Next generation navigation system (CNS/ATM) is defined as Communication, Navigation, and Surveillance system to support air traffic management, Especially, in order to accommodate the growing demand of air traffic, ICAO adopted CNS/ATM as future navigation system at the 10th Air Navigation Commission held in September 1991. Advanced countries in aviation have developed and operated various navigation and air traffic control support system by applying advanced technology to cope air traffic efficiently and safely. Next generation CNS/ATM system is different from the existing system since it is recognized as innovative measure that can enhance safety, efficiency and expand capacity for the future air traffic. For the domestic civil aviation industry, department of aviation policy of the Ministry of Land, Transport and maritime affairs, universities and research institutes have developed R&D and implementation plan to CNS/ATM However, further reviews for R&D roadmap of air navigation system needed to operate aircraft environment-friendly. Global economy has changed the efficiency of production and service in the field of transportation, and the infrastructure from regional centric to global centric. Traditional air traffic management system has also been converted to new system based on sharing and processing information. This mainly attributable to advanced air traffic management measure based on real time networking and IT technology with using satellite. In addition, due to the continuous increasing in air traffic, the air traffic surveillance and air traffic management technology has become important. As a result, improvement of efficiency is required to minimize flights cancellation rate in airports around the world. 4-D Trajectory based Operation System is expected to expand capacity of domestic airspace and airport, to increase operational efficiency, and to reduce operating cost and emission, The implementation of 4-D Trajectory based Operation System is expected to expand capacity of domestic airspace and airport, to increase operation efficiency, and to reduce operating cost and emission. The implementation of 4-D Trajectory based Operation System enables to reduce flying distance and to accommodate more air crafts within the limited airspace and airport facilities. The objective of this study is to realize low-carbon green air traffic control environment. US and EU have established long-term 4-D Trajectory system based on Operation System deployment plan. The system with targeting at operating Global 4DT will be improved up to 2025. Future air traffic control will be based on 4-D Trajectory based Operation System. Therefore, it is expected for the 4DT system to be much better in terms of safety and effectiveness since it can provide airborne separation automatically without the risk of collision.