4 optical networking, 393-418 terminal adapter (TA), 285, 286 point-to-point, 371-372 terminal box (B-Box), 149, 150 switched, 18 terminal framing bits, 170 switching hierarchy, 372-373 terminal lugs, 150 TCP/IP, 122, 123, 430-432, 435-451 Texas Instruments, 466 voice transport, 167-177 THEORYNET, 37 truncated binary exponential Three Mile Island effect, 65 backoff, 260 through-timing (SONET). 190 trunk lines, 143 tier 2 ISPs, 431 trunk units (TUs), 164-165 tier 3 ISPs, 432 trunked radio, 315 TIFF (tag image file format), 79 Truscott, Tom, 38 time-division multiple access (see Twain, Mark, 344 TDMA) twisted pair wire, 138, 148, 290 time-division multiplexing (see TDM) two-stage multiplexing, 185 T-Mobile, 324, 326, 335, 359 Token ring, 118, 258, 264, 268 token-passing rings, 264-266 toll-quality voice, 205 tone (telephones), 144, 145 ubiquity, mobility vs., 358-361 TP0-TP4 standards, 93-94, 100 UBR service (ATM), 239 tracking bytes, 181 UHF, 316 tracks (hard drive), 249-250 ultra wideband (UWB), 364 transmission: unbounded delay, 260-261 full-duplex, 17, 18 subbandled network element-platform half-duplex, 17-18 (UNE-P), 233-234 Index unbundled network elements (UNEs), video, 271-279 233, 234, 236, 237 CD-ROM process, 274-275 unified messaging, 214 digital, 274-275 uninterruptible power supply (UPS), modern technology for, 273-274 158-159 quality factors for, 276-278 Union Telegraphique, 7 videoconferencing, 289-290 unipolar signaling scheme, 27 videograph, 271-272 United Nations (UN), 6-7 Virgin Mobile, 323 United States Steel Corporation, 468 virtual channel (VC), 387 United States Telecom Association virtual circuit identifier, 91 (USTA), 13-14 virtual circuit switching, 97 United States v. AT&T. 137 virtual circuits, 91-92, 98, 370 Universal ADSL Working Group virtual concatenation (VCAT), 191-192 (UAWG), 298 virtual path (VP), 387 Universal Mobile Telephony System virtual private networks (VPNs), 91-92 (UMTS), 326, 335, 336 virtual technologies, 283-285 Universal Service Fund, 226 virtual tributaries, 187-189