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Abstract-The IEEE 802.11n network main feature is to support high throughput of more than 100Mbps at the MAC layer. To achieve this, the 802.11n Task Group has introduced frame aggregation technique which reduces the overhead and increases the channel utilization efficiency. Some recent researches have enabled an A-MSDU selective retransmission which makes it robust against error. In this paper, we propose a scheduler based on an A-MSDU aggregation mechanism that supports small size and high sensitivity traffics, and enable prioritization according to the QoS requirements of the traffic classes.

The IEEE 802.11n network main feature is to support high throughput of more than 100Mbps at the MAC layer. To achieve this, the 802.11n Task Group has introduced frame aggregation technique which reduces the overhead and increases the channel utilization efficiency. The MAC layer defines two frame aggregation mechanisms namely the MAC protocol data unit aggregation A-MPDU and MAC service data unit aggregation A-MSDU. A-MPDU is robust against error due to subframes retransmission and large aggregation size, whereas A-MSDU is effective in error free channel due to small headers. A-MPDU has poor performance in erroneous channel because of the absence of sub frames retransmission. It is worth mentioning that some recent researches have enabled the selective retransmission which makes it robust against error. The A-MSDU has becomes compatible and able to fulfill the QoS requirements for applications with small frame size such as VoIP, videos as well as interactive gaming. In this paper, we propose A-MSDU real-time scheduler by exploiting the A-MSDU attributes and adopting the idea of enabling retransmission in our aggregation scheduler algorithm to obtain aggregation with small size to support time sensitive applications and satisfying the QoS requirements.

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The tremendous increase in user demands for multimedia applications with its various quality of service (QoS) requirements has become essential for the operators to accommodate the demand for real-time services in IEEE 802.11 WLAN network. Scheduling mechanism is one of the challenging issues still open for research to fully support the various QoS requirements. In this paper, scheduling scheme is proposed to manage the channel access parameter between competitive nodes. An embedded fuzzy expert system is used to dynamically allocation these parameters to the competitive stations. The simulation results show that the proposed algorithm manages to optimize the overall system utilization.