Question

Difficulty: MediumWireless Networking Standards and Technologies

A network technician is optimizing the 2.4 GHz wireless network for a small office. Access Point 1 is currently operating on Channel 1. Access Point 2, located in an adjacent hallway, was manually configured to Channel 3, causing users in the overlapping coverage zone to experience severe throughput degradation from adjacent-channel interference. Which channel should Access Point 2 be reconfigured to in order to completely eliminate channel overlap with Access Point 1?

  1. A
    Channel 2
  2. B
    Channel 4
  3. Channel 6Answer
  4. D
    Channel 5

Answer

Access Point 2 should be reconfigured to Channel 6 to eliminate adjacent-channel interference with Access Point 1.
In the 2.4 GHz wireless spectrum, channels are 20 MHz wide and spaced 5 MHz apart. To prevent adjacent-channel interference, wireless deployments must use non-overlapping channels. The standard non-overlapping channels in the 2.4 GHz band are 1, 6, and 11. Since Access Point 1 is on Channel 1, assigning Channel 6 to Access Point 2 ensures sufficient frequency separation so their signals do not bleed into each other.

Step-by-Step Solution

1
Identify the operating frequency band and channel width.
The network uses the 2.4 GHz Wi-Fi band with standard 20 MHz channel spacing.
In the 2.4 GHz spectrum, each 20 MHz channel spans across 5 individual channel numbers.
2
Determine the non-overlapping channel scheme for 2.4 GHz deployments.
The standard non-overlapping channels in North America are Channels 1, 6, and 11.
Channels 1, 6, and 11 have 25 MHz spacing between their center frequencies, preventing spectral overlap.
3
Evaluate the channel selection against Access Point 1 operating on Channel 1.
Channel 6 provides complete isolation from Channel 1 without adjacent-channel interference.
Channels 2, 3, 4, and 5 all partially overlap with Channel 1's frequency envelope.

Key Concept

2.4 GHz Non-Overlapping Channels (1, 6, 11)
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