Achieving Receiver-Side Cross-Technology Communication with Cross-Decoding

Abstract

Cross-technology Communication (CTC) is a key technique to explore the full capacity of heterogeneous wireless. The latest CTC designs explore the PHY-layer to reach the standards' maximum rate, but leaving a critical gap to practicality -- existing PHY-layer CTCs are commonly transmitter-side techniques requiring a high-end transmitter (with a high degree of freedom in signal manipulation) to emulate the receiver signal closely. This inherently limits the reverse direction (low-end to high-end) communication. We present XBee, a unique receiver-side CTC that fills in the gap and makes a critical step towards achieving CTC bidirectionality. XBee is demonstrated as a ZigBee to BLE communication, where the key innovation lies in the unique mechanism of cross-technology decoding, or cross-decoding in short, which interprets a ZigBee frame only by carefully observing the bit patterns obtained at the BLE receiver. Technically, XBee counterintuitively explores the sampling offset to overcome the intrinsic challenge due to BLE's narrower bandwidth (1MHz) than ZigBee (2MHz). Extensive implementation and evaluation on USRP and commodity devices reach 250 kbps under 85% reliability, a 15,000x improvement over state-of-the-art ZigBee to BLE communication, and comparable with the latest PHY-layer CTCs to achieve CTC bidirectionality.