Admission Control and Profitability Analysis in Dynamic Spectrum Access Data Networks

New regulations grant network service providers with the right to lease their spectrum to short-term leased secondary users (SUs) for opportunistic usage. In this work, we tackle the challenge of determining admission control and pricing policies on SUs that guarantee profitability under general secondary demand and general traffic models, and accurately reflect the operation of modern cellular data networks in which resources are shared rather than rigidly partitioned. We first analyze the joint problem of bandwidth allocation and admission control of elastic secondary users. We assume Poisson session arrivals, where each session is composed of arbitrarily distributed, and possibly correlated, on and off periods. Under balanced bandwidth allocation, we show that the steady state distribution of the number of active users in the network is insensitive to traffic characteristics beyond their means. This result holds for arbitrary occupancy-based admission control policies on SUs. Next, we prove that the optimal occupancy-based admission control policy is of threshold type, which means that secondary user arrivals are accepted when the total number of active users in the network is below a certain threshold; otherwise, they are rejected. Finally, we identify a price,referred to as the break-even price, and an admission control policy which, together, ensure profitability for any price greater than the break-even price, irrespective of the shape of the secondary demand function.