Collaborative scheme to improve QOS in WLAN-Wired networks

Abstract: A new Quality of Service (QoS) enhancement scheme for WLAN-wired networks was developed. It consisted of: (i) An adaptive access category (AC) traffic allocation algorithm that was incorporated into the network's wireless side to improve the performance of IEEE 802.11e Enhanced Distributed Channel Access (EDCA) protocol. (ii) A Weighted Round Robin (WRR) queuing scheduling mechanism that was incorporated into the wired side of the network. The adaptive traffic allocation algorithm determined the Packet Arrival Rate (PAR) of up- and down- link traffic for each AC. It dynamically allocated the traffic of a lower priority AC to the next higher AC, when the higher AC was not receiving traffic at the time. WRR shared the network resources, based on the traffic’s quality of service requirements. The incorporation of the scheme improved the performance of the WLAN-wired network. As an example, the average QoS values for VoIP (i.e. the highest priority traffic),and File Transfer Protocol (FTP) (i.e. the lowest priority traffic) were increased from their original values by 62.2%, 29.4%, and 97%, and 46.9% under light and heavy network load respectively. Keywords: IEEE 802.11e, Quality of Service, Multimedia Transmission.