Abstract

To meet the ever growing need for wireless spectrum, the Federal Communication Commision (FCC) introduced a spectrum sharing model called the 3-Tier Sharing Framework. In this model, under-utilized federal spectrum will be released for shared use where the highest preference will be given to Tier-1 followed by Tier-2 and then Tier-3. In this paper, we present a model where a wireless operator, who is interested in maximizing its profit, can operate as a Tier-2 and/or a Tier-3 user. Tier-2 is characterized by paid but “almost” guaranteed and interference free channel access while Tier-3 access is free but has lesser guarantee and also faces channel interference. So the operator has to optimally decide between paid but better channel quality and free but degraded channel quality. Also, the operator has to make these decisions without knowing future market parameters like customer demands or channel availability. We use tools from ski-rental literature to design a deterministic online algorithm for leasing channels which does not rely on the knowledge of market statistics. The efficiency of the online algorithm is analyzed by deriving its competitive ratio (CR) and by conducting simulations. The mathematical model for leasing channels is a novel generalization of the classical ski-rental problem. We therefore make fundamental contribution to ski-rental literature which may have diverse applications beyond the problem considered in this paper.