HARE: Hybrid ARQ-Based Adaptive Retransmission Control Scheme for Synchronous Multi-Link in Wireless LANs

Abstract

As the resolution of video becomes high and the number of mobile devices proliferates, the demand for video traffic is exploding. New traffic types, such as augmented reality (AR) and virtual reality (VR), which require high-throughput and low-latency, are also emerging. Two of the promising techniques discussed in increasing throughput and lowering latency are multi-link transmission and hybrid automatic repeat request (HARQ). However, in most cases of a device using a low-cost chipset, there are potential limitations to using HARQ on multi-link. This paper proposes a HARQ-based adaptive retransmission control scheme (HARE), which determines the optimal retransmission policy by casting it as a Markov decision process (MDP) for the devices undergoing the aforementioned limitations. Through this, we can decide whether to execute HARQ and select the adequate modulation and coding rate when a retransmission occurs. Through extensive analysis, we found that HARE can greatly increase throughput compared to the ARQ-only and HARQ-only retransmission methods with a small amount of buffer occupancy. This technique expects high-resolution video and brand-new services such as AR/VR to be enjoyed even by the devices with low-cost chipsets.