Dynamic Spectrum Access for Primary Operators Via Carrier Aggregation in LTE-Advanced Environments

In this paper, we address dynamic spectrum access for Primary Operators (POs) for LTEAdvanced systems. We propose a dynamic spectrum access framework that exploits the capabilities of carrier aggregation to efficiently utilize the unutilized spectrum which varies with time and space when static spectrum access policies are adopted. A spectrum owner (SO) adopts an auction scheme for accessing spectrum for the dynamic requests when the overall demand is higher than the available bandwidth and uses peak-load pricing (PLP) otherwise. The objectives of the SO are to maximize its revenues and to increase the spectrum utilization efficiency as well as achieving social welfare. On the other hand, the objective of the POs is to maximize their benefits by reducing expenditures compared to the case of static allocation based on the projected maximum demand in a forecasting period. Furthermore, we introduce an accurate model for estimating the bandwidth required to satisfy the traffic demands of an operator’s subscribers for a projected demand model. For the auction process, we map the spectrum access problem into a bounded knapsack problem which is solved using dynamic programming in pseudo-polynomial time. The solution uses the second price strategy, i.e. the winner pays the second highest price. Simulation results show more than 20% reduction in the required spectrum and up to 80% reduction in the average unutilized spectrum as compared with traditional static spectrum access due to the on-demand spectrum assignment. Keywords— Dynamic spectrum access; auction; peak load pricing, carrier aggregation; knapsack