To improve the performance of the Galileo Open Service (OS), the E5 Quasi-Pilot signal component was introduced in the Galileo OS SIS ICD in November 2025, with the primary objective of supporting a faster Time to First Fix.
This new feature is available free of charge and is highly relevant for many applications where acquisition time is critical, such as power-sensitive devices, transportation, and emergency operations. Faster TTFF enhances usability, safety, efficiency, and energy consumption across nearly all GNSS applications.
Performance improvements
The new Quasi-Pilot signal component improves the service performance. Specifically, it is designed to provide the following advantages:
Low complexity acquisition, typically reduced by a factor of 8, compared to other E5 components, particularly adapted for receivers requiring lower power consumption.
Faster acquisition time, improved typically by factor 3.
Flexible exploitation of the signal features, allowing receivers to exploit the Quasi-Pilot signal component if desired.
The reduced complexity of the E5 Quasi-Pilot signal comes from the use of a smaller code length and the lower chip rate compared to the legacy components of E5. Shorter codes decrease the number of hypotheses that must be assessed during acquisition, thus speeding up the process, while a lower chip rate reduces the memory needed to store the sampled input signals. The technical details about the signal are provided in the updated Galileo OS SIS ICD.
Further details on the schedule of the quasi-pilot reconfiguration will be soon provided in this web page.
Future Quasi-Pilot developments
To ensure the best navigation service performance, further and improved Quasi Pilot signals are being developed, which will be deployed in future by Galileo (in E5 and in other bands). These enhancements will further increase the benefits and performance of the Galileo Open Service. Further information about the future Quasi-Pilot signal components will be published in the coming weeks in a dedicated document. This publication will support Galileo users and receiver manufacturers, with the objective of providing early information on the planned G2G Quasi-Pilot signals ahead of their official release in a future update of the Galileo OS SIS ICD. It will allow receiver manufacturers to prepare their receivers with a clear understanding of the overall Galileo signal characteristics, ensuring a smooth transition during their introduction and evolution.