On the Buffer Occupancy of an IEEE 802.11 Station in a Hot-Spot

In this paper we evaluate analytically the average occupancy of the transmission buffer of a 802.11 station (STA). The station belongs to a Wi-Fi Hot-Spot and exchanges data with a fixed host. The data exchange is regulated by the Transmission Control Protocol (TCP). The research interest is motivated by the fact that several papers assume that in these conditions the STA buffer is nearly empty. On the contrary, we prove that this assumption may be wrong and discuss the consequences of this fact. We test the proposed model by means of ns2 simulation, ascertain its accuracy, and highlight its limits.