Ultra-Wideband (UWB) technology is emerging as a robust, future-ready solution that addresses these shortcomings head-on. With sub-centimetre location precision, low power consumption, and built-in resistance to common wireless attacks, UWB is poised to become the new standard for physical and logical access. From residential smart locks to enterprise security systems and IoT integration, UWB’s potential is vast and growing.
How UWB works: high-precision ranging with low interference
Unlike traditional wireless technologies that modulate signal amplitude or frequency, UWB transmits ultra-short pulses across a broad spectrum; typically, a 500MHz bandwidth within the 3.1 to 10.6GHz range. This pulse-based transmission enables precise measurement of signal travel time, known as Time of Flight (ToF), between devices. Because UWB uses such short pulses and a wide spectrum, it minimises interference and avoids overlap with narrowband signals such as Wi-Fi and BLE.
UWB can support several deployment topologies depending on the use case. Two-Way Ranging (TWR) provides high precision with minimal infrastructure, while Time Difference of Arrival (TDoA) and Phase Difference of Arrival (PDoA) topologies support more complex networks with multiple devices. The result is a highly versatile positioning technology that works indoors, outdoors, in crowded environments, and in motion.
This high temporal resolution makes UWB ideal for determining how far a user is from a door or device and in which direction they are moving. Combined with angle-of-arrival estimation, UWB can recognise whether someone is approaching, moving past, or standing still, information crucial for intelligent access systems.
Built-in security: mitigating relay attacks and spoofing
Security is where UWB significantly outperforms most legacy wireless protocols. BLE, while convenient, is susceptible to relay attacks where a malicious actor extends the signal range between a user’s device and an access system to spoof proximity. While more secure, NFC requires very close contact and is less conducive to hands-free experiences.
UWB avoids these vulnerabilities through physical-layer cryptography. Using secure packet structures that include cryptographically randomised timestamp fields, UWB makes it nearly impossible for an attacker to replicate or manipulate signal timing. These safeguards prevent attackers from tricking the system into thinking a device is closer than it is.
In the IEEE 802.15.4z standard, this secure ranging process is enhanced further through pseudo-random binary shift keying (BPSK) modulation, ensuring each signal’s uniqueness and reducing predictability. This enables robust protection against jamming, replay, and distance-manipulation attacks.
Smart lock engineering: technical considerations for real-world deployment
While UWB holds great promise, integrating it into physical access systems such as door locks presents unique engineering challenges. Door locks are compact, battery-powered, and often installed in metal-rich environments that complicate RF performance. To unlock UWB’s potential, engineers must address several design factors:
Antenna design and placement
Metal doors and enclosures can severely affect signal propagation. Achieving optimal performance requires carefully tuned antennas operating across a wide range of materials: wood, metal, composite, each with different RF behaviours. Compact antenna integration without sacrificing gain or bandwidth is crucial.
Multipath and interference management
Indoor spaces often create complex RF environments filled with reflections, obstructions, and competing signals. While UWB is naturally resistant to multipath distortion, design techniques such as diversity reception and multi-antenna configurations can further stabilise signal quality. These techniques allow the receiver to capture multiple signal paths and combine them to extract the most reliable data.
Intent recognition and false trigger avoidance
One of UWB’s distinguishing features is its ability to determine user intent based on precise motion tracking. Systems can be designed to identify whether a user is actively approaching a door or merely passing by. This enables more nuanced behaviour, such as conditional unlocking or ignoring unintentional proximity. Implementing this capability requires high-resolution positioning and algorithmic support to interpret signal data in context.
Power efficiency for battery-operated devices
Battery life is a significant concern for access control products. Frequent battery replacement is not acceptable in either residential or commercial use. UWB systems, thanks to their short transmission bursts and low duty cycles, offer inherently low power consumption. By optimising wake-up protocols and leveraging auxiliary technologies like BLE for initial device discovery, power consumption can be further reduced to allow for multi-year operation.
Compatibility with existing systems
UWB is often deployed in conjunction with BLE and NFC to maximise compatibility. For example, BLE can wake a device or initiate a ranging session, while UWB completes the precise authentication. This hybrid approach allows UWB-enabled systems to integrate smoothly into existing infrastructure while offering a pathway to more advanced features.
Standards and ecosystem development: the role of Aliro
The promise of UWB extends beyond individual products. For broad adoption, it must integrate into a wider standards-based ecosystem. This is where initiatives like Aliro come into play.
Developed by the Connectivity Standards Alliance (CSA), Aliro provides a unified credential and communication framework for secure, interoperable access. Supported by industry leaders across hardware, software, and semiconductor domains, Aliro enables secure ranging, device-to-device communication, and user authentication across platforms and devices.
Aliro is designed to work with other CSA initiatives like Matter, which aim to unify the smart home. Together, these standards ensure that UWB access control solutions are technically feasible and scalable, user-friendly, and interoperable across vendors and device types.
Extending UWB beyond physical access
While door locks are a compelling use case, UWB’s applications extend far beyond physical access.
Logical access and device authentication
UWB can authenticate users to digital systems in enterprise environments based on proximity. Devices such as laptops, monitors, or secure kiosks can recognise when an authorised user is nearby and automatically unlock or lock when the user walks away. This frictionless approach enhances security while eliminating the need for passwords or badges.
IoT and context-aware automation
UWB can add spatial intelligence to IoT networks. In smart homes, it can enable context-aware behaviors, like turning on lights as a person moves through rooms or adjusting temperature based on room occupancy. In industrial IoT, UWB is already used for high-accuracy asset tracking, personnel location, and workflow automation.
Healthcare, automotive, and robotics
UWB’s precision makes it ideal for applications that demand spatial awareness. In healthcare, it can track equipment or monitor patient movement. In robotics, UWB supports obstacle avoidance, proximity detection, and coordination between mobile systems. In automotive, it continues to evolve from passive keyless entry to more sophisticated in-cabin presence detection and localisation.
Industry collaboration and design evolution
As adoption accelerates, ongoing industry collaboration is essential to ensure interoperability and security. Groups like the FiRa Consortium, Car Connectivity Consortium (CCC), and Omlox are working to standardise UWB implementations across industries and use cases. These efforts help avoid fragmentation and ensure consistent, reliable performance.
At the same time, innovations in RF design are making UWB easier to deploy. Miniaturised antennas, integrated UWB transceivers, and improved angle-of-arrival algorithms allow UWB to fit into smaller, more power-constrained devices without sacrificing performance. Multi-antenna designs are improving directional accuracy and supporting advanced features like presence detection and gesture control.
A new standard for secure, seamless access
Ultra-wideband is rapidly becoming the backbone of next-generation access systems. Its precise range, robust security, and low power consumption make it a superior choice for physical and digital access applications. Whether in a smart home, an office building, or a connected industrial site, UWB enables a level of control, safety, and convenience that legacy technologies cannot match.
With ongoing progress in standardisation, antenna design, and ecosystem integration, UWB is no longer a niche technology but a foundational component of the connected world. For engineers and system designers, now is the time to explore UWB’s potential and help shape tomorrow’s secure, seamless access experiences.
This article originally appeared in the May’26 magazine issue of Electronic Specifier Design – see ES’s Magazine Archives for more featured publications.
