802.11ac Wave 2
Is more of a semi-official term. It is used to designate the second wave of technology that is being released to support the existing 802.11ac technologies.
It also is meant to signal a future release of a final certification plan. Chip producers and vendors have decided to divide up specifications into a couple very distinct sets depending on their functionality.
These sets have since been described online as ‘waves’ and the term just stuck. Wave 2 boasts three main potential features; firstly, are 160 MHz channels, secondly, it will provide a fourth spatial stream, and lastly, it will support widespread beamforming.