LoRa Backscatter: Enabling The Vision of Ubiquitous Connectivity

Abstract

† Co-primary Student Authors e vision of embedding connectivity into billions of everyday objects runs into the reality of existing communication technologies -there is no existing wireless technology that can provide reliable and long-range communication at tens of microwa s of power as well as cost less than a dime. While backsca er is low-power and low-cost, it is known to be limited to short ranges. is paper overturns this conventional wisdom about backsca er and presents the rst wide-area backsca er system. Our design can successfully backsca er from any location between an RF source and receiver, separated by 475 m, while being compatible with commodity LoRa hardware. Further, when our backsca er device is co-located with the RF source, the receiver can be as far as 2.8 km away. We deploy our system in a 4,800 f t 2 (446 m 2 ) house spread across three oors, a 13,024 f t 2 (1210 m 2 ) o ce area covering 41 rooms, as well as a one-acre (4046 m 2 ) vegetable farm and show that we can achieve reliable coverage, using only a single RF source and receiver. We also build a contact lens prototype as well as a exible epidermal patch device a ached to the human skin. We show that these devices can reliably backsca er data across a 3,328 f t 2 (309 m 2 ) room. Finally, we present a design sketch of a LoRa backsca er IC that shows that it costs less than a dime at scale and consumes only 9.25 µW of power, which is more than 1000x lower power than LoRa radio chipsets.CCS Concepts: •Hardware →Communication hardware, interfaces and storage; •Human-centered computing →Ubiquitous and mobile computing;

Nephalai: Towards LPWAN C-RAN with Physical Layer Compression

“…As an extra benefit of C-RAN, the opportunity to increase the battery life for end devices is provided. Some other approaches such as optimal frequency selection [13] and backscatter [34] have been proposed, while our approach is based on spatial diversity gains. Similar to the architecture of cellular networks [8], multiple LoRaWAN gateways are commonly deployed to provide wide-area network coverage.…”