For decades, Wi-Fi has performed one principal function: transporting data between connected devices. A new generation of technology is now expanding that role with Wi-Fi networks that can also detect how people and objects are changing the surrounding radio environment. This emerging capability – known as Wi-Fi sensing – could turn access points, broadband gateways, mesh nodes and connected devices into part of a distributed sensing system.
Instead of installing cameras, motion detectors or wearable devices, Wi-Fi sensing uses radio signals that are already travelling through a home, office or other indoor environment. The immediate applications include motion and presence detection, home security, occupancy monitoring and assisted living. More advanced systems are being developed for functions such as localisation, activity analysis, fall detection, sleep monitoring and breathing measurement.
The significance of Wi-Fi sensing is therefore not simply that Wi-Fi can become another type of motion detector. The larger opportunity is that widely deployed communications infrastructure could also become a platform for understanding activity in the physical environment.
How does Wi-Fi detect movement?
Wi-Fi signals do not travel directly and cleanly from one device to another. Some of the transmitted radio energy follows a relatively direct path. Other parts of the signal reflect off walls, floors, ceilings, furniture, machinery and people before reaching a receiving device. This creates a complex and constantly changing pattern of radio propagation known as multipath.
When a person enters a room or moves through it, their body blocks, reflects and scatters some of the radio energy. Even relatively small movements can change the strength, phase, timing and propagation characteristics of the signals received across a Wi-Fi connection. Wi-Fi sensing software analyses these changes and attempts to determine what caused them.
Current commercial platforms generally rely on information extracted from Wi-Fi radios and chipsets, particularly Channel State Information, or CSI. CSI provides detailed measurements of how a wireless channel affects different components of a transmitted signal. Wi-Fi chipsets were originally developed for communications rather than sensing, and CSI is not always exposed in a form that sensing software can use. Access to consistent, sufficiently detailed radio measurements has therefore been one of the practical challenges facing the industry.
Simpler implementations can also use changes in received signal strength, although CSI normally provides a much richer picture of the radio environment.
From radio measurements to useful information
A changing radio signal does not automatically reveal whether someone has entered a room, opened a door or fallen to the floor. Signal processing and machine-learning models are needed to convert raw wireless measurements into useful events and insights. The system first identifies patterns or disturbances in the radio channel. Algorithms then classify those patterns—for example, as ordinary background variation, human movement, sustained presence, or a particular type of activity.
The precise architecture varies between vendors. Processing may take place:
- Inside an access point or gateway
- On a separate edge-computing device
- In the Cloud
- Across a combination of edge and cloud platforms
This use of AI is one of the main reasons Wi-Fi sensing has progressed from an interesting research subject into a commercially deployable technology. AI models can identify patterns in complex wireless measurements that would be difficult to define using fixed rules alone. But performance is not universal. It depends on the radio hardware, software, network topology, building layout, device placement, environmental conditions and the specific activity being detected.
What can Wi-Fi sensing do today?
The most commercially established Wi-Fi sensing functions are motion detection and presence detection. Several platforms use existing broadband gateways, mesh nodes, or other connected Wi-Fi devices to detect movement across a home. Cognitive Systems, for example, describes a platform that analyses disturbances in wireless signals to provide motion, presence, and behavioural information. Origin AI similarly uses changes in ambient Wi-Fi signals to turn ordinary wireless networks into sensing systems.
Depending on the implementation, current or emerging applications include:
- Home security and intrusion alerts
- Detection of whether a home or room is occupied
- Automatic lighting and climate control
- Monitoring daily activity
- Independent-living and elder-care services
- Fall detection
- Sleep and breathing monitoring
- Room-level localisation
- Smart-building occupancy information
These capabilities should not all be treated as equally mature. Basic motion and presence detection are already commercially deployed. More detailed functions—such as recognising activities, estimating the number of people present, or monitoring health-related indicators—require more sophisticated models and may need carefully controlled conditions or additional devices. Claims about accuracy should therefore be evaluated application by application rather than applied to Wi-Fi sensing as a whole.
Why use Wi-Fi instead of dedicated sensors?
Wi-Fi sensing has one enormous potential advantage: Wi-Fi infrastructure is already almost everywhere. Homes and businesses commonly contain several Wi-Fi radios distributed across gateways, access points, mesh nodes, televisions, speakers and other connected products. These devices already transmit signals through the spaces that operators and building owners may want to monitor.
This creates the possibility of adding sensing through software, firmware or a platform upgrade rather than installing an entirely separate network of sensors. The technology can also operate without capturing identifiable images or audio. This may make it more acceptable than cameras in bedrooms, bathrooms, care environments and other privacy-sensitive locations.
Wi-Fi signals can work in darkness and do not require the same direct line of sight as cameras. Depending on the system and building materials, sensing may also extend across rooms or through some walls. These benefits do not mean that Wi-Fi sensing will replace every other sensing technology.
Cameras, passive infrared sensors, radar, ultra-wideband and Bluetooth-based systems each provide different combinations of cost, range, resolution and reliability. Ultimately, the strongest solutions may eventually combine several sensing technologies.
Why is Wi-Fi sensing emerging now?
The underlying idea is not new. Researchers have explored the use of wireless signals for detection, localisation and activity recognition for many years. Commercial interest is now increasing because several important developments are occurring at the same time. Modern Wi-Fi networks contain more radios, antennas, frequency bands and connected devices. OFDM and MIMO technologies provide detailed information about how signals propagate across multiple subcarriers and spatial paths.
At the same time, improvements in AI and edge computing make it easier to process large quantities of radio data and identify meaningful patterns quickly. Chipset vendors and equipment manufacturers are also beginning to treat sensing as a product capability rather than an experimental use of diagnostic information.
Finally, the industry now has a formal Wi-Fi sensing standard. IEEE 802.11bf-2025 – approved in May 2025 – defines enhancements to Wi-Fi’s MAC and PHY capabilities for wireless LAN sensing. The standard is intended to support capabilities including distance estimation, motion detection and gesture recognition using Wi-Fi infrastructure.
IEEE 802.11bf does not by itself create complete sensing applications or guarantee that products from different vendors will interpret an environment in the same way. The algorithms, AI models, application logic and commercial services built above the standard will remain important areas of differentiation.
But standardisation should make it easier for Wi-Fi devices to participate in structured sensing measurements instead of relying entirely on proprietary access to radio information. We will examine precisely what IEEE 802.11bf changes in Part 2 of this guide.
A new application layer for Wi-Fi
The most important way to understand Wi-Fi sensing is as a new application layer built on top of wireless connectivity. The access point remains an access point while the broadband gateway continues to provide Internet access. But the radio network can simultaneously generate information about movement, presence and the surrounding environment.
This could give broadband operators a new set of smart-home, security and care services to offer customers. Enterprise networking vendors could add occupancy and building-management intelligence to managed Wi-Fi platforms. Consumer electronics and IoT vendors could use sensing to make devices respond more intelligently to people and activity.
The commercial opportunity is potentially significant because Wi-Fi sensing does not necessarily require an entirely new class of infrastructure. Its long-term success, however, will depend on whether vendors can deliver reliable, understandable and useful applications—not merely impressive sensing demonstrations.
WiFi NOW’s take:
Wi-Fi sensing is one of the most important expansions of Wi-Fi’s role since the emergence of large-scale managed wireless networks. Its greatest advantage is not that Wi-Fi is necessarily the most precise sensing technology for every application. It is that Wi-Fi is already installed in billions of homes, businesses and connected devices. That installed base gives Wi-Fi sensing a route to scale that entirely new sensing platforms may struggle to match.
The first large commercial opportunities will probably be relatively straightforward: Security, presence detection, smart-home automation and monitoring of daily activity. More advanced healthcare, behavioural and spatial-intelligence services will require stronger evidence of reliability, careful privacy safeguards and clearer definitions of what the systems can – and cannot – determine.
Wi-Fi sensing should therefore be viewed neither as a novelty nor as a technology capable of magically understanding everything happening inside a building. It is an emerging platform whose value will depend on the quality of the applications, algorithms and business models constructed around it.
Important disclaimer: Wi-Fi sensing has as yet not generated mass-market revenues for any of the vendors or end users – such as service providers or enterprises. We believe that this will change in time although the industry in general has yet to experience a major commercial breakthrough. Wi-Fi sensing as a technology has been around for about a decade.
Coming in Part 2: How Wi-Fi sensing works in more detail—including CSI, OFDM, MIMO, multipath, sensing architectures and what IEEE 802.11bf actually standardises.