Accurate and Resilient GNSS Timing Modules for Critical Infrastructure

April 1, 2026

Precise time synchronization is the backbone of today’s connected world, keeping telecom networks, data centers, and financial systems running seamlessly. Without accurate timing, our digital infrastructure would quickly fall out of sync.

Septentrio designs and manufactures world recognized Global Navigation Satellite System (GNSS) timing receivers for critical infrastructure and leading industry organizations. The Septentrio mosaic-T timing module delivers nanosecond-level precision for synchronization and is trusted by companies such as Meinberg, VIAVI, and Saab. Built-in AIM+ technology protects against intentional and unintentional GNSS jamming and spoofing, ensuring maximum system uptime even in challenging or hostile conditions.

Regular participation in live jamming and spoofing events, such as the recent Jammertest 2025 event in Norway, ensures Septentrio receivers remain at the forefront of resilience innovation. The next-generation mosaic-G5 T module continues this legacy, offering high precision and exceptional resilience in an ultra-compact form factor.

Rising Threats to GNSS Integrity: Safeguarding Critical Timing Systems

Incidents of GNSS interference are increasing worldwide. Airports in Eastern Europe have experienced GNSS disruptions that caused rerouting, delays, and potential safety hazards. But the impact extends far beyond aviation. When GNSS timing is compromised, the effects can cascade through telecom networks, power grids, and financial systems.

The UK’s Knowledge Transfer Network has warned in published research that organized criminals could spoof financial institutions’ clocks, manipulate trading timestamps, and then revert them to conceal fraudulent transactions.

This is the mosaic-G5 T multi-frequency GNSS timing module. Measuring just 23 × 16 mm and weighing only 2.2 grams, this receiver expands possibilities for system designers operating under strict size, weight, and power (SWaP) constraints. Its nanosecond precision, fortified by AIM+ Premium anti-jamming and anti-spoofing technology, ensures continuous and secure uptime. (Image: Septentrio)

These trends highlight that GNSS interference and spoofing pose systemic risks to critical infrastructure making robust and resilient timing references indispensable.

Industry-Trusted Timing: AIM+ Technology Powering Global Leaders

Meinberg is a world-renowned manufacturer of high-precision time and frequency synchronization systems — including GNSS time servers — used in critical infrastructure, telecom, and industrial networks. Meinberg integrates Septentrio’s multi-constellation, multi-frequency GNSS module, mosaic-T, as the timing engine inside its high-resilience products. In combination with AtomiChron technology, Meinberg achieves unmatched spoofing resilience with authentication across all four major GNSS constellations.

Figure 1. During this spoofing test the mosaic module continued to provide precise timing, while a competitor module was spoofed by three minutes to the past. (Image: Septentrio)

“Meinberg relies on technology partners like Septentrio and we have been in close contact ever since we started using the mosaic-T GNSS module in some of our products,” said Heiko Gerstung, Managing Director, Meinberg. “The level of technical expertise of Septentrio and the willingness to solve problems and find solutions is outstanding and in turn helps us to ensure that our customers can rely on getting the excellent products and support quality that they are rightfully expecting from us.”

VIAVI Solutions is another global leader providing Assured PNT solutions to safeguard critical operations for businesses, governments, and infrastructure providers. Their timing and frequency systems maintain nanosecond precision even under radio frequency (RF) interference, leveraging Septentrio mosaic for assured accuracy.

Saab integrated Septentrio receivers in their Air Traffic Management (ATM) system to synchronize their Multilateration and ADS-B surveillance. These sensors rely on GNSS timestamps for accurate synchronization. ADS-B stands for Automatic Dependent Surveillance–Broadcast, and it is a key technology used in ATM to enhance aircraft surveillance and improve safety and efficiency in the air and on the airport surface.

As seen on the news, airports around the world face an increasingly higher risk of GNSS jamming and spoofing, especially in countries that are near conflict zones where GNSS interference can spill over and propagate for over 100 km. To harden their system against GNSS jamming and spoofing, Saab selected a Septentrio receiver, which is protected by AIM+ Advanced Interference Mitigation technology. Saab demonstrated just how resilient their solution could be under live jamming and spoofing conditions at Jammertest, where powerful interference testing was conducted in a controlled environment.

Spoofing Awareness and Protection for Critical Infrastructure

GNSS spoofing is a cyberattack in which false satellite signals mislead a receiver into producing the wrong time. For timing receivers, this can disrupt entire networks. Because critical infrastructure depends on precise GNSS time, its static nature makes it particularly vulnerable to GNSS spoofing attacks.

Figure 2. During this spoofing test Septentrio’s time remained correct, while a competitor module was spoofed by two weeks. (Image: Septentrio)

Spoofing attacks can vary in type and sophistication. A cleverly set-up “pull-away” attack gradually changes the time and can bypass built-in system-level software checks. Luckily sophisticated GNSS receivers have advanced technology, such as AIM+ to flag and prevent spoofing at the core signal-processing level, maintaining reliable time integrity.

Since the receiver is at the forefront of signal tracking and reception, interference detection and protection at the receiver core is essential to prevent GNSS spoofing from corrupting downstream systems. Septentrio’s approach combines multiple defensive that work in synergy to detect and mitigate GNSS spoofing, with the following capabilities:

Multi-frequency, multi-constellation tracking maximizes signal availability and redundancy.
Advanced data analysis algorithms detect anomalies.
Cryptography, including Galileo OSNMA, authenticates signals
Trustworthy spoofing flag provides situational awareness so that the system can take preventative action.
AIM+ technology protects against jamming. Spoofing often starts with jamming, which breaks the signal lock and forces the receiver to reacquire the signal with faulty timing information.

In addition to a fortified receiver, a system can be protected further by including anti-spoofing components such as continuity checks, a specialized antenna, and services to authenticate all GNSS constellations like Fugro AtomiChron.

Jammertest Results Prove Timing Resilience

At Jammertest 2025, Septentrio’s timing receivers underwent rigorous live spoofing trials. The results confirmed their exceptional resilience to spoofing attacks. During a spoofing test shown below the Septentrio receiver maintained accurate time while a competitor’s device was spoofed by three minutes.

In another test, spoofing shifted a competitor’s clock by two weeks — while Septentrio’s remained stable.

While traditional GNSS anti-jam techniques do a good job in maintaining accurate positioning output during jamming, they tend to offset the time output. The reason is that anti-jam filters often introduce delays that are reflected in the position of the time pulse generated by the receiver. Septentrio receivers only use special types of antijam filters that have the “zero-delay” property, ensuring that the timing pulses remain stable and accurate even during jamming.

Over the years Septentrio’s GNSS timing module technology has proven to be a benchmark in precision and resilience, delivering secure, interference-resistant synchronization that keeps critical infrastructure worldwide operating reliably and in perfect time.

This article was written by Maria Simsky, Technical Content Writer, Septentrio part of Hexagon group (Leuven, Belgium). For more information, visit here .