45 signaling performance, message transfer part, slips (digital network impairment), 127, 138-139 375-377 long-term mean rate of occurrence of, 142 signaling point codes, 374 in speech telephony, 139 signaling points (SPs), 362, 365 slot filters, signaling-tone-bypass, 152 signaling relation, 365 smearing, 50 signaling requirements, ATM, 530 smooth earth path, 197 signaling route management, 367 SNAP (sub-network access protocol), 320 signaling system performance, 363 Snell's law, 232 signaling systems, structure of, 364-367 SNMP fields, 557-558 signaling traffic management, 366-367 SNMP PDU structure, 556-558 signaling transfer points (STPs), 362-363, 365, SNMPv.2, 559-560 373, 374 SNMPv.3, 560-562 postdial delay and, 363 Society of Cable Telecommunication Engineers, 15 signaling virtual channels (SVCs), 530 sockets, 326 signal level drops. See fading SOCOTEL signaling system, 159 signal magnitude (intensity), 51-52 soft switch, 395 signal message, 365 software signal mixing, 80-81 network protocol, 543 signal output, regenerative repeater, 121 in troubleshooting, 543 signal paths, coupling between, 50 solenoid, 587 signal power, 32 SONET (synchronous optical network), 196, 489, signals. See also electrical signals; signaling 490-501 congestion-indicating, 184 add-drop multiplexer, 499-501 electrical, 19 architecture, 170 everyday, 19-20 clock offsets and, 495-496 intelligence conveyance via, 19 mapping ATM cells into, 537 signal splitting, 432-433 overhead levels of, 496-498 signal strength information, base and mobile synchronous signal structure, 490-499 station, 472 SONET interface signals, line rates for, 499 signal structure, synchronous, 490 SONET/SDH frame, 513 signal-to-distortion ratio (S/D), 114 sound frequency, 24 signal-to-Gaussian-noise ratio, 120 sound waves, 25 signal-to-noise ratio (SNR, S/N), 207 source address field, MAC frame, 302 baseband LAN transmission, 294-295 source coder, pX64 kbps codec, 424-427 CATV, 434, 436-437 source coding and compression, 420-421 FM system, 446-447 source-contro