On digital/analog transmission systems

Narrowband and Wideband data hybrid transmission techniques are presented and dedicated digital radio systems are reviewed. It is shown that 1.544 Mbit/s (2.023 Mbit/s) Data Above FDM Voice/Video (DAV/DAVID) is the most economical approach. Field evaluation results of: (a) 1.544 Mbit/s above 960 (and under 840) FDM channels on a Canadian National/Canadian Pacific 8 hop RCA-MM-600 6GHz microwave systems (b) 1.544 Mbit/s above 960 FDM channels on the ANIK Satellite (c) 1.544 Mbit/s above 960 FDM channels on an 8 hop TD-2 microwave system (d) 1.544 Mbit/s above 2700 FDM channels or above the combined 1200 FDM and video signals on a 102 km Philips cable system — prove the practical applications of the theories and expectations which were previously presented by the authors.