Ultra-wideband (UWB) is usually mentioned alongside location trackers, digital car keys and smartphone features that help locate misplaced belongings. Apple's AirTag, for instance, uses the technology to guide users towards a lost item, while some smartphones use it to communicate with compatible cars and smart devices. But UWB has applications that go well beyond finding a wallet or unlocking a car.
The technology can measure the distance between objects with centimetre-level accuracy, detect movement and even pick up subtle changes in a person's breathing. It is also being explored for factory automation, robotics, indoor navigation and health monitoring. A regulatory review in the US has now brought renewed attention to the technology and the applications that could emerge as its use expands.
What is ultra-wideband and how does it work
UWB is a short-range wireless communication technology, much like Bluetooth and Wi-Fi. However, it uses a much wider radio frequency bandwidth and transmits extremely short pulses of radio signals rather than relying on conventional continuous radio waves.
A UWB signal occupies a bandwidth of at least 500 MHz or has a fractional bandwidth of 20 per cent or more. This allows compatible devices to measure the time taken by a radio signal to travel between two points with a high degree of accuracy.
This is known as Time of Flight (ToF). A UWB-enabled device sends a signal to another compatible device, which responds. By measuring how long the signals take to travel between them, the devices can calculate their distance.
Since radio signals travel at the speed of light, even tiny differences in transmission time can help determine the distance between two devices. UWB can achieve accuracy down to a few centimetres under suitable conditions, compared with the metre-level estimates commonly associated with conventional Bluetooth-based location tracking.
UWB can also determine the direction of another compatible device when supported by the hardware and positioning system. This is what allows a smartphone to show not just how far away a lost object is, but also where to move to find it.
From military research to consumer devices
UWB's development dates back to research into short-pulse radio signals and radar systems during the 1960s and 1970s. US military research institutions explored the technology for radar and communications, where its ability to distinguish between objects at close range and operate with low transmission power made it useful.
UWB remained largely restricted to specialised applications until the US Federal Communications Commission (FCC) permitted its commercial use in 2002, subject to limits on radio emissions.
Commercial applications initially focused on radar, imaging, industrial measurement and short-range communications. Its use in consumer electronics gained momentum much later.
Apple introduced UWB in the iPhone 11 in 2019 through its U1 chip. The technology subsequently became part of the company's AirTag tracking system. Samsung, Google and other manufacturers also began incorporating UWB into selected smartphones and accessories.
Where is UWB being used today
Finding lost objects is among the most familiar applications, but UWB has also found its way into automotive systems and access control.
Digital car keys are one example. A compatible smartphone can communicate with a vehicle's UWB system to determine whether the owner is approaching, standing beside or moving away from the car. This allows the vehicle to unlock when the authorised phone is nearby and lock when it moves out of range.
UWB also has an advantage in security. Its ability to measure the actual distance between devices makes it harder for someone to trick a vehicle into believing that an authorised key is nearby by relaying its radio signal from another location. This is known as a relay attack.
The technology is also used in industrial settings for tracking equipment, locating workers and monitoring the movement of assets inside factories and warehouses. Unlike
GPS, which struggles indoors, UWB can work with fixed reference points installed across a building to determine the location of objects.
Sports is another application. UWB-based tracking systems can monitor the positions and movements of players during training and matches.
What else could UWB do
The more interesting possibilities lie in UWB's ability to sense its surroundings.
Since UWB sends and receives radio pulses, changes in the signals returning from nearby objects can provide information about movement. This makes it possible to use the technology as a form of radar.
For instance, a UWB sensor could detect whether someone is present in a room without requiring a camera. It could also identify small movements associated with breathing. Such applications are being explored for contactless health monitoring, elderly care and smart home systems.
In a home, a UWB-equipped device could potentially detect whether someone has entered a room and adjust lighting or other connected appliances accordingly. In healthcare, sensors could monitor breathing patterns without requiring a person to wear a smartwatch or other tracking device.
There are also applications in robotics and autonomous machines. A robot operating inside a factory needs to know where it is, how close it is to surrounding objects and whether something is moving in its path. UWB could provide accurate distance measurements to help with navigation and collision avoidance.
These applications are particularly relevant as manufacturers develop robots and other machines that need to interact with their physical surroundings. UWB could provide an additional source of spatial information alongside cameras, lidar and other sensors.
Why has UWB not become as common as Bluetooth
Despite its advantages, UWB has not achieved the adoption of Bluetooth, partly because the two technologies serve different purposes.
Bluetooth supports a wide range of everyday connections, including headphones, speakers and wearables. It is also supported across devices from multiple manufacturers. UWB, on the other hand, is mainly used when accurate distance measurement or positioning is required, a need that most everyday wireless accessories do not have.
The cost of UWB components and limited hardware support have also slowed adoption. Both communicating devices generally need compatible UWB hardware, and smartphone support remains uneven.
Apple has incorporated the technology across several generations of iPhones, while Android support is concentrated in selected models. Google's Pixel range, for instance, reserves UWB support for selected Pro models.
Spectrum regulations are another consideration. UWB operates across a wide range of frequencies, requiring strict transmission power limits to prevent interference with other wireless services. These restrictions can affect the range and performance of certain applications.
As a result, many devices use Bluetooth Low Energy to discover nearby accessories and establish an initial connection, switching to UWB when accurate distance measurement is needed.
Could changing regulations give UWB more room to grow
Radio spectrum rules have played a part in determining how UWB devices can be deployed. Since the technology operates across a wide range of frequencies, regulators have to ensure that its signals do not interfere with other wireless services.
The rules, however, are not the same everywhere.
In India, the Department of Telecommunications introduced the Use of Very Low Power Ultra-wideband Devices (Exemption from Licensing Requirement) Rules in 2018. These rules allow specified UWB applications to operate without an individual licence, subject to technical conditions and limits on transmission power. They cover categories such as location tracking, generic UWB communication, vehicle systems and material sensing.
India's National Frequency Allocation Plan 2025 also recognises UWB as a technology relevant to areas such as medical applications, ground-probing radar and machine-to-machine communication. However, the plan does not itself introduce a new UWB spectrum regime. There is no publicly announced overhaul of India's UWB-specific rules at present.
The European Union has its own harmonised framework under Commission Implementing Decision 2019/785, which was amended in 2024. It specifies the frequency bands and power limits under which UWB equipment can operate, with conditions for applications such as indoor positioning and vehicle installations.
The US is now looking at updating its UWB framework, which dates back to 2002. In a proposal published on November 2, the FCC has suggested creating a separate category for devices that use UWB to locate or track objects and people. It also wants to review existing technical restrictions to account for newer applications of the technology, including systems that use UWB to detect movement and sense their surroundings. The commission is also seeking views on whether AI-enabled UWB sensing devices need a separate category under its rules.
Could the US move influence other markets
Potentially. If the proposed changes make it easier for manufacturers to develop and certify UWB products, other regulators could face pressure from industry groups to review their own frameworks. Global chipmakers and device manufacturers also have an interest in avoiding different technical requirements for every market.
What to expect
Wider adoption will depend on chipmakers reducing the cost and power consumption of UWB components, while device manufacturers expand support beyond selected smartphones and accessories. Industry groups such as the FiRa Consortium and Car Connectivity Consortium are also working on standards to improve interoperability.
Regulatory changes could help make newer applications easier to deploy, but UWB's expansion will ultimately depend on whether manufacturers find practical uses for it beyond device tracking and digital keys.
 "UWB: Soon, technology behind AirTag could do more than find lost things")
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