Work Package 4 (WP4) aims at supporting the Initial Trajectory Information Sharing (AF6 in CP1). It partially addresses SDM Family 6.3.1, "Initial Trajectory Information Sharing – Ground Distribution", which involves setting up ADS-C contracts with equipped aircraft, managing the downlinked trajectory information (ADS-EPP) on the ground, and distributing this trajectory data to other ATS Units.

The current work package focuses on the pre-operational implementation and deployment of SDM Family 6.3.1, contributing to the Deployment Milestones DM01, DM02 and DM03 of the SESAR Deployment Programme.
The specific objectives of WP4 are:
- To pre-operationally implement and establish a Common European ADS-C Service, which provides a common logon service (enabling a single connection between an aircraft and the ground), establishes ADS-C contracts with relevant aircraft and distributes the downlinked ADS-C EPP information to various ANSPs (ATS Units) and the Network Manager. The ANSPs mandated to implement AF6 have grouped together to procure and deploy this Service, hereafter referred to as the Logon and ADS-C Common Service (LACS). This is part of the activities DM01 and DM02.
- To upgrade the ground infrastructure of each ANSP to enable pre-operational connection to LACS prototype or industrial solution, and to handle the distributed trajectory information via the defined ground-ground SWIM interfaces. This is represented by the activities related to activity DM03.

The ADS-C common service is scaled for all European ANSPs. The present WP covers the deployment associated to:
- French UIR airspace above FL285 - DSNA
- Estonian FIR airspace - EANS
- LECM and LECB airspace above FL285. GCCC in the area defined by the lateral limits of TMA CANARIAS to the north of 26N parallel and to the east of 19W
- Meridian, from FL285, as defined in AIP GEN 3.4-1 - ENAIRE and its affiliated company CRIDA
- Slovak Republic airspace above FL 285 - LPS
- Malta airspace - MATS
- The airspace of FIR Warszawa (EPWW) - PANSA
- FIR Bucharest providing air traffic services within Romania airspace – ROMATSA RA
- WP4 tasks are aligned within all participants, as each task per beneficiary includes the following common activities:
- DM01 “Ground distribution Architecture definition”
The ground distribution architecture must meet the AF6 regulatory provisions and the required performance levels, as defined in the applicable standards and contracted service levels. The architecture will include the initial trajectory information sharing ground distribution between the LACS and the ANSPs systems.
- DM02 “Ground infrastructure deployment”.
Following the architecture defined in DM01, the LACS ground infrastructure will be developed and tested for the provision of trajectory information sharing (ATN connectivity, ATN air ground CM application for logon information, ATN air-ground ADS-C application for trajectory downlinking and ground-ground SWIM interfaces for data information distribution). The LACS will be deployed as pre-operational platform to allow potential users to perform interoperability testing.
In addition, every participant will carry out activities that contribute to DM03 as specified in each of the tasks below.
- DM03 ATS system connected to Ground distribution architecture.
This WP4 is linked to WPs 2 and 3as all of them contribute to ATM Functionality 6 “Initial Trajectory Information Sharing”.

Expected benefits of WP4:
The implementation of WP4 will contribute to:
- Develop a common service supporting the immediate and efficient ADS-C contract management and minimises fragmentation. This approach minimises the impact on the air-ground communication infrastructure and improves the deployment of Initial Trajectory Information Sharing ground distribution required by CP1 AF6.
- Harmonise Ground by using SWIM service interfaces based on modern IT standards.
- Increase cost efficiency through a common procurement initiative.
- Improve efficiency by reducing ATN air-ground network load and use of radio spectrum.
- Reduce the workload by improving processes’ automation.