The new ATM concepts proposed by both SESAR and Next Gen require a paradigm shift from an often uncoordinated system that relies on centralized, ground-based tactical separation assurance to an integrated and coordinated one centered on strategic, collaborative trajectory management. Thus, in the future European ATM system defined by SESAR, the aircraft business trajectory will become the centerpiece of a new set of operating procedures collectively referred to as trajectory-based operations (TBO). The implementation of TBO will require that the human actors in the ATM system rely on advanced decision-support tools (DSTs) that will enhance both airborne and ground-based automation systems, allowing closer adherence to the aircraft's optimal trajectory. Since many of these DSTs will need to operate with a strategic view of the aircraft's intended trajectory, they will require a trajectory predictor (TP) to carry out their functions. However, different DSTs may in principle rely on different TPs, which may produce inconsistent trajectories for the same flight, as well as inconsistencies with the aircraft generated trajectory (the trajectory generated by the flight management system). This lack of consistency among predictions is seen as a key issue affecting the integration and harmonized operation of current and future DSTs. Coordination between TPs is key to ensure coordination between DSTs and hence the successful evolution and implementation of TBO. The ability to synchronize trajectory information across the ATM system is then a prerequisite for efficient TBO and will facilitate the implementation of SESAR and Next Gen. As a consequence, much research is required to fully understand the implications of the different possible information-sharing schemes that could be implemented to support trajectory synchronization in the future ATM system. In view of this trajectory synchronization issue, Boeing Research & Technology Europe (BR&TE), General Electric Aviation Systems (GEAS), Indra Sistemas (Indra), Barco-Orthogon and Airservices Australia (ASA) have teamed up under the aegis of EUROCONTROL to provide the SESAR programme and the ATM community as a whole with the research framework and tools that can facilitate the study of the trajectory synchronization problem using real ATM systems coordinated with real Flight management systems (FMS). This research activity is called ASIS (aircraft intent synchronization infrastructure for SESAR). It is anticipated that the results of this research activity will also be of great interest to the implementation of Next Gen. This paper describes the main objectives of the ASIS initiative and reports on the results obtained to date.