DCF Performance Analysis of Open- and Closed-Loop Adaptive IEEE 802.11n Networks

This paper presents a MAC-PHY cross-layer semianalytical model allowing the goodput performance evaluation of open- and closed-loop link adaptive schemes in WLAN environments based on IEEE 802.11n. Without loss of generality, this paper considers the well-known open-loop automatic rate fallback (ARF) algorithm and a closed-loop fast link adaptation (FLA) algorithm based on exponential effective SNR mapping (EESM). In contrast to previous works, the channel conditions are not assumed to be ideal and users are allowed to use different transmission modes. Results are presented demonstrating the accuracy of the proposed model. Moreover, results serve to show the superiority of closed-loop over open-loop techniques, specially when the number of stations contending for the medium grows.