Saturation throughput analysis of an asymmetric full-duplex MAC protocol in WLANs with hidden terminals

The wireless in-band full-duplex technique enables wireless nodes to transmit and receive in the same channel simultaneously. To fully and effectively leverage this capability of the IBFD technique, new full-duplex medium access control (FD MAC) protocols that accommodate the features of the IBFD technique must be designed and analyzed. In this paper, we first propose an asymmetric FD MAC protocol, and then we develop an analytical model for the proposed protocol to evaluate the saturation throughput performance of wireless local area networks in the presence of hidden terminals. In the proposed protocol, asymmetric full-duplex transmissions can be established with the access point (AP) and two stations that hidden from each other. Thus, the well-known interstation interference problem in asymmetric full-duplex transmissions can be overcome. In the developed model, we adopt the stationary distribution of the backoff counter values at the beginning of a generic transmission to characterize the behavior of a node. The saturation throughput is then derived based on the stationary distribution. The accuracy of the proposed analytical model is verified through simulations. Using the proposed analytical model, the saturation throughput performance of the FD MAC protocols is studied with respect to different numbers of stations in each region and the minimum contention windows. In addition, the effects of hidden terminals on performance are thoroughly investigated, since the hidden terminals play an important role in the saturation throughput. Moreover, we compare the saturation throughput performance between symmetric and asymmetric FD MAC protocols to demonstrate the gains provided by asymmetric full-duplex transmissions.