This is a practical, non-mathematical introduction to data communications and is based on the author's belief that today's readers need not only a solid knowledge of how modern data communications technology operates, but also a firm grounding in how ithas evolved, and where this evolution will likely take in the future Topics are discussed at одйдй various points in the book in increasing complexity, helping the readers build a solid understanding of key communications Coverage assumes prior knowledge ofmodulation, number systems, and digital circuits, and uses only the mathematics needed for understanding Wherever possible, industry-wide standards rather than more limiting proprietary ones are used.  Издание 1976ISBN 0023972408.