Models and methodologies for simulating mobile ad-hoc networks

It is a truism that simulations of mobile ad hoc networks (MANETs) are not realistic. Today, simulations typically model propagation with either the free-space model or a "two-ray" model. Such models are valid only in open space where there are no hills and buildings. Since wireless signal at the frequencies used for MANETs is partly reflected off of buildings and is partly transmitted into the building, the presence of buildings greatly influences propagation. Consequently, these open-space propagation models are not accurate in outdoor urban areas. When propagation for Indoors is considered, the open-space models are not even applicable. There has been little effort in developing realistic mobility models. In urban areas, the mobility of vehicles and pedestrians is greatly influenced by node interaction. Furthermore, the location of streets, sidewalks, hallways, etc. restricts the position of nodes. Traffic lights also have a direct impact on the flow of nodes. We discuss the models and methodologies for realistically modeling the propagation and mobility of MANETs in urban environment. The techniques of simulation, models, model parameters and accuracy are all examined. The techniques for propagation are validated against propagation measurements.