Link Layer Packet Loss Classification for Link Adaptation in WLAN

Voice over IP (VoIP) and high quality video streaming becomes an alternative to conventional telephony and TV service in many locations by way of ongoing deployment of WLAN hotspots. The newly proved IEEE 802.11e QoS enhancement standard will be a proper solution of delay demanding for real-time multimedia applications, while the existing auto rate fallback (ARF) link adaptation scheme, designed to improve wireless transmission by dynamically selecting transmission rates and frame sizes, cannot effectively solve the QoS concerns of multimedia communication due to the growing UDP traffic. In this paper, we presented comprehensive analyses of link layer behavior to infer the cause of packet loss in a WLAN. More specifically, we classify the packet loss into either congestion or wireless errors based mainly on delays and MAC layer parameters under congestion and/or link error dominated status. A link layer packet loss classification scheme can thus be proposed to support link adaptation for VoIP applications in WLAN.