New IEEE Standard - Inactive-Withdrawn. The following constitutes a revision of IEEE No.170 (53 IRE ll.Sl), "Standards on Modulation Systems: Definitions of Terms, 1953." It is not intended to cover the subject matter of Information Theory which is contained in IEEE No.171 (58 IRE ll.Sl ), IRE Standards on Information Theory: Definitions of Terms, 1958. Nevertheless, a few borderline terms, such as Coding and Nyquist Rate, have been included in the list. This merely reflects the fact that the two Standards define terms in adjoining areas of subject matter. The definitions given in this Standard are intended to reflect the latest usage and also to improve the clarity and precision. Terms such as Capture Effect have been newly added, while terms no longer in use, such as Two-Source Frequency Keying, have been deleted.