Internet of Things Think Tank Organized and released
Introduction
Since 1997, Wi-Fi has been constantly developing, and its speed, coverage and overall performance have been continuously improving. In the perception of most people, Wi-Fi is only used to connect to wireless networks, but Wi-Fi, as an electromagnetic wave signal, can actually be used to reflect the activity of objects.
Nowadays, many consumer electronic devices already have proximity sensing based on Bluetooth signal detection, and can unlock paired mobile phones and computers through smart watch . Previously, the article in the think tank "Is it still talking about identification?" Based on RFID , the positioning, tracking and perception are the future. In 》, it has also analyzed that passive RFID is developing from recognition to perception. These changes indicate that new demands and trends have emerged, and more wireless communication technologies will also join this ranks to continuously improve the user experience.
Recently, Intel has shown the Wi-Fi Proximity Sensing (Wi-Fi Close-Awareness) technology that allows computers to standby intelligently. When the user walks to the computer, the computer will automatically light up the screen, and the desktop or lock screen interface will appear. When the user leaves for 30 seconds, the computer will shut down the screen and go to sleep.
Currently, this technology is only available on Intel 13th Generation Core platform and includes the standard Intel Wi-Fi network interface chip. After that, Intel will soon launch drivers that enable this technology, and most devices using the processor will be able to support this feature. In addition, the Wi-Fi network interface deeply integrated on the processor requires additional communication from the operating system to activate, but it should be difficult for too old processors to implement this feature.
Intel did not disclose whether the feature would detect only humans and whether pets would be detected. Or, if you often leave your computer for a long time while playing games, it may not be suitable to enable this feature. Anyway, this feature is free after all, which reduces the power consumed by the system.
Reconstructs the existing functions of Wi-Fi
Although in the field of wireless communication , many technologies can be used to complete perceptual functions, such as Bluetooth and RFID, in comparison, Wi-Fi is still very attractive.
Currently, Wi-Fi is deployed in almost all indoor scenarios, and is applied to perception. It only needs to be updated at the technical level and integrated with new technologies such as artificial intelligence . It can reuse the existing Wi-Fi function to realize next-generation perception applications in various fields such as security, remote services, and automation. The additional cost investment is very low, and no special equipment, sensors, etc. is required. The principle of using Wi-Fi for perception is that when electromagnetic waves pass through different objects, their reflection and refraction characteristics are different, such as phase, signal attenuation, etc., that is, CSI (channel state information) is different. If different CSIs are analyzed and distinguished, different spatial characteristics and motion conditions can be described. uses the concept of Fresnel region in optics, and takes into account the reflection characteristics of electromagnetic waves and the frequency diversity of WiFi signals. After the combination of several theories, the model can capture tiny movements at the subwavelength level of the human body, so that the WiFi signal can be used to sense the behavioral changes at the millimeter level of the human body, such as: human movement, elderly falls, pet movements, etc. Compared with traditional camera video surveillance, Wi-Fi perception can achieve better privacy protection, more comprehensive space coverage, and will not increase the hardware overhead of Wi-Fi itself.
Take Aerial Technologies as an example. Through close cooperation with Onsemite Semiconductor , Aerial integrates AI detection and Wi-Fi and uses existing networks to provide solutions for various applications and services. When an object moves in space, it will interfere with the transmission of WiFi signals. By analyzing these interferences using models, Aerial can perceive, identify, classify various movements and give them meanings.
As we all know, artificial intelligence is the key to a future-oriented platform and can be used to improve people's lives.After using artificial intelligence technology, the robustness and adaptability of Wi-Fi-aware applications can be more effectively guaranteed. These AI models will also learn user habits and behavior patterns in various environments, thereby providing users with customized services.
In addition, is similar to other technological evolution routes, and ongoing standardization work can also further improve the development of technology, thereby facilitating the next generation of Wi-Fi-aware applications. , for example, Aerial Technologies, as a member of the IEEE WiFi Perception Group 802.11 bf and the Wireless Broadband Alliance, is committed to industry standardization to promote the standardization of Wi-Fi-aware CSI, which is conducive to shortening the development speed of many perception applications.
new standard helps Wi-Fi sensing
As early as 2019, the mesh routing launched by Linksys already supported motion detection functions, and since then, companies such as Plume and Origun Wireless have also launched similar products with basic perception functions. However, the perception functions of these products are achieved through their respective software and hardware rather than standards. There is no interoperability between products of different companies, and it is difficult to form economies of scale in the long run.
Against this background, the new WiFi standard 802.11 bf, which is being planned by the IEEE 802.11 team, is developed by the WiFi Alliance and the IEEE 802.11 team, aiming to transform wireless devices into sensors, collect data about people and objects by calculating the interference and reflections of signals caused by people and objects in physical space. The existing Wi-Fi devices will become part of the use of determining the location and network interaction of people and objects in a specific area. At present, 802.11 bf is still in the proposal stage, and the formation of formal standards may be until 2024, and the launch of new products may be until 2025.
Specifically, the 802.11 bf standard protocol consists of two parts: first, the signal will be blocked when the object moves in space. The device can use the spatial changes in signal intensity to determine whether an object is moving, and the low-frequency electromagnetic waves of 1GHz to 7.125GHz can sense the motion in space; secondly, high-frequency electronic waves above 45GHz are used to sense the distance of motion. Once the is formulated in the 802.11 bf standard, future motion perception will become a standard function. Routers and other products will be able to use the fluctuations of Wi-Fi signals to sense motion. There is no need for consumers to purchase additional sensors. Network devices of different brands can also form networks with each other to form a larger detection range, and wireless networks will also play a greater role. For example, future Wi-Fi will be used for fall detection, and if a fall is detected, an alarm will be automatically issued. can even be used to monitor the respiratory rate, because normal breathing of a person will also change the radio frequency characteristics of .
Of course, this protocol also faces many challenges. The most typical one is that the 802.11 bf protocol requires higher bandwidth to support it. This requires the widespread use of protocols such as Wi-Fi 6. However, so far, Wi-Fi 6 released in 2019 can be considered basically popular. Most routers used in companies and homes already support Wi-Fi 6. With Gigabit optical broadband, the premise of Wi-Fi perception is basically available. In addition, the 802.11 bf protocol must ensure that routers and other devices support perception functions while not affecting normal network usage. After all, the most important requirement for Wi-Fi is network speed and quality.
For areas with poor WiFi coverage, more nodes can be deployed to form a mesh sensing network, and grid nodes now support higher-order MIMO, which is also beneficial to improve perception robustness. Additionally, the 4x4, 5x5, 8x8 MIMO-based solutions used in routers or gateways can help overcome noise and obstacles that affect Wi-Fi to provide maximum coverage.
Wi-Fi perception can also be broad-minded
Based on the backscattering mechanism and the multipath effect of in the transmission environment, the energy absorption of interfering with the object, and other factors. RFID system can perceive the specified object based on the dynamic characteristics of the environmental factors carried in the tag reflected signal, such as limb behavior recognition, breathing and heartbeat monitoring. Similarly, when deploying WiFi signal transmitters and receivers at home, you can perceive the continuous behavior of people, which avoids privacy-related troubles compared to using a camera.
Not only that, smart homes no longer require manual or voice control. For example, air conditioners can control the number and location of the room perceived through Wi-Fi, and control the wind speed, intensity, direction, etc. in real time to achieve a more senseless user experience. The perception functions and sensorless monitoring of can also be applied to more scenarios, such as motion detection, gait recognition, diet management, vital sign monitoring, location tracking, etc., and home WiFi can also achieve 24-hour all-weather monitoring without additional sensor deployment.
Just like the development of many technologies, the reality of the future comes mostly from the past imagination. I believe that these Wi-Fi-aware applications will also become widely used basic functions, allowing users to get a better user experience without feeling.
Reference:
October 10 Online live broadcast
Internet of Things Intelligent Wind Power Industry Digital Upgrade
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-