||With the impressive growth rate of rich multimedia and network applications, there is an exponential increasing demand for the mobile broadband in the new technological era. The Third Generation Partnership Project (3GPP) has devoted to some investigations, including the carrier aggregation (CA), coordinated multi-point transmission and reception (CoMP), and the heterogeneous networks (HetNets). The HetNets consists of normal base station and some low power nodes, such as Pico, femtocell, and relay nodes. Instead of the relatively high deployment cost and high transmission power, these nodes which feature some advantages like serving users in coverage holes, low cost and high design flexibility, are seen as a promising way to increase the capacity of the network.|
In the HetNet, the Cell Range Expansion (CRE) is proposed to drive more users attaching the small nodes, which assigns a fixed bias value in the traditional way, but it will cause some issues about load balancing between the Macrocell and Picocells. The 3GPP also brings an energy-efficient mechanism to HetNets for switching off the small cells when the loading of them are low.
Hence, we proposed an efficient method to calculate the suitable bias value, and adapt it dynamically with the implement of Small Cell Switch off mechanism. Within this new adaptive method, we can balance the loading between the Macrocell and Picocells with the goal of minimizing energy consumption and improving the total network throughput through a better tradeoff.