ProCCA: Protective Clear Channel Assessment in IEEE 802.11 WLANs

In wireless local area network, all transmissions are preceded by clear channel assessment (CCA), which determines the availability of wireless medium. Ideally, CCA should enable concurrent transmissions, whenever possible, to improve network capacity via spatial reuse. However, current CCA method is inherently limited in exploiting spatial reuse. Only the received signal strength of an incoming frame is utilized for CCA, and hence, the feasibility of a concurrent transmission should be determined without the knowledge of the frame's transmitter, the corresponding receiver, etc. In this letter, we propose a novel CCA method which utilizes additional information delivered in the physical layer header to properly determine the feasibility of concurrent transmissions. Simulation results show that the proposed method increases network throughput by up to 54% by promoting spatial reuse.