The Green-Dyspan project is structured into 5 Tasks:

  • - Task 1: Efficient Spectrum Sensing in Opportunistic and Dynamic Environments. In order to aggregate spectrum in an efficient way, the first step is to identify available spectrum resources. The first task studies the question of how to efficiently identify available spectrum resources by developing a decision-theoretical framework to investigate the spectrum sensing problem in an opportunistic and dynamic environment, designing practical energy efficient spectrum sensing algorithms and protocols.
  • - Task 2: Dynamic Spectrum Allocation and Sharing under Spectrum Aggregation. The second task studies the fundamental question of which spectrum to access if multiple ones are available. Specifically, in this task, we focus on the design of energy-efficient cognitive Medium Access Control (MAC) protocols that coordinate multiple secondary users to access the spectrum under spectrum aggregation.
  • - Task 3: Joint Spectrum Sensing and Access for Ultra-wide Frequency Band. In this task, we jointly address the problems tackled in tasks 1 and 2 in a cross-layer fashion to optimize spectrum access while considering physical layer spectrum sensing and primary users' traffic statistics. This is motivated by the observation that spectrum sensing and spectrum access are two functions that are tightly linked one to the other in many practical scenarios, and hence should be jointly optimized. We plan to develop practical protocols and algorithms that lead to efficient joint spectrum sensing and access mechanisms, thus achieving a desirable balance between energy and spectrum efficiencies.
  • - Task 4: Energy-Efficient Large-Span Spectrum Aggregation. In this task, we consider the dynamic spectrum aggregation problem with practical constraints posed by the hardware limit, e.g., limited spectrum aggregation range, and energy cost induced by electronic circuits. Based on the results of previous tasks, we plan to investigate the energy efficient spectrum aggregation problem and develop efficient strategies to make the spectrum aggregation technique more adapted to practical networks.
  • - Task 5: Experimental measurements and prototyping. We will perform a careful experimental evaluation of the proposed mechanisms and protocols, based on real testbed implementations. In fact, simulation results are often insufficient to capture the impact of unexpected, and hard to predict/simulate, link- level operation.
The following figure illustrates the project structure, summarizing the mathematical tools to be used, as well as the relationship among all the proposed tasks.