Experimental evaluation of asymmetric QoS in IEEE 802.11g wireless networks

Abstract

Quality of Service (QoS) can be provided in a Wireless Local Area Network (WLAN) using the Enhanced Distributed Channel Access (EDCA) mechanism specified in IEEE 802.11e. However, 802.11e WLANs are not widely deployed and not all WLAN vendors implement the 802.11e mechanisms. In this paper, we propose and evaluate an asymmetric QoS solution, in which QoS support is provided only at the wireless Access Point (AP). We believe that this approach provides a practical solution for many cases where wireless clients may not support EDCA QoS. The feasibility of this solution is studied, using an experimental approach. A QoS testbed is designed and implemented using a centralized wireless controller and lightweight AP. The measurement results show that VLAN-based asymmetric QoS provides effective prioritization and excellent performance for high-priority traffic classes, including Voice over IP (VoIP) and TCP traffic, even during severe congestion conditions. Furthermore, this approach can be easily implemented using minimal equipment.

Modelo de Calidad de Servicio a Nivel de Enlace de Datos para Tráfico de Misión Crítica sobre Redes IEEE 802.11g en Modo Infraestructura

“…Una investigación de (Hu, et al, 2011) presenta un modelo de QoS asimétrico evaluado de manera experimental en donde se muestra que debido al parcial despliegue que ha tenido la tecnología IEEE 802.11e, es necesario mejorar las condiciones de QoS en clientes que no admitan dicha tecnología. Los resultados muestran un buen rendimiento, incluso en escenarios de congestión y con tráfico sensible al retardo como VoIP.…”