text: Traditional regulatory methods for spectrum licensing have been recently identified as one of the causes for the under-utilization of the valuable radio spectrum. Governmental agencies such as the Federal Communications Commission (FCC) are seeking ways to remove stringent regulatory barriers and facilitate broader access to the spectrum resources. The goal is to allow for an improved and ubiquitous sharing of the precious radio spectrum between commercial service providers. In this paper, we propose a novel noncooperative game theoretic approach, to show how to foster more sharing of the radio spectrum via the use of regulatory power. We define a two stage game in which the government regulators move first, followed by the providers. The providers are incentivized by lower spectrum allocation fees from the regulators in return for proof-of-sharing. The providers are offered discounted spectrum bands, potentially at different locations, but will be asked to provide coverage to users that are not subscribed to them so as to maintain their subsidy incentives from the government. In a simplification of the model, analytical expressions for the providers' perfect equilibrium strategies are derived, and we argue for the existence of the government's part of a perfect equilibrium. Our analysis shows that through subsidization, the government can provide small service providers a fair chance to compete with the large providers, thereby avoiding monopolization in the market.
  @cite_14: To facilitate ubiquitous access for mobile users machines in spectrum efficient way, effective integration of multiple wireless networks possibly belong to different service providers (SPs) is greatly required for future wireless spectrum sharing networks, such as Machine-to-Machine (M2M) communications. With the aid of cognitive radio or dynamic spectrum access, cooperative spectrum sharing should ensure sufficient incentives to licensed users (LUs) and additional incentives for SPs such that LUs may leverage other SPs' services accordingly as vertical handoff or roaming, which creates another intellectual challenge. We formulate this fundamental problem as a market model by introducing a roaming rate as the incentive for each SP to gain extra revenue when its LUs temporarily leverage other SPs' service. We obtain the equilibrium at which all SPs and all LUs satisfy the amount of the allocated bandwidth and the price simultaneously by using the concept of demand and supply from economics. Two iterative algorithms are proposed to reach the equilibrium for decentralized implementations and their stable conditions are analyzed. Furthermore, the optimal roaming rate obtained by backward induction with the equilibrium maximizes the overall social welfare (i.e., sum of profit of all SPs and payoff of all LUs) by gradient ascent method, such that all SPs as well as all LUs have satisfactory incentives in this cooperative spectrum sharing scheme.
summary: @cite_14 , a roaming market model is introduced, which uses the roaming rate as an incentive for service providers to gain revenue, when they allow other users to access their network. Optimal roaming rate is derived to maximize the social welfare of all the service providers and licensed users. Our approach for subsidization, while also allows inter-operator sharing of spectrum similar to roaming, is fundamentally different than these earlier work, since it involves the government as the subsidy source to facilitate spectrum sharing.