# Improving DL-MU-MIMO Performance in IEEE 802.11ac Networks through Decoupled Scheduling

## TL;DR

This paper proposes a decoupled scheduling mechanism for IEEE 802.11ac WLANs that improves DL-MU-MIMO performance by reducing head-of-line blocking, leading to better throughput and traffic prioritization.

## Contribution

Introduction of DEMS, a new queuing mechanism that decouples EDCA and DL-MU-MIMO scheduling to enhance WLAN performance.

## Key findings

- Increased throughput with DEMS compared to traditional scheduling.
- Higher probability of transmitting high-priority traffic.
- Reduced competition between frames for different users.

## Abstract

The IEEE 802.11ac standard introduces new downlink multi-user MIMO (DL-MU-MIMO) transmissions to up to four users in order to increase spatial reuse in wireless local area networks (WLANs). We argue that even better WLAN per- formance can be achieved by slightly modifying the DL-MU-MIMO scheduling. To this end we propose a new queuing mechanism based on the decoupling of EDCA and DL-MU-MIMO scheduling (DEMS) to avoid head-of-line blocking. We show that DEMS outperforms traditional 802.11ac scheduling based on first in, first out transmission queues. The improvement is shown in terms throughput achieved with: (a) more efficient channel usage, (b) increased probability of transmission of high priority traffic, and (c) decreased competition between frames destined to distinct users.