Travelling wave tubes see TWT Terrain, attenuation from, 9/13-14 TMs (Trunk Modules), DMS, 32/21-2 Tree cabling, 33/6 Terrestrial links, frquency allocations, TNV (Telecommunication Network Trellis coder diagram, 14/11 Voltage) circuits, safety, 23/5-8 Trellis encoding, modems, 39/6 Test case software generation, 25/15 Token passing, multiple access, 13/17-19, Treshold of hearing/audibility, 8/6 Testing, measuring and monitoring, 56/8-9 Triangular data windows, 2/17 active monitors, 61/15 Token Ring, 56/7 Tromboning, 37/6 AF and speech codec, 61/30 protocols, 13/19 Troposphere, alarm reporting, 61/13 TOP (Technical and Office Protocol), beyond-the-horizon transmission, 9/12, CCIR recommendation 594-1, 61/10-11 OSI, 16/8 9/14-15, 27/13-14 CCITT recommendation G.821, 61/8-10 Top-down software testing, 25/14-15 effects in space communications, 9/15-16 CCITT recommendation G.921, 61/11 Topology, features and history, 9/11-12 CCITT recommendation M.550, 61/11 ATM, 41/7 propagation modes, 9/12-17 cellular radio, 61/21-4 multiplexers, 40/14 scatter propagation, physical basis, 9/15 clock frequency, 61/5 SDH, 42/22-5 study techniques, 9/17 coding, 61/5 TOPS (Traffic Operator Position System), Tropospheric absorption, satellites, 51/11 data networks, 61/12-16 DMS, 32/23 Tropospheric ducting, PMR effects, 46/8 digital circuits, 61/3 TRAC (Technical Recommendations Tropospheric refractive index effects, error performance, 61/7-11 Application Committee), 22/16, 22/19, 6/17-18 framing, 61/5-6 22/21 Tropospheric scatter, PMR use, 46/8 GSM, 61/24-32 Traces, software, 25/16 TRs (Technical Reports) OSI/NM forum, interfaces, 61/3-7 Traffic capacity table, 29/18 22/14 ISDN equipment, 61/16-21 Traffic control, ATM based ISDN, 41/8, Trunk reservation, 29/16 jitter and wander, 61/6-7 41/13 teletraffic, 5/4-8 large networks, 61/115-16 Traffic types, multiplexers, 40/14 Trunk satellite telecommunications, 51/15 optics and vision, 7/4-8 Tranmultiplexers, FDM and TDM, Trunk telephone circuits, 29/8-10 OSI layers, 61/24-30 20/18-19 Trunk t