Setting up a Wi-Fi Sensing system can transform a home into a seamlessly connected environment, but achieving accurate and reliable motion detection requires optimal coverage. By designing the network to meet a space’s unique factors from the start, you can ensure enhanced performance and user satisfaction.
The blog below will cover considerations for setting up an optimized Wi-Fi Sensing network.
Wi-Fi Coverage and Its Impact on Building Materials
When setting up a Wi-Fi Sensing system, it is crucial to consider the construction materials of the house due to their significant impact on electromagnetic wave propagation, or, in other words, how Wi-Fi signals travel through the air and other materials. Different construction materials affect the weakening (attenuation) of EM waves, which varies with frequency.
Studies by the Wireless Broadband Alliance (WBA) show that lower frequency waves, like 2 GHz, experience less attenuation than higher frequencies like 5 GHz or 6 GHz. This means 2.4 GHz Wi-Fi signals penetrate walls and obstacles better, providing better coverage in buildings with thick or dense materials. Higher frequency signals (5 GHz and 6 GHz) offer faster speeds but have a shorter range and are more easily weakened by obstacles. For a more in-depth study on Wi-Fi attenuation, read the WBA’s Wi-Fi Sensing Deployment Guideline whitepaper.
In North American homes, drywall and plywood, which are commonly used for walls and floors, can cause minimal signal weakening, whereas European homes, which commonly employ masonry blocks, experience higher attenuation. Modern single-family dwellings typically have materials like wood and drywall that support better signal propagation, although high-attenuation materials like concrete or brick and obstacles like ducts can weaken Wi-Fi signals.
For precise motion detection using Wi-Fi Sensing, it is essential to ensure adequate coverage by considering the impact of different building environments on Wi-Fi signal reception.
Device Selection
Choosing motion sensors that are stable, fixed, and powered by a fixed AC source offers the most reliable Wi-Fi Sensing systems. Stationary (fixed) devices maintain a constant sensing environment by remaining in one place, ensuring consistent and reliable data patterns. On the other hand, stability refers to a device’s ability to maintain a steady Wi-Fi connection, enabling accurate readings through consistent reference points for precise measurements of motion or environmental changes. If a chosen device cannot maintain its Wi-Fi connection reliably, this may inadvertently introduce variables into the sensing system, potentially compromising data accuracy.
Mobile devices like smartphones and laptops are not ideal as motion sensors for Wi-Fi Sensing due to their mobility, which introduces variability and inconsistencies in data collection. Their movement can cause signal strength and Wi-Fi connectivity to fluctuate, resulting in inaccurate readings and unreliable motion detection. This compromises Wi-Fi Sensing systems’ performance and reliability, leading to noise, false positives, and complications in data interpretation. Moreover, battery-operated devices may struggle to maintain continuous participation, further impacting data integrity and system performance.
For a smoother setup experience, it’s beneficial to explore using device fingerprinting (a method that helps identify the device). This way, only devices that are stable, fixed, and suitable for motion are presented to the end user, ensuring a seamless experience.
Device Location
Each environment where Wi-Fi Sensing is deployed is unique, requiring specific considerations during initial setup. Key factors include the physical space, technical Wi-Fi network details, available connected devices, and the end user’s desired functionality. Here are some general guidelines for device location:
1. Detection Areas and Zones
Position devices strategically in detection areas and zones to cover key points of interest based on expected motion or patterns, considering that high-traffic spaces like entryways and living rooms are common. In other words, setup should prioritize the rooms that are most critical for the end user to monitor. As well, it is important to be able to generally visualize the Wi-Fi Sensing coverage pattern, which typically resembles an ellipse shape. With this shape in mind, it can be easier to ensure that key areas are within the effective sensing range for accurate data collection and motion detection.
2. Access Point Location
Wi-Fi Sensing operates through the existing network’s signals, making signal strength and coverage vital for an optimized sensing network. Keep in mind that the placement of the access point (AP) not only affects connectivity but also impacts Wi-Fi Sensing coverage, potentially conflicting with areas where motion detection is needed.
3. Minimize Traditional Obstacles to Coverage
It’s important to keep in mind that unlike other traditional motion detection equipment, Wi-Fi Sensing can penetrate both walls and ceilings, allowing fuller coverage of a space. However, signal penetration varies based on barrier materials and thickness; for instance, drywall allows better penetration than concrete or metal. Consider that where you place devices on separate floors could cause signal interference.
Regular Assessment and Adjustment
Regularly assessing and testing Wi-Fi Sensing coverage is crucial for maintaining optimal performance and accuracy. Over time, changes in the environment, such as new furniture, electronic devices, or structural modifications, can affect signal strength and coverage patterns. By periodically evaluating the system, you can identify and address any weak spots or interferences, ensuring reliable motion detection and data collection. Adjusting device placement and settings as needed helps maintain consistent coverage, enhances the user experience, and maximizes the effectiveness of the Wi-Fi Sensing network.
For detailed recommendations on optimizing Wi-Fi Sensing coverage, download our comprehensive Wi-Fi Sensing Coverage whitepaper below.
Download and read the full White Paper here