GPS disruptions and outages are making headlines almost daily. Global Navigation Satellite System (GNSS) jamming is increasingly becoming a dominant form of electronic warfare.

The Norwegian Communication Authority has reported that in 2024, it experienced disturbances to its GPS navigation for 44 days until February 22 — which practically means every day. Further GPS disruptions have been reported in the Baltics region, affecting parts of Poland, Lithuania, and southern Sweden, demonstrating that GNSS jamming poses risks to global navigation and the safety of aviation, shipping, and other transport networks and causes significant financial damages.

– Pavlofox, Pixabay

According to a report by London Economics, the economic loss for the UK due to a GNSS outage for seven days has been estimated at £7.6m ($9.5m) or about £1.4 billion ($1.8bn) in a 24-hour outage. Applications in emergency services, maritime, and road transportation account for 87.6 percent of the total economic loss.

Why is precise time key for critical infrastructure networks?

The increasing reliance on GNSS for timing is proving increasingly problematic. GNSS was initially developed for navigation but now plays a pivotal role in providing highly accurate time synchronization for critical national services, including telecommunications, financial services, power grids, broadcast networks, national security and defense systems, and emergency services. Numerous vital systems and operations hinge on precise time for coordination and synchronization.

Mobile networks, particularly 5G and the emerging 6G, heavily depend on accurate timing for synchronization. 5G brings an increased focus on TDD (Time Division Duplex) technology, which requires a much more stringent synchronization, compared to FDD (Frequency Division Duplex) in most 4G/LTE networks.

In addition, new features and advanced network techniques such as Massive MIMO, Carrier Aggregation (CA), License Assisted Access (LAA), and Coordinated Multi-Point (CoMP) transmission and reception technologies require further enhancements in synchronization. GNSS is commonly utilized to establish a unified time reference for various network elements and within the Radio Access Network (RAN).

Power grids require precise timing to synchronize electricity generation and distribution effectively. GNSS ensures the seamless operation of different grid components. This requirement will only intensify with the transition to renewable energy sources and digital power stations.

Emergency services, military operations, and national security efforts also often integrate GNSS timing with communication systems, especially in collaboration with 5G networks.

A new path to precise timing

Traditional network-based synchronization solutions require significant and complex infrastructure upgrades, dramatically bumping up 5G rollout costs. However, new synchronization solutions enable GNSS-independent time distribution by leveraging existing infrastructure, including leased lines. The outcome is a notable reduction in CAPEX and a faster deployment of 5G networks across urban and rural areas.

Key components of this innovative synchronization technology are currently being standardized within International Telecommunications Union (ITU) study group 15.

The new GNSS-independent precise time model decouples the synchronization functionality from the hardware, establishing a synchronization overlay across the existing IP infrastructure without requiring PTP IEEE1588 hardware support in intermediary nodes. This approach allows for the efficient transmission of precise time from central time reference sites to the RANs without increasing costs. However, when it comes to transmitting accurate time over wide area networks, operators need to address two challenges: network jitters and link asymmetries.

Network jitters and Packet Delay Variation (PDV) typically arise from traffic congestion in network switches and routers, resulting in noise and diurnal wander in time distribution, leading to dynamic time offsets at the receivers. In addition, static link asymmetries, such as those caused by differing fiber lengths or static delays in switches, can be easily compensated for.

However, dynamic asymmetries, including those stemming from protection switches or changes in wavelengths, pose challenges in detection and compensation.

New precise time technology operates by streaming timestamps at a significantly higher rate, powering the implementation of advanced filtering mechanisms and algorithms. Combined with collaborative clock links, this approach effectively reduces jitter noise, improving time accuracy.

This technology also integrates real-time algorithms for asymmetry control with centralized intelligence, enabling the detection and compensation of dynamic asymmetries to eliminate constant time errors from the synchronization network. As a result, innovation in GNSS-independent synchronization enables the development of a secure and highly available 5G infrastructure that supports critical national services and key advanced business services that drive the monetization of 5G technology.

Beating uncertainty with precise time

Although the geopolitical dynamics are shifting fast, instability will remain the dominant trend. GPS jamming will continue to be a significant risk for the foreseeable future. Mobile operators, governments, and regulators need to safeguard and future-proof their critical infrastructure networks to ensure they are better positioned to deal with these challenges.

GNSS-independent synchronization technology delivers the benefits of precise time without the vulnerabilities and costs that compromise GPS-powered solutions. In times of economic and geopolitical headwinds, ensuring the safety and efficiency of national networks is more important than ever. Innovation in time synchronization provides the foundations for the critical services of the future.