57-458 harmonic telegraphs, 130 and MSOs, 463 Harvard Method LANs, 259, 264 networks of, 458 hash functions, 86 regulatory requirements for, 229-231, H-Channels, 288 233-237, 239 HDSL (High-Bit Rate Digital services of, 459-460 Subscriber Line), 296-297 subsidies of, 228, 231 headend, 304-305 unmet expectations for, 232-233 headers: IM (Instant Messaging), 324, 475, 476 ATM, 385-386 image coding, 72-79 IP, 438-439 BMP, 72-73 TCP, 446-447 GIF, 78-79 Hear-See machine, 272 JPEG, 73-79 Hertz (Hz), 245, 246 TIFF, 79 Hewlett-Packard, 222 IMTS (Improved Mobile Telephone H.GCP, 220 Service), 315 hierarchy of needs, 477 IMUX (inverse multiplexers), 289 High-Bit Rate Digital Subscriber Line in-band signaling, 163-164 (HDSL), 296-297 incumbent local exchange carriers (see high-order virtual concatenation ILECs) (HOVC), 192 industrial, scientific, and medical high-quality television (HQTV), 270 devices (ISM), 334 Hi-G-Tek. 342 Information Management (Tim HiperMAN, 363 Berners-Lee), 34 Hockham, Charles, 395 Infrared Communication Systems, 334 HomePlug Alliance, 429 infrastructure costs, 226 Homer, The lliad, 94-95 in-house BPL, 429 Hooke, Robert, 130 input/output (I/O) devices, 244, 251 hop count, 99 inside plant (telephone network), 197, 198 house wiring, 148 inside vapor deposition (IVD), 397 HQTV (high-quality television), 270 Instant Messaging (see IM) HTTP (Hypertext Transfer Protocol), Instructional Television Fixed Service 35-36, 66 (ITFS), 333 Hush-a-Phone Corporation, 134-135 Integrated Data Link Controller Hypertext Transfer Protocol (see HTTP) (IDLC), 114 Hz (Hertz), 245, 246 integrated services digital networks (see ISDN) Intel, 298, 363, 466 interexchange carriers (IXCs), 462, 479 interior gateway protocols, 443 IBM, 255, 282, 466, 467 Interior Gateway Routing Protocol ICO Global Communications, 347-348 (IGRP), 109 Identify: Friend or Foe (IFF), 337 interlaced video, 277 IEEE 802.5 committee, 266 intermodulation effects, 406 Index International Electrotechnical IP (Internet Protocol), 6, 100, 122, 430 Commission 