Will IEEE 802.15.4ab Propel Sensing to the Forefront of UWB Use Case Innovation?

Over the last 7 years, there has been a huge resurgence in Ultra-Wideband (UWB) technology, based predominantly on the IEEE 802.15.4z amendment, which enables the secure and accurate calculation of the relative position of other UWB-enabled devices via its short-range Impulse Radio (IR) technology. The initial wave of UWB adoption has focused on these accurate and secure ranging capabilities, predominantly for automotive digital key and personal tracking applications, as defined by the Car Connectivity Consortium’s Digital Key Specification, and UWB-enabled personal tracking devices such as the Apple AirTag. Meanwhile, many leading automotive Original Equipment Manufacturers (OEMs) have already deployed IEEE 802.15.4z for secure vehicle access applications and, by 2030, ABI Research expects that 53% of vehicles shipped globally will come equipped with UWB technology.

However, when deploying UWB technology in real-world environments, several limitations of the existing IEEE 802.15.4z technology were discovered. These can negatively impact the end-user experience when it comes to reliability, power consumption, accuracy, and range of operation. These limitations led to the development of IEEE 802.15.4ab, a further amendment, which brings significant new enhancements to UWB technology, most notably through the Multi-Millisecond (MMS) mode. MMS provides enormous link budget increases to bring significant enhancements to the ranging distance of UWB, offers enhanced resilience against multipath, reduces interference, and enables more robust ranging capabilities even in non-line of sight or back pocket scenarios. It is important to remember that UWB is not just a ranging technology. Many UWB solution providers and automotive OEMs have begun to combine the ranging capabilities with sensing and radar functionality for child presence detection and seat belt reminder features, among other sensing use cases, which, to date, have been based on the existing IEEE 802.15.4z technology.

In addition to the aforementioned ranging enhancements, IEEE 802.15.4ab brings standardization and further enhancements to these sensing capabilities, enabling a much wider range of sensing-related use cases to be targeted. IEEE 802.15.4ab also introduces support for higher data rates for low-latency data communications, and it is this combined value and versatility of UWB that is further incentivizing UWB adoption in the vehicle. This, in turn, is spurring on investment in further internal- and external-facing use cases, and will help unlock UWB’s potential in the future, both within the automotive market and beyond.

UWB sensing currently operates by analyzing the variations in Channel Impulse Response (CIR) to determine the presence, movement, and position of objects. However, despite already being deployed in many scenarios today, there are some inherent limitations that restrict the potential of UWB sensing to certain use cases and proprietary implementations.

First, most current implementations of UWB radar are limited to a single UWB anchor that both transmits and receives radar signals. Unsurprisingly, this limits the sensing coverage area, can cause blind spots, makes it difficult to detect the angular resolution, makes it more susceptible to multipath issues, and makes it difficult to detect stationary objects. Second, even where multiple anchors in a vehicle can be leveraged for sensing, due to a lack of coordination between them, this can cause interference issues due to overlapping transmission of sensing packets. Finally, most current implementations of UWB radar are proprietary, with a lack of a standardized framework for setup, sensing packet transmission, and CIR reporting. This makes it difficult to exchange information between different anchors and lacks multi-vendor interoperability.

To solve these issues, IEEE 802.15.4ab introduces UWB sensing as a standardized MAC/PHY capability, while addressing several key existing limitations. First, 802.15.4ab provides a standardized foundation for monostatic, bi-static, and multi-static sensing, enabling sensing information to be gathered from multiple different perspectives, significantly improving the coverage of the sensing activity, while offering greater deployment flexibility. Second, as the setup, transmission, and reporting mechanisms to achieve this are now standardized, coordinated sensor networks can be developed, improving not only the sensing capabilities, but also opening the potential for cross-vendor interoperability.

Many automotive OEMs currently combine the benefits of UWB ranging for digital key applications along with integrated UWB sensing, predominantly for use cases such as Child Presence Detection (CPD), intrusion detection, and seat occupancy and seat belt reminder. Instead of investing in multiple UWB hardware anchors solely for smart access and digital key applications, vehicle OEMs can now maximize their Return on Investment (ROI) by reusing the already deployed hardware to support vital sensing activities and support regulatory requirements such as the Euro New Car Assessment Program (NCAP) for Child Presence Detection (CPD). These multiple UWB use cases help avoid any redundant systems and reduce the overall cost of sensing deployments. This combined UWB ranging and radar value proposition is accelerating much wider UWB adoption in the vehicle.

However, this represents just the first wave of sensing-related applications within the automotive market. Some of the emerging sensing use cases we are seeing in the market include kick-sensing to help open up the trunk, other gesture recognition for feature activation and control purposes, environmental monitoring and mapping for obstacle avoidance, sentry mode activation, and potentially others in the future.

When we look at the benefits of UWB for automotive OEMs, they really are compounding. First, from a use case perspective, integrating UWB can, of course, bring enhanced safety and security, enable regulatory compliance for CPD, create new user experiences to improve brand loyalty and satisfaction, and deploy valuable new services for end users to adopt. Meanwhile, the ROI of deploying UWB for smart access is maximized, and the reuse of digital key anchors for sensing purposes can reduce the Bill of Materials (BOM) and integration cost compared to alternative sensor technologies.

It is clear from ABI Research’s perspective that UWB’s versatility will allow it to have multiple roles to play in the wireless connectivity ecosystem. This is due to its ability to support secure ranging, sensing and radar, and highly accurate positioning, as well as acting as a low latency, low-power, and high-throughput personal area network communications technology.

Various automotive OEMs already see the increased value of combining several of UWB’s unique capabilities to help maximize ROI, eliminate legacy technologies to reduce BOM cost, and create valuable new use cases and services to better differentiate. Given the maturity of IEEE 802.15.4ab, this is expected to accelerate rapidly in the coming years.

IEEE 802.15.4ab can bridge all of these enhancements and create a powerful, flexible, and multi-functional foundational platform device manufacturers can use to drive future innovation. The significant boost in ranging performance, along with significant enhancements to radar and sensing, will drive future innovation and open up an increasingly diverse set of use cases across automotive, smart home & building, consumer devices, smart healthcare, industrial, smart city, and many other applications. Many of these will rely on different features of UWB technology, often in combination. This ranges from digital key in automotive, smart home, and smart building applications to presence and occupancy detection, gesture control and recognition, point-and-trigger applications, high-accuracy Real-Time Location System (RTLS) positioning, delivery drone localization, low-latency peripheral connectivity, and data-driven applications in wireless audio, Augmented Reality (AR), and other emerging applications. This combination of the best elements of ranging, radar, and data communications into holistic solutions will drive innovation, centered on the key innovations enabled by 802.15.4ab.

When considering that IEEE 802.15.4ab brings much more than just ranging upgrades, it requires a more holistic approach to design that can maximize the multi-functional benefits of combined UWB sensing, ranging, and data communications. We are also seeing a lot of innovation from the vendor ecosystem—solution providers like Calterah have been early pioneers in IEEE 802.15.4ab technology, being one of the first to market with its latest UWB ranging and radar System-on-Chip (SoC) solutions. Given its history and background in radar and sensing, it is also well placed to provide unique differentiation versus the competition in the years to come. Meanwhile, STMicroelectronics recently introduced its portfolio of IEEE 802.15.4ab solutions, key among which is its ST64UWB-A500 series, which adds Artificial Intelligence (AI) acceleration and digital signal processing to support edge AI-powered radar applications, including CPD, kick sensing, and outward-facing use cases such as parking sensors and radar-based vehicle sentry modes. Meanwhile, other vendors such as NXP and Qorvo were early to market in developing their converged radar and ranging portfolios based on IEEE 802.15.4z.

ABI Research expects a relatively swift transition to next-generation UWB technology in the automotive realm, thanks to the combined benefits and additional regulatory incentives. However, it is also important to remember that we are still in the very early stages of UWB maturity, not just in terms of IEEE 802.15.4ab, but also more broadly in terms of ecosystem maturity. Therefore, we expect to see enormous innovations in the coming years as vendors optimize their portfolios, new vendors emerge, competition and differentiation increases, industry consortia such as the FiRa Consortium also integrate these features, and new use cases are developed.

Ultimately, IEEE 802.15.4ab will become a foundational interoperable platform to help accelerate UWB adoption and use case diversity in the coming years, which will propel the technology forward both in the automotive market and beyond.