A guide to the principles and use of military communication systems, which as the preface points out are designed for use in hostile environments, and often subject to counter-intelligence efforts. Discusses strategies such as frequency hopping designed to account for and combat attempts by the enemy to jam signals, intercept, interfere with, or cancel frequencies. Also includes a chapter on cryptographic digital communications (i.e., coded messages and ciphers), appendices covering frequency-shift keying, noncentral chi-squared distribution, the discrete Fourier transform and the signal spectrum, and matrix analysis, with an extensive index