In wireless local area networks (WLANs), which of the following is not a disadvantage when compared with wired Ethernet—considering throughput, reliability, and radio interference?

Introduction / Context:
Wireless LANs (WLANs) provide mobility and flexible deployment, but they also face well-known trade-offs relative to wired Ethernet. This question tests whether you can distinguish real disadvantages (such as lower throughput, higher error rates, and radio interference) from distractors and identify the option that is not a disadvantage.

Given Data / Assumptions:

• We are comparing typical enterprise/home WLANs (for example, IEEE 802.11) with wired Ethernet (for example, IEEE 802.3).
• Environment includes common issues like attenuation, multipath, adjacent/co-channel interference, and shared-medium contention.
• Throughput referenced is effective user throughput, not only the PHY rate printed on the box.

Concept / Approach:
Against wired networks, WLANs routinely exhibit: (1) lower effective throughput because half-duplex CSMA/CA and overhead (headers, control frames, retries) reduce usable data rate; (2) higher error rates because radio links are susceptible to noise, fading, and blockage; and (3) interference from overlapping access points or neighboring devices using the same spectrum (microwaves, Bluetooth, Zigbee). Therefore, each listed item is a true disadvantage. The correct choice for “which is not a disadvantage” is that none of them qualify as non-disadvantages—hence “None of the above”.

Step-by-Step Solution:

Verification / Alternative check:
Measure TCP/UDP throughput on a typical 802.11 network versus a gigabit Ethernet link; verify increased retransmissions and lower goodput on Wi-Fi under contention or at range. Spectrum analysis will reveal interferers, confirming the interference claim.

Why Other Options Are Wrong:

• Higher error rate: This does happen due to the wireless medium.
• Interference among computers: Co-channel and adjacent-channel interference are common.
• Slower data transmission: Effective throughput is typically lower than wired.
• All of the above: The prompt asks for what is not a disadvantage; saying “All of the above” would assert they are all disadvantages, but does not answer the “not” criterion.

Common Pitfalls:
Confusing PHY rate (for example, 300 Mbps) with real application throughput; ignoring effects of distance, walls, and contention; or assuming modern Wi-Fi eliminates interference entirely—it does not.

Final Answer:
None of the above (all listed items are genuine disadvantages of WLANs)