CWS CWS WLAN Hardware and Antennas 5 — Questions and Answers
Question 1: What is the primary advantage of a distributed antenna system (DAS) in large venues?
- Higher per-antenna transmit power for greater range
- Even signal distribution using many low-power antennas to eliminate dead zones (Correct answer)
- Lower cost than standard access points
- Exclusive use of the 6 GHz Wi-Fi 6E band
Correct answer: Even signal distribution using many low-power antennas to eliminate dead zones
DAS uses many small, low-power antennas distributed throughout a space to provide consistent coverage without the dead zones created by fewer high-power antennas.
Question 2: Which 802.11 Wi-Fi 6 feature allows an AP to schedule client transmissions to reduce contention in dense environments?
- Beamforming
- OFDMA (Orthogonal Frequency Division Multiple Access) (Correct answer)
- WPA3
- Band steering
Correct answer: OFDMA (Orthogonal Frequency Division Multiple Access)
OFDMA divides channels into smaller resource units (RUs) and allows the AP to schedule multiple clients simultaneously on different sub-carriers, improving efficiency in dense deployments.
Question 3: What is the purpose of antenna beamforming in modern WLAN systems?
- To physically rotate the antenna toward the client
- To focus transmitted energy toward a specific client using phase manipulation (Correct answer)
- To increase the operating frequency of the radio
- To combine 2.4 GHz and 5 GHz signals into a single beam
Correct answer: To focus transmitted energy toward a specific client using phase manipulation
Beamforming uses signal phase adjustments across multiple antenna elements to constructively focus energy toward a targeted client, improving signal strength and reducing interference.
Question 4: A -70 dBm received signal level at a wireless client is generally considered to be:
- Excellent signal, suitable for all applications
- Good signal, suitable for most applications (Correct answer)
- Weak signal, may cause connection issues
- No signal, client cannot connect
Correct answer: Good signal, suitable for most applications
-70 dBm is generally considered a good received signal level, adequate for most WLAN applications though not as strong as -50 to -60 dBm.
Question 5: What is the function of the RF spectrum analyzer in WLAN site surveys?
- To measure TCP/IP throughput between client and server
- To identify non-802.11 interference sources such as microwaves and Bluetooth devices (Correct answer)
- To configure access point channel and power settings remotely
- To calculate the number of access points needed for coverage
Correct answer: To identify non-802.11 interference sources such as microwaves and Bluetooth devices
An RF spectrum analyzer displays all RF energy across a frequency band, allowing technicians to identify interference from non-Wi-Fi sources that standard Wi-Fi tools cannot detect.
Question 6: What is the recommended minimum overlap between adjacent access point coverage cells in an enterprise WLAN for seamless roaming?
- 5-10%
- 10-15%
- 15-20% (Correct answer)
- 25-30%
Correct answer: 15-20%
A 15-20% cell overlap ensures that roaming clients maintain a usable signal from the new AP before completely losing signal from the old one, enabling seamless handoff.
Question 7: Which wireless hardware component is responsible for converting digital data into radio frequency signals for transmission?
- Ethernet switch port
- RF transceiver (radio) (Correct answer)
- PoE injector
- Wireless LAN controller
Correct answer: RF transceiver (radio)
The RF transceiver (radio) in an access point performs the digital-to-analog conversion and modulates data onto the carrier frequency for transmission over the air.
CWS CWS WLAN Hardware and Antennas 5
What is the primary advantage of a distributed antenna system (DAS) in large venues?