| 摘要 |
<p>A plurality of digital services are carried in a multiplex data stream to a plurality of remote locations. The multiplex data stream comprises a continuous sequence of frames. Each frame comprises two consecutive fields, and each field comprises a plurality of lines. A first group of the lines in each field defines a transport layer region of that field, and a second group of the lines defines a service data region. Portions of the service data region of each field are allocated to respective ones of the video services in proportion to respective data rates of each service. A multiplex control packet is generated for each field that specifies, for each service, which portion of the service data region is allocated to that service. The multiplex control packet for each field is inserted into the transport layer region of that field along with a plurality of other packets that contain system related information. A multiplex map is generated and inserted in the first line of the transport layer of each field that specifies the number and location of packets within the transport layer. A multiplex map is transmitted with each field, and therefore, the number and location of packets within the transport layer may be dynamically adjusted on a per field basis. Additionally, the service allocation within the service data region of each field may be altered on a per frame basis to support statistical multiplexing.</p> |
