Skip-Correlation for Multi-Power Wireless Carrier Sensing

USENIX NSDI |

Carrier sensing is a key mechanism that enables decentralized sharing
of unlicensed spectrum. However, carrier sensing in its current form
is fundamentally unsuitable when devices transmit at different power
levels, a scenario increasingly common given the diversity of Wi-Fi
APs in the market and the need for Wi-Fi’s co-existence with new
upcoming standards such as LAA/LWA.  The primary contribution of this
paper is a novel carrier sensing mechanism — skip correlation — that
extends carrier sensing to accommodate multiple transmit power levels.
Through an FPGA based implementation on the WARP platform, we
demonstrate the effectiveness of our technique in a variety of
scenarios including support for backward compatibility.