Picocell-density based energy-saving for QoS provisioning in heterogeneous networks

In order to reduce the energy consumption, we propose a novel Macro Base Station (MBS) sleep scheme based on the density of Pico Base Station (PBS) including three sleep approaches for current heterogeneous networks (het-net). Our scheme consists of two parts. In the first part, by setting thresholds for PBS density according to the total coverage of PBSs in a macro-coverage, we divide the network into three scenarios where PBSs are deployed densely, sparsely, and commonly correspondingly. In the second part, the MBS chooses one sleep approach of our scheme by comparing its PBS density with the thresholds. In each approach, minimizing the system energy consumption and meeting the QoS requirements are both considered as our goals. Particularly, the offset value is designed to guarantee blocking probability, especially when the neighboring MBSs are in charge of taking over the migrated users from the sleep MBS. Finally, simulation results demonstrate that the proposed scheme is much more efficient than the other existing schemes in terms of the power consumption and the blocking probability.