Reducing Channel Overlap in AP-on-a-Stick Surveys

300-425 By islever Editorial Last updated

Short answer

CD Enable UNII-2e channels and use directional antennas to limit coverage area and reduce channel overlap.

Question

An engineer is performing an AP-on-a-stick survey and finds that the 5 GHz channel overlap is too high when an appropriate number of APs are used for the density requirements. Which two actions during the survey reduce channel overlap? (Choose two.)
  1. Raise the minimum data rate to 24 Mbps.
  2. Increase AP transmit power to improve the SNR.
  3. Allow the use of UNII-2e channels. Correct Answer
  4. Use directional antennas to limit the coverage area of some APs. Correct Answer
  5. Enable power saving mode.

Key Takeaways

Tests knowledge of spectrum availability and antenna directivity; the trap is confusing client-side power saving with network interference mitigation.

Learn how to minimize 5 GHz channel overlap during density surveys using UNII-2e channels and directional antennas. This guide explains why these options are correct for CCNA 300-425.

Common mistake: Many learners select A or B, thinking higher data rates or power reduce overlap, but these actually increase cell size or do not address spectral contention.

Expert Analysis

Why the Answer Is Correct

The correct actions are C and D. Enabling UNII-2e channels (Option C) expands the available non-overlapping spectrum in the 5 GHz band, directly reducing overlap when AP density is high. Using directional antennas (Option D) confines the RF coverage area, preventing signals from interfering with neighboring cells on the same channel.

Why the Other Options Are Wrong

Raising minimum data rates (A) reduces cell size but does not solve spectral overlap issues and can degrade performance at the edge. Increasing transmit power (B) expands coverage, worsening overlap and interference. Power saving mode (E) is a client-side feature and has no impact on RF channel planning or overlap.

Community Comment Notes

Community consensus strongly supports C and D. User crabb63 notes that power save mode disconnects clients, making it irrelevant for survey design. Farhad123 confirms that power save is a client choice and doesn't affect channel overlap, validating the exclusion of E. Another user points out that raising min data rate reduces cell size but isn't the primary solution for overlap compared to spectrum/antenna changes.

Official Reference

https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/config-guide/b_wl_17_9_cg/m_access_point_power_control.pdf

This link opens the official vendor documentation in a new tab.

Exam Strategy

When dealing with channel overlap in dense deployments, prioritize expanding available spectrum (more channels) and spatial isolation (directional antennas). Avoid options that only affect signal strength or client behavior.

Frequently Asked Questions

Why doesn't raising min data rate fix channel overlap?

It shrinks cell size but doesn't add spectrum or isolate cells, so overlap remains if channels are reused.

Does power saving mode help with RF interference?

No, it's a client-side battery-saving feature and has no effect on AP channel planning or interference.

More 300-425 FAQ →

Community Votes

CD
100%

100% of anonymous learners picked answer CD. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

  1. crabb63 👍 7
    I believe the answer is C and D. Clients are disconnected in power-save mode. https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/config-guide/b_wl_17_9_cg/m_access_point_power_control.pdf
  2. [Removed] 👍 4
    AD power saving mode no-sense Raise the minimum data rate to 24 Mbps actually reduce AP cell.
  3. Farhad123 👍 1
    need to correct my previous answer , Power save mode is working on client, where is not a choice here. as the question is about how to reduce channel overlapping during site survey , then data rate also is not an portion
  4. Farhad123 👍 1
    D and E are the right solutions

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