Examkin

Question

Difficulty: MediumWireless Network Deployment and Standards

An enterprise administrator is finalizing the channel allocation plan for four wireless access points deployed in a linear arrangement along a long hallway to support 2.4 GHz legacy telemetry sensors. To minimize both co-channel interference (CCI) and adjacent-channel interference (ACI), which sequence of 2.4 GHz channels should be configured on the access points sequentially from one end of the hallway to the other?

  1. Channels 1, 6, 11, and 1Answer
  2. B
    Channels 1, 4, 7, and 10
  3. C
    Channels 1, 3, 6, and 9
  4. D
    Channels 2, 5, 8, and 11

Answer

Channels 1, 6, 11, and 1
The correct answer specifies using channels 1, 6, 11, and 1. In standard 2.4 GHz Wi-Fi deployments, 20 MHz channel widths require 25 MHz separation between center frequencies to prevent spectral overlap. Channels 1, 6, and 11 are the only three non-overlapping channels available. When deploying four access points in sequence, recycling channel 1 on the fourth access point places identical channels as far apart as possible, minimizing co-channel interference.

Step-by-Step Solution

1
Identify the band and channel bandwidth constraints
The 2.4 GHz ISM band uses 20 MHz wide channels operating on center frequencies spaced only 5 MHz apart.
Because 20 MHz channels require 25 MHz of total spectral separation to avoid overlapping, only three channels can operate simultaneously without interfering with each other.
2
Determine the non-overlapping channel set
Channels 1, 6, and 11 form the industry-standard non-overlapping set.
Channel 1 spans 2.401-2.423 GHz, channel 6 spans 2.426-2.448 GHz, and channel 11 spans 2.451-2.473 GHz.
3
Apply frequency reuse across four sequential access points
Assign channels sequentially as 1 -> 6 -> 11 -> 1.
Placing the recycled channel 1 at the opposite end of the hallway maximizes physical distance from the first access point, keeping co-channel interference to a minimum.

Key Concept

2.4 GHz Non-Overlapping Channels and Frequency Reuse
Estimated Time:1m 15s
Rate this question

Topics

Wireless Network Deployment and Standards

More questions from this topic