First Standard for Galileo Timing Receivers

The Galileo second generation (G2G) introduces a dedicated Galileo Timing Service, particularly targeting the critical infrastructure sectors and offering end-to-end performance for timing and synchronization applications. This service is the first to incorporate integrity capabilities for timing users, including specific timing flags for the users. To ensure end-to-end performance, the European Commission (EC) initiated the development of the first international standard for Galileo Timing receivers, supported by the STARLITE project and elaborated by WG9 of the JTC5 “Space” under CEN/CENELEC. The standard adopts a performance-based approach, defining functional and performance requirements along with corresponding tests for the essential requirements. Key functional requirements include Galileo-only mode, dual-frequency operation, static user dynamics, integrity capabilities, and anti-jamming and anti-spoofing capabilities. Performance requirements focus on accuracy, availability, and integrity. The verification involves 13 tests, primarily using a Record and Replay (R&R) approach, with two tests requiring a GNSS simulator. The R&R technique has advantages for test execution as it is cost effective. At the same time, it is a technique that requires some technical knowledge. The paper discusses key technical aspects to be considered for both recording and replay. In addition, recommended test configurations for this technique are proposed. Tests cover aspects such as Timing Flags processing, performance for Galileo System Time (GST) and Universal Time Coordinated (UTC) solutions for the different service levels, performance in obstructed and light indoor environments, robustness to interferences, Timing Receiver Autonomous Integrity Monitoring (T-RAIM) performance, and receiver noise contribution. The paper not only explains the most relevant details of each test, but also the justification and logic behind them.