Cross-Layer Protocol Design for CSMA/CD in Full-Duplex WiFi Networks

The device in conventional half-duplex (HD) WiFi networks cannot perform carrier sensing while in data transmission, thus it suffers from long collision duration. To mitigate this problem, this letter presents a new WiFi cross-layer protocol design based on CSMA/CD, which facilitates simultaneous carrier sensing and data transmission by using the full-duplex (FD) technology. As the FD technology introduces the residual self-interference (RSI), we study two types of errors caused by the RSI against the FD-WiFi sensing (i.e., false alarm and miss detection). Meanwhile, we derive the normalized throughput when considering the sensing performance in the proposed FD-WiFi CSMA/CD protocol. Both analytical and simulated results show that sensing threshold should be properly designed to balance the two types of sensing errors, and our proposed cross-layer protocol can achieve significant throughput improvement.