Ultra-wideband Technology to Secure the Connected Car

Multiple reference points, called anchors, are positioned in a vehicle, a room, or a venue and are time-synchronized. The mobile UWB devices will then send high-frequency bursts, and when an anchor receives the signal, it will timestamp it. Those timestamps from the different anchors are then calculated by the UWB gateway using multilateration algorithms based on TDoA to compute the approaching device’s location.

Because UWB is not designed to carry any additional information besides the encryption and security keys, basic UWB devices can operate for several years with a small button-cell battery.

Recently, some smartphone manufacturers, namely Apple and Samsung, have been adding UWB chipsets and capabilities to their high-end models. According to the UWB Alliance, “Since 2019, UWB has been expanding into a mainstream consumer technology for smartphones, wearables, automotive, and industry, forecasted to drive sales volumes in excess of 1 billion devices annually by 2025.”^[1]

Securing car access using UWB

Currently, the most widely used system for vehicles’ remote keyless systems is a transponder key, typically based on a Megamos chipset.

Devices with these technologies are used in key fobs and vehicle immobilizers for most of today’s car models. While the level of security varies with the model and availability of software updates, on many occasions, it has been demonstrated that transponder keys are hackable,^[2] allowing access to the vehicle and, in some cases, starting the engine.

The biggest security problem for those systems is the lack of precise location measurements. The car will open the doors if it receives the correct authorization signal paired with the encryption key, no matter where the signal originated. Here is where ultra-wideband can help.

Using several “anchors” strategically installed in different parts of the vehicle, the UWB system can measure the ToF and angle of the approaching UWB device, a key fob, or a UWB-equipped smartphone.

This not only allows the car’s subsystem to determine the distance between the user and vehicle, but it also “knows” the direction the person is approaching the car and where he/she wants to access the car — whether it’s by the driver or passenger door, or to open the trunk. This way, the system could open the nearest door to the user, making it more difficult for anyone else to access the car.

Last year, NXP and Volkswagen^[3] announced a UWB-enabled concept car with several ultra-wideband applications. According to NXP, “UWB will enable interesting new use cases such as automated trailer hitch activation, in-cabin passenger detection, automated valet parking, hands-free parking, lot access, and drive-through payment, to name a few. Another interesting application is walking pattern recognition for car access, which was demonstrated in the VW concept car. The Volkswagen UWB car key used high-precision sensing technology and artificial intelligence to learn personalized user gestures.”

Hands-free access, without the need to press any buttons on the key fob or use one’s smartphone, could be a lifesaver in some dangerous situations when the driver doesn’t want to waste time looking for the keys.

“The first UWB application we see is in theft protection — another security milestone which you will see in volume Volkswagen car models starting this year,” said Maik Rohde, head of body electronics and car access at Volkswagen. “But this is only the beginning. UWB, especially when combined with high-precision sensors and artificial intelligence, can deliver further benefits. Some of these you can experience in our concept car.”^[4]

FiRa Consortium and UWB Alliance

In July 2019, NXP, together with Samsung and HID Global, co-founded the FiRa Consortium.^[5] FiRa stands for Fine Ranging. As of October 2020, the consortium has over 45 members onboard, demonstrating the industry interest in the ecosystem and the advantages of the technology.

Apart from the founding companies, current members of the FiRa Consortium include industry names such as Bosch, Sony, STMicroelectronics (ST), SGS, Qorvo, and Thales. Additionally, the membership also includes two academic institutions: Yale University and the Dresden University of Applied Sciences.^[6]

Another ultra-wideband industry association is the UWB Alliance,^[7] working on the technology’s regulatory and standardization aspects. Membership includes several car manufacturers, including Kia and Hyundai, as well as industry leaders such as Analog Devices, Spark Micro, Oppo, Xiaomi, Tokai Rika, and iRobot.

UWB in other applications

In addition to the automotive industry, there is a significant interest in UWB for many other applications, especially in the security industry. The unique low-power and high position accuracy of the technology make UWB suitable for numerous applications, including smart home, facility access, proximity detection, and more.

In a recent technical paper,^[8] Analog Devices demonstrated the advantages of ultra-wideband for first responders’ precision location where GPS positioning is not available. The objective is to pinpoint location to within a few meters. The system combines the precision location and mapping system of UWB and MEMS inertial sensors to maintain an accurate fix of the first responder when he/she enters a structure.

Thales, the French aerospace and defense group, together with the European Space Agency, has developed Geonav IoT.^[9] This high-precision positioning algorithm combines satellite positioning with ultra-wideband wireless networks. The technology can be used to monitor the movement of players in group sports, such as rugby, football, and soccer. A chip placed on a player’s shirt, just between the shoulder blades, allows for the accurate tracking of the players’ movements in real time.

Recently, NXP introduced Trimension,^[10] the company’s new concept brand of UWB chipsets. In addition to the automotive chipsets, the brand now includes new products for smartphones and IoT devices. The Trimension OL23D0 is user-programmable, enabling running basic IoT applications directly on the device.

Conclusion

Although ultra-wideband adoption is relatively new in the industry, most believe it will be the future standard for car-access applications. Additionally, UWB could significantly improve access control and user experience in offices, hospitals, educational institutions, and homes.