ments (LSAs), 261 VPWS, 371 Link-state routing protocols, 259-262 Layer 3 VPNs, 363-364 Liquid crystal display (LCD) switches, 467-469 Layers, ATM, 233-235 Little LEOs, 70 LCD (liquid crystal display) switches, 467-469 LMDS (Local Multipoint Distribution Service), 623 LDAP (Lightweight Directory Access Protocol), 445 LMP (Link Management Protocol), 477, 485 LDP (Label Distribution Protocol), 370-371, Loaded pairs, DSL, 496 447-448 Local area networks. See LANs (local area networks) Leased lines Local exchange carrier (LEC), 105 advantages/disadvantages of, 24-25 Local exchanges dark fiber and, 78, 212 overview of, 8-9 DDSs and, 205-206 PSTN architecture, 112-113 defined, 11 Local loop microwave replacing, 56-57 broadband PLT as, 530 as nonswitched service, 109-110 in fiber optics, 78 overview of, 203-204 PSTN, 107 SDH/SONET backbone and, 212 Local Multipoint Distribution Service (LMDS), 623 T, -E, -J carrier backbone and, 206-211 LocustWorld protocol, 656 VS. VPNs, 357 Logical four-wire circuits, 5 WANs based on, 201 Long-Term Evolution (LTE), 612 LEC (local exchange carrier), 105 LonWorks standard, 542 LEDs (light-emitting diodes), 75-76 Loop carriers, DSL, 496 Legacy support, 321 Loop signaling, 130-131 LEO (low-earth-orbit) satellites, 69-70 Loop start, 131 LF (low-frequency) RFID, 679 Low bit-rate vocoders, 576-577 LIB (Label Information Base), 447 Low-Delay CELP (Code-Excited Linear Predic- Licensed band CR, 692 tion), 324-325 Licensing, 12 Low-earth-orbit (LEO) satellites, 69-70 LIDO Organization, Inc., xxi, xxiii-xxiv Low-frequency BFWA, 621 LIDO Telecommunications Essentials, xxi LPC (linear predictive coding), 577 Light-emitting diodes (LEDs), 75-76 LSAs (link-state advertisements), 261 Light sources, fiber-optic, 75-76 LSPs (label-switched paths), 446-450 Lightning strikes, 54 LSRs (label-switching routers), 447-448 Lightweight Directory Access Protocol (LDAP), LTE (Long-Term Evolution), 612 Lucent Technologies, 632 Line-coding techniques, 154 Line of sight, microwave beams, 56 Linear predictive coding 