Adaptive traffic splitting for transmission power minimization with QoS enhancement in 5G HetNets

In this paper, we propose an adaptive data rate splitting algorithm for 5G HetNets comprised of both macro cells and small cells. Dual connectivity with data rate splitting has been considered a solution for achieving energy efficiency and enhancing network throughput. However, previous work did not optimize both transmission power and throughput for dual connectivity. For the minimization of transmission power with quality of service (QoS) enhancement, we employ a data rate splitting ratio for dual connectivity users. To that end, we formulate the problem of minimizing transmission power based on users’ minimum rates, and we derive a theoretical expression to obtain the optimal data rate splitting ratio. An algorithm is proposed for adaptive data rate splitting considering channel conditions and the UE data rate demands. The algorithm finds the data rate split ratio iteratively to minimize total transmission power and fulfill QoS requirements. Using NS-3, we verify the analysis and show that the proposed algorithm minimizes total transmission power while satisfying QoS requirements. In addition, we show the impact of user mobility and the number of small cells on the data rate splitting ratio.