Book excerpt: A unique book with systematic and thorough coverage of HAP related issues, problems and solutions. Handbook of Broadband Communications from High Altitude Platforms provides a thorough overview and state of the art of the HAP enabling technologies, as well as describing recent research activities with most promising results. It outlines the roadmap for future development of HAPs. Focuses on placing HAPs in the perspective of current and future broadband wireless communication systems, providing the readers with an overview of the constraints affecting HAP-based broadband communications Provides a thorough overview of HAP enabling technologies, describes recent research activities with most promising results, and outlines the roadmap for future development of HAPs Covers enabling technologies and economics of HAP-based communication system including issues related to aeronautics, energetics, operating scenarios, applications and business modeling Examines the operating environment, advanced communication techniques for efficient radio link resource management, and suitable antennas Addresses multiplatform constellations, presenting the multiple HAP constellation planning procedure and discussing the networking implications of using multiple HAPs