The programme

|User needs and service definition

|GALILEO services

|System architecture

|Programme phases

GALILEO Services

Four navigation services and one service to support Search and Rescue operations have been identified to cover the widest range of users needs, including professional users, scientists, mass-market users, safety of life and public regulated domains. The following GALILEO satellite-only services will be provided worldwide and independently from other systems by combining GALILEO's Signals in Space:

• The Open Service (OS) results from a combination of open signals, free of user charge, provides position and timing performances competitive with other GNSS systems.

• The Safety of Life Service (SoL) improves the open service performances providing timely warnings to the user when it fails to meet certain margins of accuracy (integrity). It is envisaged that a service guarantee will be provided for this service.

• The Commercial Service (CS) provides access to two additional signals, to allow for a higher data rate throughput and to enable users to improve accuracy. It is envisaged that a service guarantee will be provided for this service. This service also provides a limited broadcasting capacity for messages from service centres to users (in the order of 500 bits per second).

• The Public Regulated Service (PRS) provides position and timing to specific users requiring a high continuity of service, with controlled access. Two PRS navigation signals with encrypted ranging codes and data will be available.

• The Search and Rescue Service (SAR) broadcast globally the alert messages received from distress emitting beacons. It will contribute to enhance the performances of the international COSPAS-SARSAT Search and Rescue system.

The GALILEO satellite-only services can be enhanced on a local basis through combination with local elements for applications with more demanding requirements.

GALILEO signals can also be combined with other GNSS system (Glonass, GPS) or non-GNSS systems (e.g. GSM and UMTS) to allow enhanced services for specific applications.

A service-oriented approach has been used to design the GALILEO architecture. The GALILEO global component, comprising the constellation of 27 active satellites + 3 spare satellites in Medium Earth Orbit and its associated ground segment, will broadcast the Signal in Space required to achieve the satellite-only services. The local service enhancements will be facilitated, as the global component will be designed to easily interface with local elements. In the same way, the interoperability between GALILEO and external components will be a major driver of the Galileo design to allow the development of applications combining GALILEO services and external systems services (e.g. navigation or communication systems).