thernet Alliance (GEA), 232 establishment of, 74 Global Schoolhouse Project Federal Radio Commission, 72 Index distance learning, 32 H.321, 13, 123 government and public sector enterprises H.322, 13 uses of videoconferencing, 54 introduction of standard, 13 graphical user interface, 5 H.323, 12, 123, 293 graphical user interface (GUI), 5, 434 H.323 gateways, 245 graphics coprocessor, 433 H.324 group systems, 241 ACELP, 128 groups of blocks (GOB), 119 MP-MLQ, 128 groupware, 433 Unrestricted Motion Vectors, 128 Guaranteed Delay, 180 guardband, 433 ITU-T's standard for switched 384 Kbps, Guglielmo Marconi, 66 H.130, 112 HO dialing, 278 HO standard H.221, 120, 121 defined, 120 how DSOs are combined into a single 384 Kbps channel, 207 H.222, 123 H.222.1, 123 dialing, 278 H.223, 127 ITU-T's standard for switched 1.536 H.230, 121 dialing, 121 definition, 121 H.231, 121 dialing, 279 definition, 121 ITU-T's switched 1.920 dialing H.233, 263 specification, 121 H.242 HDTV, 86, 87, 89, 105, 111, 122, 210, 219, 220, 248, 336, 340, 346, 347, 393, 414, definition, 122 432, 436, 439, 444, 452, 461, 487 H.243 Advanced Television Systems Committee control procedures for H.231 MCUs, 120 (ATSC), 219 H.245, 123 data casting over, 219 H.261, 245, 258, 298 Heinrich Hertz, 66 H.263, 99, 103, 126, 127, 128, 129, 176, 177, Hertzian waves, 66 244, 247, 248, 298, 301, 308, 361, 387, HFC, 440 407, 417, 434, 436, 437, 455, 474, 475 high-resolution still images, 307 H.264, 212, 221, 246, 247, 371, 382 history H.320, 12, 120, 142, 245, 258, 293 early history of videoconferencing, 6 enhancing the standard, 249 History of Videoconferencing, 6 its impact on the global videoconferencing market, 245 Hitachi, 245 H.320-to-H.323 gateway, 293 horizontal blanking, 82 Video Communication: the Whole Picture horizontal resolution, 440 International Multimedia Teleconferencing Huffman encoding, 99, 440 Consortium (IMTC), 111, 140 HVAC (heating, venting and air International Standards Organization (ISO), conditioning) 337, 446 problems caused by, 273 Interna