This document provides standards for Aeronautical Telecommunication Network functions for aircraft systems and equipment. These standards are in the form of performance criteria for ATN functions; qualification criteria for demonstrating performance requirements; descriptions of evidence that indicate that performance objectives have been satisfied. Performance objectives@ qualification and evidence are discussed as they relate to satisfying the requirements for airworthiness approval of ATN functions. The functions covered by the MOPS can be incorporated in a wide variety of hardware configurations onboard an aircraft. Section 2 of the document expresses the requirements for airborne ATN systems. Section 3 describes the means of qualification by providing an overview of the testing process and listing detailed tests.