Economic gain of source- and channel-encoding

The economic gain of data-compression and error correction equipments are discussed. Many methods and codes have been developed for data-compression (source encoding) and for reducing the error rate of transmission channels (channel encoding). The economic gain of these methods is discussed. It is shown that an optimum value exists for the reduction factor of the data rate which is lower than the possible maximum value given by information theory or the demands for quality of the reconstructed signals. It is shown for data transmission between computers that error correction systems are very economical equipments in spite of the high prices. The economic gain of error correction systems is discussed as a function of the error reduction factor.