This document describes the data link service provider system inputs, outputs and functions from the perspective of the data link user. The functions are described in the detail necessary to provide a complete understanding of what the functions do while not restricting the data link service provider network internal implementation. Where there are differences in message formats or functions provided between the various service providers which affect the data link user interface, the differences are specifically described.

Purpose of this Document

This document sets forth the desired interface characteristics of the data link service provider to the data link user. The intent of this document is to provide data link users the information needed to develop applications and to encourage uniformity and standardization, to the extent possible, among the various data link service providers. This document contains general and specific guidance concerning the interfaces between the data link service providers and both the airborne and ground user.