- Current wireless systems are called vendor-central systems because, users should subscribe to a service provider (vendor) and receive the service through the spectrum assigned to that vendor at all times. Vendorcentral systems suffer from low utility performance defined in terms of spectrum efficiency, blocking rate, and revenue. Variety dynamic channel allocation schemes have been proposed to address the weak utility performance of vendor-central systems. In this work, a futuristic user-central wireless system architecture that leads to an ultimate freedom in channel allocation will be introduced. This architecture is implemented based on the capabilities of cognitive radios. In user-central systems, a user has the freedom of receiving the service through a1 n optimum vendor at any time instance and geographical location. The optimum vendor is selected by an intelligent mobile based on parameters such as the vendor signal power, channel availability, congestion rate, cost-per-second...