Framework for performance evaluation of cognitive radio networks in heterogeneous environments

Cognitive radio networks use information about their environment and user requirements to achieve specified objectives. There are many radio and network parameters that may be adapted in response to changes in the environment, and these may interact resulting in an emergent state that is not predictable by considering the parameters separately. The cognitive radio network may therefore be considered as a complex adaptive system; further, multiple independent networks form a complex system of systems. Thus, the evaluation of mobile networks operating in congested, heterogeneous environments must consider the high-level objectives rather than those of individual radio and network components. This paper discusses the requirements for the modelling, simulation and evaluation of cognitive radio networks in heterogeneous environments.