A new load equation for 802.11 MAC performance evaluation under non-saturated conditions

IEEE-802.11-based WLAN MAC performance evaluation is of great importance, especially under non-saturated conditions. A new load equation, respect to the non-saturation, is proposed for analysis of the MAC mechanism in this paper. The load equation together with a backoff equation and a transmission equation are sufficient to analyze the MAC performance under non-saturated conditions. In the new load equation, both traffic arrival and first order buffer memory are considered. In addition, a lower bound derived from the new load equation is found if traffic arrival obeys Poisson distribution. From NS2 simulation results, it is shown that the load equation using the bound outperforms the one only considering traffic arrival significantly, especially as the offered traffic load at each station is moderate.