From time to time, marshalling events occur in stable markets placing difficult new requirements on established system designs. Subsequently, innovative new design tools and processes emerge to address shortcomings in the legacy design flows for the established systems. In the case of wireless systems, the emergence of coexistence represents one of these marshalling events. In particular, the connectivity boom in consumer electronics and the importance of electronic warfare in military environments is requiring radios to perform in spectrally rich environments. As a consequence, system simulation is emerging as a necessary complement to static analysis for designing wireless systems.