Utilizing IEEE 802.11n to enhance QoS support in wireless mesh networks

Wireless mesh networks (WMNs) have the potential in supporting multimedia applications with last-mile Internet access. To achieve this objective, shortcomings such as scarcity of the wireless link capacity and the lack of robust QoS scheduling must be overcome. In this paper, we consider WMNs utilizing the new IEEE 802.11n standard. Based on the standardpsilas physical and medium access control (MAC) layer enhancements, we propose adapting the modulation and code scheme (MCS) index and aggregation frame length according to the online assessed link quality, performing frame aggregation by packing multiple small subframes. We also propose performing QoS bandwidth provisioning by optimally aggregating subframes according to their QoS constraints and fairness. Performance results show that incorporating link adaptation, frame aggregation, and QoS bandwidth provisioning can considerably improve the system performance in terms of MAC delay, achieved throughput and packet dropping ratio. The results also show that packet aggregation scheme has a crucial impact on system performance when aggregating small packet sizes.