Cognitive Network Access using Fuzzy Decision Making

In this paper, we consider a scenario in which wireless users want to connect to the Internet using one of several available network access opportunities, possibly using different radio technologies. We propose a distributed cognitive network access scheme with the aim of providing the best quality of service with respect to both radio link and core network performance and user application requirements. Knowledge of the service quality experienced by active connections is shared, and prospective users use Fuzzy Logic techniques to process cross-layer communication quality metrics and to estimate the expected transport-layer performance. These estimates are compared to the Quality of Service requirements of the application, and Fuzzy Decision Making is used to choose the most suitable access opportunity. The proposed scheme is compared by simulation to commonly used algorithms as well as omniscient decision schemes in a variety of scenarios, and is shown to have superior performance and much better flexibility.