Preemptive Scheduling of Latency Critical Traffic and its Impact on Mobile Broadband Performance

In this paper, we present an exhaustive system level analysis of using preemptive scheduling for latency critical traffic in coexistence with mobile broadband for the 3GPP 5G New Radio. Enhanced recovery and HARQ retransmission mechanisms exploiting base station a priori knowledge of punctured radio resources from using preemptive scheduling are proposed. It is demonstrated that a scheme with HARQ multi-bit feedback and selective retransmission of punctured resources is an attractive solution. Furthermore, the performance sensitivity from using either fully interleaved or frequency-first code block layouts is assessed. The impact on the mobile broadband performance is evaluated at TCP-level, studying both the penalty on throughput and smoothened TCP round trip time in order to assess how preemptive scheduling affects the end-to-end performance of other traffic.