Keeping up with the bits: tracking physical layer latency in millimeter-wave Wi-Fi networks

TL;DR

This paper introduces a simulation framework to analyze and identify physical layer latency sources in millimeter-wave Wi-Fi networks, aiding in meeting strict low-latency requirements for real-time applications.

Contribution

It presents a novel simulation framework for PHY latency analysis in mmWave Wi-Fi, enabling virtual experiments and detailed bottleneck identification.

Findings

The framework can accurately track PHY-level packet latency.

It demonstrates how LDPC decoding iterations affect latency.

The approach accelerates latency analysis in laboratory settings.

Abstract

The wireless communications landscape is anticipated to offer new service levels following the introduction of the millimeter-wave (mmWave) spectrum to consumer electronics. With their broad bandwidths and corresponding multi-Gbps data rates, these mmWaves are a perfect fit for data hungry applications, such as streaming video to extended reality devices. However, the latter are also bound by maximal latency constraints as low as 1 ms. Understanding where such minuscule time delays lurk requires a close-up study of individual layers in the network stack. Starting from the bottom up, the present work describes an endeavor at uncloaking the origins of physical layer (PHY) latency in mmWave Wi-Fi networks. It proposes a newly designed simulation framework and sheds light on how any conventional laboratory can be turned into a virtual experiment setting, speeding up computation. A case study based on the IEEE 802.11ad standard demonstrates the framework's ability to track packet latency at the PHY-level and identify individual bottlenecks. In particular, it evaluates the impact of the number of LDPC decoding iterations on latency in short transmission sequences.