rt), 25/7 LCA (Line Concentrating Arrays), DMS, applications, 44/13 KBS (Knowledge Based Systems), 25/7, 32/19-20 Centrex, 35/3, 35/5-6, 36/7 25/9-10 LCMs (Line Concentrating Modules), facsimile equipment with, 60/12-13 Kendall queuing notation, 3/4-5 DMS, 32/19-20 interfaces, 44/6-7 Key systems, PABX, 34/14-16 LCN (Logical Channel Number), packet international standards, 44/3 Keypad, telephone push-button, 31/5-6 switching, 54/11-12 layers, 44/7-10 KiloStream, BT TDM, 21/15, 39/13, 56/5 LCR (Least Cost Routing), PABXs, 34/13 Index/12 LDDC (Long Distance DC) line Loss, Manager-secretary facilities, PABXs, signalling, 43/4-5 optical fibres, 53/5-9 34/12 Learning automata, telephone routing, transmision see Transmission loss Manchester code, 28/10 5/11-12 Loss probability, MANs (Metropolitan Area Networks), Leased lines, modems, 39/10 network models, 5/7-8, 5/11, 5/14 13/3, 55/9-10 LEDs (Light Emitting Diodes), optical single link teletraffic models, 5/4 Manual exchanges, 31/9 fibres, 53/9-14 Loss/frequency distortion, telephone, MAP (Maintenance and Administration light/current characteristics, 53/12 30/5, 30/9 Positions), DMS, 32/24 population inversion, 53/10 Lossless channels, 4/7 MAP (Manufacturing Automation spontaneous emission, 53/9-11 Lost calls, 29/16 Protocol), OSI, 16/8 Legendre polynominals, 2/5 Loud and soft talk factor, 20/10 MARECS satellites, 51/17 Lempel-Ziv algorithm, modems, 39/8 Loudness, 8/6-9 Market forces, spectrum management, LFSR (Linear Feedback Shift Register), measurement, 8/7 26/18 14/7-8 transmission systems, 30/4, 30/12 Markov, LGC (Line Group Controller), DMS, Loudspeaking telephones, 58/10 chain, 3/16, 4/10 32/19-20 LPC (Linear Predictive Coding), PCNs, equations transformation, 3/9-10 L'Hopital's rule, queuing theory, 3/10 48/8-9 probability density, 13/3 LID (Light Injection and Detection), LPI (Low Probability of Intercept) process and chains, queuing theory, 3/5-8 optical cables, 15/16 signals, 14/12 MAS (Maintenance Subsystem), APZ, Life cycle pricing, 11/11 LPP (Link Peripher