Calian has introduced two pole mount variants of its controlled reception pattern antenna (CRPA) line. The new models support L1/E1 + L2/E5b (CR8894PXF+) and L1/E1 + L5/E5a (CR8854PXF+), giving customers expanded deployment and frequency support options for resilient GNSS applications.
The new architecture increases installation flexibility across critical infrastructure, timing, marine and defense environments while maintaining Calian’s CRPA and extended filtering plus (XF+) interference mitigation performance.
Flexible deployment
The pole-mount design integrates into fixed and marine installations such as communications towers, vessels, monitoring stations and critical infrastructure, supporting rapid setup and optimal antenna placement.
With dual-band options, the platform aligns with modern multi-frequency GNSS architectures, improving accuracy, robustness, interference rejection and compatibility with current and next-generation receivers.
Advanced anti-jamming features include:
GPS and Galileo support
Operation across L1/E1 and L2/E5b or L5/E5a
Mitigation of three jamming sources per band
Integrated XF+ filtering for superior out-of-band rejection and cross-band isolation
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Dedicated research and development, funded by European Union (EU) and European Space Agency (ESA) programs over the years, has played a key role in Galileo Second Generation.
Among the innovations that will benefit the new satellites are the development of new atomic clocks, links that allow the satellites to “talk” to one another in orbit and a prototype ground station that can precisely pinpoint satellites in the sky. These advanced technologies will ensure Galileo continues to provide world‑class positioning, navigation and timing to users worldwide.
The importance of R&D
Satellite navigation is constantly evolving, with new technologies being deployed. But before a technology can fly on a satellite, it must be derisked and qualified. This is where research and development (R&D) comes in, laying the groundwork for new technologies long before they see the light of day.
Horizon 2020 and Horizon Europe are R&D programs funded by the EU. A significant budget from these programmes is delegated to ESA for R&D to derisk new technologies for evolutions of Europe’s Galileo and EGNOS systems.
Complementing these EU R&D programs, ESA programs such as the General Studies Programme (now Discovery and Preparation), General Support Technology Programme and the former European GNSS Evolution Program (EGEP) have also performed R&D for future satellite navigation technologies.
R&D spurs the innovation that allows Galileo and EGNOS to modernise and develop new applications and services. Several activities funded through these programmes have contributed to Galileo Second Generation (G2). Some of these technologies will already fly on the G2 satellites when they are launched in the coming years.
New ways of keeping time
Galileo relies on highly precise onboard atomic clocks to ensure accurate global positioning and timing. Here, an iodine optical clock by SpaceTech, Germany (Credit: ESA)
Galileo delivers world-class positioning and timing, and its onboard clocks are the key to its performance. Each first generation Galileo satellite carries two passive hydrogen maser and two rubidium atomic frequency standard clocks. These clocks, developed by Leonardo and Safran Timing Technologies, respectively, are currently Galileo’s only space-qualified clocks.
A rubidium pulsed optically pumped (Rb POP) clock by Leonardo, Italy. (Credit: ESA)
To keep up with the latest technologies and allow for a broader diversity of European qualified clocks, R&D activities have encouraged European companies to develop new types of space-worthy atomic clocks. This investment is critical due to the time and expertise it takes to develop such complex and sensitive technologies. These activities aimed to develop alternative atomic clocks for Galileo that can improve performance and robustness and support Europe’s place as a leader in satellite navigation.
A Mercury ion clock (MIC) from Safran Timing Technologies, Switzerland. (Credit: ESA)
Seven innovative clock technologies were developed by European companies from France, Germany, Italy and Switzerland. After initial development activities, three of these clocks — proposed by Leondardo, SpaceTech and Safran Timing Technologies — were selected to progress to hardware development in preparation for a first flight.
Leonardo’s Rubidium Pulsed Optically Pumped clock is currently under development and planned to fly as an experimental clock on a Galileo Second Generation satellite. The Iodine Optical clock developed by SpaceTech is undergoing early development and shows potential for future use as an experimental clock on Galileo satellites. The Mercury Ion clock by Safran Timing Technologies recently launched its development activities.
Following an analysis of the clocks’ eventual in-orbit performance, a programme decision by the European Commission will be made before starting the operational phase of these new clock technologies.
Conversations in the sky
An intersatellite link transceiver by Thales Alenia Space. (Credit: ESA)
The Galileo system currently relies on links between satellites and ground stations to monitor and control the satellites and to determine the onboard clock skew. Clock skew occurs when a clock signal reaches different parts of a system at different times, which can cause errors in position calculations.
Galileo Second Generation will introduce inter-satellite links (ISL), allowing the satellites to ‘talk’ directly to one another in orbit. This will enable additional time synchronisation and ranging measurements that will improve knowledge of the satellites’ orbit and clock skew.
ISL will also allow faster data dissemination. If a particular satellite is not visible to a ground station, information can be sent to a different satellite and then passed on instead of waiting for the satellite to be visible.
An intersatellite link transceiver by Airbus Defence and Space. (Credit: ESA)
Two early models of ISL transceivers that are essentially identical to those which will fly on the Galileo Second Generation satellites were designed and developed. The transceivers, which can both send and receive signals, were developed by Thales Alenia Space (Spain) and Airbus Defence and Space (Germany).
One of these transceivers is about to enter the formal testing phase, while the other has undergone successful environmental qualifications. After the transceivers have completed their qualifications and testing, they will be ready for their trip to space.
Precisely pinpointing satellites
Accurate positioning, navigation and timing relies on knowing precisely where satellites are in their orbits. Galileo satellites are located by tracking their L-band antenna transmissions from the ground. Each satellite also has a laser retroreflector, which allows measurement of their orbit to within a few centimeters. Known as satellite laser ranging (SLR), this method measures the time it takes for a laser pulse to make the trip from a ground station, called an SLR station, to the satellite and back, then uses these measurements to determine the satellite’s orbit. Presently, SLR stations are owned and operated by scientific community users and serve multiple space missions.
One of the challenges of current SLR is the fact that the lasers are not safe for human eyes and cannot be used if an aircraft is flying nearby as the lasers could blind the pilots. This means SLR stations must coordinate with civil aviation and may not be allowed to use all parts of the sky. SLR stations also have limited availability due to local atmospheric conditions (clear skies are key), and low levels of automation (intensive need for human operators).
A prototype satellite laser ranging station in Matera, Italy. (Credit: ESA)
To mitigate these limitations, a modernized, eye-safe SLR station prototype for Galileo satellites has been developed by DiGOS (Germany) and commissioned in Matera, Italy. Due to the station design and laser wavelength used, there will be no need to coordinate with civil aviation. The station’s new technologies also explore increased automation using a predefined schedule to reach satellites. Although human operators are still needed, their workload is reduced.
A field campaign of the prototype SLR station is planned for this year as part of the Galileo Second Generation System Test Bed tasks. It will evaluate the potential benefits of SLR as a complement to L-band ground ranging. If the station is added to the Galileo ground segment, it could enhance the system’s robustness by providing an independent means of determining the satellites’ locations. In this case, interface design adjustments would need to be made to allow operational use of the station.
Beyond providing another method for determining Galileo satellite orbits, this station could also help contribute to the Galileo Terrestrial Reference Frame and could support ESA navigation scientific missions such as Genesis.
The United Kingdom has issued a summary of input it requested on positioning, navigation and timing (PNT) technologies. The UK deems PNT resilience critical for the UK’s economy.
After a call for evidence, the UK Department for Science, Innovation & Technology received 128 responses from business, industry, academics and the public. These views on opportunities and challenges for the UK’s PNT industry are gathered in a document available online.
Key themes identified
A viable market exists for GNSS-independent PNT, with respondents citing applications in defense and critical infrastructure.
Awareness of GNSS vulnerabilities in end users and critical infrastructure sectors is low.
Potential opportunities in GNSS-independent PNT and other technologies include eLoran, LEO-PNT, 5G, quantum PNT, inertial systems, and applications for GNSS-denied environments.
Short-term challenges include funding constraints and a lack of legislation and standards.
Long-term challenges include scalability, lack of sovereign manufacturing capability, and insufficient planning .
The industry is experiencing a skills shortage, especially in engineering, with a limited talent pipeline and lack of dedicated training opportunities.
In all, 128 responses were received from businesses (sellers and users of PNT), academics, industry bodies and the public. Respondents could select multiple sectors when describing their background; the defense sector was selected most frequently (39 responses), followed by space (35 responses), aviation and drones (28 responses), maritime (28 responses) and communications (27 responses).
Responses will be used, along with wider research, to inform future government policy interventions to support the UK PNT sector.
Achieving PNT resilience for critical infrastructure applications
GNSS are magic. They are. One dictionary defines magic as “a power that allows people (such as witches and wizards) to do impossible things by saying special words or performing special actions.” By this definition, we have all become witches and wizards, doing what previous generations would have deemed impossible.
This magic, however, can be affected by external forces that render it useless at best and, at worst, dangerous. Warnings about GNSS positioning, navigation and timing (PNT) service vulnerabilities have been raised for 25+ years. Numerous organizations have warned of the potential safety, security and economic impacts of GNSS interference. Still, like modern-day Cassandras, their warnings have been ignored, and sole use of PNT services that rely on space-based signals continues to expand.
“Magic services” are addictive and cannot be ignored. Yet, it is well past the time to merely admire the problem of GNSS interference — benefitting from magical GNSS services while ignoring existing and emerging threats and challenges. It is time to draw a line and implement resilient, complementary PNT solutions to support all critical infrastructure sectors and applications in the event of any GNSS disruption, due to jamming or spoofing or systemic causes. “Magic” is magical when it works. When it does not, first and foremost, it should “do no harm.”
Threats, Challenges and Needs
Presidential Policy Directive (PPD) 21, Critical Infrastructure Security and Resilience,issued in 2013, defines resilience as “the ability to prepare for and adapt to changing conditions and withstand and recover rapidly from disruptions.” It also notes that “resilience includes the ability to withstand and recover from deliberate attacks, accidents, or naturally occurring threats or incidents.”
In 2016, the UK Department of International Development noted that “Resilience covers both ‘physical and societal systems” through four “R” principles: robustness, redundancy, resourcefulness and rapidity (see Figure 1).
Figure 1. Infrastructure resilience properties. (Image: UK Department of International Development)
More recently, Andy Proctor (RethinkPNT) pointed out that “A resilient PNT system protects its critical capabilities (assets) from harm by using protective resilience techniques to passively resist or actively detect threats, respond to them, and recover from the harm they cause.”
Policies, processes, financial arrangements and incentives are also crucial to achieving resilience — and that has been, and remains, the problem. Lacking the emergence of strong leadership from our institutions, the ability to achieve actual resilience will continue to falter and admiration of the problem will continue.
Developing a resilient PNT system is always a balance of technical complexity and non-technical aspects, for example, costs. The key consideration for users must be the required performance metrics they need for their use-case(s) to ensure their resilience — including accuracy, availability, integrity, continuity and coverage. The one least understood and many times omitted is integrity — the level of trust a user/use-case needs to safely and securely use the PNT services. The ability to trust PNT services must always be a consideration for critical infrastructure applications.
Unfortunately, many users of critical infrastructure PNT do not know some of the PNT metrics they need to ensure safety and security. More troubling, there is no guidance as to what constitutes “significant economic impact” (see PPD 21) or acceptable economic loss — and over what period or range of use cases. This understanding will require analysis of their design, development and operational experiences, and working with PNT systems engineers to first derive these metrics and then drive the continuous improvements (see Figure 2) needed to achieve and retain truly complementary PNT capabilities. Without clear metrics and guidance, one cannot claim that any solution will meet any “required level of resilience.”
Figure 2. Resilient PNT lifecycle.
Supporting PNT Users
As with all systems engineering (SE) activities, PNT system resilience begins with identifying and documenting user needs based on their specific user stories/use cases. Figure 3 depicts different aspects of resilience that can be sought, depending on the unique use-case “demands.”
Figure 3. Resilience aspects. (Photo: UK Space Agency)
While the resilience needs of different use cases will differ, for any specific use case, a given “PNT solution” will either achieve the required/threshold level of resilience (based on the operational environment) or it will not. Some use cases may also require fail-safe or fail-soft capability and the ability to recover to known, trusted and usable states. Shouldn’t many, if not all critical sector use cases require this?
Equally important is the identification of risks and threats, as they are critical to understanding the challenges that the system must face while continuing to provide the necessary P, N and/or T service performance. It is also key to understand and document the system architecture and environment in which it must perform. With knowledge of a user’s needs, the threats, hazards and challenges they face, and the system architecture, the SE process can develop an understanding of the “gaps” that exist and of the levels of risk they impose on a critical infrastructure system’s functional, physical and operational performance. Understanding this, essential use-appropriate mitigations can be identified, or if need be, developed, and a resilient, solution-agnostic PNT requirement document created.
The Way Forward
The Critical Infrastructure Resilience Institute (CIRI), a U.S. Department of Homeland Security Center of Excellence, notes that “critical infrastructure systems are facing a myriad of challenges. Solutions must address the cyber, physical and human dimensions.” They keyed into four areas where critical infrastructure resilience activities should be directed: building the business case, information policy and regulation, developing new tools and technologies, fostering and educating the workforce.
These include the recognition that “policy and regulation have a powerful impact on market forces.” While the fact that “most U.S. infrastructure is owned and operated by the private sector” is a challenge, it should not be an excuse.
We must start immediately to re-establish strong SE practices, policies, and principles to help critical users understand their needs and determine the metrics required to ensure safety and “preclude significant economic impact.” Only then can we understand from a national perspective, the needed safety and security metrics and what constitutes significant economic impact, and then establish categories of solution-agnostic requirements. Lacking these clear resilience targets, detailed planning, and required resource commitments, the growing threats of PNT vulnerability will continue only to be admired, rather than be mitigated. Hope is not a strategy, but this systems engineer hopes that it does not take a truly catastrophic event to finally prompt much needed and long overdue actions.
Mitch Narins is the principal consultant/owner of Strategic Synergies LLC, a consultancy he formed following more than 40 years of U.S. government service. He is a Fellow of the Royal Institute of Navigation, a aenior member of the Institute of Electrical and Electronic Engineers, a member of the Institute of Navigation and head of its Washington, D.C., section, and a member of RTCA, RTCM, IEEE and SAE Standards Committees.
Chinese scientists say they have succeeded in an experiment that could improve satellite navigation and redefine the second as a unit of time, reports the South China Morning Post.
The scientists performed the experiment in Urumqi, capital of Xinjiang Uygur autonomous region in western China. They placed two terminals in laboratories 113 km (70 miles) apart. Each terminal was equipped with a laser, a telescope and two optical frequency combs that measure exact frequencies of light. Laser pulses sent between the terminals allowed researchers to confirm the time.
The research team was led by quantum physicist Jian-Wei Pan at the University of Science and Technology of China (USTC).
Sending signals over long distances would enable a global network of optical clocks that can help improve the accuracy of satellite navigation services.
China also is sending three atomic clocks to its Tiangong space station to establish a space-based timekeeping system of exceptional accuracy. The clocks can work together to measure time with 10-19 stability, missing only one second every few billion years, and is expected to be thousands of times more accurate than a hydrogen maser.
On July 14, the U.S. House passed its version of the National Defense Authorization Act (NDAA) for fiscal year 2023, which begins Oct. 1, 2022.
The report released with the legislation contains several provisions of interest for the GPS and positioning, navigation and timing (PNT) communities. Perhaps most intriguingly, it indicates the National Guard is considering a program to ensure it has one or more sources of time independent from GPS.
Here are some of the more interesting PNT-related mentions in the report.
GPS Disruption & RF-Based Alternatives
A provision entitled “Briefing on Disruption of Global Positioning System” reiterates concerns Congress has expressed repeatedly over the last two decades.
On the civil side, these concerns have resulted in prohibiting the U.S. Coast Guard from disposing of old Loran facilities until a backup for GPS is decided upon and requiring the Department of Transportation to establish a timing alternative to GPS.
Most of Congress’ attention has been focused on the Department of Defense (DOD), though. Over the years, it has tasked the department with a wide variety of briefings and actions including reporting on threats to GPS, how DOD will operate in GPS-denied environments, progress (or lack thereof) in OCX and M-code, and development of alternative PNT systems.
The 2021 NDAA took a more activist approach and required DOD to “generate resilient and survivable alternative positioning, navigation and timing signals.” It also directed the department to work with the National Security Council, the departments of Transportation, Homeland Security, and others “to enable civilian and commercial adoption of technologies and capabilities for resilient and survivable alternative positioning, navigation, and timing capabilities to complement” GPS. The act mandated that this all be completed within two years.
Photo: Andrea Izzotti/Shutterstock.com
The 2023 NDAA reinforces Congress’ long standing concerns about “increasing threats of disruption” to GPS, stating “it is critical to invest in technologies that provide resilient and assured positioning, navigation and timing capabilities…”
Language in that same provision, though, focuses just on alternate navigation capabilities as opposed to full PNT. The act requires a briefing before the end of this year about DOD’s plan across the Future Year Defense Program (FYDP) for “alternative navigation broadcast services.” The briefing is required to include information about “progress on radio frequency-based alternative navigation solutions,” what the department is doing now, and cost estimates for infrastructure and other expenses across the FYDP.
Army MAPS Program
The Army’s Mounted Assured PNT System (MAPS) is focused on ground vehicles. Information on the service’s website seems to indicate the upgrade in the first generation of MAPS is an anti-jam antenna. The overall program of record is more ambitious, according to the site, and includes M-code, other GNSS and inertial sensors.
“Path to ALTNAV” and “Open Standards Interfaces” are also listed as features in the MAPS final version. This is likely incorporation of DOD’s mandate for modular open system architecture to ensure the ability to easily integrate future navigation and timing systems and signals.
The Army is already producing and fielding the Gen 1 version of MAPS. In March 2022, the Aberdeen Proving Ground News announced that 1,000 units had been fielded.
In its report accompanying the NDAA, Congress expressed concern with the pace of the MAPS program. It notes the Army has procured 2,000 units — a small fraction of the 225,000 ground vehicles the service operates.
The text of the congressional report also seems to indicate the program is not much beyond the point described on its website two years ago. The website says a Program of Record technical solution was planned to have been finalized in September 2020.
The House version of the bill would require the Army to provide a briefing on:
technical performance of candidate systems to incorporate into MAPS
the cost of these systems and integration
plans to deploy MAPS to the Army’s fleet of vehicles
plans to upgrade the Gen I MAPS units already fielded.
Another indication of the delayed pace of the program is that this briefing is not due for more than a year, in December 2023.
Autonomy Software for PNT-Denied Environments
While much less specific, another interesting PNT-related provision is a requirement for DOD to “Report on autonomy software for Next Generation Air Dominance.”
It describes a developing Air Force strategy for using piloted and unpiloted aircraft alongside each other. The software “could enable the continued operational capability of systems in positioning, navigation and timing-denied environments.” The Navy and Marine Corps are developing a similar concept.
Photo: Brian Kinney/Shutterstock.com
Little public information is available concerning any of the Next Generation Air Dominance programs or supporting systems. Experts have speculated, though, that operation in PNT-denied environments would likely involve some of the aircraft remaining outside the denied area and providing PNT information to the others via one or more links.
National Guard and Nationwide Alternative Timing
At the end of a section entitled “Collaboration on positioning, navigation, and timing research,” the House report reveals that the National Guard is concerned about relying entirely on GPS for timing and seems to have begun to address that shortfall.
It requires a report no later than February 2023 on the Guard’s “Nationwide Integration of Time Resiliency for Operations (NITRO) effort.” The report should address, among other things, mission need, capability gaps, estimated costs and how the department is collaborating with other federal, state and local entities.
The budget item for NITRO cites malicious cyberattacks that can impact command and control (C2) systems. It says the Guard’s ability to support civil authorities and critical infrastructure is at risk if not mitigated with resilient time.
While attempts to reach the National Guard for comment have been unsuccessful, PNT expert Pat Diamond said the Guard’s concerns and efforts are well justified. “Precision timing is a seriously weak link for everyone in the United States, including critical infrastructure and organizations like the National Guard,” Diamond said. “If GPS timing was not available for some reason, land mobile radios, common operational pictures, the ability to navigate, plus command-and-control systems would suffer greatly, potentially being completely degraded. It’s outstanding that the Guard has realized this and seems to be moving out. All the power to them.”
A Must-Pass Bill
The House version of the 2023 NDAA has yet to be conferenced and reconciled with that of the Senate. While the Senate’s version of the NDAA has been filed, the accompanying report has not yet been released. Since the House provisions seem relatively non-controversial, they are almost certain to be included along with others from the Senate in the final bill and report.
The resulting legislation is almost certain to pass into law.
Congress often struggles to pass even routine legislation. For example, it has only funded the government on time in four of the last 40 years. The annual defense authorization is an exception. NDAA’s are considered “must-pass” bills. Congress has sent one to the president in each of the last 61 years.
Dana A. Goward is President of the Resilient Navigation and Timing Foundation. He is also a member of the President’s National Space-based Positioning, Navigation, and Timing Advisory Board.
Focus Telecom has installed its GPS Resilient Kit (GRK) cyber protection system in the national time systems of the State of Israel at the National Physics Laboratory in Jerusalem.
“A cyber protection system like the one installed in the National Laboratory, as well as many other systems we have developed to protect critical infrastructure, enable our customers to deal with the growing global threat and ensure the function of GPS-based systems, on which their business activity is based — even under jamming and spoofing attacks of various kinds,” said Shlomi Mazor, vice president of sales, Focus Telecom.
The company has developed a holistic model made up of several layers that can protect a GPS-based organization, according to the company.
Focus Telecom has been a leader in the field of synchronization and atomic clocks since 1995, and serves as Israel’s national timekeeper.
The company’s technology can detect an attack on an organization’s time sources, neutralize the threat of intrusion into the organization, provide alternative time from a secure highly accurate source, and protect internal organizational time distribution through a fiber-optic protection system through which time protocols are transmitted. It provides alerts for spoofing or jamming attacks as they happen.
Focus Telecom provides solutions in several layers, including secure NTP/PTP time servers, grandmaster atomic clocks, and radio frequency firewalls. These are protected by an active protection system that can detect and neutralize disruptions before they reach timing servers, and by additional technological solutions that provide effective protection against threats.
Focus Telecom cites recent jamming and spoofing incidents as highlighting the need for protection. For instance, pilots reported disruptions of GPS signals in June 2019, making it difficult to access Ben Gurion Airport. These disruptions resumed in January 2022 and pose a renewed challenge to pilots.
In a May 2021 incident, farmers on the northern border and in the Gaza Envelope reported disruptions affecting the GPS-based guidance system installed in tractors used for sowing and harvesting.
Focus Telecom’s systems are successfully integrated into the Israel Defense Forces, defense industries, financial institutions, communications companies, and Israel’s transportation, electricity and water infrastructure.
Learn more about cyber threats on the company’s website.
On March 24, the U.S. Department of Energy (DOE) released information about a program designed to provide resilient timing to the electrical grid by fiber.
More than just an academic center for research, CAST is building a network of atomic master clocks and methods of time delivery by fiber that will ensure power grids always have failsafe and resilient time.
Timing is essential to a wide variety of equipment and network functions essential to electrical grids. Most of these use time signals that come directly from, or can be traced back to, signals from GPS.
Electrical-grid timing dependent equipment and networks
Transmission-line fault detection
Frequency measurement
Synchrophasors/phasor measurement units
Internet-based market transactions
Substation control/resynchronization
Disturbance monitoring event recorders
Protective relays
Bulk metering
SCADA networks
Synchrophasor networks
An industry expert once observed, “Electrical grids won’t fail without accurate time signals, but they are impossible to manage. And who wants an unmanageable grid?”
According to David Wells, program leader for CAST at DOE headquarters, “It has been no secret there are vulnerabilities within the timing and synchronizations platforms used by the energy sector.” Wells said that for grid timing “a secure, verifiable, and reliable solution is paramount.”
He sees CAST as a necessary part of tech evolution for electrical grids and service. “The sector has been going through a transition from analog to digital and then from digital to internet protocol (IP). Technologies have been bolted on, but with each bolt-on added, access vulnerabilities are added as well. Embedded stratum timing systems based through digital carriers allowed our networks to be closed-loop (zero-trust) for 50 years. During the age of IP conversion, the ability to provide timing via stratum was lost, so the sector moved to GPS and NTP, which provided precision at the locations, but lack security, validation and true wide-area synchronization.”
CAST’s goal is to establish “true closed-loop (zero-trust) with secure bi-direction timing validation and synchronization over IP networks,” with multiple clocking sources, according to Wells. The system, he said, will be able to reach all power substations and remote locations.
While Wells, his office and ORNL are the primary players, a whole cast of other organizations contributes to the effort. These include DOE’s Office of Electricity; its Office of Cybersecurity, Energy Security and Emergency Response; Savannah River National Laboratory; Sandia National Laboratory; and industry partners.
CAST will not be creating new infrastructure, but rather leveraging fiber already in place. “This is not a dedicated fiber network for timing,” said Wells. “CAST uses existing fiber in the form of dark fiber (underutilized fiber), commercial fiber and optical ground wire, and works with wireless technologies to extend secure timing and synchronization to users.”
While CAST is narrowly focused on electrical grids and fiber, some see a potential for it to be the basis of a wider national security effort.
Marc Weiss is a timing expert and consultant who served for more than 40 years as a theoretical physicist for the National Institute of Standards and Technology. “CAST could be part of the foundation of an architecture that benefits all sectors and citizens, not just power grids,” he said. “The Department of Transportation has identified the need for Americans to have access to timing signals from space, from terrestrial wireless transmitters, and via fiber to have the kind of resilience they need. So, CAST is certainly a big step in the right direction.”
DOE’s DarkNet initiative is a joint initiative by the Office of Electricity and the Office of Cybersecurity, Energy Security, and Emergency Response (CESER). Additional information on DarkNet and CAST can be found at https://darknet.ornl.gov
Managing live sky and terrestrial time sources to protect critical infrastructure against cybersecurity threats
By Greg Wolff, Microchip Technology
Critical public infrastructure systems that rely on GNSS for reception of positioning, navigation and timing (PNT) data have been identified by national security agencies across the globe as potential cybersecurity attack vectors. Late in 2020, the U.S. Department of Homeland Security (DHS) published the “Resilient PNT Conformance Framework” guidelines, providing a common reference point to help critical infrastructures become more resilient to PNT attack threats. Within the framework, a cybersecurity approach has been proposed.
Prevent. In this first layer of defense, threats are prevented from entering a system. However, it must be assumed that it is not possible to stop all threats.
Respond. Atypical errors or anomalies are detected and action taken, such as mitigation, containment and reporting. The system should ensure an adequate response to externally induced, atypical errors before recovery is needed.
Recover. The last line of defense is returning to a proper working state and defined performance.
Figure 1. The four levels of resilience defined in the DHS “Resilient PNT Conformance Framework” guidelines. (Image: Microchip)
Four Levels of Resilience
Based on the Prevent-Respond-Recover cybersecurity model, the PNT Conformance Framework document describes four levels of resilience. Note that the resilience levels build upon each other — Level 2 includes all enumerated behaviors in Level 1, and so forth.
The framework provides a clear set of PNT resilience guidelines for equipment, whether at the silicon, module or system level. Although the framework is not specific to the use of GNSS, much of the focus has centered on GNSS vulnerabilities and the ability to be resilient to GNSS outages, whether caused by unintentional disruptions or intentional threats. However, the GNSS resiliency of specific equipment or technology does not fully address the needs of critical infrastructure operators who are managing the use of PNT services over large geographical areas.
Critical Infrastructure Expansion
Critical infrastructure is typically constructed in a tiered manner, beginning with a set of core sites connected to secondary sites that are ultimately connected to remote sites. With the rollout of 5G networks, densification and massive deployment of wireless access points will improve coverage and enable higher bandwidths to support the internet of things (IoT) and related services. However, this massive scale of access points will also require accurate timing at a much larger number of endpoints.
Within the power utility infrastructure, the power grid is being augmented and expanded with alternative energy sources, such as solar and wind. The modernized smart grid is a highly distributed architecture that is dependent on accurate timing for coordination, monitoring and logging of data for operation and identification of power-outage fault detection. Additionally, power utilities rely on timing services for communications and transport of telemetry data throughout their entire operations.
To date, GNSS has been the go-to source for timing, creating an exponential increase in the dependency on GNSS. Because of this massive dependency, the impact of errors or interruptions today is more significant than ever before.
Figure 2. Example view of timing network at data centers across the globe. (Image: Microchip)
Terrestrial Time Distribution
As an alternative for delivering accurate time to large numbers of locations and reducing dependency on GNSS, critical infrastructure operators are turning to the use of terrestrial distribution using packet protocols so that high accuracy distribution can be achieved using Precision Time Protocol (PTP).
The virtual Primary Reference Time Clock (vPRTC) is a highly secure and resilient network-based timing architecture developed to meet the expanding needs of modern critical infrastructures. The vPRTC is simple in concept. It blends proven timing technologies into a centralized and protected source location, and then uses commercial fiber-optic network links and advanced IEEE 1588 PTP boundary clocks to distribute 100-ns PRTC timing where it is needed in end points that might be hundreds of kilometers away.
Just as a GNSS-satellite-based timing system distributes timing to end points using open-air transmission, the vPRTC distributes timing using a terrestrial (typically fiber) network. The difference is that the operator remains 100% in control of the network and can secure it as necessary. This network-based timing is referred to as trusted time. It can be distributed as the primary source of timing or it can be deployed as a backup to GNSS timing solutions.
Even with the many reliability and security benefits of the vPRTC approach, however, sole dependency on terrestrial time can become a single point of failure, just like a strategy dependent solely on GNSS. Because of this, critical infrastructure operators are deploying architectures that use both GNSS and terrestrial time. To do this effectively, operators find themselves with the need to have centralized management and visibility of both key sources of time. Further, to deliver on the promise of timing resiliency, a unified management system needs to include capabilities that can deliver a cybersecurity solution encompassing the Prevent-Respond-Recover DHS security guidelines across all nodes of the timing network.
Figure 3. A measurement of phase difference between GNSS time and terrestrial time. (Image: Microchip)
Unified Time Management
Having a bird’s eye view of all nodes of a timing network is essential for providing timing security and resiliency. In the case of a GNSS anomaly or terrestrial time instability, when a problem occurs the most immediate need is to quickly identify whether the event is isolated to a specific location, affects a region, or in some cases is caused by a global situation. A centralized management and monitoring system provides a green, yellow and red threat-status indication representing different locations of interest. It is a simple way for operators to know the overall health of their timing infrastructure.
When problems surface, critical infrastructure operators next need visibility of “observables” that can quickly isolate the root cause. With today’s timing networks relying on both GNSS time and terrestrial time, the ability to see observables that represent both timing sources in a unified manner is critical.
GNSS Observables
Multipath interference, weather anomalies, jamming and spoofing are terms commonly used when referring to GNSS vulnerabilities. Gaining insights (visibility) into the details to identify the root cause, however, requires more specific characterization of the signal.
Visibility into the quality of GNSS reception is accomplished by monitoring GNSS observables. Table 1 provides a sample of key GNSS observables that can be tracked and monitored.
Table 1. Sample of key terrestrial time GNSS observables.
Terrestrial Time Observables
Characterizing the quality of terrestrial time requires time measurements between equipment interconnections within a single location (intra-office) or across nodes of a network (inter-office) — for example, comparison of equipment inputs and outputs or comparison of signals at different sites.
Additionally, with the standardized use of PTP, the ability to evaluate network timing packet metrics is needed to verify time transfer from location to location. Terrestrial time performance calls for a different set of observables to be made visible and monitored. Table 2 provides a sample of key terrestrial time observables.
When managing a large geographical area, being able to measure the phase difference between GNSS time and terrestrial time at multiple locations simultaneously enables an operator to determine how well these two sources of time compare. As described previously, critical infrastructure operators are ultimately in need of resiliency, which can best be achieved using both time sources.
Measuring the two sources against each other at multiple locations creates the highest level of trust knowing that these independent time sources are well aligned.
Table 2. Key terrestrial time observables that must be made visible and monitored.
Conclusion
With cooperation from industry, standards organizations and government organizations such as DHS, the use of timing services has become recognized as a foundational technology for critical infrastructure operations. Leveraging industry-standard cybersecurity models will help strengthen and harden timing equipment.
Although equipment resiliency is vital, having a bird’s eye view of timing performance across the entire network is the starting point for providing complete network visibility that is critical to providing timing security and resiliency. To deliver on the promise of timing resiliency across critical infrastructure, operators need a unified management system that enables simple and complete visibility of both GNSS and terrestrial time observables.
With a unified management of these two timing sources, operators have a platform to apply Prevent-Respond-Recover to timing threats and achieve the highest levels of resiliency and cybersecurity protection.
Greg Wolff is senior product line manager of Frequency & Time Systems at Microchip Technology. He has worked in the time and frequency industry since 1988 and was an early pioneer in the marketing of network synchronization solutions to major critical infrastructure operators across the globe. He is an active contributor to emerging standards supporting PNT resiliency and most recently, as part of Microchip Technology’s Frequency and Time Systems group, launched the BlueSky GNSS Firewall. He holds a degree in engineering science from California Polytechnic State University – San Luis Obispo.
Upgraded range of synchronization solutions now includes enhanced PNT resiliency against jamming and spoofing attacks and cyberthreats
ADVA has announced a new software release of its core and edge timing technology, to provide higher levels of positioning, navigation and timing (PNT) security and resilience to synchronization networks. The new release follows the Resilient PNT Conformance Framework issued by the U.S. Department of Homeland Security (DHS).
The upgraded series of PTP grandmaster clock solutions now enables operators to automatically harness public key infrastructure. Along with enhanced certificate management, this delivers more robust security and removes complexity, the company said.
ADVA’s core and mid-sized PTP grandmaster devices now also integrate enhanced aPNT+ technology, providing advanced jamming and spoofing detection as well as mitigation with automatic switchover in the event of cyberattacks.
The software replaces costly hardware devices previously used for PNT protection and achieves enhanced DHS Level 4 Resiliency in PNT self-survivability, the highest in the industry. The new software release also supports 100 Mbit/s over fiber for interconnectivity with optical timing channels from third-party vendors as well as support for PTP profiles for a wide range of industries.
“Today’s timing networks require greater accuracy than ever before. But mission-critical national networks need improved resilience and security as defined by the latest standards. With our trusted PNT assurance solutions, we’re providing the GNSS protection and cybersecurity that today’s operators need to meet current and future challenges,” said Gil Biran, GM of Oscilloquartz, ADVA. “From phase synchronization in critical national infrastructure to traceable timestamping in financial networks, highly precise and protected timing is key to successful operations. This upgrade sets a new standard for secure synchronization and delivers it to more networks than ever before.”
The new 11.1.1 software release features upgrades to ADVA’s comprehensive range of Oscilloquartz edge timing products, the OSA 5412/22 series, as well as its core synchronization devices, the OSA 5430/40 series. The solutions now provide multi-layered security for synchronization infrastructure through improved certification management and PKI.
As part of ADVA’s intelligent and scalable assured PNT platform, the ADVA aPNT+, the solutions also feature innovation for detection of spoofing and jamming as well as countermeasures to prevent service disruption. With PTP capabilities for new verticals, including the PTP broadcast profiles (SMPTE ST-2059-2/AES67), the new release will bring precise, reliable synchronization to many new customers.
Chronos Technology Ltd., a UK-based resilient synchronization and timing company, has transitioned to employee ownership through the Chronos Technology Employee Ownership Trust (EOT) Ltd.
Charles Curry who established Chronos Technology in September 1986 and was co-owner alongside his wife, Angela Curry, had been deliberating succession planning and their exit from the business. Various options such as a third-party sale or a management buyout were considered but quickly dismissed.
“I am aware of business owners who had exited through third-party sales and had not enjoyed the experience of working under new management for the agreed handover period,” Curry said. “New owners generally change the dynamic of the business, often introducing new staff and work practice without giving opportunity to existing staff and process, and we did not want this for Chronos.”
“Over the years we have established a work ethic that puts the customer first,” Curry continued. “The EOT protects the loyal Chronos family and ensures the customer-facing continuity of the business and, most importantly, safeguards jobs. Going forward, in the hands of the employees, the company will benefit from increased customer engagement and the commitment to a team approach to steer the business on the next phase of its journey.”
Chronos Technology specializes in resilient synchronization and timing systems, smart technologies, GNSS and cybersecurity solutions for critical national infrastructure, with industry experience gathered over 35 years in specialist technologies such as GNSS, PTP, NTP and SyncE.
The company provides GPS coverage solutions in hangars, manufacturing areas and underground, as well as smart technology solutions and GNSS jamming detection and location solutions for law enforcement. Customers include telecom, finance, energy, data centers, broadcast, aerospace, defence and security, enterprise/IT, emergency services, transport and manufacturing.
