This work provides the specification of a PHY and MAC layers simulator that allows to evaluate the IEEE 802.11e service quality. A detailed state transition diagram is presented along with a description of the related attributes and methods, an identification of the associated events and input variables, and a description of functions for events. For validation purposes, results of the goodput as a function of the signal to interference noise ratio were obtained with an error margin lower than 10%. Higher values are found for the goodput for background and video services, mainly because the frames transmitted in these services are longer than the voice application ones. However, the number of supported users is higher for voice. This simulator will allow for tuning-up several parameters like the ones related to how to use BlockACK, normal ACK, and NO ACK policies.