CWDP Channel Planning and RF Design 2

Question 1

What channel width is recommended for high-density enterprise WLAN deployments to maximize the number of available non-overlapping channels in the 5 GHz band?

Accepted Answer

20 MHz

Answer

20 MHz channels maximize the number of non-overlapping channels available, which is critical in high-density environments to reduce co-channel interference.

Question 2

When using 40 MHz channel bonding in the 5 GHz band, what is the effect on the number of available non-overlapping channels compared to 20 MHz channels?

Accepted Answer

It roughly halves the number of available channels

Answer

Bonding two 20 MHz channels into a 40 MHz channel consumes twice the spectrum, cutting the number of non-overlapping channel pairs to roughly half the 20 MHz count.

Question 3

What is the purpose of DFS (Dynamic Frequency Selection) in the 5 GHz band?

Accepted Answer

To detect radar systems and move 802.11 devices off channels that interfere with them

Answer

DFS is a regulatory requirement that forces 802.11 devices to detect radar signals on certain 5 GHz channels and vacate those channels to avoid interfering with radar systems.

Question 4

Which hexagonal cell channel reuse pattern is standard for 2.4 GHz WLAN deployments?

Accepted Answer

Channels 1, 6, and 11 in a honeycomb pattern

Answer

A hexagonal cell pattern using channels 1, 6, and 11 — the only three non-overlapping 2.4 GHz channels in the US — is the standard approach for minimizing co-channel and adjacent-channel interference.

Question 5

In RF design, what is the 'cell edge' and why does it matter?

Accepted Answer

The outer boundary of an AP's coverage area where signal strength approaches the minimum usable threshold

Answer

The cell edge is where RF signal strength drops to the minimum acceptable level; designing consistent cell edges ensures overlap between APs and reliable roaming.

Certified Wireless Design Professional (CWDP) Practice Test

Certified Wireless Design Professional (CWDP) Practice Test

CWDP Channel Planning and RF Design 2