serving area, telephone, 67 receiving system figure of merit (G/T), 223-226 serving time, 63 RF bandwidth for, 37 session initiation protocol (SIP), 395, 397 technical problems of, 217-219 SetRequest verb, 557 very-small-aperture terminal networks, 229-231 sidebands, 81 satellite exchange, 74 sidetone, 93 satellite links, signaling link delays over, 376-377 level, 93 satellite pointing loss, 226 sigma notation, 604 satellite reception, CATV, 434 signal currents, decibels with, 621-623 satellite relay, TV transmission by, 416-417 signal drums, 20 satellites, 217. See also geostationary orbit (GEO) signal element duration parameter, 158-159 communication satellites; INTELSAT; low signal energy, hybrid transformer, 76-77 earth orbit (LEO) satellites signal fires, 19-20 digital communication by, 228-229 signal generator, 24 scanning, in video transmission, 404, 405f signal hills, 20 scanning generators, 408-409 signaling, 4, 55, 149-167 scatternet, Bluetooth WPAN, 347 associated and disassociated channel signaling, "scratch-pad" memory, 74 162-163 "SEAL" (simple and efficient AAL layer), 526 call-progress, 5 secondary station, HDLC, 284 CCITT, 13 section overhead (SOH), 491, 498, 502, 504 compelled, 158-160 sectorization, 478 on data circuits, 388 security associations (SAs), 357 effects of numbering on, 161-162 security management, network, 541 evolution of, 151 segmentation and reassemblyXprotocol data unit functional areas of, 149-150 (SAR-PDU), 524, 525f link-by-link versus end-to-end, 160-161 segmentation and reassembly (SAR) protocol metallic trunk, 165-166 functions, 279 purpose of, 149 segmentation and reassembly sublayer, 523 in the subscriber loop, 164 seized operating condition, 157 supervisory, 31 selective (continuous) ARQ, 257 techniques of, 150-158 selective broadcast signaling virtual channels voice and data, 512 (SBSVCs), 530 signaling area/network code (SANC), 378 selective dynamic overload control (SDOC), signaling bit rate, 368 552-553 signaling connection control part (SCCP), 378-381 selective re