What is Galileo Public Regulated Service (PRS)?

What is Galileo PRS or Public Regulated Service?

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- everything RF

Aug 28, 2022

The Galileo PRS (Public Regulated Service) is an encrypted positioning, navigation and timing service provided by the Galileo satellite system, an independent, global, European-controlled satellite-based navigation system. Galileo provides a number of guaranteed services to users equipped with Galileo-compatible receivers. The PRS service provides encryption and is designed to be more robust, with anti-jamming mechanisms and reliable problem detection. This service is restricted to government-authorized users for sensitive applications which require a high level of service continuity and is intended for security and strategic infrastructure (e.g. energy, telecommunications and finance).

The Galileo PRS ensures better continuity of service to authorized users when access to other navigation services may be degraded (resilience) and in cases of malicious interference, PRS increases the likelihood of the continuous availability of the Signal-in-Space (robustness).

The Galileo Public Regulated Service is accessible through two signals - one in the 1575.42 MHz band and the other in the 1278.75 MHz band - which are broadcasted permanently (see Galileo frequency bands). These wideband signals are resistant to involuntary interference or malicious jamming and therefore offer better continuity of service. The signals are encrypted and allow the implementation of an access control scheme. PRS has a 95% accuracy providing horizontal positioning accurate to up to 6.5 m and vertical positioning accurate to up to 12 m. Permanent broadcasting means it is available 99.5% of the time and also has timing accuracy of up to 30 ns w.r.t. UTC/TAI. PRS also supports ionospheric correction based on DF measurements.

A major feature of the PRS is the robustness of its signal, which makes it more expensive and difficult to attack, thus the service is more resistant to jamming and spoofing. PRS provides a higher level of protection against the threats to Galileo Signals in Space through the use of appropriate interference mitigation technologies. PRS was designed to work against analyzed and identified threats posed by economic terrorists, malcontents, subversives or hostile agencies to the Galileo system which could result in damaging reductions in national security, law enforcement, safety or economic activity within a significant geographic area.

The objective of the PRS is to improve the probability of continuous availability of Galileo’s GNSS signals in the presence of interfering threats, to those users with such a need. The introduction of interference mitigation technologies carries with it a responsibility to ensure that access to these technologies is adequately controlled to prevent misuse of the technologies against the interests of Member States.

Key Elements Required to Provide the Galileo PRS Service:

  • Galileo Security Facility: this includes the Galileo Security Monitoring Centre (GSMC)
  • Ground Segment: this includes the Galileo Control Centre, which consists of the Galileo Mission System (GMS), Galileo Control System (GCS), Galileo Sensor Stations (GSS) and the Uplink Station (ULS)
  • Space Segment: Galileo satellites broadcast the PRS signal in space
  • User Segment: this includes individual end-users with PRS receivers and a support and management framework within each authorized PRS participant.

PRS is controlled by the authorities to be defined at the European level, through the encryption of the signals and the appropriate key distribution. Member States maintain control of the distribution of receivers. 

PRS also requires Member States to set up a "Competent PRS Authority (CPA)". This authority manages and controls end-users as well as the manufacture of PRS receivers. It also ensures adherence to clearly-defined security standards. PRS maintains coordination on a European level and guarantees consistency and conformity with the high level of security required.

Applications of Galileo PRS (Public Regulated Service)

On a trans-European level, PRS is used by:

  • Law Enforcement (EUROPOL, Customs, European Anti-Fraud Office - OLAF)
  • Security Services (Maritime Safety Agency) or Emergency Services (peacekeeping forces or humanitarian interventions)

As PRS also allows control to a certain degree by the Member States, it is also used by:

  • Law enforcement
  • Customs
  • Intelligence Services

Other PRS applications include emergency services, critical transportation, energy or telecom and defense purposes. PRS is intended for use by groups such as fire brigades, health services (ambulance), humanitarian aid, border control, civil protection units, search and rescue, police, coast guards and customs. Respective civil institutions control the access to the encrypted PRS. Access by regions or user groups follows the security policy rules applicable in Europe.

Galileo is the first civilian GNSS service in the world but is also used by the Member States for military purposes. This is why PRS has an important impact on Europe's Common Foreign and Security Policy (CFSP) and on the European Security and Defence Policy (ESDP).