VDV Wireless Technology 3 — Questions and Answers
Question 1: Which 802.11 amendment introduced the 6 GHz band for Wi-Fi use?
- 802.11ac
- 802.11ax (Correct answer)
- 802.11be
- 802.11ad
Correct answer: 802.11ax
802.11ax (Wi-Fi 6E) was the first amendment to include the 6 GHz band, providing additional spectrum with less interference.
Question 2: What is the primary function of a wireless LAN controller (WLC) in an enterprise network?
- To provide DHCP addresses to wireless clients
- To centrally manage and configure multiple access points (Correct answer)
- To amplify wireless signals between floors
- To convert wireless to wired signals
Correct answer: To centrally manage and configure multiple access points
A WLC centrally manages AP configurations, roaming, security policies, and firmware updates across the enterprise WLAN.
Question 3: In wireless communications, what is 'multipath fading'?
- Signal loss due to rain or atmospheric conditions
- Signal degradation caused by multiple reflected copies of a signal arriving at different times (Correct answer)
- Fading caused by operating too many channels simultaneously
- Gradual signal loss over long cable runs
Correct answer: Signal degradation caused by multiple reflected copies of a signal arriving at different times
Multipath fading occurs when reflected RF signals arrive at the receiver slightly delayed, causing destructive interference with the direct signal.
Question 4: What type of antenna pattern is most appropriate for providing coverage in a long hallway?
- Omnidirectional antenna
- Yagi directional antenna (Correct answer)
- Panel antenna mounted at one end
- Patch antenna aimed upward
Correct answer: Yagi directional antenna
A Yagi antenna's narrow, elongated beam pattern is ideal for directing RF energy down a long hallway corridor.
Question 5: Which wireless standard is specifically designed for short-range, high-bandwidth transmission in the 60 GHz band?
- 802.11n
- 802.11ad (WiGig) (Correct answer)
- 802.11ac
- 802.11g
Correct answer: 802.11ad (WiGig)
802.11ad (WiGig) operates in the 60 GHz mmWave band, offering multi-gigabit speeds over very short distances.
Question 6: A technician is deploying an outdoor point-to-point wireless bridge over 3 miles. What is the most critical calculation to perform?
- DHCP lease time
- Fresnel zone clearance (Correct answer)
- SSID broadcast interval
- Channel bonding width
Correct answer: Fresnel zone clearance
Fresnel zone clearance ensures the radio path is free of obstructions that would attenuate the signal on a long-distance wireless link.
Question 7: What does EIRP stand for in wireless system design?
- Effective Isotropic Radiated Power (Correct answer)
- Enhanced Internal Radio Protocol
- Equivalent Interference Reduction Parameter
- Extended Infrared Reception Profile
Correct answer: Effective Isotropic Radiated Power
EIRP (Effective Isotropic Radiated Power) is the total power radiated in a single direction, combining transmitter output power and antenna gain.
VDV Wireless Technology 3
Which 802.11 amendment introduced the 6 GHz band for Wi-Fi use?