  This paper reports our work on extending the Omnet INET Framework with a
directional radio model, putting a special emphasis on the implementation of
asymmetrical communications. We first analyze the original INET radio model,
focusing on its design and components. Then we discuss the modifications that
have been done to support directional communications. Our preliminary results
show that the new model is flexible enough to allow the user to provide any
antenna pattern shape, with only an additional reasonable computational cost.
