ts contained in a file. File sizes are always in octal numbers. A 1-KB file actually contains 1024 bytes, a 1MB file contains 1,048,576 bytes. Other potential points of confusion abound with fixed size ATM cells, variable size Ether- net, and IP packets. ATM cells are always 53 bytes long, and more specifically in ITU documentation and practice each cell is usually referred to as an octet containing 8 bits, no more, no less. But Ethernet packets range in size from 46 to 1500 bytes. Internet packets can be between 68 and 65,535 bytes long. PRACTICAL IP AND TELECOM FOR BROADCAST ENGINEERING AND OPERATIONS Rate of Delivery or Movement: Kilobits-per-second (Kbs) Megabits-per-second (Mbs) Gigabits-per-second (Gbs) These terms also used to refer to channel or link speed. Be careful because in content transport network design and operation, the two are almost never equal because of additional overhead bits required by error correction, or even still more bits used to map ATM, IP or TDM PDH into SONET/SDH channels. KEY STANDARDS AND DESIGN PARAMETERS Please see Table 1-2, Content Creation, Table 1-3, Content Distribu- tion, and Table 1-4, Content Delivery and Other Applications, on pages 33 through 35. TABLE 1-2 Content Creation Application Analog B/W Sample Rate Bits / Sample Interface Payload Bitrate Audio Coding Channels Studio Mastering 20-20,000 Hz 48 KHz 16-20 AES 10-1991 125 Mbs Digital VTR 20-20,000 Hz 48 KHz 16-20 AES 2/3-1985 384-768 KBs Live Broadcast 20-20,000 Hz 48 KHz 16-20 AES 2/3-1985 192-768 Kbs 20-20,000 Hz 48 KHz 16-20 MPEG2 192-768 Kbs Video Sub-Sample Frame Rate Digitized NTSC ~6 Mhz 13.5 Mhz 4:2:2 YUV 29.94 SMPTE 259 143 Mbs Digitized PAL ~8 Mhz 13.5 Mhs 4:2:2 YUV SMPTE 259 177 Mbs SD 720x480/576 ~15 Mhz 27 Mhz 4:2:2 YUV 29.94 SMPTE 259 270 Mbs HD1920 X 1080 ~30 Mhz 74.25 Mhz 4:2:2 YCbCr 29.94 SMPTE 292 1,485 Mbs TABLE 1-3 Content Distribution Application Analog B/W Sample Rate Bits / Sample Coding Scheme Interface Payload Bitrate Audio Coding Channels Digital VTR 20-20,000 Hz 48 KHz 16-20 AES 2/3-1