Advanced progress in IEEE 802.11 WLAN standardization

Today, IEEE 802.11 wireless LAN (WLAN) systems are becoming more and more important to provide last-one hop wireless access to user terminals in various scenes such as home, enterprise and public areas. WLAN systems are also quite attractive because it offers traffic offload for the explosive growing traffic of cellular networks. This paper describes recent WLAN standardization activities and their specifications. First, the technical overview of the latest “very high throughput” WLAN standard, 802.11ac is introduced. To achieve more than 1 G bit/s of the system throughput, the physical layer parameters are extended for peer-to-peer bit rate increase. In addition, downlink (DL) multiuser (MU-) MIMO technique is supported for more efficient usage of spatial resources. Then, the future forecast of the next generation WLAN standard is presented. The task group (TG) ax in the 802.11 working group is formed in May 2014 and it is now working to create the post-802.11ac standard. The most crucial problem that TGax addresses is poor throughput performance of the current WLAN systems in congested environment.