H12-323_V2.0 · Question #276
WLAN air interface is a complex environment, and its performance is related to many factors. In addition to the co-frequency and adjacent-frequency interference between WLAN devices themselves…
The correct answer is A. Wireless game controller B. Cordless phone with the same frequency band C. Bluetooth devices D. Microwave oven. All four options are correct because they all operate in or near the same unlicensed ISM frequency bands (primarily 2.4 GHz) as WLAN devices, causing non-WLAN radio frequency (RF) interference. Wireless game controllers (A) typically transmit in the 2.4 GHz band and can disrupt…
Question
WLAN air interface is a complex environment, and its performance is related to many factors. In addition to the co-frequency and adjacent-frequency interference between WLAN devices themselves, non-WLAN devices will also interfere with the WLAN air interface performance. When deploying APs, you should avoid which of the following devices to prevent interference from affecting air interface performance? (Multiple choice)
Options
- AWireless game controller
- BCordless phone with the same frequency band
- CBluetooth devices
- DMicrowave oven
How the community answered
(34 responses)- A100% (34)
Explanation
All four options are correct because they all operate in or near the same unlicensed ISM frequency bands (primarily 2.4 GHz) as WLAN devices, causing non-WLAN radio frequency (RF) interference. Wireless game controllers (A) typically transmit in the 2.4 GHz band and can disrupt nearby AP signals. Cordless phones (B) operating in the same band generate direct co-channel or adjacent-channel interference, degrading throughput and increasing retransmissions. Bluetooth devices (C) share the 2.4 GHz band and use frequency-hopping spread spectrum, which still collides with Wi-Fi transmissions enough to reduce performance. Microwave ovens (D) are notorious 2.4 GHz interferers because their magnetrons leak broadband RF energy around 2.45 GHz, effectively jamming nearby APs. Since there are no wrong choices here, the key exam takeaway is that any device sharing or overlapping the 2.4 GHz or 5 GHz spectrum - not just other Wi-Fi devices - is a deployment concern.
Memory tip: Think "BCMG band crashers" - Bluetooth, Cordless phones, Microwaves, and Game controllers all crowd the 2.4 GHz band; when placing APs, physically distance them from all of these.
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