r and clock timing recovery pattern, 221 (CEPT) carrier frequency, 81 channel banks, PCM, 118 carrier systems, 66 channel capacity, 272 four-wire, 75-76 channel efficiency, versus redundancy, 254-255 out-of-band signaling on, 152 channel patching, 153 carrier-to-noise ratio (C/N), 226, 227 channel signaling, 162-163 in CATV systems, 437-438 Chappe semaphore, 20 carrier transmission, 28 characteristic impedance, 77, 597 CATV (cable television) check pointing, 287 amplifiers, gains and levels for, 439 chip rate, 474 headends, 416 chromatic dispersion, 243 standards, 15 CIF picture scanning format, 424-425 two-way systems, 448-451 CIR (committed information rate), 334 CATV signals, digital transmission of, 447-448 circuit-directionalization control, 552 CATV trunks, transmitting uncompressed video on, circuit group, 66 447-448 size versus efficiency in, 66 C-bit, 277 circuit identification code (CIC), 382 CCIR 5-point picture quality scale, 45. See also International Consultative Committee for circuit loudness rating (CLR), 44 Radio (CCIR) circuit path lookup tables, 526-527 circuits CCITT. See also International Consultative Committee for Telephone and Telegraph alternating-current, 33 (CCITT) coupling loss between, 50 group formation, 82-83 direct-current, 23 modulation plan, 81-83 one-way and two-way, 9-10 No. 5 signaling code, 152, 155, 156 PSTN, 9 CCITT Rec. V.110, data transmission based on, circuit shortage, 551 277-278 circuit-switched network controls, 551-552 CCITT Signaling System No., 7, 13, 361-386 circuit-switched service, 318 architecture, 362-363, 364-367, 374-375 circuit-turndown control, 552 connection control, 378-381 circular routings, 184 data link layer, 367-368 cladding, 232, 243 functions and messages, 372-374 clear back operating condition, 157 international signaling point code numbering clear DSO channel, 278 plan, 377-378 clear forward operating condition, 157 link layer, 368-372 clear-to-send (CTS) packet, 343 message transfer, 375-377 clipping functions, 426 relationship to OSI, 363 clo