Data Communications Overview
Data communications in the NAS is envisioned to be implemented in three segments to meet the mission shortfalls in a practical, evolutionary approach to achieve the NGATS vision. The basis of the functions in this document are the data communications services described in the Communications Operating Concept and Requirements for the Future Radio System, COCR Version 1.0, dated March 6, 2006. The following sections describe the services and capabilities envisioned for each segment in the Data Communications in Support of NGATS Program.
Segment One (2012-2017)
The first segment in implementing data communications will provide the basic capabilities for controllers and flight crews to transfer ATC clearances, requests, instructions, notifications, voice frequency communications transfers, and flight crew reports as a supplement to voice. Procedures using trajectories to manage continuous descent approaches will be implemented on a limited basis at certain airports with aircraft meeting capability requirements.
The initial capabilities will concentrate on implementation in the Tower and En Route environments. These capabilities within Segment One serve as the initial building block for trajectory based operations.
Tower functionality for segment 1 is limited to a single option whicle En Route functionality has 3 different alternatives. Tower functionality is split between tower and national-level functions following the existing and currently planned architecture in the Tower environment.
Segment Two (2017-2022)
Segment Two data communications is focused on transitioning data communications capabilities to all domains e.g. Terminal, Tower and En Route. In addition, an implementing rule will become effective requiring data communications capabilities to be part of the aircrafts minimum equipment requirements for access to certain areas of airspace. This expansion, including the rulemaking and implementation of enhanced data communications services, provides the basis for evolving the NAS from tactical control to management-by-planning and intervention-by-exception. This is also the time when traffic levels are projected to rise to the point where voice communications is anticipated to restrict air traffic growth, and therefore data communications will evolve to become the necessary means of air-ground communications. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：Functional Architecture for the Data Communication System(3)
