This document characterizes the principles of operational use of integrated digital air/ground voice and data systems in the domestic National Airspace System (NAS). Ideas presented are intended to provide a framework for NAS communications subsequent to 2010. NEXCOM operational objectives@ intentions and capabilities are found in section three and form the basis for success criteria used to determine system acceptability. Section four describes the operational communications services to be used for Air Traffic operations. Operational Scenarios are included that describe how air traffic operations are supported. Section five characterizes the environment within which NEXCOM is expected to operate.