TABLE OF CONTENTS Another name for the multiplexed aggregate bit stream is transport stream passed to a standard network interface, transported to a distant location, and then demultiplexed into the original streams. Figure 4-5 shows how audio, video, and data (elementary) streams are aggregated into a transport stream in MPEG.
In MPEG multiplexing, elementary streams are multiplexed into a higher order bit stream similar to that done in communications networks. Multiple program transport streams can in turn be multiplexed into higher order streams. In some cases statistical multiplexing techniques may be used to allocate unused aggregate bits to each of the program sources, depending on activity.
The main point to make here is that the connection between the multiplex and demultiplex can be any standard communications channel capable of interfacing the end units and providing the band width, class, and quality of service required by the television signals being transported. Note that in this depiction, audio, video, and data are arbitrarily shown with one-way paths. These could easily be twoway, requiring full-duplex network facilities. Note also the 10/100BT access requires full-duplex layer 2 as well.
