A simple full-duplex MAC protocol exploiting asymmetric traffic loads in WiFi systems

The pressing need to accommodate increasing wireless traffic demands coupled with exhausting many advancements in Modulation and Coding Schemes (MCS) requires alternative techniques. Full-Duplex (FD) communications can be a potential candidate since channel capacity is theoretically doubled by employing Simultaneous Transmission and Reception (STR) over a single channel. In this paper, we adopt a simple FD-MAC protocol to IEEE 802.11 Distributed Coordination Function (DCF) in order to improve the aggregate goodput of a typical WiFi system. Furthermore, we look at the concept of FD communications from an unconventional perspective to propose a mechanism that increases the symmetry between uplink (UL) and downlink (DL) traffic loads while preventing complete node starvation. Simulation results show an increase in the aggregate goodput of the system due to increasing UL/DL traffic symmetry. While the simple FD-MAC protocol alone improves the aggregate goodput by an average increase of ∼85% compared to standard IEEE 802.11 DCF, introducing our proposed scheme in the system improves the aggregate goodput by an additional average factor of up to ∼20%.