In wireless networks, wireless channels are often shared between multiple nodes, which may interfere when they transmit simultaneously. The media access control (MAC) scheme coordinates channel access between the different nodes. In this article, we focus one specific method of channel access, Elimination-Yield Non-Preemptive Priority Multiple Access, EY-NPMA, which is part of the European standard wireless HIPERLAN. EY-NPMA is a wireless MAC method that partly relies on "active signaling": i.e. transmitting (activity) to simply signal a node's presence (with pseudo-noise), rather than transmitting data (bits). In this article, we focus on the implementation of EY-NPMA channel access scheme as a module in the ns-3 network simulator. We are interested particularly to study the adaptation of the ns-3 Wifi module to support EY-NPMA features. Hence, our main focus in this work is the implementation of a such an extension, yielding Ey-Wifi, in a module of the network simulator, ns-3, with the emphasis on the software architecture. We are interested further to present some simulation results, analyzing the performance of both Wifi and Ey-Wifi.