 networks) Point of presence (POP) Personal broadband, 630 evolution of, 285-289 Personal Communication Services (PCS), and ISPs, 266 587-588 Point-to-point leased lines, 203-204 Personal Digital Cellular (PDC), 567, 592 Point-to-Point Protocol (PPP), 264 Personal video recording (PVR), 392 Point-to-point pseudo-wires, 371 Pervasive computing, xxxvii Point-to-Point Tunneling Protocol (PPTP), PGP (Pretty Good Privacy) algorithm, 379 353-354 Phase Policy, and presence, 337 defined, 14 Policy-based management, QoS, 445 error, DSL, 496 Policy controllers, IMS, 424 modulation, 155 Policy decision points (PDPs), 444 Phase Alternating Line. See PAL (Phase Policy enforcement points (PEPs), 444 Alternating Line) Politics in networking, 33-40 Phase-shift keying (PSK) Internet governance, 36-37 IEEE 802.11b using, 644 main regulatory issues, 35-36 in wireless signal modulation, 561 overview of, 33-34 Phased-array antennas, 71, 557-558 policy and regulatory players, 34-35 Phone lines, HANs over, 537-538 regulatory background, 34 Physical four-wire circuits, 5 standards organizations, 37-40 Physical interfaces, 152-154 Polled Access, VoWLANs, 650 Physical layer PONs (passive optical networks) ATM networks, 233 architecture, 526-527 HANs over powerlines and, 539 defined, 472 OSI reference model, 168 EFM using, 482 Picocells, 565 overview of, 525-526 Picsel Technologies, 713 types of, 527-528 Pipe, Flash-OFDM, 632 POP (point of presence) Pixels, 392 evolution of, 285-289 PKE (public key encryption), 377-379 and ISPs, 266 PKI (public key infrastructure), 379-381 Port number, TCP, 256 Plain old telephone service. See POTS (plain Ports old telephone service) circuits terminating at, 4 Plaintext, 375-376 selecting optical switches, 465 Index Postel, Jonathan, 248-249 Provider edge model (VPNs), 348 POTS (plain old telephone service) Provider edge routers, 363-364 defined, 108 Provider Provisioned VPNs (PPVPNs), 347, 370 ISPs providing, 291 Provider routers, 363 next-generation digital loop carriers and, 472 Provisioned circuits, AS