A few days ago, the think tank released “June 1 onwards! Japan mandatory microchip implantation for dogs and cats, “animal networking” first” in the article, once mentioned in the domestic and foreign pets implanted in the chip are applied to the radio frequency identification technology (Radio Frequency Identification, RFID), that is, we often say that the electronic tags. After years of development, RFID has been everywhere in daily logistics, access control, retail and other scenes. In the wisdom of the second party – Internet of Things think tank a few days ago organized by the [wind – “passive” win “active” – perception of passive – intelligent far away] theme of the live event, the Shanghai Jiaotong University RFID and the Internet of Things Institute Director, Dr. Wang Dong, Ph.D. tutor, Shanghai Jiao Tong University RFID and the Internet of Things Institute of postdoctoral Zhang Qian, but also more in-depth for us to bring the latest achievements of RFID related to the introduction.
Since 2003, when Walmart announced the use of UHF RFID technology to track goods, in the subsequent close to 20 years of development time, with a reader, RFID tags have been in the fragmentation of the long tail of the market has been used in large quantities. In the initial nearly 10 years of time, the main development direction of RFID is recognition, that is, to obtain the tag EPC, so that the reader reads farther away, read faster, such as in the supply chain of each link through RFID technology to achieve the physical flow of information quickly and automatically identify, and then realize the entire supply chain visualization, to support the supervision-oriented, enterprise product traceability, consumer goods anti-counterfeiting and other application scenarios Demand.
From 2013 to the present, passive RFID technology for perception has become a new development direction. RFID reader can provide RFID tag ID information, but also provide the tag to return the signal strength value (RSSI), phase value (Phase) and Doppler frequency (Doppler Frequency) and other parameters, the use of these parameters can be realized. RFID-based centimeter-level accurate positioning, tracking, movement and behavior perception, etc., greatly expanding the scope and level of RFID applications, so that RFID technology from identification to perception.
1.From passive perception to ubiquitous perception
As an emerging technology in recent years, passive perception has gradually become the core support technology in the field of ubiquitous perception computing with its unique perception mechanism and method.
Compared with traditional active sensing, passive sensing mainly relies on the energy obtained from the environment to complete the computation, sensing and communication, and does not require a continuous power supply to the terminal nodes, so it has potential advantages in terms of endurance, deployment, maintenance, etc., which are unmatched by traditional active sensing. However, most of the passive sensing technologies are only based on unlabeled reflective signals for sensing, which cannot distinguish the specific sources of multiple reflective signals, nor can they effectively differentiate between the simultaneous existence of multiple sensing objects, resulting in the application scope is limited.
Among the many sensing technologies, RFID has become an important medium for passive sensing due to its lightweight, taggable and easy-to-deploy features, etc. The emergence of RFID not only provides the ability of “identification” of objects, but also realizes “taggable” passive sensing. The emergence of RFID not only provides the ability to “identify” items, but also provides new opportunities for realizing “taggable” passive sensing.
Based on the backscattering (backscatter) mechanism, the RFID system realizes the communication between the reader and the tag. In the process of backscattering, the reader antenna transmits a continuous wave signal modulated and reflected by the RFID tag, thus enabling the reader to effectively identify the tag signal.
Since the RFID tag backscattered signal itself is very weak, and at the same time, it is easily interfered by various environmental factors, including the multipath effect in the transmission environment, the energy absorption of the interfering object, and so on. Therefore, the information containing environmental factors will be naturally included in the backscattered signal of RFID tag. At the same time, the identifiable characteristics of RFID can effectively distinguish the source of the backscattered signal, thus ensuring the passive sensing mechanism of “taggability”. The use of backscatter communication mechanism of environment-sensitive features, RFID systems can be based on the tag reflected signal carried in the dynamic characteristics of environmental factors on the designated object for perception, such as physical behavior recognition, breathing and heartbeat monitoring, etc., and these characteristics are RFID technology can be realized by the “recognition” to the “perception”. The fundamental reason for the metamorphosis of “perception”.
2.RFID brings a new way of interaction
In 1991, Mark Visser put forward the concept of “Ubiquitous Computing” (pervasive computing), since then, people have been committed to realizing a wide range of “human-machine-object” interconnection, hoping to provide services and interact in the most natural way, and emphasizing the concept of computing and environmental integration, so that computing devices disappear from people’s sight. Since then, there have been efforts to realize a wide range of “human-machine-thing” interconnections, hoping to provide services and interactions in the most natural way, and emphasizing the concept of computing that is integrated with the environment, so that computing devices disappear from people’s sight. Pervasive computing itself is a topic involving a wide range of research, including the integration of distributed computing, mobile computing, human-computer interaction, artificial intelligence, embedded systems, perceptual networks, and information fusion and other technologies. Under the paradigm of pervasive computing and the fusion of information space and physical space, computer computing is dying out, replaced by sensor networks, and people’s ultimate vision is to be able to access and process information at any time, in any place, and in any way.
In response, he and his team members envisioned three forms of computing devices:
- Tabs, measured in centimeters, similar to sticky notes
- Pads, measured in decimeters, like a piece of paper, a book or a magazine.
- Boards, measured in meters, like a chalkboard or bulletin board.
It is worth mentioning that he predicts that future items will contain a computer or label, people can easily get information about the items, which is coincident with the design of RFID tags.
The development of perceptual technologies such as RFID also brings the realization of pervasive computing one step closer.
If you often go to Uniqlo, that probably has experienced the store self-checkout function: no camera shots, just put the clothes in the designated location, can be recognized, this almost senseless experience behind the use of RFID.
But RFID can do more than that. Shanghai Jiao Tong University RFID and Internet of Things Institute of postdoctoral Zhang Qian in his speech, if the mall’s clothing attached to the RFID tag, then through the tag’s phase or signal strength information can be judged by the customer’s behavior and action.
As shown in the figure below, when the customer “remove” and “put back” clothes, the RFID tag on the clothes of the phase information will change dramatically, and when “looking” clothes, the tag’s phase will also change accordingly. When “looking over” the clothes, the phase of the tag will also change accordingly. Using this information, customer behavior can be sensed. Online user behavior data can be easily obtained by tracking the user’s web browsing, click records and product reviews, shopping cart information, purchase records, etc. Through RFID sensing technology, merchants can also obtain offline customer behavior data.
Figure: “Remove” the clothes when the RFID tag phase changes dramatically
In addition to the label on the clothes, RFID tags can also be deployed in the environment, the use of human behavioral actions generated by the multipath environmental changes to achieve non-contact sensing, and due to the easy deployment of tags, low-cost, passive characteristics, the actual scene can be deployed through the deployment of multiple tags composed of tag arrays to comprehensively perceive the multipath changes, for example, their team will be deployed in the RFID tag arrays and reader antennas were deployed on the two sides of the corridor, different people passing by due to different gait, body type, etc., will cause different signal changes. Corridor on both sides, different people pass by, due to gait, body type and other differences, will cause different signal changes, based on this change can be realized on the user’s identity recognition. The spatial diversity generated by multiple tags can also effectively mitigate the impact of different gait factors such as backpacks, etc., to achieve a more robust perception.
Fig. Contactless gait recognition based on RFID tag arrays
Flexible RFID tags can also be used to improve the experience of human-computer interaction. As the sales of VR/AR and other devices continue to grow, the next generation of smart terminals is likely to be none other than it, and traditional human-computer interaction methods and devices such as keyboards, mice, touch pads and so on are completely incapable of the interaction tasks of the next generation of terminals.
Researchers from Nanjing University, built the use of flexible RFID tags gesture micro-motion sensing system, the tags were attached to the glove’s five fingers, the use of RFID antennas on multiple tags for continuous scanning to collect backscattered signal characteristics, such as signal strength, phase, etc., which allows the user to use a limb or even finger somatosensory interaction, manipulation of the display screen or the air’s virtual objects! This allows users to use their limbs or even fingers for somatosensory interaction, manipulate the display or virtual objects in the air, and realize the precise perception of centimeter-precision “micro-gestures” to use the relevant applications in VR in a more natural way.
Figure: RFID-based gesture micro-motion sensing system
Further more, besides RFID radio frequency signals, wireless signals in space can be said to be ubiquitous, such as acoustic waves, millimeter waves, WIFI carriers, and so on. With the same or similar principles of RFID wireless sensing, these different wireless signals can also be used for sensing and interaction.
Impinj SHORTDIPOLE Monza R6 Chip Tags
3.Ubiquitous “Transparent” Computing
In fact, similar scenarios have entered every aspect of our lives.
In most people’s perception, the function of WiFi is only to connect to a wireless network, but WiFi, as an electromagnetic signal, can actually be used to reflect the activity of objects. Using the concept of the Fresnel zone in optics, and taking into account the reflective properties of electromagnetic waves and the frequency diversity of WiFi signals, a model that combines several theories can capture minute movements of the human body at the sub-wavelength level, making it possible to use WiFi signals to sense the millimeter-level behavior of the human body.
Therefore, when WiFi signal transmitters and receivers are deployed in the home, continuous human behaviors such as sleeping, breathing, falling, etc. can be sensed without any contact and additional cost. Privacy related concerns are also avoided as compared to the use of cameras.
Figure: WiFi sleep monitoring
Not only that, with the WiFi sensing function, some smart homes no longer need manual or voice control, such as air conditioning can be sensed through WiFi room number and location, real-time control of wind speed, intensity, direction and so on.
After this “brain hole” is opened, this similar sensorless monitoring can be applied to more scenes, such as: motion detection, gait recognition, diet management, vital signs monitoring, location tracking, etc., and home WiFi can also be done 24 hours a day, all-weather monitoring, but also do not have to deploy additional sensors.
In addition, sensorless monitoring can also be used in unexpected scenarios: the use of smart devices (cell phones, smartwatches, etc.) built-in speakers, so that the modulation and frequency set to produce inaudible acoustic signals (17KHz ~ 24KHz), and then use the device’s microphone to collect the acoustic signals reflected back from the environment, through the processing of signals can be sensed the changes in the surrounding environment, the shorter ultrasonic signals, the shorter ultrasonic signals, the shorter ultrasonic signals, the shorter ultrasonic signals, the shorter ultrasonic signals. The short wavelength of ultrasonic signal (about 2cm) makes it very suitable for fine-grained human-computer interaction action perception.
UHF RFID Integrated Reader Built in 9 dBi Antenna
For example, Shanghai Jiao Tong University RFID and Internet of Things Institute teacher Wang Dong’s team used ultrasonic perception to realize the end-to-end finger writing recognition and more fine-grained lip recognition, and they also through the ultrasonic lip perception signals to achieve multimodal voice enhancement, so that users in the cell phone to send voice messages or record voice notes with the help of ultrasonic perception technology can effectively filter out the noise in the surrounding environment. filter out the noise in the surrounding environment.
Figure: End-to-end ultrasound-based lip recognition.
4. Ubiquitous “Transparent” Computing
When pervasive computing was first proposed, many people thought it was nonsense. However, after years of development, computers have gone through centralized, distributed, embedded and other stages, the Internet of Things and artificial intelligence are also accompanied by a variety of terminals have been widely deployed and applied, and a variety of sensing and control devices, the rise of equipment, all of which makes pervasive computing gradually become possible.
If the theory of pervasive computing is to be put into practice, it is necessary to utilize various devices for ubiquitous sensing. In the past and present, the “presence” of various devices, such as computers and cell phones, has always been very strong, making the situation in which machines are supposed to serve people become a situation in which people are “kidnapped” by machines. In the future, only by combining basic theory and artificial intelligence in a more organic way can “senseless” perception become oxygen in the air, become human-centered, and automatically adapt to changes in user needs.
In addition, as a branch of pervasive computing, the continuous development of smart cities, smart buildings, smart homes, etc., will also make the “infinite perception” really become “ubiquitous”.
5.Conclusion
RFID-based localization, RFID tracking, and sensing represent the future of smart automation across industries. By enabling real-time asset visibility, contactless data collection, and seamless integration with IoT systems, RFID technology is transforming supply chains, retail, healthcare, and manufacturing. As advancements in UHF RFID, sensor-enabled tags, and AI-driven analytics continue to evolve, businesses can achieve unprecedented efficiency, accuracy, and cost savings. The potential for RFID extends beyond tracking—it paves the way for fully autonomous operations, predictive maintenance, and enhanced customer experiences. Companies adopting these solutions today will lead the next wave of digital innovation.
6. Frequently Asked Questions
6.1 How does RFID localization work compared to GPS or Bluetooth?
RFID localization uses radio waves to identify and track tags within a defined area (e.g., warehouse or retail store). Unlike GPS (for outdoor, wide-area tracking) or Bluetooth (short-range, ~10–100m), RFID excels in high-precision indoor RFID tracking (cm-to-m accuracy) and doesn’t require line-of-sight. Passive RFID tags are also battery-free, reducing maintenance costs.
6.2 What’s the difference between passive and active RFID for tracking?
- Passive RFID: No battery, activated by reader signals. Range: up to 10m (UHF). Used in inventory management (e.g., retail tags).
- Active RFID: Battery-powered, longer range (100m+), and continuous tracking. Ideal for high-value assets (e.g., medical equipment).
6.3 Can RFID sensors monitor temperature or humidity?
Yes! Sensor-enabled RFID tags (like Seiko’s solutions) integrate environmental sensors. For example:
- Healthcare: Track vaccine temperature in real-time
- Food Logistics: Monitor perishable goods’ humidity levels.
6.4 Which industries benefit most from RFID tracking?
- Retail: Smart shelves, anti-theft, and checkout-free stores (e.g., Amazon Go)
- Healthcare: Equipment tracking and patient safety (e.g., RFID wristbands).
- Manufacturing: Tool/asset tracking and workflow automation.
6.5 How do “smart shelves” use RFID?
Shelves with embedded RFID readers automatically:
- Detect item removal/restocking.
- Update inventory in real-time.
- Trigger reorders when stock is low.
6.6 What are RFID’s challenges in large factories?
- Metal interference: Can disrupt signals (solved with anti-metal tags).
- Scale costs: High initial investment (offset by long-term ROI).
- Integration: Requires IoT/ERP system compatibility.
6.7 Will RFID replace barcodes?
Not entirely. RFID is superior for real-time, bulk scanning (e.g., 100+ items at once), but barcodes remain cheaper for simple labeling. Hybrid solutions are common.
6.8 How does AI enhance RFID data?
AI analyzes RFID-generated data to:
- Predict equipment failures (predictive maintenance).
- Optimize warehouse routes (smart logistics).
- Detect anomalies (e.g., theft or spoilage).
6.9 Are there privacy risks with RFID?
Potential risks (e.g., unauthorized tracking) are mitigated by:
- Tag encryption (e.g., GDPR-compliant tags).
- Kill switches to deactivate consumer tags post-purchase.
6.10 How to choose an RFID solution?
Consider:
- Frequency (LF/HF/UHF) for your range needs.
- Tag type (passive/active/sensor-enabled).
- Integration with existing software (e.g., SAP).