ting, 25/16 HF communication antennas, 17/17 IDFT (Inverse Discrete Fourier Intelligent networks, 11/14, 31/16 Hi Vision HDTV, 57/11 Transform), 2/9 cellphone, 47/17 High Definition TV see HDTV IDN (Integrated Digital Network), INTELSAT satellites, 51/3, 51/9-17 High Level Data Link Control see HDLC 29/10-12 antenna for, 17/13, 17/15 High level languages, 25/12-14 signalling, 43/8-11 Inter-register signalling, 34/8-9, 43/7 Histograms, 1/3 IEC (International Electrotechnical Interactive Voice Response system, 35/5 HLR (Home Location Register), Commission), 22/13, 22/14-15 Interfaces, PCN/cellphones, 47/10, 48/4 O and P members, 22/13 B-ISDN layers, 44/15-17 HOL formal software design, 25/5 safety standards, 23/4, 23/9 ISDN layers, 44/6-10 Holland, Paging frequencies, 45/3-4 IEEE (Institute for Electrical and measurements on, 61/3-7 Homes passed, cable TV, 57/18 Electronics Engineers), 22/24, 22/25 physical, mutiplexing, 40/13 Hop counts, multiplexed traffic, 40/15 IFL (International Frequency List), 26/5 Interference, 26/5-6 Horizontal polarisation, 6/5-6 IFRB (International Frequency cellphone co-channel, 47/5-7 Horn feeds, reflector antennas, 17/10-12 Registration Board) of ITU, 22/7, 26/9 coupling, EMC, 23/15-16 Hospitals, call management, 36/5 Illuminance/illumination, 7/5 cross-frontier, 26/5 Hotels, call management, 36/5 Illumination efficiency, antenna, 17/9 prediction, 9/17 HRP (Horizontal Radiation Pattern), 6/11, IMEI (International Mobile Equipment satellite link problems, 26/7-10, 51/4-5 Identity), cellphone, 47/14 see also Noise HRX (Hypothetical Reference Immunity standards, EMC, 23/13-14 Interferomters, 7/7-9 Connection), 61/8-10 imp unit of video impairment, 57/22-3 Interlacing, television, 57/4 Index/11 Interleaved codes, 14/6 modem comparison, 39/3, 39/13 Kirchhoff's integral, 6/6 Interleaving, TDM, 40/5 multipoint systems, 52/3, 52/7-8 Knife edge diffraction, 6/14 Intermodulation distortion, 10/9 network aspects, 44/5 Knowledge based systems see KBS Intermodulation noise, 10/11 numbering and add