Physical-Layer Cross-Technology Communication (PHY-CTC), which achieves direct communication among heterogeneous technologies, brings great opportunities to help diverse IoT devices achieve harmonious coexistence through explicit coordination. The core technique of PHY-CTC is signal emulation which utilizes the signal of one technology (e.g., WiFi) to emulate the signal of another technology (e.g., ZigBee). The signal emulation based approach, however, inevitably introduces emulation errors which further lead to unreliable communication. In this paper, we aim to recover the intrinsic emulation errors and establish reliable PHY-CTC. We propose TwinBee which (i) explores chip-level error patterns and (ii) corrects emulation errors with symbol-level chip-combining coding/decoding and soft mapping. To achieve this, TwinBee dose not require accessing chip information as well as making hardware changes. We implement TwinBee on commodity devices (i.e., Laptops with Atheros AR2425 WiFi card and TelosB motes) and the USRPN210 platform (for physical layer evaluation). Experiment results show that TwinBee significantly improves the Packet Reception Ratio (PRR) of PHY-CTC from 50%-60% to more than 99%. Furthermore, we demonstrate the reliability of TwinBee in a data dissemination application over a network of 20 TelosB nodes, achieving over $42\times $ reduction of data dissemination delay compared to the state-of-the-art.
- Reliable communication
- cross technology communication