A-MSDU real time traffic scheduler for IEEE802.11n WLANs

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 AMSDU 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.