Simplifying Backscatter Deployment: Full-Duplex LoRa Backscatter

Authors: 

Mohamad Katanbaf, Jeeva Wireless and University of Washington; Anthony Weinand and Vamsi Talla, Jeeva Wireless

Abstract: 

Due to the practical challenges in the deployment of existing half-duplex systems, the promise of ubiquitous backscatter connectivity has eluded us. To address this, we design the first long-range full-duplex LoRa backscatter reader. We leverage existing LoRa chipsets as transceivers and use a microcontroller in combination with inexpensive passive elements including a hybrid coupler, inductors, tunable capacitors, and resistors to achieve 78~dB of self-interference cancellation and build a low-cost, long-range, and small-form-factor Full-Duplex LoRa Backscatter reader.

We evaluate our system in various deployments and show that we can successfully communicate with a backscatter tag at distances of up to 300~ft in line of sight, and through obstacles, such as walls and cubicles, in a 4,000~ft^2 office area. We reconfigure our reader to conform to the size and power requirements of a smartphone, and demonstrate communication with a contact-lens-form-factor prototype device. Finally, we attach our reader to a drone and demonstrate backscatter sensing for precision agriculture with an instantaneous coverage of 7,850~ft^2.

NSDI '21 Open Access Sponsored by NetApp

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BibTeX
@inproceedings {262011,
author = {Mohamad Katanbaf and Anthony Weinand and Vamsi Talla},
title = {Simplifying Backscatter Deployment: Full-Duplex LoRa Backscatter},
booktitle = {18th {USENIX} Symposium on Networked Systems Design and Implementation ({NSDI} 21)},
year = {2021},
isbn = {978-1-939133-21-2},
pages = {955--972},
url = {https://www.usenix.org/conference/nsdi21/presentation/katanbaf},
publisher = {{USENIX} Association},
month = apr,
}

Presentation Video