Impact of Wireless Devices over Real-time Applications: An Empirical Test-bed Analysis

Wireless Local Area Network (WLAN) has enabled greater communication capabilities compared to LAN counterpart. However, when it comes to quality of service (QoS), WLAN has lower reliability, where it has higher latency and packet-loss, especially for real-time streaming applications such as voice over internet protocol (VoIP) and multimedia. Thus, improving QoS in WLAN is a major research challenge, where packet-loss is considered most critical while other factors, such as latency and jitter are acceptable to certain level of tolerance. Theoretically WLAN can provide higher bandwidth and lower latency; however, practical results disagree with this statement. In this paper, we investigated the dilemma using different combination of wireless devices within a local area network to identify the problem. We propose an infrastructure based scheme to improve the QoS for real-time traffic over WLAN. We setup a wireless network using different types of wireless devices and tested VoIP traffic over it. Our simulation results for G.729.2 codec on IPv4 and IPv6 using virtual access point (v-AP) showed better performance than physical access point (ph-AP). We also observed that usage of different wireless devices within a network highly reduced real-time application performance.