Abstract:
WiFi backscatter communication has required unwanted constraints on either excitations or receivers since its inception eight years ago. We present Chameleon, the first native WiFi backscatter system where WiFi tags can generate native WiFi packets using uncontrolled productive WiFi as carriers. Our tag-only solution requires no particular excitation patterns and no change for software/hardware on WiFi NICs. The key insight is that the Chameleon tag can demodulate productive WiFi and backscatter this arbitrary carrier into a full-function packet using on-the-fly modulation. We prototype WiFi tags using ultra-low-power FPGAs and evaluate them in real-world scenarios where excitations are ambient traffic and backscatter receivers are a range of COTS NICs. Comprehensive field studies show that the maximal backscatter throughput of Chameleon is almost 1 Mbps, which is over 1000× and 100000× better than FS-Backscatter and WiFi-Backscatter. Also, we show that Chameleon can natively communicate with various COTS WiFi devices on Windows, iOS, and Android platforms. We believe this native WiFi backscatter design will enable ubiquitous WiFi connectivity for billions of IoT devices via widely available mobile gadgets and existing wireless infrastructure.
Authors:
Longzhi Yuan，Wei Gong.
Publication:
ACM MobiSys(CCF-B)
Keywords:
Backscatter communication, WiFi, Internet of things
