Energy-efficient cognitive access approach to convergence communications

This article studies the cognitive access in convergence communications. Convergence communi- cations provide upper-layer applications with uniform communication service, converging different lower-layer networks into a uniform access pattern such as all-IP communications. As an import access in convergence com- munications, the cognitive access provides users with a flexible and dynamic access to networks. In this article, we do not only take into account the spectrum usage of convergence communication networks, hut also consider theirs energy efficiency. An energy-efficient access algorithm is proposed to improve network performance and efficiency. Different from the existing cognitive access, we regard energy efficiency as the optimal objective to turn the energy-efficient cognitive access into an optimal problem. The collision avoidance and sleeping mecha- nisms are used to reduce energy consumption and raise network throughput. The utility function is proposed to maximize networks＇ energy efficiency and then achieve the energy-efficient cognitive access. Simulation results show that the proposed approach is effective and feasible, which can significantly improve networks＇ energy efficiency.