—We analyze IEEE 802.16e medium access control (MAC) sublayer and provides a simple analytical model to compute the 802.16e MAC throughput. Our approach is to begin with a key approximation made by [1] in IEEE 802.11. This study leads to a fixed point equation, which characterizes the operating point of system. It allows us to compute the attempt rate of a mobile in saturated case as well as the throughput formulas for the overall network. Moreover, our performance model deals with a recently released IEEE802.16 criterium : the tr parameter, which have a main impact on the MAC performance. I. INTRODUCTION Concerning the IEEE802.16 standard [3], research and industrial actors agreed the ongoing massive exploitation of this new communication technique. The standard will be able to offer what 3G, DSL, and HFC cable technologies can collectively offer. In addition, the standard allows to link the others commonly used wireless technologies as 3G, 802.11 and HSDPA. The WiMAX technology promises to deliver both high data rates and long-range coverage [2], and is optimized for outdoor applications as well as Metropolitan Area Networks (MAN). The MAC layer in IEEE 802.16 is based on Orthogonal Frequency Division Multiple Access (OFDMA), itself based on OFDM. In this paper, we are interested in the performance evaluation of the MAC layer, in the assumption of ideal channel condition. In particular, we provide a simple model that accounts for all the exponential backoff protocols. This analysis allows us to compute the attempt rate for each node and the distribution of the number of ranging requests received successfully at the base station in each slot. This short paper is extruded from a technical report [4].