InIEEE 802.11 there are various working groups that deal with higher data rates, greater data throughput, extended deployment areas (TGy) or with the direct links between WLAN clients, such as the Direct LinkSetup Study Group(DLSSG).
The 802.11ac Very High Throughput (VHT) working group focuses on the techniques used in 802.11n' s high through put technology, such as BlockACK( BA), Reduced Guard Interval( GI), and Reduced Interframe Space( IFS), Reduced Interframe Space ( RIFS). Furthermore, it deals with the different bandwidths with which 802.11ac WLANs can operate. In addition, the VHT working group is developing scenarios for gigabit WLANs in the terahertz range. As a future scenario, even terabit WLANs are being discussed. The proposals are in the discussion phase and range from an independent new WLAN concept to further development of existing standards.
Very High Throughput (VHT) is a data field comparable to the HT(High Throughput) data field in 802.11n, which can, however, only be interpreted by WLAN devices according to 802.11ac. The data field is divided into two half data fields: The Signal A field and the accompanying Signal B field. The data fields contain several training frames such as the Short Training Field (STF) and the Long Training Field (LTF), which occur in the frame as VHT- SFT or VHT-LTF.
Together, both data fields describe the various attributes such as the channel bandwidth, the Modulation and Coding Scheme( MCS), and whether a data packet is a single- user frame or multi-user frame.
802.11ac is an 802.11 WLAN with Very High Throughput (VHT) with which data rates of several gigabits per second can be realized. Other 802.11 WLANs are 802. 11ad, 802. 11ax and 802.11ay, with which data rates of 6 Gbit/s (802.11ad), 20 Gbit/s (802.11ax) and over 100 Gbit/s (802.11ay) can be achieved.