In this paper, we focus on gigabit solution in the 5 GHz band where the emerging 802.11ac amendment could provide a maximum PHY data rate of close to 7 Gbps. To be more specific, it promises MAC throughput of more than 500 Mbps for a single user scenario and aggregated MAC throughput of more than 1 Gbps for a multi-user scenario,both utilizing no more than 80 MHz of channel bandwidth.Consequently, 802.11ac is targeted at higher data rate services such as high-definition television, wireless implementation of high-definition multimedia interface (HDMI replacement), and lately the wireless display applications which according to the report in [4] could result in an expected shipment of 50 million wireless video devices in 2015. To the best of the authors’knowledge, this is one of the first studies to introduce the draft 802.11ac amendment and analyze its potential benefits in terms of MAC performance gains as compared to existing 802.11n devices over various frame aggregation mechanisms.The remainder of this paper is organized as follows.Section II presents an overview of the key mandatory and optional PHY features together with the MAC enhancements of 802.11ac over the existing 802.11n standard. Section III provides the numerical analysis of 802.11ac and 802.11n MAC performances in terms of maximum throughput and MAC efficiency. Section IV validates the numerical analysis with simulation results, and compares the performance analysis between 802.11ac and 802.11n over various frame aggregation mechanisms. Finally, Section V concludes this paper with some directions for future work.