A new dynamic EDCA mechanism to improve VoIP services in 802.11ac networks

Abstract

Due to real-time nature of multimedia data, the 802.11ac standard applies the EDCA method to prioritize different types of traffics. The EDCA method supports four different access categories each with its own queue so that the highest priority is assigned to voice packets. However, the EDCA method only works well when the amount of voice packets is small compared to other types of traffics. As the density of the voice packets increases, the collision among them increases which results in delay and loss ratio increasing. This in turn can highly degrade the quality of the VoIP service. To address this EDCA issue, a new dynamic model called D-EDCA is proposed in this work. The new D-EDCA model provides a deterministic QoS by continually monitoring the voice packets and their corresponding queue to dynamically adjust the corresponding parameters when the density of the voice packets is above a threshold. The D-EDCA model is designed and implemented using NS3 simulator tool. Furthermore, in order to validate and compare the performance of the proposed D-EDCA with the conventional EDCA, a learning-based framework is designed that operates in three phases in the uplink mode of 802.11ac network. The results prove that the D-EDCA model can highly improve VoIP communication compared to the conventional EDCA in terms of network metrics.

Keywords

• 802.11ac
• edca
• mimo
• channelization
• voip
• guard interval