How the Growing Threat of GPS Jammers Puts Critical Network Timing at Risk—and What Industries Can Do to Safeguard Against Disruptions

Part 2-3 from a GPS World magazine interview with Syncworks’ Beacham Still and GPS World Editor-in-Chief Matteo Luccio

As the world becomes more interconnected, critical infrastructure network timing faces growing threats, particularly from GPS jammers. Despite being federally illegal in the U.S., GPS jammers are easily available online, and their use is on the rise. Sectors like telecommunications, utilities, and transportation rely on GNSS-based timing to maintain precise synchronization, making them highly vulnerable to disruptions. Here, we explore how GPS jammers impact critical infrastructure, expose unique timing vulnerabilities, and discuss strategies for enhancing network timing resilience.

The Growing Threat to Critical Infrastructure Network Timing

GPS jammers, which emit signals in the GNSS frequency range, are designed to disrupt satellite timing and positioning data. While often used by individuals to evade corporate tracking, these jammers are becoming a substantial threat to critical infrastructure network timing. A small consumer-grade GPS jammer can impact GNSS signals within a radius of up to 10 meters, while industrial-grade jammers, typically emitting around 10 dBW (decibel-watts) of power, can disrupt GNSS over several kilometers, depending on line of sight.

For sectors that rely on GNSS-based network timing, even brief interference can create widespread instability. According to a 2022 study by the European Commission, GPS jamming events in urban areas increased by 30% over the previous five years, leading to more frequent service interruptions in sectors like telecom and utilities. In the U.S., high-traffic areas such as truck stops and highways are prone to repeated interference, as GPS jammers are frequently used by drivers to avoid tracking.

Impact of GPS Jammers on Network Timing Systems

The impact of GPS jammers on network timing systems is particularly severe due to the reliance on GNSS signals for synchronization. GNSS satellites orbit approximately 20,200 kilometers (12,550 miles) above Earth and transmit at about -160 dBm (decibel-milliwatts) — a weak signal that’s especially susceptible to interference from local jammers operating in the 1.5 GHz L1 GNSS frequency band.

For instance, telecommunications networks use critical infrastructure network timing to maintain signal synchronization across vast distances, ensuring uninterrupted connectivity. Even a small timing error caused by interference can lead to “timing slips” — brief lapses in signal alignment that may affect call quality, data transfer speeds, or network security. Similarly, in power utilities, synchronization is crucial for grid stability, with any timing discrepancy causing phase misalignments that can lead to equipment damage and service outages.

Challenges in Detecting and Mitigating GNSS Interference

Identifying and mitigating GNSS interference remains challenging for network operators. GNSS-based network timing systems are sensitive and can be disrupted by various factors, including solar flares and ionospheric conditions. To accurately detect intentional interference from jamming, organizations must deploy advanced RF monitoring tools capable of analyzing GNSS frequency bands in real time. High-precision spectrum analyzers, combined with directional antennas, are often used to pinpoint the source of interference, especially in high-risk areas near critical infrastructure.

Additionally, proactive critical infrastructure network timing design helps counteract interference. Techniques like adaptive antennas, which steer away from jamming sources, and frequency hopping, which avoids persistent interference, are increasingly common. Regular audits at key sites, particularly those near high-traffic areas, further help operators monitor and manage interference levels.

Resilient Design Strategies for Critical Infrastructure Network Timing

Syncworks and other timing solution providers work with industries to develop resilient network timing infrastructure designed to withstand GPS jamming. One crucial approach involves integrating oscillators for holdover. Oscillators act as timing backups, maintaining synchronization even if GNSS signals are temporarily lost. Rubidium and cesium oscillators are commonly used for holdover in critical infrastructure, offering varying levels of precision and duration:

• Rubidium oscillators provide reliable timing for up to three days without GNSS, with accuracy drifting by only 1 microsecond per day.
• Cesium oscillators offer even greater stability, drifting less than 5 nanoseconds per day, allowing timing systems to maintain accuracy over several weeks without GNSS input.

Both types are valuable for critical infrastructure network timing where even brief lapses can have widespread effects. Additionally, alternative timing sources, like terrestrial-based eLoran and low Earth orbit (LEO) satellite timing, reduce reliance on GNSS and add resilience. LEO satellites, which orbit closer to Earth at around 500-2,000 km, provide stronger signals that are less prone to local jamming.

Preparing Critical Infrastructure Network Timing for the Future

The rise in GPS jamming presents a pressing challenge for critical infrastructure network timing. As the demand for resilient timing solutions grows, many industries are now investing in additional protections, including oscillators, alternative timing sources, and advanced monitoring tools. Syncworks remains a trusted partner in this effort, helping organizations design network timing infrastructure that’s resilient against the growing threat of GPS jammers and other forms of interference.

By building robust network timing solutions, Syncworks ensures that critical infrastructure remains stable, secure, and prepared for an increasingly jamming-prone world.