Description / Abstract: This document provides the interoperability requirements for Air Traffic Services (ATS) supported by NEXCOM Very High Frequency (VHF) Digital Link (VDL) Mode 3. It identifies NEXCOM interoperability requirements for ATS supported by digital voice communications in the U.S. National Airspace System (NAS). Interoperability requirements are the minimum technical and functional requirements that provide the basis for ensuring compatibility between the aircraft system, the ATS Provider system, and the operator’s provisions to use the air traffic services.