Examkin

Soru

Zorluk: ZorWireless Networking Standards and Technologies

A tier-2 IT technician is optimizing three newly mounted access points installed along an open-plan office floor. The access points operate in the 2.4 GHz band using standard 20 MHz channel widths. Access Point 1 is configured on Channel 1, and Access Point 2 is configured on Channel 6. A junior technician suggests setting Access Point 3 to Channel 3 to 'space out the channel numbers evenly.' Which of the following statements correctly identifies the flaw in this suggestion and states the proper configuration?

  1. Channel 3 causes adjacent-channel interference with both Channel 1 and Channel 6; Access Point 3 must be assigned to Channel 11.Cevap
  2. B
    Channel 3 creates co-channel interference with Channel 1; Access Point 3 must be assigned to Channel 14.
  3. C
    Channel 3 forces Access Point 3 into 40 MHz channel bonding mode; Access Point 3 must be assigned to Channel 9.
  4. D
    Channel 3 operates outside the unlicensed ISM spectrum; Access Point 3 must be assigned to Channel 5.

Cevap

Channel 3 causes adjacent-channel interference with both Channel 1 and Channel 6; Access Point 3 must be assigned to Channel 11.
In 2.4 GHz Wi-Fi networks using 20 MHz channel widths, each channel's transmission mask spills over onto neighboring channel numbers. Channels 1, 6, and 11 are the only three channels that do not overlap with one another. Choosing Channel 3 causes adjacent-channel interference with both Channel 1 and Channel 6. Assigning Access Point 3 to Channel 11 completes the non-overlapping channel plan and ensures clean wireless transmission.

Adım Adım Çözüm

1
Analyze the 2.4 GHz wireless frequency structure.
The 2.4 GHz ISM spectrum ranges from 2.412 GHz to 2.472 GHz, divided into channels spaced 5 MHz apart, while each channel requires 20 MHz of bandwidth.
Because each 20 MHz channel spans across 4 adjacent channel steps (20 MHz width / 5 MHz spacing), channels closer than 5 channel numbers apart share frequency space.
2
Evaluate the non-overlapping channel set.
The three primary non-overlapping channels in the 2.4 GHz band are Channel 1 (2.412 GHz), Channel 6 (2.437 GHz), and Channel 11 (2.462 GHz).
These three channels maintain a minimum 25 MHz separation between center frequencies, eliminating cross-talk and adjacent-channel noise.
3
Determine the impact of selecting Channel 3.
Channel 3 (center frequency 2.422 GHz) spans from 2.412 GHz to 2.432 GHz, overlapping Channel 1 (2.402–2.422 GHz) and Channel 6 (2.427–2.447 GHz).
This overlap produces severe adjacent-channel interference (ACI), causing packet corruption and frame retransmissions. Selecting Channel 11 avoids all overlap.

Anahtar Kavram

2.4 GHz Non-Overlapping Wi-Fi Channels
Tahmini Süre:1m 30s
Bu soruyu puanla

Konular

Wireless Networking Standards and Technologies

Bu konudan daha fazla soru