The book begins with a critical review of the legacy aeronautical communications system and a discussion on the impetus and needs behind its replacement with network centric digital technologies. Wireless channel characterization for the 5GHz band over airport surfaces are then described in chapter three. Orthogonal Frequency Division Multiple Access (OFDMA), coded OFDM (CODFM0), scalable OFDMA, and how they are applied in the majority of wireless networks follow in chapter four. Topics such as Division Duplexing (FDD), Adaptive-Modulation-Coding, methods of controlling sub-channel interference, and error control coding of scheduling services are covered next in chapter five. Chapter six to eight introduce AeroMACS , unique features of the new AeroMACS standards, and the challenges and benefits surrounding IEEE 802.16j-based multihop relays. The final chapter discusses future trends and developments of AeroMACS networks as they are deployed in the US, Europe, and eventually across the world, focusing on concepts that may be applied to improve the future capacity.