QoS Aware Scheduling and Cross-Radio Coordination in Multi-Radio Heterogeneous Networks

Multi-radio heterogeneous networks (Het-Nets) are an important focus area for next generation cellular standards, with the 3GPP community actively developing WiFi/LTE interworking solutions for small-cell deployments. This paper explores coordinated usage of multiple radios (e.g., LTE and WiFi) to improve quality of service (QoS) in multi- radio heterogeneous networks. We focus on heterogeneous network deployments based on co- located WiFi-LTE small cells that allow for tighter multi-radio coordination. To evaluate QoS enhancements, we consider on-time throughput, a metric that captures the deliverable data rate for traffic with delay deadlines. A QoS-aware scheduling algorithm is designed to optimize on-time throughput. Cross-RAT coordination schemes are also explored to further enhance QoS. Through combining the QoS-aware scheduling algorithm and intelligent radio link assignment, we observe significant improvement in per user on-time throughput. Our results indicate that tightly coupled integrated LTE-WiFi small cell architectures can significantly increase the number of user achieving their targeted QoS.