We study revenue-maximizing in a wireless system where interested users share a common spectrum and interfere with each other. Capacity is increased in proportion of the number of users. Our objective is to design a scheme that achieves an optimal solution for the provider with respect to users strategy, bandwidth management and some fairness criteria. We consider a flat rate pricing for users. Two cases are studied: firstly, an approximation to the original problem when the provider has a perfect knowledge about the channel state of each user is proposed. In the second case, a decision theoretic approach based on a POMDP framework is elaborated when the provider has only a partial information on the system state. Additionally, we provide numerical results that illustrate the performance of the proposed solutions