| 摘要 |
<p>The program transport capacity of an RF broadcast channel is upgraded by replacing analog services with digitally multiplexed services. RF channels can be obtained from one or more parties, e.g. parties holding MDS (1 and 2), MMDS (E1-F4) and ITFS (A1-D4) licenses for microwave video channels in the high end of the UHF frequency range. Once rights to use the channels have been acquired, a digital multiplexing system (10), including multiplexers (12), modulators (13), and RF combiner (15), is deployed for broadcasting a digital transport stream over each available RF broadcast channel. For license holders who offered an analog service over one channel, the digital transport stream for one channel will include compressed digital data representing information from that program service. The provider therefore can use this transport capacity to continue to offer the existing service. The broadcast transport stream for that channel also includes compressed digital data representing one or more new program services.</p> |
