Super-multichannel trans-selector systems for upgradable broadband networks

In CATV systems, frequency division multiplexing (FDM) played an important role in increasing the number of multiplexed channels. Very economical channel selectors or tuners have been realized by taking advantage of FDM technologies. It is suggested that the number of total channels in broadband distribution systems such as video on demand could exceed 10000 channels by the year 2000. Trans-selectors which is defined to select multiple channels from a large number of multiplexed channels with minimal demultiplexing are investigated for such super-multichannel systems. It is shown that the combined use of inverse multiplexing and rate adaptation can play an important role in realizing very simple and economical super-multichannel trans-selectors: all signals are converted to have a unified rate and, as a consequence, multiplexing and demultiplexing can be carried out in an interleaved fashion, and therefore, be considerably simplified. Technologies for rate adaptors as well as the economy of trans-selector systems are also discussed.