When compared with legacy Power Save mode, how does VHT TXOP power save improve battery life for devices on a WLAN?

You have received a report of poor wireless connections on the third floor of a building under your administration. Three individuals have reported the problem. Apparently, the connections are reporting a strong signal, but the users cannot access the Internet. With the problem identified, what is the next logical step in the troubleshooting process?

You are troubleshooting a client issue on a Windows laptop. The laptop can see and connect to 2.4 GHz APs, but is does not even see 5 GHz APs. While evaluating the issue, you determine that this problem is happening for all of the laptops of this model in the organization. Several other tablets connect on channel 48 and channel
52 in the same work areas. What is the likely problem?

Which one of the following frequency ranges is not specified for use by IEEE 802.11 radios as of
802.11-2012?

Which data rate is supported by 802.11g radios that is not supported by 802.11a radios?