title: Laissez-Faire: Fully Asymmetric Backscatter Communication.
abstract: Backscatter provides dual-benefits of energy harvesting and low-power communication, making it attractive to a broad class of wireless sensors. But the design of a protocol that enables extremely power-efficient radios for harvesting-based sensors as well as high-rate data transfer for data-rich sensors presents a conundrum. In this paper, we present a newfully asymmetricbackscatter communication protocol where nodes blindly transmit data as and when they sense. This model enables fully flexible node designs, from extraordinarily power-efficient backscatter radios that consume barely a few micro-watts to high-throughput radios that can stream at hundreds of Kbps while consuming a paltry tens of micro-watts. The challenge, however, lies in decoding concurrent streams at the reader, which we achieve using a novel combination of time-domain separation of interleaved signal edges, and phase-domain separation of colliding transmissions. We provide an implementation of our protocol, LF-Backscatter, and show that it can achieve an order of magnitude or more improvement in throughput, latency and power over state-of-art alternatives.
authors.affiliation: College of Information and Computer Sciences University of Massachusetts, Amherst, MA 01003.
authors.forename: Pan
authors.initials: P
authors.lastname: Hu
authors.affiliation: College of Information and Computer Sciences University of Massachusetts, Amherst, MA 01003.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Zhang
authors.affiliation: College of Information and Computer Sciences University of Massachusetts, Amherst, MA 01003.
authors.forename: Deepak
authors.initials: D
authors.lastname: Ganesan
keywords: Architecture; Backscatter; Wireless