Exam N10-009 topic 1 question 66 discussion

Actual exam question from CompTIA's N10-009

Question #: 66
Topic #: 1

A network administrator is configuring access points for installation in a dense environment where coverage is often overlapping. Which of the following channel widths should the administrator choose to help minimize interference in the 2.4GHz spectrum?

A. 11MHz
B. 20MHz
C. 40MHz
D. 80MHz
E. 160MHz

Show Suggested Answer

Suggested Answer: B 🗳️

by chrys at Nov. 13, 2024, 5:24 p.m.

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chrys

Highly Voted 7 months, 2 weeks ago

20 MHz is absolutely correct. The wider the channel, the higher the risk that somewhere in its frequency range it will be hit with interference. Since 2.4 GHz is an especially crowded band, you want to avoid the risk of interference, even though it means that each mobile client will be stuck with less overall bandwidth for their connection

upvoted 5 times

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Alyssaleeb

Most Recent 1 month, 4 weeks ago

Selected Answer: B

The 2.4GHz band only has a few non-overlapping channels (channels 1, 6, and 11). If you use 20MHz width, each channel stays nice and narrow, reducing overlap and cutting down interference between nearby access points. Wider channels (like 40MHz or bigger) would overlap a lot more, creating more collisions and slower speeds, especially in a dense environment where tons of devices are close together. It wouldn't be 11MHz because its not a standard wifi channel width, its not used.

upvoted 1 times

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cdozier2

3 months, 1 week ago

Selected Answer: E

somebody please explain

upvoted 1 times

JBanksny

2 months ago

Correct answer: B. 20 MHz Why? In the 2.4 GHz band, the only widely supported channel width defined by 802.11 standards is 20 MHz. At that width you get three non-overlapping channels in North America (1, 6, 11). Narrower channels mean fewer adjacent-channel collisions. If you try to bond channels into 40 MHz (or wider) you consume most of the already-crowded 2.4 GHz spectrum, leaving little room for neighboring APs and greatly increasing co-channel and adjacent-channel interference. The other options are either too wide (40/80/160 MHz, suited to 5 GHz or 6 GHz where there is more spectrum) or non-standard for 2.4 GHz WLANs (11 MHz isn’t an IEEE-specified width)

upvoted 1 times

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HeatSquad77

6 months ago

Selected Answer: B

20 MHz

upvoted 2 times

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