Jiayi Zhang
Benefited by rapid evolutions of IEEE 802.11 standards for wireless local area networks (WLAN), Wi-Fi has been widely adopted for accessing data communication networks in both business and daily life for the last two decades. Billions of Wi-Fi devices have been globally deployed in various emerging applications, such as virtual/augmented reality, self-driving cars, smart homes/buildings, smart grids, smart manufacturing, smart agriculture, etc. These applications in the home, enterprise, or industrial environments may rely not only on the broadband internet but also on the internet of things and/or cyber-physical systems. The cyber-physical systems integrate the functionalities of communication, sensing, localization, computing, and control capabilities.
Wi-Fi modules/devices have unique advantages when they support integrated sensing and communication features in terms of relatively small physical size, lightweight, low cost, the flexibility of deployment and management. Naturally, the electromagnetic wave signals of Wi-Fi transceivers are capable of providing some physical information, such as signal strength and channel state information which can be utilized for sensing to detect the transmission distance and surrounding environment. Importantly, Wi-Fi signals of communication and sensing share the unlicensed spectrum, thus saving the licensed spectrum which has become increasingly crowded and pricey. Because of these advantages, Wi-Fi sensing has been attracting the attention of both academia and industry to push progress in research, standardization, development, and productization.
However, due to the original design of Wi-Fi, the performance metrics are oriented toward data communications. Straightforward implementations of the commercial off-the-shelf Wi-Fi chips/modules based on existing WLAN standards limit the potential to improve the performance of sensing. Fortunately, IEEE 802.11 working group for WLAN standards has initiated a new task group bf (TGbf) to devote to the standardization of WLAN sensing [1], which is well known as Wi-Fi sensing. As a technique, WLAN sensing leverages the received Wi-Fi radio signal by one or more stations with WLAN sensing capability to detect the feature(s) of an intended target(s) within a given surrounding environment. The features could be range, velocity, angular, motion, presence or proximity, and gesture, while the target could be an object, human, or animal. The environment refers to a room, house, vehicle, enterprise, etc. Some typical use cases include user tracking, motion detection, fall detection, activity recognition, gesture recognition, imaging, monitoring in home security, appliance control, healthcare, and in-car sensing applications.
The utilization of Wi-Fi sensing may depend on the use cases and environment. For wide coverage sounding measurement, Wi-Fi sensing can be operated in a sub-7 GHz signal supported by the IEEE 802.11n/ac/ax/be standards. In addition, Wi-Fi sensing can target dedicated coverage with sounding measurement which inherits the nature of radar. This feature, namely directional multi-Gigabit sensing, is operated in a 60 GHz signal by narrow beams supported by the IEEE 802.11ad/ay standard amendments.
Ofinno’s Next-Gen Wi-Fi team continues to drive research in WLAN standards to design cutting-edge technologies to provide efficient and reliable communication and sensing networks, along with other members of the IEEE 802.11 working group.
References
[1] Status of Project IEEE 802.11bf, https://www.ieee802.org/11/Reports/tgbf_update.htm
About the Author
At Ofinno, Jiayi focuses on the standards and technologies for the next-generation Wi-Fi systems. His research interests rely on the air interface algorithms/protocols designed for wireless standards, such as IEEE 802.11 and 3GPP LTE-Advanced/5G New Radio, etc.
Prior to joining Ofinno, he was a guest researcher/associate in radio access and propagation affiliated with the National Institute of Standards and Technology in Gaithersburg, MD, and before that a research scientist in wireless access with Alcatel-Lucent Bell Labs in Shanghai. Jiayi holds MSc and PhD in Electronics and Electrical Engineering both from the University of Southampton, England. He is a senior member of the IEEE and has served on the technical program committee of major IEEE ComSoc/VTS conferences and he also has been invited to review over 100 IET/IEEE journal paper submissions.
