RCTC: Rateless Cross-technology Communication

Abstract

Cross-Technology Communication (CTC) is an emerging technique that enables the direct communication across incompatible wireless technologies. Without modifying any hardware, CTC establishes mutually sensible side channel by manipulating the packet transmissions and encodes information by constructing transmission patterns in terms of signal strength, packet interval, and etc. However, the transmission patterns are prone to the coexisting interference, leading to the unreliability of CTC. Most of the existing methods deal with the reliability problem by reactive retransmission of the corrupted packets, which incurs large delay. In this paper, we propose RCTC, a rateless-coding based CTC that proactively copes with the unreliability. Since the computation ability of low-power ZigBee nodes is limited, we carefully design the coding combination with proper degree distribution to balance the trade-off between reliability and decoding latency. We also propose a coding adaptation algorithm to adapt to the channel dynamics. We implement a prototype on commercial WiFi and ZigBee platforms. The experiment results show that RCTC can reduce the BER by up to 92.6%, compared to existing CTC methods.