Enabling bit-by-bit backscatter communication in severe energy harvesting environments

Micro-powered wireless sensors present new challenges due to the severe harvesting conditions under which they need to op-erate and their tiny energy reservoirs. However, existing low-power network stacks make a slew of design choices that limit the ability to scale down to such environments. We address these issues with QuarkNet, a backscatter-based network stack that is designed to enable continuous communication even if there is only enough harvested energy to transmit a few bits at a time while simultaneously optimizing throughput across a network of micro-powered devices. We design and imple-ment QuarkNet on a software radio based RFID reader and the UMass Moo platform, and show that QuarkNet increases the communication distance by 3.5 × over Dewdrop, 9 × over Buzz, and is within 96 % of the upper bound of achievable range. QuarkNet also improves the communication through-put by 10.5 × over EPC Gen 2, 5.8 × over Dewdrop, and 3.3× over Flit for tag-to-reader communication and by 1.5 × over EPC Gen 2 for reader-to-tag communication. 1