isotropic antenna, 6/10 Riometers, 9/10 LF (Low Frequency), 27/6 Reflection, RITL (Radio In The Loop), 11/14 line of sight, 27/10-13, 50/1-17 by ionosphere, 9/6 RLR (Receive Loudness Rating), 30/9 MF (Medium Frquency), 27/6 light, 7/11-12 Roaming number, PCNs, 48/7 microwave, 27/10-13, 50/3-7 Reflection of waves, 6/4-6 Rocking armature telephone receivers, millimetre path design, 50/7-10 Reflectors, antenna, 17/6 noise, 27/5 Refraction, Rocking armature telephone transmitters, over the horizon, 9/12, 9/14-15, 27/13-14 ionospheric effects, 9/5 pencil beam patterns, 17/3 waves, 6/3-4 Rodent protection, optical cables, 15/14 polarisation, 6/11-12 Refractive index of ionosphere, 6/21 Rods, eye, 7/10 power, 6/8, 6/9, 6/10-11, 27/4, 27/10 Refractometers, 9/17 Roll call polling, 13/16 satellite communications, 27/14, 51/11 Register exchanges see Crossbar ROSE (Remote Operation Service Skywaves, 27/6-10 exchanges Element), OSI, 16/9 tropospere effects on, 9/11-17 Register of frequency assignments, 26/3 Round trip delay, trunk telphones, 29/9-10 UHF and VHF, 27/10-13 Register insertion ring, multiple access, Rounded hill top antenna loss, 6/15-16 see also Antenna; Electromagnetic 13/19 Route addressing system, packet waves; Millimetre wave system paths Regression, 1/5-6 switching, 54/10 Rain, Regression software testing, 25/16 Rout(e)ing, attenuation from, 6/18, 9/13-14, 9/16, Regulating authorities, paging, 45/6 algorithms, 3/4 50/11, 52/3 Regulation, FDM equalisers, 20/21 ATM switches, 41/7 satellites communication effects, 51/11 Regulations, EEC, 11/8 packet switching, 54/10, 54/12-15 RAISE (Rigorous Approach to Industrial Regulatory influences, telephone networks, 29/15-16, 30/3, 31/9 Software Engineering), 25/5 telecommunications industry, 11/11-12 alternative, 29/19 Raised cosine data windows, 2/17 Relative permittivity, 6/3 Routers, LAN, 56/13-14, 56/15 Random routeing, 5/7 Relaying, OSI layer services, 12/7 RPB (Regional Processor Bus), APZ Random signals, 10/7 Relays, microwave systems, 50/11 subsystem, 32/17 Ran