Tag: GNSS timing

Viavi launches ePRTC360+ clock alternative to Cesium-accuracy holdover clock

Viavi Solutions Inc. has launched the patent-pending Cesium-less ePRTC360+ holdover solution to safeguard at-risk critical power grids, transportation, aviation and public safety systems, 5G mobile networks and AI data center infrastructure against the increased threat of GNSS timing disruptions. It is the only alternative to Cesium clocks to meet ITU-T G.8272.1 standards.

The international ITU-T G.8272.1 standard stipulates that Enhanced Primary Reference Time Clock (ePRTC) holdover must have short-term drift of less than 30 ns when entering into holdover and a long-term drift of less than 100 ns over 14 days, all traceable to UTC. Previously achieved only by Cesium atomic clocks, VIAVI’s ePRTC360+ now also meets this standard.

The ePRTC360+ has been successfully tested across a range of live-sky defense and commercial jamming/spoofing environments, and has been integrated into VIAVI’s SecurePNT 6200 product series. The technology can maintain 100 ns accuracy during GNSS-denied threats through the resilient altGNSS GEO-L service with no time limit.

It also combines an augmented VIAVI SecureTime GEO anti-jamming antenna and an enhanced GNSS anti-spoofing antenna that also receive eGNSS GEO service with GPS/GNSS-NMA authentication for spoofing detection and mitigation.

Unlike conventional GNSS omni-directional signals, which can be drowned out by low-power interference, VIAVI’s GNSS-independent GEO-L service leverages encrypted and highly directional L-band signals transmitted from geostationary satellites. Coupled with the augmented VIAVI SecureTime GEO antenna, the altGNSS GEO-L service provides enhanced anti-jamming protection and a resilient timing reference for the ePRTC360+’s internal Rubidium holdover oscillator and enables smooth multi-orbit source switchover, even when primary GNSS frequencies are jammed, spoofed or subject to sophisticated meaconing attacks.

The affordability of ePRTC360+ clocks compared to Cesium clocks enable operators to deploy them beyond the core and across the network. They also complement non-RF Cesium clocks at the core. This boosts end-to-end sync network robustness and holdover reliability through meshed network PTP feeds as backup between the clocks, especially in case of local or regional jamming and/or spoofing threats.

In addition, the ePRTC360+ addresses constraints posed by the use of Cesium clocks for holdover timing. These include sensitivity to shock, delicate and multi-stage startup procedures that take days to complete, the need for ECCN 3A001.i licenses for export, long GNSS learning period of up to 40 days, as well as strict shipping and storage protocols. In addition, Cesium tubes need to be replaced approximately every seven years, and the dismantling and disposal of Cesium clocks are classified as a hazard due to their material content.

The ePRTC360+ eliminates these hurdles and has been designed for rapid and easy integration into any vendor’s grandmaster clock system. It enables operators to meet stringent ePRTC requirements while reducing total cost of ownership.

The ePRTC360+ will be demonstrated at VIAVI’s Stand 5B18 at Mobile World Congress (MWC) Barcelona 2026, March 2-5, in Barcelona, Spain.

February 20, 2026
First Fix: It’s time to give time its due

Image: agsandrew/iStock/Getty Images Plus/Getty Images

Timing — the unglamorous yet essential T in PNT (positioning, navigation and timing) — has been called “the invisible utility.” In fact, it’s been a long time since we last put a GNSS-timing receiver on the cover. (Partly that’s because, like with simulators, it’s hard to come up with a visually compelling image that conveys the role of such a device.)

From St. Augustine (“What, then, is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know.”) to theoretical physicist Carlo Rovelli (who argues that time is “part of a complicated geometry woven together with the geometry of space”), time is both one of the greatest mysteries of nature and one of our most practical concerns. For satellite navigation, time is both essential to its functioning and a fabulous by-product. As David Wells and Alfred Kleusberg wrote in the first “Innovation” column, in the first issue of this magazine, “One of the by-products of getting an SPS [Standard Positioning Service] position fix is that a clock in the user’s receiver is automatically synchronized to clocks in the GPS satellites to an accuracy of one ten-millionth of a second. Therefore, any GPS receiver is a very accurate time distribution device.” (“GPS: A Multipurpose System,” January-February 1990.)

As Richard Langley wrote in another early “Innovation” column, “Thanks to minute energy changes in individual atoms of cesium and rubidium, humankind possesses the ability to synchronize clocks anywhere in the world to better than 10 nanoseconds. But given this amazing ability to measure time, we still don’t know what time actually is.” (“Time, Clocks, and GPS,” November-December 1991.)

I procrastinated the task of writing this editorial and now another aspect of time is here to impose its claim: our production deadline. So, just one anecdote and a final quote, and I will be done, just in time.
The anecdote. A quarter century ago, during my first time around on this magazine’s staff, when Glen Gibbons was the group editorial director, Alan Cameron the senior editor, and I the managing editor, we had just one meeting a month, called “edit check,” a couple of days before the deadline to send each issue to the printer. We printed out all the pages, laid them down in order around a large conference room table, and walked around the table examining each one and making notes about small final corrections and revisions.

Only one page routinely had a large empty area: It was the one for Glen’s monthly editorial, which he always finalized (wrote?) at the last possible moment. I once joked that it would be blown in at the printing plant like the magazine’s subscription cards. Well, as I finish this editorial, we are at T minus two days for the November issue. Enjoy it!

Oh, and the final quote, again from Rovelli: “The events of the world do not form an orderly queue like the English. They crowd around chaotically like the Italians.”

November 5, 2024
ADVA releases software to boost timing resiliency

Screenshot: ADVA

ADVA has released new software that extends its Oscilloquartz timing assurance technology to synchronization networks using Network Time Protocol (NTP).

ADVA’s Ensemble Sync Director management system provides assurance control, helping mission-critical services across many industries that depend on reliable and accurate NTP timing.

The new NTP capabilities are extended from ADVA’s robust Oscilloquartz Precision Time Protocol (PTP) product range and supported by Syncjack GNSS monitoring. They also leverage multiple form factors with redundant synchronization devices, multiple holdover options and versatile multi-technology gateways between GNSS, PTP and NTP, ensuring robust, scalable and highly resilient NTP timing architectures.

“Despite the availability of PTP, NTP remains the most widely used time synchronization protocol,” said Gil Biran, GM of Oscilloquartz, ADVA. “It’s applied in many legacy networks as well as new IoT (internet of things) applications. What’s more, the sophistication of NTP timing is increasing, while the NTP protocol itself remains unchanged. Now we’re enabling our customer to deploy robust, reliable and secure NTP implementations built on our unique expertise and experience in delivering assured synchronization.”

ADVA uses a combination of NTP architecture and highly accurate GNSS timing backed up with PTP timing domains.

Because ADVA’s products now support assured NTP technology, they offer customers virtually unlimited scale, Biran said. “With hardware-implemented NTP functionality, even the smallest SFP (small-form factor pluggable) NTP server can support up to 500,000 transactions per second.”

To ensure NTP delivery is able to withstand a broad range of risk scenarios, ADVA’s resilient synchronization solution is engineered for both device and network redundancy. It features multiple backup options such as PTP- and GNSS-delivered time, as well as a variety of oscillator solutions that allow different levels of holdover.

Comprehensive monitoring by ADVA’s Ensemble Sync Director management system helps guarantee the levels of performance required for time-critical network applications. Designed from the bottom up to support continuous assessment and assured timing precision, it automatically responds to any issues before applications can be disturbed by timing inaccuracies.

ADVA’s solutions also offer centralized GNSS monitoring and assurance, protecting timing networks from vulnerabilities, including jamming and spoofing attacks.

Customers can build NTP-based networks today and switch to PTP with one click, commented Nir Laufer, vice president of product line management at Oscilloquartz, ADVA. “Our customers no longer need to hope for the best from their NTP servers,” Laufer said. “With real-time GNSS monitoring and comprehensive probing and analysis of timing quality, they can rest assured that their synchronization services have the highest levels of accuracy, integrity, availability and scale.”

March 3, 2022
ADVA offers embedded timing for third-party hardware

ADVA has introduced its OSA 5400 SyncModule embedded timing solution, designed to enable technology suppliers to integrate precise synchronization into their hardware. Its M.2 form factor can add crucial timing capabilities to switches, routers, open compute servers and other IT devices.

The OSA 5400 SyncModule provides GNSS, precision time protocol (PTP) and network time protocol (NTP) engines as well as comprehensive PTP and GNSS monitoring and assurance functionality. According to ADVA, the module can enable assured sub-microsecond timing in public and private networks as well as critical infrastructure.

“Our OSA 5400 SyncModule brings something completely new and very valuable to the market,” said Gil Biran, general manager, Oscilloquartz, ADVA. “For the first time, third-party technology manufacturers will be able to embed the most advanced synchronization capabilities into their designs and easily control them with our Ensemble Sync Director or their own management system.”

Featuring multiple interface options for easy integration, the OSA 5400 SyncModule comes with an open API. It can also be managed by ADVA’s proven Ensemble Sync Director management system.

Image: ADVA

November 3, 2021
ADVA launches ePRC optical cesium clock for network backup

Photo: ADVA

ADVA has launched a ePRC optical cesium atomic clock solution to protect synchronization networks during GNSS disruptions. The OSA 3350 ePRC+ offers vital backup for mission-critical infrastructures that depend on satellite-based timing, such as mobile networks and power utilities.

The Oscilloquartz OSA 3350 ePRC+ provides high stability and long life, as well as built-in support for Simple Network Management Protocol (SNMP) . It also meets stringent performance demands as well as the cost points needed for mobile networks transitioning to 5G.

Featuring an all-digital design, the OSA 3350 ePRC+ leverages optical-pumping techniques. It greatly improves performance by providing an extremely stable frequency source.

When used with enhanced primary reference time clocks (ePRTCs), the OSA 3350 ePRC+ delivers holdover for 14 days with an accumulated error of up to 35 nanoseconds. This far exceeds the ITU-T ePRC G.811.1 standard that requires an accumulated error under 70 nanoseconds.

The OSA 3350 ePRC+ also delivers optimum stability for more than 10 years, much longer than the lifespan of high-performance magnetic cesium clocks.

With a fully modular design, the optical cesium solution features a wide range of telecom synchronization output interfaces and supports modern and secured management capabilities with SNMP. It is RoHS-compliant and is fully integrated into ADVA’s Ensemble management and control software suite for operational simplicity and ease of use.

June 3, 2020
Focus Telecom installs GPSdome to protect Israel’s ‘national clock’

Photo: InifiDome

The national time system at Israel’s National Physics Laboratory (INPL) in Jerusalem is now protected by a GPSdome unit for cyber protection of GPS/GNSS signals, according to Israel’s Homeland Security, a private company established in 2012.

Microchip partner Focus Telecom installed the GPSdome cyber protection system under a support and maintenance contract. GPSdome was developed by infiniDome, an Israeli startup.

INPL’s Nadya Goldovsky will now test and measure the system for its ability to protect the GPS/GNSS satellite signals from jamming and other interference. Over the course of several months, Goldovsky will test the system’s ability to protect its four independent atomic clocks, which continuously supply Israel’s national time.

The cyber protection system is designed to enable continuous, uninterrupted GPS/GNSS service, which allows for full operation of the clocks. During a GPS cyber-attack, infiniDome’s Communication Module will report it to infiniDome’s Cyber Security Cloud.

“GPSdome is a cyber protection system developed based on military technologies and principals which was adapted to non-military, commercial use,” said Omer Sharar, infiniDome’s CEO. “Our systems are already deployed and operational in Israel at multiple sites in the defense/HLS sector, border protection, financial sector and telecom sector.”

The company has signed a global distribution contract with an international PNT solution provider to sell its GPSdome systems in more than 120 countries, Sharar said.

May 22, 2020
Microchip offers phase noise analyzer for precision oscillator characterization

Next-generation phase noise instrument combines timing technologies in a smaller, higher performance measurement instrument

Photo: Microchip Technology

To help research and manufacturing engineers make precise and accurate measurement of frequency signals, including those generated by atomic clocks and other high-performance frequency reference modules and subsystems, Microchip Technology Inc. has announced the availability of the new 53100A Phase Noise Analyzer, a next-generation phase noise test instrument.

The 53100A Phase Noise Analyzer is designed for engineers and scientists who rely on precise and accurate measurement of frequency signals generated for 5G networks, data centers, commercial and military aircraft systems, space vehicles, communication satellites and metrology applications.

Capable of measuring radio frequency (RF) signals up to 200 MHz, the new test instrument rapidly acquires frequency signals and characterizes the phase noise, jitter, Allan deviation (ADEV) and time deviation (TDEV) quickly and precisely. All attributes of a frequency reference can be completely characterized with a single instrument within minutes.

The 53100A Phase Noise Analyzer enables a variety of configurations by allowing up to three separate devices to be tested simultaneously using a single reference, enabling higher capacity for stability measurements. At 344 x 215 x 91mm (13.5 x 8.5 x 3.6 inches), the phase noise test instrument is small enough for integration into manufacturing automated test equipment (ATE) systems, yet powerful enough for laboratory-grade metrology. Its interface provides backward compatibility with Microchip’s 51xxA test sets’ command and data stream, reducing the need to redesign existing ATE infrastructure.

The 53100A Phase Noise Analyzer provides flexibility by allowing an input reference device to be connected through the front panel at a different nominal frequency than the device under test — allowing a single reference to characterize a variety of oscillator products. Rubidium frequency standards such as Microchip’s 8040C-LN or a quartz oscillator such as Microchip’s 1000C Ovenized Crystal Oscillator (OCXO) could be used as a reference as well as other manufacturers’ precise oscillators.

The 53100A Phase Noise Analyzer is available now. Microchip supports the 53100A Phase Noise Analyzer with technical support services as well as an extended warranty.

May 1, 2020
How resilient PNT protects global networks from attack or failure
Time, time, time… See what resiliency brings

With the smartphone revolution, we are increasingly reliant on today’s global technology networks. The importance of protecting data centers and mobile devices with resilient PNT can’t be overstated. But what is the best way to accomplish this?

By Rohit Braggs, Orolia

Connected devices and cloud applications are the primary technology sources for most people today, and an exponentially growing number of those devices are connected to data centers in some way. Across the world, you can drive past countless acres of data centers that are storing, updating and retrieving the world’s data.

[Editor’s note: A complimentary webinar on Thursday, June 27, “Advanced Simulation Test Systems for Controlled Reception Pattern Antennas,” covers much of this material in greater technical detail. The full webinar is also available for download and viewing after that date.]

GNSS signals localize and timestamp the data collected from connected devices scattered across the world in diverse time zones and locations. They also provide the critical time synchronization that supports high-efficiency data storage, routing and exchanges across multiple data centers in various locations.

It is essential to protect data centers and their GNSS signal connections from system failure, jamming, spoofing, interference and denial of service. As the reliance on GNSS signals and the number of connected devices grow, so too does the threat of GNSS failure. False or unavailable positioning, navigation and timing (PNT) information at any point within this network can compromise security and completely disrupt user service.

This article explores the role of data centers and how their constant connection to devices enables almost every digital technology that we use today. It identifies key reasons why we should protect this interconnected data system from GNSS signal interference and disruption, in addition to providing information on how to ensure continuous signal monitoring and protection with a practical, cost-effective approach.

See also:

The latest tech fights for GNSS resilience

Is internet time good enough for cybersecurity?

Global Technology Networks

Data centers and connected devices affect nearly every aspect of our digital lives, from cloud software and applications to mobile phones and laptops. They store our personal documents, photo libraries and other priceless personal data. They also keep track of business documents, software licenses and other essential business information. In critical infrastructure, they support the daily operations of society’s most important services such as public utilities, banking and financial transactions, telecom, security, medical and defense systems, among others.

Data centers use timestamps as a key mechanism to store, organize and retrieve data. In addition to categorizing data by authorized users and other relevant identification information, the timestamp enables data centers to monitor revisions and retrieve the most recent version of the data.

A good example of timestamped data use is in cloud-based applications, accessed simultaneously by hundreds of thousands of users. In such environments, data is dynamic and changing frequently, which can lead to data conflicts. With accurate, reliable timestamps, a cloud-based application can resolve such conflicts to determine the order in which the data was received.

Why do we need to protect data centers and connected devices from GNSS signal interference?

GNSS signals are the quiet facilitators of many of our day-to-day tasks. In discussing why it is important to protect these signals, it is often easier to imagine what would happen without the accurate, reliable PNT information that these signals provide.

We need to understand two key pieces of information to operate systems: location and time. We need to know exactly where data or assets are located, and we need reliable, consistent time references to synchronize the movement of data and assets for system operations.

There are many documented examples of GNSS signal jamming, spoofing and denial of service attacks worldwide, and these are easy to find with a simple internet search. Here are a few examples of what can happen when the signal is compromised at a mobile or fixed location, but not taken offline. The user might still see that the signal is working, with no indication that the two critical pieces of information, location and time, are being disrupted:
- Imagine that the timestamp on a security camera system was spoofed to show a different time than the actual time. Incorrect or missing timestamps on video from surveillance systems is the most common reason for video evidence being deemed as inadmissible in a court of law. A bad timestamp corrodes the credibility of the video as irrefutable evidence and makes it easy to dispute.
- Imagine that a bad actor spoofed the time used by financial trading systems. Since these critical systems rely on GNSS-based time and synchronization, an attack on their underlying timing infrastructure could significantly impact the market and cause billions of dollars in damage.
- What if the GPS guidance system on your phone or vehicle gave you wrong directions? You could get lost in a wilderness or encounter dangerous driving conditions by trusting the route shown on your device.
- What if more people started using commercially available jammers? Some truck drivers have already been caught using unauthorized GPS jammers in their vehicles to avoid monitoring by their employers. In many cases, these deevices have affected nearby critical systems such as air traffic control, financial data centers, and other critical operations simply by being driven past with active jammers. The incidence of these disruptions is on the rise.
- Imagine a secure facility using an access control system that is set to automatically lock and unlock doors at a specific time. If someone spoofed the time used by that system, they could trick the doors into unlocking and gain entry.
We are also seeing an uptick in unintentional or environmental signal interference, which can occur in high-density development areas where various wireless transmitting systems can interfere with GNSS reception.

Which technology solutions are best suited to protect data centers and GNSS signals?

The first step toward protecting a GNSS-reliant system is to test the system for vulnerabilities. GNSS simulators and testing protocols can simulate a spoofing, jamming or denial of service attack to evaluate how the system responds to each situation. Knowing the system’s unique challenges and weaknesses can help resilient PNT experts design the best solution for that system.

One of the most common configurations for a fixed site location includes a highly reliable network time server to ensure that accurate timestamps are applied to each data point. A time server that can identify erroneous or spoofed GNSS signals is recommended for any critical application. In addition, a time series database could be installed to categorize and organize the time-stamped data, while identifying any irregularities in the data.

Once you have reliable timestamps and time server management systems, you also need to continuously monitor the signal to detect interference and raise an alarm. A GNSS signal monitoring system can let you know the minute your system is under attack. A GNSS threat classification system can identify the type of threat and mitigate it, depending on the nature of the threat, by filtering the signal to neutralize the interference.

The best way to prevent GNSS jamming is to deny interfering signals access to the receiver in the first place. Smart antenna technology focuses antenna beams to track the good signals from the satellites and reject the bad signals from interferers. Less sophisticated solutions such as blocking antennas can be employed to reject terrestrial-based interference, which is where most GNSS interference sources exist, and they provide a good first-level protection.

Continuous PNT access can also be achieved by using an alternative signal that operates separately from GPS/GNSS and is less vulnerable to the signal attacks that plague GNSS signals.

Emerging PNT Technologies

Over the next few years, new applications of mobile PNT data will further emphasize the need to maintain system integrity against threats. Here are a few examples of emerging technologies.

5G is here for mobile Internet and telecom service, yet with the specific need for microsecond-level synchronization, the challenge to protect the fidelity of the time used in these systems will become more important.

With rising awareness of the need to protect GNSS signals against threats, individuals will need to determine how they can protect their own GNSS-reliant systems as they navigate the Internet of Things and GIS enabled e-commerce. Personal PNT protection is an emerging technology area that could help protect people and their mobile devices on an individual basis, to ensure GNSS is there when it matters. Whether you are embarking on a remote hiking or sea expedition, sharing your coordinates with an emergency dispatcher after an accident, or simply trekking your way through a new city late at night, having resilient GNSS signal support is becoming a necessity.

Alternative signals are now available, and these new signal options, such as STL (Satellite Time and Location), could play an important role in providing better privacy and security functionality. This signal diversity will help protect against threats and interference by adding resilience to the device’s ability to receive reliable PNT data.

Another exciting technology development is the concept of smart cities, where technology has the opportunity to increase efficiency, reduce waste and provide many conveniences for the public. As we automate more city systems, it is essential to protect these systems from both accidental and malicious GNSS-based interference to ensure that these systems can make decisions based on reliable, precise PNT data.

Intelligent Transportation Systems (ITS) have the capacity to transform how people and freight travel today, saving lives and bringing goods to market more efficiently than ever. The need to know exactly where a driverless vehicle is in relation to other vehicles at any moment in time is just one of the resilient PNT technology requirements that will rely on GNSS signals.

Finally, authenticated time and location information can help increase cybersecurity for many applications, by limiting data access to a very specific window of time and only in a precise location. This is an area of cybersecurity which has the potential to add new layers of authentication to protect users and their data. With connected devices at the forefront of our access to the world, secure and reliable PNT technologies are more critical than ever.

These are just a few examples among many of the new technology innovations that are in the works to provide us with new benefits in leaps and bounds.

Protecting Our Virtual Brain

Data centers are the technology hubs of today, and their constant connection to devices fuels our ability to access critical information instantly. This networked system serves as a virtual brain that holds our personal memories, charts our progress, enables us to share results and helps us deliver new technology advancements faster than we could ever do before.

As we prepare to embrace our new technology, we should first address the PNT technology challenges of today and ensure that our GNSS signals are resilient and reliable. With this strong foundation in place, we can better protect our current systems and keep pace with evolving threats that would otherwise jeopardize the functionality, safety and security of these new capabilities.

Rohit Braggs is the chief operating officer at Orolia. Based in Rochester, New York, he is responsible for the development and execution of the company’s global business strategy and corporate initiatives. He also serves on the board of directors for Satelles Inc., which provides time and location solutions over the Iridium constellation of low-Earth-orbiting satellites.
June 24, 2019