 10/6 18/14-15, 21/3 PSS (Packet-Switched Service), 29/15 Radiation, PPs (Portable Parts), cordless telephones, PSTN (Public Switched Telephone optical spectrum, 7/3 49/10, 49/12 Network) see Telephone networks see also Antenna; Electromagnetic PRA (Primary Rate Access) ISDN Psychoacoustics, 8/13-16 waves; Radiowave propagation interface, 61/16-17 PTI (Payload Type Identifier), 41/4, 44/16 Radiation resistance, 6/9 PRBS (Pseudo Random Binary PTOs (Public Telephone Operators), Radio channelling plans, 26/4 Sequence) generator, 14/12 11/4-6, 29/3 Radio communications, ionospheric, 9/6-7 Pre-emphasis, Public mains supplies, 24/3 Radio as EMC source, 23/10 FM, 18/12 Public switched data natworks, Radio modems, 39/10 repeaters, 20/20-1 numbering, 29/15 Radio multipoint systems, Presentation layer, OSI, 12/9, 16/9 Pulse code modulation see PCM rural, 52/7-11 PRI (Primary Rate Interface), Pulse dispersion, optical fibres, 15/10, frequencies, 52/7 Centrex, 35/5 modulation/demodulation methods, TDM, 21/9 Pulse shape measurements, 61/4 52/11 Pricing, Pulse time modulation, 18/14-15 urban, 52/3-7 telecommunications industry, 11/11-14 PVCs (Permanent Virtual Circuits), frequencies, 52/3 teletraffic, 5/8-10 40/12-13 modulation/demodulation methods, Primary standards, radiometric instruments, 7/8-9 Radio relay cable TV, 57/19 Printers, facsimile, Radio spectrum management see electrophotographic, 60/11 Q3 interface, TMN, 16/19 Frequency assignment, allocation and ink jet, 60/11 QAF (Q Adapter Function), TMN, management thermal, 60/11 16/17, 16/18 Radiodetermination, frequency Private interconnect, cellphones, 47/16 QAM (Quadrature Amplitude allocations, 26/13 Private line working, PABXs, 34/12 Modulation), 18/6, 19/11 Radiometry, 7/3-9 Private Mobile Radio see PMR facsimile equipment, 60/8 Radiopaging, Private networking, 34/7-11 modems, 39/4 code formats, 45/5 Private Radio Bureau, FCC, 22/25 QCIF (Quarter CIF), 57/27 ERMES (European Radio Messaging PRK (Phase Reversal Keying), 19/9 QoS (Quality of Service), B-ISDN, Service),