ccupy virtual channels of the common channel or bitstream. Communications networks use still other multi- plexing techniques and standards, some of which are statistical in their operational function. Generally, these techniques will not sup- port content transport, unless it is properly packaged. For example, content packaged into Ethernet or IP packets and carried live or real time, requires a network capable of transporting and delivering the packets in the proper sequence and timing, and low levels of packet loss to be successful and satisfactory. The payload bitrate across the interface between the broadcast oper- ations facility and the network transport facility will probably be a serial interface. The capacity across the interface depends on several factors. Establishing the maximum capacity required is a simple matter of accounting for and summing up the basic parameters of each program and any required overhead included in multiplexing and other functions, such as error protection and correction. Table 1-1 summarizes the range of payloads encountered when carry- ing high definition, standard definition, and streaming video typically found in creation, distribution, and delivery of program content. ISO MPEG standards cover audio, video, and data signals com- pressed and multiplexed into a common output stream. The process adds overhead bits, increasing the size of the payload handed off to the network. It is also possible to combine or multiplex two or more TABLE 1-1 Range of Payload Bitrates Across the Program Content Food Chain Content Creation Content Distribution Content Delivery Type of Material (Before Compression) (After Compression) (Before Decompression) 1.2-1.5 Gbs 20-150 Mbs 12-20 Mbs 270 Mbs 8-30 Mbs 4-10 Mbs Streaming Video 270 Mbs Or Analog 300 Kbs-6 Mbs Note: See Table 1-2 through 1-4 for more details regarding analog bandwidth, interface, sampling, and payload bitrates. 1 BASIC FUNDAMENTALS, DEFINITIONS, AND KEY TERMS MPEG program streams into a common transport channel such as a cable, D