t carrier sense multiple NEXT (Near End Crosstalk), 15/5 access, 3/16-17 NA (Numerical Aperture), optical fibre, NIC (Near Instantaneous Compander), Normal distribution, 1/7, 1/8 19/21 Normalised frequency, optical fibres, 53/3 National reference clock source, 29/11 NICAM (Near Instantaneous Companded NPR (Noise Power Ratio), National/international numbers, 29/12-15 Audio Multiplex), 57/12, 57/16, 57/17 FDM, 20/15 NATO, facsimile for, 60/4 Nickel-cadmium battery cells, 24/13 microwave receivers, 50/16-17 Navigation systems, cw, 9/6 NIST (National Institute for Standards NSC (Network Service Centre), NAVSTAR satellite links, 9/6 and Technology), 22/14, 22/23, 22/24, System, 12 32/8, 32/12 NBS (National Bureau of Standards), NSF (Non Standard Facilities) fax 22/24 NM (Network Module), DMS, 32/19 signals, 60/12 NDC (National Destination Code), ISDN, NMs (Network Modules), DMS, 32/19 NT Meridian Mail system, 35/5 44/5-6 NMT (Nordic Mobile Telephone), NT (Network Termination), layer 1 NDC (Network Destination Code), 29/15 cellphones, 47/9 ISDN, 44/7-8 Near field terms, 6/8 NNI (Network Node Interface), NTN (Network Terminal Number), 29/15 NEF (Network Element Function), TMN, SDH, 42/6, 42/17 NTSC television, 57/7-9 16/17, 16/18 specification and measurement, 61/3 NTT (Nippon Telephone and Telegraph Neper, 8/5 No-break power supplies, 24/7-8 Corporation), 22/6 NETs (Norme Europeene de Noise, NTU (Network Terminating Unit), BT Telecommunication), 22/19, 22/21 atmospheric, 27/5 TDM, 21/15 Netview, IBM, 56/6 band limited Gaussian, 10/15 Numbering, Network management, Brownian, 20/10 PCNs, 48/7 monitoring for, 61/16 cable screening, 33/7 telephone networks, 29/12-15 OSI, 16/7-14, 40/15 compander advantages, FDM, 20/17-18 Nyquist, minimum bandwidth, digital SDH, 42/18-19 companding, 19/16 transmission, 19/3, 19/8, 28/4 SNMP, 16/19-24 crosstalk, 10/11 Nyquist rate, 4/12, 19/12, 19/19 SPC, 31/16 digital transmission, 28/3-4, 28/6 Nyquist sampling, structure, hierarchy and functions, 16/3-7 effective noise bandwidth, 10/10 dig