WibZig: Reliable and Commodity-device Compatible PHY-CTC via Chip Emulation in Phase

Physical layer cross-technology communication (PHY-CTC) opens new horizons for spectrum utilization and wireless cooperation in the crowded ISM band. Current PHY-CTC technologies can be divided into two categories: one aims for high communication reliability, but sacrifices compatibility with commodity devices and the other maintains compatibility but suffers dramatically limited reliability. The latter mainly leverages the WiFi OFDM signal to emulate the ZigBee signal, while the Cyclic Prefix (CP) in OFDM brings inevitable signal disturbance and errors. To address these issues, we present WibZig, the first WiFi-To-ZigBee PHY-CTC technology that achieves high reliability and is fully compatible with commodity devices. By carefully selecting a cluster of CCK codewords that exhibit similar phase characteristics to ZigBee chips, we can emulate any given ZigBee symbol with great accuracy. In addition, WibZig adaptively controls the first CCK codeword of each cluster to eliminate inter-cluster phase discontinuity when emulating a ZigBee packet with multiple clusters. WibZig requires no hardware modification and is compatible with most commodity devices. We implement WibZig on both USRP and commercial devices and conduct extensive evaluations under various settings, which demonstrate a 15x improvement in reliability and a 7x increase in range compared to the latest PHY-CTC work.