An Overview of Ultra-Wideband (UWB) Technology and its Applications
Introduction
Ultra-Wideband (UWB) technology, with its excellent positioning and sensing capabilities, is exhibiting clear signs of becoming a principal element in the transformation of connectivity experiences across all aspects of life. Overall, UWB market dynamics indicate that many established companies design and build products and services utilizing UWB technology. The most visible examples are the inclusion of UWB in handsets by major mobile handset manufacturers such as Apple, Google, Samsung, and Xiaomi and the use of UWB to access automobiles [1].
UWB is the commercially available wireless technology that delivers highly accurate and precise location and fine-ranging measurements while also supporting high-level security to protect access credentials and data communications.
This research article presents an overview of UWB technology, emphasizing location-based services and provides brief information about the UWB ecosystem built on IEEE standards for technology deployment. We discussed the three primary categories of UWB use cases: hands-free access control, location-based services, and device-to-device (peer-to-peer) applications. Fundamentals of UWB technology are built on IEEE Standards for efficient utilization of communication channels and making UWB technology much more robust from a security viewpoint and far less vulnerable to attacks.
Indoor Locating and Positioning Requirements
Developing an efficient technology for indoor positioning at the micro-level demands several things. To start with, location readings need to be very precise with correctness. The technology must be protected since the location often needs to be kept private. Even in severe environments, it must be reliable and easily scalable to focus on the thousands of people and assets in large venues. Additional requirements include low power and affordability. Such technology can be embedded in everything from high-end, e.g., complex devices like smartphones, to low-end, e.g., simple devices like asset tags. Also, the technology must have low latency to track the movement of objects in real-time[2]. Figure 1 shows the overall Indoor locating and positioning requirements.
Figure 1: Micro-based Indoor Positioning (Source)
How does UWB Compare With Existing WiFi and BLE
While designing the first indoor location systems, engineers used the innovative technologies available to them: WiFi and Bluetooth Low Energy (BLE). Such technologies are great for data communication, but none of them was invented for Real-Time Location Services (RTLS). Such an invention didn't meet all micro-based indoor positioning needs.
WiFi, Bluetooth, and other narrowband radio systems can reach an accuracy of several meters. However, its reliability doesn't meet the 99.9% criteria for building a safe and trusted system.
It is quite difficult to report their position in real-time due to collisions and interference in a large number of electronic devices. As a result, they struggle to provide real-time location services. For example – BLE is class-leading for low power data communications; the number of measures and post-processing required to get acknowledgment for one location point can consume colossal power consumption and latency up to seconds[2].
Ultra-Wideband (UWB) Technology Deployment
Why Does UWB Need a Consortium?
The marketplace witnessed a significant shift in the UWB development where many established companies designed and built products and services utilizing UWB technology. However, as UWB technology transitions to mass-scale usage, the consumer electronics companies know its success is based on the interoperable, universal, and interconnected ecosystem.
The FiRa Consortium provides a way for the consumer electronic companies to solve the ecosystem and interoperability challenges for combined future success [3].
FiRa Consortium
The FiRa Consortium (FiRa) is a non-profit association that supports the use of Ultra-wideband technology for the use cases such as access control, location-based services, and device-to-device services. UWB offers fine-ranging and security capabilities and operates in the available 6–9 GHz spectrum [4]. The ASSA ABLOY Group, which includes HID Global, NXP Semiconductors, Samsung Electronics, and Bosch, companies leading in secure connectivity and mobile/CE device solutions, announced the launch of the FiRa Consortium. The new association is designed to grow the Ultra-Wideband (UWB) ecosystem so that the new use cases for fine-ranging capabilities can succeed, ultimately setting a new standard in seamless user experiences.
The FiRa name "Fine Ranging" highlights UWB technology's unique ability to deliver precise location and distance concerning a target's relative position. Moreover, UWB technology outperforms other technologies in precision, power consumption, robustness in RF connection, and security by a wide margin [5].
Building on the IEEE Foundation
IEEE 802.15 Working Group standardized UWB in June 2020 as per:
IEEE 802.15.4z-2020 – IEEE Standard for Low-Rate Wireless Networks–Amendment 1: Enhanced Ultra-Wideband (UWB) Physical Layers (PHYs) and Associated Ranging Techniques.
Amendment 1 in the IEEE standard for low-rate wireless networks covers enhanced ultra-wideband (UWB) physical layers (PHYs) and associated ranging techniques. The various ranging capabilities, such as High Rate PHY (HRP) and Low Rate PHY (LRP), are applicable under IEEE 802.15.4 standard. The IEEE 802.15.4 standard specifies the PHY, MAC, and sublayers, focusing on low-data-rate wireless connectivity and precision ranging. In addition, various license-free brands are defined under different PHYs for devices in diverse geographic regions.
FiRa’s journey toward developing a UWB-enabled ecosystem began with leveraging the IEEE standard 802.15.4 and the IEEE 802.15.4z Amendment 1. By supporting the IEEE's work with an interoperable HRP standard, FiRa will be capable of developing service-specific protocols for various verticals and defining the necessary parameters for a wide range of applications.
In response to the need for enhanced function, the 802.15.4z task group was formed to define PHY and MAC layers for HRP and LRP. The IEEE 802.15.4z standard focuses on additional coding and preamble options and enhancements to existing modulations to increase the reliability and accuracy of ranging measurements, with a typical range of up to 200 meters for the radio.
The FiRa Consortium aims to build upon what the IEEE has previously established for HRP. It means to support the IEEE's work with an interoperable HRP standard that incorporates performance needs, test methods and techniques, and a certification program based on the IEEE's described features. It also means defining mechanisms out of the scope of the IEEE standard, comprising an application layer that discovers UWB devices and services and configures them in an interoperable manner [6]. Figure 2 shows the functional layers with the relevant IEEE standards.
Figure 2: IEEE 802.15.4/4z Functioning layers (Source)
UWB applications include iPhone owners finding their AirTags, and Samsung phones locating their Galaxy SmartTag+.
Ultra-wideband use cases
With precise ranging capability, UWB has an advantage in accuracy and security over Bluetooth and WiFi. The FiRa Consortium develops specific protocols for multiple verticals and defines the necessary parameters for various applications. The FiRa Consortium’s initial focus is on three primary categories of use cases: hands-free access control, location-based services, and device-to-device (peer-to-peer) applications [7], as shown in Figure 3.
Figure 3: Core UWB Services (Source)
UWB in Details
A security extension is currently stated in the IEEE 802.15.4z (at the PHY/MAC level), making it a unique and secure fine-ranging technology.
Why UWB for Indoor Locating?
Ultra-Wideband (or UWB) is a fast, secure, low-power radio technology used to determine location with precise accuracy unmatched by any other wireless technology. While similar to Bluetooth, it is more accurate, reliable, and effective [8].
UWB evolved from an OFDM-based data communication to an impulse radio technology specified in IEEE 802.15.4a (2ns pulse width);
UWB securely determines the relative location of peer devices with a very high level of accuracy and can operate with the line of sight at up to 200 meters. Furthermore, in contrast to narrowband wireless technologies, wide bandwidth means UWB provides stable connectivity with little to no interference and exact positioning, even in congested multipath signal environments. Figure 4 depicts the difference in NB and UWB signals.
Figure 4: Power spectral density of UWB and NB signals. (source)
Figure 5, as illustrated below, compares narrowband and Ultra-wideband. The UWB pulse (center & right image) is two nanoseconds (ns) wide. It makes it immune to reflected signal (multipath) interference. The center and right images show that the reflected signal (orange) doesn't affect the direct signal (blue). The UWB signals have much faster rise and fall edges than the narrowband signals (left). UWB signals retain their integrity and structure even in noise and multipath effects. Moreover, the UWB clean signal edges precisely determine arrival time and distance.
Figure 5: Comparing narrowband and UWB signal, Impulse Radio with direct (blue) and reflected signal (orange). (Source)
How Does UWB Work?
The operating concept is simple. Once a device is equipped with a UWB radio, such as a smartphone, wristband, or intelligent key, the devices start ranging when it comes into range of another UWB device. The range is calculated by performing Time of Flight (ToF) measurements between the devices. First, the ToF shall be determined by calculating the roundtrip time of challenge/response packets. Then, depending on the type of the function (e.g., asset tracking, device localization), either the mobile or the fixed UWB device calculates the device's precise location. For example, suppose the device runs an indoor navigation service. In that case, it must know its relative location concerning the fixed UWB device and calculate its position on the area map. Figure 6 shows the general working principles of UWB.
UWB uses a considerable channel bandwidth (500 MHz) with short pulses of about two (2) ns each; this helps in achieving centimeter accuracy. In addition, the UWB positioning process happens in real-time to track device movement very accurately.
The FiRa Consortium supports the 500 MHz frequency band in the Channel 5 to Channel 14 range. As Channel 9 offers the most significant worldwide regulatory acceptance, it is the only channel utilized across FiRa Certified™ devices [9].
Figure 6: UWB Ranging Process (Source)
How UWB Senses Object Motion and Its Relative Position?
The UWB-enabled system provides the precise location of a device, whether it's stationary or moving towards or away from a given object, based on its accurate UWB measurements. The exact accuracy of UWB ranging permits the use cases to define the precise intent range to prevent false triggering. The exact accuracy of UWB ranging permits the use cases to define the precise intent range to prevent false triggering.
For example, a UWB-enabled system can sense whether an object moves toward or away from a locked door. The UWB system can also sense whether the user is on the inside or outside of the doorway to keep the lock closed or open when the user reaches a certain point [9].
Enhancing Security
Today's technologies for ranging purposes rely on signal strength to calculate distance and determine the exact location. If UWB measures the device's signal strength and presumes a strong signal, it means the device is nearby. Unfortunately, attackers have found a technique to trick these systems using a relay station attack. In this type of attack, wireless signals are intercepted and amplified, causing the locked door to unlock.
What is lacking in these approaches is the precise calculation of actual physical distance, which UWB brings to the application. With UWB, any attempt to intercept and amplify the signal during a relay attack will only delay the arrival of the responding device's acknowledgment signal, making it clear to the UWB-based lock that the responding device is farther away, not closer. Any UWB signal that attackers succeed in intercepting and boosting won't trick a UWB-equipped lock into the opening. Moreover, the extension of IEEE 802.15.4z adds PHY level protection to all known attacks on legacy UWB radio[9].
The IEEE standard 802.15.4z HRP UWB PHY inserts a scrambled time stamp (STS) field into the packet. The objective is to keep ToF-related data from being either accessible or predictable by adding up cryptographic keys and Integer randomness to the PHY packet. It prevents various external attacks that use the deterministic and predictable nature of the original UWB PHY to manipulate distance readings.
The STS field contains a set of pseudo-random Binary Phase-Shift Keying (BPSK) modulated pulses. A cryptographically secure pseudo-random integer generator ensures the pseudo-randomness of the BPSK modulation sequence. Due to the pseudo-randomness of the arrangement, there is no recurrence pattern, thus providing reliable, highly accurate, and object-free channel delay estimates generated by the receiver [10]. The IEEE 802.15.4z amendment provides PHY-level protection to all known attacks on legacy UWB radios. It makes UWB much more robust from a security standpoint and far less vulnerable to attacks.
Industry Outlook for UWB
Despite progress, public interest woke up with the September 2019 statement that Apple would incorporate UWB in the iPhone 11 with a dedicatedly designed U1 UWB transceiver. Soon, such an innovation encouraged other smartphone makers like Samsung and Xiaomi to follow suit. In addition, silicon vendors like Qorvo or ST Microelectronics immediately identified the market opportunity to enter the UWB market through the acquisitions of DecaWave and BeSpoon.
To avoid isolated incompatible UWB implementations, the UWB Alliance was formed with an initial focus to help define and promote the IEEE 802.15.4z UWB specification. These efforts added security level to the previously existing IEEE standard 802.15.4a specification, defined in 2007 for data communication of consumer electronic devices. In addition, a new standard aimed to enhance the position locating features of UWB was created. As a result, the UWB Alliance has widely promoted IEEE 802.15.4z.
On top of the consumer side, Apple's U1 chip is now embedded in devices such as iPhones, Apple Watches, iPads, and AirTags. Furthermore, Apple has also opened the U1 interface to app developers and synchronized it to the IEEE standard 802.15.4z, making the U1-chip compatible with Qorvo and NXP transceivers. Such an alignment enables the user location awareness applications to behave smartly depending upon the precisely-determined relative position of the user[11].
Samsung UWB Adoption
Samsung is a founding partner of the FiRa Consortium, a member-driven organization dedicated to developing and providing seamless user experiences using the secured fine-ranging and positioning capabilities of ultra-wideband (UWB) technologies. FiRa Consortium presently has about 70 members ensuring an interoperable UWB ecosystem across chipset, device, and service infrastructure [12].
UWB is a new technology that consumer electronics companies are working on to enhance its capabilities to provide wider applications. The FiRa Consortium, of which Samsung is a member, had focused on fostering the adoption of UWB technology and providing updates to the UWB standards and certification programs to safeguard interoperability.
Already there are a few exciting applications in the Samsung Galaxy leveraging UWB. For example, the new Nearby Share app for device-to-device file transfers was improved by using UWB. By pointing your phone at another UWB-equipped device, Nearby Share automatically lists that device at the top of your sharing panel.
Samsung has also integrated UWB into its SmartThings Find application. Using augmented reality (AR) and intuitive directions, you can precisely locate other UWB-equipped devices. And as Samsung announced at its January 2021 Unpacked, the new Galaxy SmartTag+ will feature UWB and attach to almost any item, so you can even track belongings that don't have their built-in connection[13].
Apple UWB Adoption
Overview
The Apple Nearby Interaction app helps locate the position of devices with a U1 or Ultra-Wideband (UWB) chip embedded in devices such as iPhone 11 or later, Apple Watch, and third-party accessories. To engage in an interaction, devices in physical proximity run an app and share their position and device tokens that uniquely identify them. When the app runs in the foreground, Nearby Interaction notifies the interaction session of the peer's location by reporting the peer's direction and distance in meters [14].
Apple to introduce some new APIs that make it possible to use Nearby Interaction with compatible third-party hardware. Apple Nearby Interaction's third-party hardware support on standards has worked with industry groups like FiRa to make this API work with a wide range of accessories. For prototyping, experimenting, and building accessories, Apple has been working with the chipset manufacturers like NXP & Qorvo, making available development kits containing hardware and firmware that can interoperate with U1 in iPhone [15].
Secure UWB Development Kits That Interoperate with Apple U1
NXP now offers beta UWB development kits that interoperate with the U1 chip in supported Apple® products. Using these development kits to evaluate the design of new UWB-enabled IoT applications [16].
Apple U1 Ultra-Wideband (UWB) Analysis
Apple is the first consumer electronics company to offer a UWB chip in a smartphone device. According to Apple, the U1 chip enables the iPhone 11 to detect other U1 devices using spatial awareness technology. UWB in Apple iPhones communicate on two different frequencies – 6.24 GHz and 8.2368 GHz. Apple applied for an "Ultra-wideband radios for time-of-flight-ranging and network position estimation" patent in 2006 (before the first iPhone's release). Since then, it has applied for at least three more UWB-centric patents in its future product offerings [17].
The Apple U1-chip is embedded in the iPhone 11 and later series of iPhone (excluding the second and third-generation iPhone SE), an Apple Watch Series 6 and Series 7, the Home Pod mini, and AirTag trackers. AirTag is a small and elegant design accessory that allows iPhone users to securely locate and track their valuables using the Find My app.
AirTag is embedded with the Apple-designed U1 chip using Ultra-Wideband technology, facilitating accurate location finding for iPhone 11 and iPhone 12 users. This innovative technology can more accurately determine the distance and direction of a lost AirTag when it is in range. Precision Finding fuses input from the camera, ARKit, accelerometer, and gyroscope as a user moves. It then will guide them to AirTag using a combination of sound, haptics, and visual feedback [18].
The following chart provides the list of Apple Devices utilizing U1-Chip (Source)
Conclusion
This research article discussed the Ultra-Wideband(UWB) technology with a detailed and updated overview of UWB positioning techniques and their applications. Furthermore, we also discussed some external factors ( threats) that affected this technology and provided the Market outlook for UWB technology adoption by top consumer electronic companies.
In-door Positioning is one of the most critical and demanding phases in navigation systems, where different innovations have been developed to enhance performance. Nowadays, UWB is bringing value to products and services covering the consumer, automotive, industrial, and commercial market sectors by enhancing operational efficiencies in factories, improving worker protection, driving robots, and drone self-navigation. Its secure distance bounding capability also enables safe, hands-free access to cars, front doors, homes, and offices.
Over the years, Lumenci had a dedicated technical team helping our clients develop IP strategies around advanced telecommunication, wireless and mobile technologies, products and services of the future, and related infrastructure equipment. Our technology consultants are trained to consistently deliver the technical, business, and the legal insight required to help our clients succeed in this fast-paced and ever-evolving industry segment. We are best known for our ability to deliver accurate test and claim analysis promptly to earn the trust of our clients. Our diverse backgrounds, professional industry experience, and knowledge of patent law have allowed us to prosecute some of the most complex technologies and cutting-edge innovations.
References
[1]. https://www.firaconsortium.org/sites/default/files/2022-02/FiRa-Annual-Report-2021.pdf
[2]. https://www.qorvo.com/design-hub/blog/road-to-ultra-wideband
[3]. https://www.firaconsortium.org/about/consortium
[4]. https://www.eetimes.com/fira-consortium-aims-to-revive-uwb-drive-interoperability/
[6]. https://www.firaconsortium.org/discover/what-uwb-does
[7]. https://www.firaconsortium.org/discover/use-cases
[9]. https://www.firaconsortium.org/discover/how-uwb-works
[13]. https://insights.samsung.com/2021/08/25/what-is-ultra-wideband-and-how-does-it-work-3/
[14]. https://developer.apple.com/documentation/nearbyinteraction
[15]. https://developer.apple.com/videos/play/wwdc2021/10165/
[17]. https://decaforum.decawave.com/uploads/short-url/uhCupY69fW8GDAYpdAKwKB1Nzfq.pdf
[18]. https://www.apple.com/in/newsroom/2021/04/apple-introduces-airtag/
Author
Iman Ali
Associate at Lumenci
Iman is experienced in the IP domain with the expertise in Infringement analysis, Patent Portfolio Mining, and (EoU)/Claim Chart creation service. He has knowledge and interest in Wireless Cellular technologies, IoT, DIP & Network traffic analysis (NTA). He has Patented innovative ideas recognized by Intellectual Property India in various technologies. He is an electronics and communication engineer from Amity University, India.
Editorial Team at Lumenci
Through Lumenci blogs and reports, we share important highlights from the latest technological advancements and provide an in-depth understanding of their Intellectual Property (IP). Our goal is to showcase the significance of IP in the ever-evolving world of technology.