Multi-user support in next generation wireless LAN

For the first time in the WLAN technology, multi-user downlink transmission will be made possible by the upcoming IEEE standard, 802.11ac. In this paper, we will report its current status, focusing on the MAC modifications and enhancements that are necessary to support the unique feature of downlink multi-user MIMO transmission. Specifically, the technique of TXOP sharing and its related issues and solutions will be discussed and illustrated.