Data compression by redundancy reduction

Because of the increasingly pressing problem of spectrum overcrowding in data transmission channels, it is becoming more and more necessary to develop schemes to optimize the use of the available frequencies. The Proceedings of the IEEE is devoting its March issue to the subject of ``Redundancy Reduction and Bandwidth Saving.´´ This article, timed to coincide with the Proceedings issue, briefly describes some of the salient features of the various approaches to redundancy reduction.