How L5 Band-Only Solutions Can Help Solve Growing GNSS Jamming and Spoofing Challenges

By Andrew Zignani | 3Q 2024 | IN-7476

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On July 22, 2024, Global Navigation Satellite System (GNSS) solution provider oneNav announced that its L5-direct™ Global Positioning System (GPS) solution has been successfully tested in field trials that demonstrated its effectiveness against active jamming and spoofing of GNSS signals. The study was conducted in and around Haifa in Israel, and compared oneNav's GPS receiver against those found in iPhone, Samsung Galaxy, and Google Pixel smartphones, alongside Garmin watches. The study, the first of which to be conducted in an active conflict zone, found that all the other receivers experienced navigation failure due to GPS interference, while the L5-direct™ GPS solution was found to be resilient to active jamming and spoofing, and able to maintain accurate location fixes.

Since being founded in 2019, the California-based oneNav has raised over US$50 million for its L5-direct™ GNSS receiver technology, which it aims to deploy in smartphones, wearables, drones, and other tracking devices. This solution, as the name implies, is the first GNSS receiver that uses only the modernized L5 wideband signals and bypasses the L1 band altogether. In contrast, most current consumer and commercial solutions currently being deployed in smartphones, navigation systems, aircraft, and other tracking solutions leverage either the L1 band alone or are dual-frequency hybrid solutions that must first acquire an L1 signal before they can take advantage of the benefits of L5. In essence, this means that devices, whether single or dual frequency, must rely upon L1 signals, which are much more susceptible to jamming and spoofing as demonstrated in recent high-profile cases around the world. According to oneNav, L5 signals are up to 30X more difficult to jam than L1 signals, and they provide additional performance benefits, while not compromising on accuracy.

oneNav's solution is also multi-constellation, offering support for GPS, BeiDou, Galileo, and QZSS, and uses a single Radio Frequency (RF) chain to receive L5 signals only, reducing the RF footprint, cost, and power consumption. Another key innovation is the company's acquisition engine architecture. The company has developed a parallel processing engine that can acquire L5 signals with sub-1 Second (s) Time to First Fix (TTFF). The solution also leverages Artificial Intelligence (AI) to better combat multipath errors.

oneNav is uniquely placed to take advantage of this type of solution and is currently the only receiver to use signals in the L5 band alone. Earlier this year, the company announced that it had been granted a second patent for its L5-direct™ solution, which covers the "acquisition of one or more secondary codes in L5-band GNSS signals without using L1 GNSS signals." This means that all GNSS receivers that perform the independent acquisition of L5-band signals will effectively be covered by the patent.

In June 2023, the company launched its L5-direct™ Acquisition Receiver Core (pARC). This is a standalone solution that can be used to augment the existing GNSS solutions of customers by enabling direct L5 acquisition on their devices. The Intellectual Property (IP) core is now available for evaluation by chip developer partners, with chips and modules soon expected to be available for select partners. The intention is for the solution to be easily integrated into modems, application processors, and a standalone chip.

Enhancing GNSS performance, both in terms of accuracy, but perhaps more importantly, robustness to attacks and reliability, are becoming increasingly vital in an age when Positioning, Navigation, and Timing (PNT) applications are both increasingly relied upon and being threatened. Jamming and spoofing events have increased considerably in recent years, particularly for those more directly affected by geopolitical events, such as Eastern Europe. From August 2023 to April 2024, some 46,000 aircraft logged GNSS issues while flying over the Baltics, speculated to be caused by various jamming and spoofing attacks. While this, of course, applies to conflict zones, the consequences are even further reaching, and governments around the world are investing resources into PNT alternatives and redundancies to help protect critical infrastructure. In 2023, the United Kingdom announced a new alternative PNT strategy, having previously estimating that a 7-day outage of GNSS would cost the economy £7.6 billion. This follows on from other recent incentives in the United States, such as the Department of Transportation's Complementary PNT Action Plan, which seeks to engage various stakeholders, help develop specifications and standards, conduct field trials, create a vetted and qualified solution provider marketplace, and directly target key tailored services in maritime, aviation, rail, and other vital sectors. ABI Research's The Future of GNSS: Opportunities and Challenges for Mass Market Positioning report also highlights some alternative PNT technologies, including Low Earth Orbit (LEO), terrestrial, and other solutions.

Given this combination of features, the growing reliance on GNSS, and the acknowledgement of growing challenges from GPS jamming and spoofing across numerous sectors, oneNav's L5-direct™ solution is well placed to take advantage of this market opportunity. However, the next challenge will be integrating and scaling its technology through the availability of commercial solutions and forming partnerships that can enable its technology to be more readily deployed in real-world devices.