Abstract—Modern frequency-agile radios are capable of dynamically changing the spectrum width and central frequency of its channels. Existing spectrum sharing algorithms often fail to exploit this characteristic to realize efficient spectrum utilization. In this paper, we present a theoretical framework that capitalize on the frequency agility of modern radios. We solve a joint spectrum sharing and end-to-end rate control problems for general wireless networks to achieve optimal spectrum efficiency with regard to network utility. Analytical and simulation results show the effectiveness of our design.