ST is launching today the TeseoVI, our first single-die quad-band GNSS receiver, which also features anti-jamming and anti-spoofing technologies. As car makers demand more precision and reliability for applications like level 2 and level 3 autonomous driving, we also wanted to lower costs to make those technologies even more accessible to mainstream vehicles. Indeed, by offering a single-die system, we can significantly lower the bill of materials without compromising the smarter capabilities car makers bring to their drivers. The TeseoVI also features a pin-to-pin compatibility between its safety-capable (ASIL-B) and non-safety versions for greater design flexibility.
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TeseoVI: Moving to a single die
Why is a single die a challenge?
Most GNSS receivers for automotive feature multiple dies in one package. There’s the digital microcontroller, a baseband radio, and sometimes a third die for memory. The industry adopted this approach because it bypassed significant manufacturing challenges that come from putting everything on the same die. Moreover, adding enough memory can also lead to a big die size, lowering yields and making devices more expensive. Using multiple dies also makes optimizing the RF easier, which leads to greater precision. Single-die GNSS receivers are typical in smartphones and much smaller systems that don’t require as much accuracy but have remained a problem for cars.
How did TeseoVI overcome this challenge?
That’s why the TeseoVI is special. It brings the convenience and cost-effectiveness of the single-die approach that’s so popular on smartphones while overcoming the precision and reliability challenges that prevented such an approach from serving cars. To make this possible, ST optimized the RF and the phase-change memory (PCM), among other things. For the former, we employed a new generation of baseband processing, opening the door to new features (more on that later).
TeseoVI: Jamming protection
What are the L1 and L5 signal bands?
One of the features brought on by the new baseband processor is the ability to track L1 and L5 signals independently. L1 is the oldest GNSS signal, using a frequency of 1575.2 MHz. It’s the slowest and doesn’t travel well through obstacles, but its maturity means it is a preferred signal for most satellite positioning applications. L5 uses the 1176 MHz frequency and is the most advanced GNSS signal. Launched in 2021, it targets critical applications, like aviation, but is also available for consumer systems. It offers greater bandwidth thanks to higher power levels, improved accuracy thanks to interference rejection, and better robustness. Indeed, thanks to its lower frequency, it features a longer wavelength that deals better with obstacles.
How to jam the L1 signal?
Another reason supporting L1 and L5 signals independently is essential is because it provides anti-jamming protection. Jamming happens when a signal overwhelms the receiver. It can result from unintentional electromagnetic interference from antennas or large infrastructure emitting intense radiation. There are also dedicated jammers to bypass fleet monitoring, insurance trackers, and more. The L1 frequency is very easy to jam. It doesn’t have redundancy features, and its low signal strength is easy to overwhelm, which causes the GNSS receiver to lose its lock on the signal, thus failing to acquire navigation data. It’s so easy that L1 jammers, although illegal in most countries, may cost less than US$20, according to The Resilient Navigation and Timing Foundation.
TeseoVI and anti-jamming
Interestingly, even GNSS receivers that track L5 signals may require the L1 signal. Indeed, many devices acquire timing data from the L1 signal during their boot sequence and then use it to lock onto the L5 signal. The problem is that even a low-cost jammer could prevent a device from acquiring data from the L1 signal, meaning the receiver can’t use the L5 band. The new baseband processing in the TeseoVI introduced an L5-only mode, meaning it doesn’t need L1 to acquire data on L5. Consequently, it can bypass jammers. Additionally, L5 is so robust some estimate it to be 30 times harder to jam than L1.
TeseoVI: Spoofing protection
How to spoof a GNSS signal?
The new TeseoVI also supports the open service navigation message authentication (OSNMA) from the Galileo constellation. In a nutshell, the feature prevents spoofing attacks by cryptographically authenticating the source of a message. Very simply, the technology uses a message authentication code (MAC) to guarantee the authenticity of a signal’s provenance. It doesn’t encrypt the whole message but sends a series of codes, which is a far more efficient use of the bandwidth. Consequently, since Galileo generates the code, hackers can’t fake it. Additionally, since the standard sends multiple codes over time, hackers can’t just grab one key and reuse it in a replay attack. By the time they do so, the key has expired.
How to support OSNMA?
To support OSNMA, hardware manufacturers must update their firmware and their software stack and offer enough processing power to handle the extra computations. This is why ST also provides extensive software implementations with its GNSS receivers. We know that taking advantage of new features can be complex. In this instance, decoding the OSNMA fields and managing the keys requires complex libraries that must pass audits and receive regular updates. Hence, the TeseoVI not only supports this anti-spoofing technology but enables developers to take advantage of it in their applications rapidly.
Making multiband more accessible
More advanced features to mainstream cars
One of the greatest benefits of a single-die design is the ability to lower the cost of materials. In fact, since there’s no need for external RF and external memory, engineers may target a BOM cost of about a dollar. Obviously, this is only a general reference point. In practice, the price will vary based on the complexity of the design and volumes. However, in all cases, it means that previous customers who used to avoid multiband solutions because they were too expensive will now be able to jump on the bandwagon. For instance, we can expect level 2 and 3 autonomous driving features to reach more mainstream vehicles.
More flexibility to integrators
The TeseoVI is also the first GNSS receiver for automotives to have a pin-to-pin compatible version for safety applications, the TeseoAPP2 (STA9200MA), which features the same QFN56 package as the TeseoVI (STA8600A). As a result, developers can simply create one reference design and switch between the ASIL-certified and the non-certified part number, depending on their needs.
ST will also be offering the TeseoVI+ (STA8610A). It’s the same device as the TeseoVI, but the TeseoVI+ can welcome custom algorithms thanks to dual M7 Core Processing and External Memory Interface (Flash/RAM). Hence, teams wanting to use their application can do away with our positioning and measurement software. Finally, we also offer a module with a 6-axis inertial sensor, the Teseo-VIC6A, and its safety alter ego, the Teseo-ELE6A.
- Learn more about the TeseoVI
