FIPS (Federal Information Exponential distribution, 1/8, 1/9 Fault tracing, networks, 40/15 Processing Standards), 22/24 Exponential probability density, 13/3 FAW (Frame Alignment Word), 28/16-19 FITL (Fibre In The Loop), 11/14 Fax see Facsimile Fixed routing, implied costs, 5/8-10 accommodation, 7/11 FCC earth station antenna, 17/12 Fixed station links, frequency allocations, defects, 7/11 FCC (Federal Communications 26/7, 26/16 structure and performance, 7/9-11 Commission), 11/6, 22/24 Flash converters, 19/14 Eye diagram, digital signals, 28/5-6 FCCH (Frequency Correction Channel), Fletcher-Munsen curves of hearing, 8/6 Eyring formula, sound absorption, 8/10 PCN, 48/8 Flexible intercept, Centrex, 35/3 FCS (Frame Check Sequence), Flicker noise, 10/11 packet switching, 54/9 Flicker, television, 57/3-4 F layer/region, 9/3-5, 27/6, 27/8 PMR, 46/12 Flood wiring, building cabling, 33/4 see also Ionosphere statistical TDM, 40/6 Flutter fading, 9/6 F-region see Ionosphere FDDI (Fibre Distributed Data Interface) FM (Frequency Modulation), 18/7-12 Fabry Perot etalon/interferometer, 7/7-8 LAN, 42/26 modems, 39/4-5 Fabry Perot laser, 53/11 FDL (Facilities Data Link), 21/8 FMS (File Management Subsystem), I