Question

Difficulty: MediumTroubleshooting Wireless Connectivity and Signal Issues

A network technician is investigating performance degradation in a newly renovated office wing. Users report high packet loss and frequent disconnections when connected to the 2.4 GHz wireless network. An RF spectrum audit reveals that neighboring access points in the wing are currently operating on channels 1, 4, and 6. Which of the following configuration changes should the technician implement to resolve the transmission issues?

  1. Reconfigure the access point operating on channel 4 to use channel 11.Answer
  2. B
    Change the access point operating on channel 4 to operate on channel 3 to align closer with channel 1.
  3. C
    Increase the DHCP scope lease pool on the local router servicing the wireless subnet.
  4. D
    Modify the access switch port duplex setting from full-duplex to half-duplex for the access point.

Answer

Reconfigure the access point operating on channel 4 to use channel 11.
In 2.4 GHz Wi-Fi deployments, 20 MHz channels require a 5-channel separation to prevent overlapping frequencies. Channels 1, 6, and 11 are the standard non-overlapping channels. Operating on channel 4 causes adjacent-channel interference with neighboring access points on channels 1 and 6. Reconfiguring the channel 4 access point to channel 11 establishes a clean, non-overlapping channel design.

Step-by-Step Solution

1
Analyze the 2.4 GHz channel deployment plan.
Identified channels in use: 1, 4, and 6.
The 2.4 GHz band has 14 total channels, but only channels 1, 6, and 11 do not overlap with one another.
2
Identify the cause of wireless performance degradation.
Channel 4 partially overlaps with channel 1 and channel 6, creating adjacent-channel interference (ACI).
Adjacent-channel interference causes signal degradation and frame corruption because radios cannot cleanly decode transmissions from partially overlapping frequencies.
3
Determine the proper non-overlapping channel configuration.
Reassign channel 4 to channel 11.
Using channel 11 completes a proper 1/6/11 non-overlapping channel cell pattern across the office wing.

Key Concept

2.4 GHz Non-Overlapping Channel Selection and Adjacent-Channel Interference Mitigation
Estimated Time:1m 30s
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