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220-1201 Practice Question: A technician is setting up a wireless network for…
A technician is setting up a wireless network for a small office that experiences heavy interference from neighboring businesses. The office uses many Bluetooth devices and cordless phones. Which 802.11 standard and frequency combination would minimize interference and provide the best performance?
⚠ Common exam trap
The 220-1201 exam often tests the misconception that newer standards like 802.11ax automatically solve interference problems, but the trap is that the frequency band choice (2.4 GHz vs. 5 GHz) is the primary factor in avoiding interference from common office devices like Bluetooth and cordless phones.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
802.11ac on 5 GHz
802.11ac operates exclusively on the 5 GHz frequency band, which is far less congested than 2.4 GHz. This avoids interference from Bluetooth devices and cordless phones (which predominantly use 2.4 GHz), providing cleaner channels and better performance in a dense interference environment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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802.11b/g on 2.4 GHz
Why it's wrong here
Choosing 802.11b/g on the 2.4 GHz band is a poor choice due to its inherent limitations. This frequency spectrum is highly congested, not only by other Wi-Fi networks but also by numerous non-Wi-Fi devices such as Bluetooth peripherals, cordless phones, and microwave ovens. This severe interference significantly degrades performance, leading to unreliable connections and substantially reduced throughput, making it unsuitable for modern wireless networking needs.
- ✗
802.11n on 2.4 GHz
Why it's wrong here
While 802.11n offers higher theoretical speeds than 802.11b/g and can operate on both 2.4 GHz and 5 GHz, configuring it solely for 2.4 GHz severely limits its potential. Despite its advancements like MIMO, operating in the crowded 2.4 GHz band means it still contends with the same pervasive interference from other devices. This congestion drastically reduces actual throughput and reliability, negating many of the standard's benefits.
- ✓
802.11ac on 5 GHz
Why this is correct
802.11ac is an excellent choice as it operates exclusively within the 5 GHz frequency band. This band offers a significantly larger number of non-overlapping channels and is far less susceptible to interference from common household appliances and older wireless technologies that crowd the 2.4 GHz spectrum. This allows 802.11ac to achieve much higher data rates and provide a more stable, high-performance wireless experience, ideal for demanding applications.
- ✗
802.11ax on 2.4 GHz
Why it's wrong here
Although 802.11ax (Wi-Fi 6) is the latest standard with advanced features like OFDMA and MU-MIMO designed for efficiency and capacity in dense environments, deploying it on the 2.4 GHz band still subjects it to fundamental physical limitations. The inherent congestion and interference from non-Wi-Fi devices in the 2.4 GHz spectrum will severely diminish the performance gains offered by 802.11ax. While it can improve efficiency within the 2.4 GHz band, it cannot overcome the pervasive external interference sources.
Go deeper
Related to this question
Learn chapter
Network Configuration: IP, DNS, DHCP
Key term
Bluetooth
Bluetooth is a short-range wireless technology used to connect devices like keyboards, mice, headphones, and smartphones without cables.
Key term
Basic Service Set Identifier
A Basic Service Set Identifier (BSSID) is the unique hardware address that identifies a specific wireless access point or a group of wireless devices communicating together.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.