Terminology » Radar Sensing vs Wi-Fi Sensing : Key differences

Radar Sensing vs Wi-Fi Sensing : Key differences

Introduction : In this page, we will explore distinctions between radar sensing and Wi-Fi sensing as per IEEE 802.11bf. We will compare their operating bands, detection mechanisms, applications and limitations to understand which is optimal for your sensing needs.

Radar Sensing

Like radar, this sensing technique emits EM signals and analyzes received reflections in order to detect objects, measure their distances, velocity (if in motion) and other environmental parameters.
The common applications include mmwave radar and SAR radar.

Wi-Fi Sensing

This technique uses existing Wi-Fi signals to sense environmental changes such as human presence, motion, gestures etc. It does not require target to have any dedicated sensor hardware.
The technique uses CSI (Channel State Information), signal strength and phase data transmitted using 2.4 GHz, 5 GHz, 6 GHz or 60 GHz bands.
The technique has become popular due to its standardization activities under IEEE 802.11bf.

Difference between Radar and WiFi sensing

Feature	Radar Sensing	Wi-Fi Sensing
Signal Type	It is active technique which emits specific radar signals.	It is passive technique which uses existing Wi-Fi waves.
Hardware Requirements	Requires radar transmitter/receiver and antennas	Uses existing Wi-Fi routers or APs, no additional sensor devices needed.
Coverage & Penetration	It is often LOS (Line of Sight) and limited by beam shape. It is better in clear path scenarios.	It is omni-directional. It can sense through walls and have fewer blind spots.
Cost & Deployment	More expensive due to specialized hardware.	Lower cost due to use of existing hardware
Interoperability	Standalone systems and does not require integration into existing network infrastructure.	Seemlessly integrated with existing Wi-Fi network and also with IoT devices.
Privacy Impact	Captures reflections that can be sensitive; higher privacy risk	Less invasive as it does not capture identifiable imagery or high res data
Applications	High precision distance and velocity measurements (e.g., automotive, surveillance)	Motion detection, gesture recognition, vital signs, presence detection

Conclusion: Choosing between radar and Wi-Fi sensing depends on your application’s range, resolution and infrastructure constraints. While radar excels in long range detection, Wi-Fi sensing offers cost effective integration into existing networks; perfect for smart and connected environments.