Adaptive TXOP Allocation Based on DiffServ for QoS Enhancement in IEEE 802.11e WLAN

IEEE 802.11e WLAN has provided a new access mechanism called the hybrid coordination function (HCF) for quality-of service (QoS) support[1]. Here, we provide HCF scheduler to allocate transmission opportunities (TXOPs) for the stations. TXOP is the time under which a station can send its burst of data packets to other stations. An station can be either in the good or bad channel state and it can be either in constant bit rate or variable bit rate. In the HCF scheduler, channel interference, busty traffic streaming and packet loss causes insufficiency in the strict periodic TXOP allocation scheme. In this, we propose a mechanism of adaptive TXOP allocation. This method works in accordance with channel and traffic conditions, adaptively to compute. The computation is carried by using Differentiated Service (DiffServ) and prediction, providing more access to the time-bounded multimedia applications such as Voice over IP (VoIP), videoconferencing etc... KeywordsIEEE 802.11e, QoS, Transmission Opportunities (TXOPs)