CCNA: Cisco Certified Network Associate — Question 718

What must be considered when using 802.11a?

Answer options

• A. It is chosen over 802.11b when a lower-cost solution is necessary
• B. It is susceptible to interference from 2.4 GHz devices such as microwave ovens
• C. It is compatible with 802.11b- and 802 11g-compliant wireless devices
• D. It is used in place of 802.11b/g when many nonoverlapping channels are required

Correct answer: D

Explanation

The correct answer is D because 802.11a offers a greater number of nonoverlapping channels in the 5 GHz band compared to 802.11b/g, which operate in the crowded 2.4 GHz band. Option A is incorrect as 802.11a is generally more expensive, option B is false since 802.11a is less susceptible to 2.4 GHz interference, and option C is wrong because 802.11a is not compatible with 802.11b and 802.11g devices.