Capacity and Congestion Aware Flow Control Mechanism for Efficient Traffic Aggregation in Multi-Radio Dual Connectivity

Multi-Radio Dual Connectivity (MR-DC) is a crucial 3GPP technology that enables traffic aggregation to leverage the radio resources of two base stations (BSs), thereby increasing the per-user data rate. However, the traffic aggregation management in MR-DC is left up to vendor implementation. In this paper, we show that enabling an efficient traffic aggregation method is crucial to increase the throughput performance of both TCP- and UDP-based applications in MR-DC operation. Targeting the state-of-the-art gap on this topic, we propose a flow control mechanism, which efficiently aggregates traffic based on the assigned radio resources and buffering delay statistics of both BSs. The proposed traffic aggregation mechanism is applicable irrespective of the employed MR-DC architecture option, MAC packet scheduler design, and transport layer protocol in use. By means of exhaustive testbed experiments, we show that the proposed method achieves at least 85% and 95% of the theoretical aggregate throughput when employing MR-DC for TCP and UDP traffic, respectively.