ure), 11/7 layer 3, network, 12/10, 44/9 with OSI seven layer model, 54/7-12 One stop billing, 11/17 testing, 61/30 with PMR, 46/11-12 ONP (Open Network Provision), 11/8 layer 4, transport, 9/9-10 principle, 54/3-5 OOK (On Off Keying), 19/7 layer 5, session, 9/9 routeing, 54/12-15 Open System Interconnection see OSI layer 6, presentation, 9/9 transmission time, 3/16 Operator Position System, system, 12 32/8 layer 7, application, 9/9 X.25 standard, 40/6, 40/10-13, 54/3-15, Optical amplifiers, 42/27 application standards, 56/4, 56/14 Optical bandwidth, 53/6 ACSE, 16/9 see also Fast packet switching; Optical communication systems, 19/7 CCR, 16/9 Multiple access Optical fibre, FTAM, 16/9 PAD (Packet Assembler/Disassembler), cable standardisation, 15/16, 15/18-19 MHS, 16/9 54/5-6 cables, 15/11-16 RTSE, 16/9 Pagefax, 60/4 cables design, 15/13-16 architecture, 12/4-8 see also Facsimile (Fax) cables on high voltage power lines, 15/15 concept and services, 12/5-6, 22/22, Paging see Radiopaging characteristics, 53/5-9 22/26 PAL plus HDTV, 57/12 detectors, 53/14-18 cordless telecommunications, 49/10 PAL television, 57/7-9 dopants, 15/9 facsimile eqipment operation, 60/13 PALAPA satellites, 51/3 laser light source, 53/9-14 LAN standards, 56/9 PAM (Pulse Amplitude Modulation), LED light source, 53/9-14 Network Management, 16/7-14, 22/14 18/12-15, 21/3 light transmission principles, 53/3-5 packet switching, 40/10-13, 54/7-12 Parabolic antenna reflectors, 17/8 losses in, 53/5-9 and SNMP, 16/23-4 Parabolic profile optical fibre, 53/5 monomode propagation, 53/4-5 subscriber numbering, 29/15 Parametric amplifiers, 51/16 multimode propagation, 53/4-5 OSIE (Open System Interconnection Parity checks, 14/4 operation and features, 15/9-11 Environment), 12/3-4 see also Codes/coding optical bandwidth, 53/6 common application standards, ROSE, Parking satellite orbits, 51/5 parabolic profile, 53/5 Parseval's relation, 2/4, 2/6 plastic and plastic cad, 53/5 OSS (One Stop Shopping), 11/17 Parsing, modems, 39/8 receivers, 53/18-22 Ossicles, e