The IEEE 802.11-2012 standard requires VHT capable devices to be backward compatible with devices using which other 802.11 physical layer specification (PHY)?

What statement about 802.11 WLAN performance is true?

During a post-implementation survey, you have detected a non-802.11 wireless device transmitting in the area used by handheld 802.11g scanners. What is the most important factor in determining the impact of this non-802.11 device?

The requirement for a WLAN you are installing state that It must support unidirectional delays of less than 150 ms and the signal strength at all receivers can be no lower than -67 dBm.
What application is likely used that demands these requirements?

In addition to coverage analysis results, what should be included in a post-deployment site survey report to ensure WLAN users experience acceptable performance?