English
Military users in European Union member states will soon have access to a new generation of GNSS receivers, supporting both the Galileo PRS and GPS M-Code encrypted signals.
The Public Regulated Service (PRS) is one of four services offered by the Galileo global navigation satellite system; Europe’s version of GPS. It broadcasts encrypted signals on two frequencies, providing secure, authenticated positioning and timing for military use and for applications of national importance.
PRS is designed to be highly resistant to jamming, spoofing and other types of disruption, enabling authorised users – including armed forces, police, coastguard, and operators of critical national infrastructure – to continue operating in adverse conditions. PRS will still be available, for example, even if a decision is taken to turn off the open Galileo signal for defence purposes.
M-Code, similarly, is a new encrypted GPS signal developed as part of the GPS modernisation programme that’s been ongoing since 2000. M-Code is restricted for authorised military use, and provides advanced protection against jamming and spoofing, as well as improved signal availability through the use of directional antennas.
A new generation of military-grade GNSS receivers is on the horizon
PRS has been available with limited functionality since 2016, during Galileo’s early operational phase. But with the constellation now approaching full operating capability, and M-Code scheduled to become available in 2022, manufacturers are starting to develop a new generation of military-grade receivers that support both encrypted signals.
These receivers will be marketed as providing maximum performance and robustness in the face of jamming and spoofing attacks and other types of RF interference.
Testing new PRS + M-Code receivers will require advanced simulation
Receiver developers and integrators will have to ensure their new PRS and PRS + M-Code receivers work as promised, and that means subjecting them to thorough performance testing. Simulation is by far the most effective method of testing and validating receiver performance, quickly and efficiently, in a wide range of conditions.
For PRS and M-Code-reliant applications, that means simulating conditions the receiver is likely to encounter in the real world. In addition to jamming and spoofing, developers will want to simulate realistic atmospheric interference, as well as signal obscuration and multipath effects caused by the signal reflecting or refracting off objects in the environment.
It also means simulating rare-but-not-impossible ‘corner cases’ – for example, what happens if a fault occurs in the space or ground segments of either Galileo or GPS.
Simulation is by far the most effective method of testing and validating receiver performance, quickly and efficiently, in a wide range of conditions.
A 30-year track record of simulating encrypted GPS and Galileo signals
A fundamental aspect of any simulator chosen for a PRS testbed will be its ability to faithfully and accurately replicate PRS signals in the E1 and E6 bands and M-Code signals in the L2 band.
Spirent has been developing GNSS signal simulation hardware and software across four decades, including long-standing experience of generating GPS Directorate-approved encrypted GPS signals, including Y, M and M-Code.
Spirent has also been closely involved with Galileo since the early days of the project. In 2006, we were contracted by the European Space Agency to provide reference test equipment for the Ground Receiver Chain (GRC) portion of the Galileo ground segment, adapting our then-market-leading GSS7700 GPS simulator platform to generate the planned Galileo signals.
SimPRS – the world’s first PRS simulation software – is now available as prs[ware]
As part of that project requirement, we also developed SimPRS, the first PRS simulation software in the world, whose design and architecture was verified and tested by ESA.
Since then, we have built on that foundation, launching the GSS8000 multi-GNSS simulator with SimPRS in 2008, and the powerful and flexible GSS9000 multi-GNSS simulator with SimPRS in 2014.
In 2018, in anticipation of the United Kingdom leaving the EU (and therefore being excluded from EU Restricted programmes), we formed a partnership with Fraunhofer IIS and LZE GmbH in Germany to ensure continuity of supply of PRS capability to authorised receiver developers and manufacturers.
SimPRS became PRS[WARE], and is available via LZE for use with Spirent GSS9000 simulators. Fraunhofer IIS, meanwhile, owns the technical design and roadmap for PRS[WARE] and is committed to updating the software in line with developments in the PRS signal.
Find out more about simulating secure signals with Spirent
Thanks to our state-of-the-art equipment and long-standing working relationships with the architects of GPS and Galileo, the Spirent GSS9000 remains the industry’s approved simulation platform of choice for performance testing of secure receivers for military and national security purposes.
If you’d like to discuss Spirent’s capabilities in simulating encrypted Galileo and GPS signals, please do get in touch.
