NS-2 is most used simulator within the network community mainly because it implements most of network protocols and is freely available in the public domain. However, part of the simulator is very poorly written, and it is the case for the 802.11 module that does not implement rigorously the IEEE specifications. We have thus started a project to develop a new 802.11 module for ns-2 with support for several Physical layer models, multirate options for 802.11a/b and 802.11e functions to provide service differentiation. The module also contains an implementation for the classical ARF PHY rate control algorithm and the AARF improved mechanism that we have proposed previously. This work has been done by Mathieu Lacage, Dream Engineer at INRIA, in close collaboration with the NS-2 team. The new module that can be downloaded at the following URL: http://www-sop.inria.fr/planete/software/ .