Zero-Effort Proximity Detection with ZigBee

This letter presents ZIP (zero-effort ZIgBee Proximity detection), a novel technique to detect the proximity of two Internet-of-Things devices. Based on the ZigBee technology, ZIP embodies the first zero-effort solution by differing from existing ones that resort to the use of tailor-made hardware, multiple antenna installments, the employment of a third-party device, or user involvement. At the heart of ZIP is the construction of a feature-designated decision tree built on received signal strength. An ensemble prediction method is further designed to aggregate the outputs of multiple decision trees for detection accuracy improvement. Practical experiments are conducted to show the reliability and robustness of ZIP.