Poster Abstract: Physical-layer Cross-Technology Communication with Narrow-Band Decoding

Recent advances on physical-layer Cross-Technology Communication (PHY-CTC) achieve high throughput direct communication across different wireless technologies, by emulating the standard waveform of the receiver. However, this signal emulation method faces the challenges of inherent unreliability due to the imperfect emulation. Therefore, it’s not suitable to achieve PHY-CTC from WiFi to BLE, since a BLE receiver can not tolerate any bit error in preamble checking when receiving a BLE frame. We present NBee, the first WiFi to BLE physical-level CTC. The key insight lies in Narrow-Band Decoding, i.e., 22MHz bandwidth WiFi (802.11b) signal can be correctly decoded at the BLE RF front-end with only 1MHz bandwidth, if the WiFi payload bits are selected by a specific pattern. More specifically, NBee leverages the unique signatures in the WiFi signal distorted by 1MHz Low Pass Filter (LPF) at BLE to extract information. Evaluation results on commodity BLE chips show NBee can achieve 1Mbps CTC with 95% packet reception rate (PRR), 3400x faster than the state-of-art CTC from WiFi to BLE.