UWB Beyond Ranging: What IEEE 802.15.4ab Means for Your Firmware
Too many times we’ve seen or heard a situation where a child falls asleep in the back seat. The driver steps away. Fifteen minutes later, the cabin temperature starts climbing. So, what if somewhere inside the dashboard, the same UWB chip that unlocked the car door when the driver approaches can do something entirely different. Like reading the faint reflections of its own radio pulses bouncing off the child’s chest, detecting the tiny rise and fall of breathing, and triggering an alert before heat becomes danger.
That capability will soon be available in modern production vehicles. The existing Ultra-Wideband (UWB) radio already inside the dashboard is learning a valuable second skill.
UWB has earned its place as the most accurate indoor positioning radio available, delivering centimeter-level distance measurements using time-of-flight (ToF): the time it takes a pulse to travel from one device to another and back. Our decision framework for indoor positioning radios covered the firmware realities of choosing between UWB, Bluetooth Low Energy (BLE), and Wi-Fi. That comparison assumed UWB was a ranging radio.
This article, which talks about the next-generation standard, IEEE 802.15.4ab, widens the assumption. With standardized radar sensing, a UWB anchor in a hospital hallway can detect whether an elderly patient has fallen, without a camera in the room. With 30x extended range, fewer anchors cover the same warehouse floor, cutting deployment costs and calibration overhead. Ranging is still there. Radar sensing, extended range, and 18x higher data rates now sit alongside it. For firmware teams, the radio’s job description just expanded, and the software has to keep up.
How UWB Radar Works (With Hardware You Already Know)
UWB ranging is a conversation between two devices. A tag sends a pulse, an anchor replies, and the system measures the round-trip time to calculate distance. Both sides participate.
UWB radar is an echo. One device sends pulses into a room and listens to what bounces back. No second device needed. The reflections carry information: where objects are, whether something is moving, and how far away it sits. What the device captures is called a channel impulse response, or CIR. Think of it as clapping once in an unfamiliar room. Every surface sends back an echo at a slightly different time and volume. A CIR is the full recording of all those echoes at once, preserving the timing and strength of each reflection path.
The physics underneath is the same as ranging: short pulses across a 500 MHz bandwidth. The difference is entirely in what the firmware does with the signal. Ranging firmware reads timestamps and computes distance. Radar firmware reads the CIR and runs detection algorithms: is something present? Is it moving? Is it breathing?
Two parameters control the trade-off. First, more samples per radar sweep extend the detection range from centimeters to several meters. Second, higher sweep rates improve accuracy but cost more power. Even at several meters of detection range, UWB radar draws under 10 milliwatts. That number keeps battery-powered devices on the table.
The practical result: a UWB anchor installed for digital key access can double as a presence sensor. Same hardware. No extra cost.
What IEEE 802.15.4ab Actually Changes
The current generation of UWB silicon, including Qorvo’s DW3xxx series and NXP’s Trimension platform, is built on IEEE 802.15.4z. That standard defined secure ranging and physical-layer (PHY) security: the lowest level of the radio hardware, where pulses are shaped and timed. It gave firmware teams a reliable foundation. Time-of-flight measurement with distance-bounding that prevents relay attacks (where a thief amplifies your car key signal from a distance to trick the lock into opening). Every production UWB ranging product on the market today runs on 802.15.4z.
IEEE 802.15.4ab is the successor, expected to be officially released in the first half of 2026. It is backward compatible with 802.15.4z, building on the existing foundation rather than discarding it. Going forward, three additions will matter for teams building on UWB:
1. Radar sensing becomes part of the standard: Under 802.15.4z, radar-like sensing was possible but vendor-specific. Qorvo published application notes on CIR-based presence detection using existing DW3xxx hardware. NXP shipped the Trimension SR250 with combined ranging and radar support. Each implementation used proprietary firmware interfaces. 802.15.4ab writes radar into the standard itself, defining how Impulse Radio UWB (IR-UWB) transceivers operate in sensing mode.
That means interoperable radar behavior across chipmakers. Not just interoperable ranging. Ceva is pushing this further: their Ceva-Waves UWB IP, the industry’s first 802.15.4ab-compliant design, supports combined ranging-and-radar sensing on a single silicon block. Because Ceva also licenses edge AI processors (NeuPro) and sensor fusion cores (MotionEngine), chipmakers can place the UWB radio and the radar detection algorithms on the same chip, rather than offloading CIR processing to a separate microcontroller.
For firmware engineers, this collapses two separate worlds into one. Today, your ranging code and your radar code (if you use it) talk to different vendor libraries with different data structures and different timing rules. A standardized radar mode means chipmakers will converge on common interfaces. Your architecture needs to anticipate a unified API (Application Programming Interface, the set of commands your code uses to control the chip) rather than two bolted-together SDKs (Software Development Kits).
2. Secure ranging pushes from pocket distance to building scale: Current 802.15.4z secure ranging works reliably at close proximity: digital keys, item finders, short-range access control. 802.15.4ab introduces multi-millisecond (MMS) ranging techniques. Instead of a single fast pulse exchange, MMS accumulates multiple measurements over a longer window, trading speed for signal gain. The result is more range at the same transmit power, and the early numbers suggest the gain is substantial.
How much more range are we talking about? Ceva’s 802.15.4ab-compliant UWB IP, announced on March 10, 2026, claims up to 30x range extension over current 802.15.4z. That moves UWB from “is the user next to the door?” to “where in this space are they?” UWB still works best within line-of-sight or through lightweight partitions, so “this space” means a floor, a warehouse zone, or an open facility rather than through concrete walls and steel framing. It pushes UWB into territory held by Wi-Fi Round-Trip Time (RTT) positioning and BLE Angle of Arrival (AoA), but with UWB’s inherent accuracy and security.
For firmware teams, longer-range sessions consume more energy per cycle, making your sleep and wake scheduling more consequential. Your power model has to account for these longer windows.
For decision-makers, the implication is simpler: UWB can now cover warehouse-scale and campus-scale spaces where teams previously had to fall back on BLE or Wi-Fi. Fewer compromises on accuracy, fewer radios to manage.
3. Data rates jump 18x: Current UWB devices communicate at 6.8 Megabits per second (Mbps). 802.15.4ab supports up to roughly 125 Mbps. That opens up use cases that pure ranging applications never needed: low-latency audio transport, richer protocol exchanges, and combined sessions where a single UWB transaction delivers both a position fix and a data payload.
For most Real-Time Location System (RTLS) and access control firmware, 6.8 Mbps has been more than enough. But if your product roadmap includes streaming sensor data alongside ranging, or pushing firmware updates over UWB rather than a separate BLE link, the additional bandwidth changes what your radio can carry.
In practice, you end up with one radio link that handles positioning, data transfer, and firmware updates. That is fewer radios in the design and fewer integration headaches in the field.
The volume signal underneath all of this: Grand View Research projects the global UWB market to grow at a CAGR of 18.9% from 2024 to 2030, reaching $4.37 billion by 2030 from an estimated $1.40 billion base in 2023. The ecosystem is moving. Also, Ceva’s announcement signals that compliant silicon IP is available for licensing now, meaning chipmakers can integrate it into next-generation Systems on Chip (SoCs: single chips combining processor, radio, and memory). Production parts built on 802.15.4ab are a design cycle away.
What This Demands From Your Firmware
Here is where the standard meets the code your team writes.
a) Dual-mode scheduling: If your transceiver supports both ranging and radar, your Real-Time Operating System (RTOS: the software layer that decides when each task on the chip gets to run) has to manage two types of radio sessions with different timing profiles.
Think of it as air traffic control for a runway shared by two kinds of aircraft. Ranging sessions are the small fast jets: short bursts, tight timing, nanosecond-level precision. Radar sweeps are the heavy cargo planes: longer windows, more data collected, a different processing pipeline on the ground. Interleaving them without collision is a scheduling problem that ranging-only firmware never had to solve.
b) A new signal processing layer: Ranging firmware reads timestamps from the transceiver. Radar firmware reads CIR data: arrays of amplitude and phase samples that need filtering, thresholding, and classification to extract meaning (is someone present, are they moving, are they breathing). These are algorithmic problems that require more flash memory and RAM. If your current firmware barely fits in a DW3xxx’s companion microcontroller (MCU: the small processor running your tag’s software), radar processing will force a hardware reassessment.
c) Power budget complexity: A tag that ranges every 500 milliseconds has a predictable power profile. Add radar sweeps every 2 seconds and the profile shifts. Add adaptive logic that triggers radar only when ranging detects proximity, and the profile becomes state-dependent. Your power model needs to account for these layered modes. Otherwise, battery life estimates built for ranging alone will miss the mark.
d) The abstraction question: This one is about future-proofing. An abstraction layer in firmware works like a standard electrical outlet in a house. You plug in any appliance without rewiring the wall. Without that standard interface, every new device would mean tearing open the drywall. If your firmware talks directly to a 802.15.4z transceiver without a clean hardware abstraction layer between them, swapping in an 802.15.4ab chip later will mean rewriting that boundary. A few days of architecture work today prevents a quarter of rework after your product ships.
What This Unlocks
Automotive child presence detection: The European New Car Assessment Programme (Euro NCAP), the body that rates vehicle safety, have started tightening their scoring of vehicles on child presence detection (CPD) systems from 2025 onward. UWB radar detects micro-movements like breathing inside a cabin using the same anchor hardware as the digital key. No extra sensors. This is the first application where UWB radar will ship at volume, because regulation demands it.
Occupancy sensing without cameras: UWB radar detects presence and motion without capturing images. For healthcare facilities (fall detection in elder care), enterprise buildings (meeting room utilization), and smart buildings (heating, ventilation, and air conditioning automation), that privacy advantage changes the deployment conversation entirely.
Sparser infrastructure for indoor positioning: With 30x range improvement, fewer anchors cover the same floor space. Fewer anchors means lower deployment cost and less calibration overhead. Those two factors have been UWB’s most persistent adoption barriers.
Planning for What Comes Next
If your team is mid-development on 802.15.4z, finish your product. The current silicon is stable and proven. But design your firmware with enough abstraction that the next chip does not demand a rewrite.
However, if you are in early product definition, factor in the widening value proposition. A radio that does ranging today and radar tomorrow carries a different cost-benefit weight than ranging alone.
Now, if your team is designing UWB firmware and wants to stress-test the architecture against what 802.15.4ab will demand, embedUR runs 30-minute architecture reviews. The review maps your requirements to firmware topology, models your power budget, and flags where your abstraction layer needs room to grow. That conversation costs less than the rework it prevents.
Which is cheaper for your team: the abstraction layer now, or the rewrite later?
