The paper “Efficient Two-Way Edge Backscatter with Commodity Bluetooth” was published at the IEEE INFOCOM 2024 conference. This work introduces EffBlue, an efficient two-way backscatter system design for commercial Bluetooth devices.
As a passive communication technology, backscatter technology has extremely low power consumption and provides a foundation for the large-scale passive Internet of Things. Two-way backscatter is essential to general-purpose backscatter communication as it provides rich interaction to support diverse applications on commercial devices. However, existing Bluetooth backscatter systems suffer from unstable uplinks due to poor carrier-identification capability and inefficient downlinks caused by packet-length modulation.
Figure：EffBlue overview
EffBlue employs a simple edge backscatter server that alleviates the computational burden on the tag and helps build efficient uplinks and downlinks. Specifically, efficient uplinks are designed by introducing an accurate synchronization scheme, which can effectively eliminate the use of non-compliant packets as carriers. To break the limitation of packet-level modulation, we design a new symbol-level WiFi-ASK downlink where the edge sends ASK-like WiFi signals and the tag can decode such signals using a simple envelope detector. Experimental results show that EffBlue can identify the target excitations with more than 99% precision. Meanwhile, its WiFi-ASK downlink can achieve up to 124 kbps, which is 25x better than traditional FreeRider.
The study was jointly completed by researchers Maoran Jiang, Xin Liu, Dong Li, and Wei Gong from the University of Science and Technology of China, Ohio State University, and Macau University of Science and Technology. Maoran Jiang is a doctoral candidate at the School of Computer Science and Technology at the University of Science and Technology of China, and Wei Gong is a professor at the School of Computer Science and Technology at the University of Science and Technology of China and the corresponding author of this paper, who led this work. This research was supported by the National Natural Science Foundation of China (NSFC) projects (No. 61932017 and 61971390), and hardware services were provided by the Information Laboratory Center of the University of Science and Technology of China.