Standards & Frontier
IEEE 802.15.4ab
The UWB technology family keeps evolving on top of the IEEE 802.15.4 standard: 4a introduced the HRP-UWB PHY for ranging and positioning; 4z strengthened secure ranging on that basis; and 802.15.4ab is best described by the phrase "capability expansion". If 4z was about whether the measurement is secure, 4ab asks: now that UWB is in phones, cars, IoT, smart homes and industry, what further capabilities are needed to support the next generation of short-range wireless applications?
What 4ab enhances
802.15.4ab enhances the UWB PHY, MAC and related ranging techniques while remaining backward compatible with ERDEV (Enhanced Ranging Capable Devices, introduced in 4z). The scope of the enhancements is very broad:
- Extensions to coding, preamble and modulation schemes;
- New operating frequencies and interference mitigation (coexistence);
- High-integrity ranging and low-power mechanisms;
- Narrowband assist;
- UWB sensing (radar-style sensing);
- Low-power low-latency streaming and high-data-rate streaming.
Four device capability classes for HRP-UWB
Building on the HRP-ERDEV of 4z, 4ab further defines and strengthens HRP-EMDEV, and introduces HRP-SDEV, HRP-ARDEV and HRP-LLDDEV, pushing UWB from "ranging" towards a "multi-capability platform":
HRP-EMDEV (base enhanced layer)
The base enhanced mode of 4ab: mandatory support of the K=7 convolutional code for PHR and Payload, and support for rates such as 1.95 / 62.4 / 124.8 Mbps. Stronger coding, richer modulation and more flexible data rates lay the foundation for later low-latency data, enhanced ranging and sensing.
HRP-SDEV (standardised sensing)
Standardises UWB's move from ranging and positioning to radar sensing. SENS configuration 0 is mandatory, 1 and 2 optional, and SENS reuses the same preamble code as SYNC/SFD. Its sensing pulse shape requirements are stricter than ERDEV — energy both before and after the pulse must stay below 4% (ERDEV constrains only pre-pulse energy) — so that echoes can be interpreted cleanly.
HRP-ARDEV (enhanced ranging)
Further improves the integrity and accuracy of ranging on top of ERDEV, for scenarios with higher requirements on secure ranging such as digital car keys.
HRP-LLDDEV (low-latency / low-power data)
Targets low-power low-latency streaming and high-data-rate streaming — scenarios that need to "transmit data while ranging", letting UWB carry communication tasks as well.