al Processor), 32/21 32/17 Life times, multiplexed traffic, 40/15 LSE (Local System Environment), 12/4 Masking sounds, 8/15-16 Light, LSI (Large Scale Integration), exchanges, Mass law, sound isolation, 8/12-13 monochromatic, 7/3 Mass Media Bureau, FCC, 22/25 polychromatic, 7/6 LSM (Line Switch Modules), APT Master International Frequency Register refraction and reflection, 6/4, 53/3-5 system, 32/15 see MIFR see also Optical fibre; Optics and vision LSTR (Listener SideTone Rating), 30/7 Mastergroups and supermaster groups, Lightning, 23/8 LTC (Line Trunk Controller), DMS, FDM transmission, 20/5-6 Lightning protection, optical cables, 15/14 32/19-20 Material dispersion, optical fibres, 15/10 LIM (Link Interface Module), DMS, LUF (Lowest Usable Frequency), 27/9 MATV (Mast Antenna TV), 57/18 32/21 Luminance, 7/5 Maxwell's demon, 4/5 Line circuits, PABXs, 34/11 television, 57/5 Maxwell's equations and wave equations, Line codes see Codes/coding Luminous exitance, flux/power and Line concentration units, 31/7 intensity, 7/5 mBIC block code, 28/11 Line of sight systems, Luminous source intensities, 7/6 mBnB block code, 28/11 multipoint systems, 52/3, 52/7 MBS, Swedish Mobilsoekring paging, see also Microwave systems; u-law codec, 22/4, 37/7, 56/5 45/11 Millimetre wave system paths M/G/1 queue, in equilibrium, 3/9-10, 3/11 MCI Communications, 11/7 Linear block codes, 14/4 M/M/1 queue, 13/3 MCU (Main Control Unit), TX4 Linear predictive coding, 4/12 MAC (Multiplexed Analogue exchanges, 32/6-7 Linear system analysis, 2/11-12 Components) television, 57/7-10 MDF (Main Distribution Frame), 33/8 Linear time-invariant digital systems, McCabe's cyclomatic number, 25/14 Mean deviation, 1/4, 1/5 2/10-13 Macrobending loss, optical fibre cables, Mean square error, 2/3 Linearity, z-transforms, 2/13 15/11 Means, Link budgets, multipoint systems, 52/5-6 Magnetic field, earth's, effect on arithmetic, 1/3 LISN (Line Impedance Stabilising ionosphere, 9/4 geometric, 1/4 Network), 23/15 Magnetic induction, 23/16 harmonic, 1/4 Listener echo