Systems for Multiplexing Frequency Modulation (FM) Sound Broadcasting with a Sub-Carrier Data Channel Having a Relatively Large Transmission Capacity for Stationary and Mobile Reception
The ITU Radiocommunication Assembly considering that many countries use the Radio Data System (RDS) according to Recommendation ITU-R BS.643; that although RDS is able to accommodate many of the data services required, the data capacity is nevertheless limited; that it is a fundamental requirement that compatibility be achieved between FM stereophonic services including RDS and any new additional sub-carrier system; that a much larger data capacity may be needed for some applications; that sub-carrier data radio channel systems can provide a much larger capacity compared to RDS and are capable of meeting the requirement stated in § c) as regards protection ratios and interference levels; that high speed data systems have already been put into operation; that the diversity of applications as described in ITU-R BS.1350 precludes the suitability of a single system for all applications.