Impact of Packet Retransmission on VoWiFi Cell Capacity Using Fifth-Generation WLAN

Abstract

AbstractThe rapid increase in the deployment of Wireless Local Area Network (WLAN) particularly over the existing infrastructure is growing tremendously. Such an infrastructure-based WLAN, widely known as Wireless Fidelity (WiFi) network, needs to support voice service because, in general, it contributes a large portion of the traffic supporting personal communication. Voice over Internet Protocol (VoIP) over WiFi commonly known as VoWiFi can be used for providing voice services. In order to provide quality of service (QoS) to such voice calls, it is essential to establish a call admission control (CAC) policy. This policy requires VoWiFi cell capacity. In this paper, we have estimated the number of VoWiFi calls possible using the IEEE 802.11ac standard Access Point (AP). To estimate the cell capacity, we have used DCF Inter-frame Spacing (DIFS) to sense channel status before sending data and Short Inter-frame Spacing (SIFS) is used for acknowledgement, Request To Send (RTS), and Clear To Send (CTS) frames. We have estimated the VoWiFi cell capacity using different voice codecs like G.729 and G.723.1. We have used packet retransmission technique to avoid packet loss and Arbitration Inter-frame Space (AIFS) to enhance the VoWiFi cell capacity.KeywordsVoWiFiDIFSAIFSRetransmissionCapacity analysis