2.4 CQ Flashcards
Which of the following would a company most likely use for authentication to a server room?
Image A. 802.11ac
Image B. 802.15-4
Image C. RFID
Image D. Z-Wave
Image E. MIMO
C. RFID (radio-frequency identification) is commonly used for access to areas of a building such as a server room. It is often implemented as a proximity-based ID card or badge. The other options are not usually associated with authentication. 802.11ac is a WLAN (Wi-Fi) standard that runs on 5 GHz and can provide 1 Gbps of data transfer. 802.15-4 is the IEEE standard for Zigbee. Z-Wave, like Zigbee, is a home automation and wireless sensor control technology. MIMO (multiple-input and multiple-output) is a multiple propagation technology used to increase data transfer in 802.11n and 802.11ac wireless networks.
Which standard can attain a data transfer rate of 1 Gbps over a wireless connection?
Image A. 802.11a
Image B. 802.11b
Image C. 802.11g
Image D. 802.11ac
Image E. 802.3ab
D. 802.11ac can attain speeds in excess of 1 Gbps over wireless. 802.11a and g have a typical maximum of 54 Mbps. 802.11b (rarely used today) has a maximum of 11 Mbps. 802.3ab is the IEEE specification for 1-Gbps transfer over twisted-pair cables—it is wired, not wireless. By the way, this is also known as 1000BASE-T.
Which of the following is often broken down into groups of channels including 1-5, 6–10, and 11?
Image A. 802.11ac
Image B. 2.4 GHz
Image C. 5 GHz
Image D. 802.11a
B. In the United States, the 2.4-GHz frequency range is broken down into three categories: Channel 1–5, 6–10, and 11. By placing separate wireless networks on separate distant channels (such as 1 and 11), you can avoid overlapping and interference. 802.11ac and 802.11a are standards, not frequencies. 5 GHz uses channels such as 36, 40, 149, 153, and so on.
