Wireless Technologies & Network Fundamentals Flashcards

Which 802.11 amendment introduced the concept of BSS Coloring to reduce unnecessary channel deferral in dense deployments?

Answer: 802.11ax

BSS Coloring, introduced in 802.11ax, tags frames with a color identifier so stations can differentiate overlapping BSSs and reduce unnecessary backoff.

A Fresnel zone clearance calculation is most critical when designing which type of wireless link?

Answer: Point-to-point outdoor bridge

Fresnel zone clearance is essential for outdoor point-to-point bridges to ensure the signal path is unobstructed and minimize diffraction losses.

What is the function of the 802.11k amendment?

Answer: Enables radio resource measurement to assist client roaming decisions

802.11k provides Radio Resource Management (RRM), allowing APs to share neighbor reports with clients so they can make better-informed roaming decisions.

Which CSMA mechanism do 802.11 stations use to avoid collisions before transmitting?

Answer: CSMA/CA

802.11 uses CSMA/CA (Collision Avoidance), where stations sense the medium and use random backoff timers to minimize the chance of simultaneous transmissions.

What does a wireless site survey heat map primarily display?

Answer: Signal strength or coverage levels overlaid on a physical map

A heat map visually represents RF signal strength (typically RSSI) or coverage quality overlaid on a floor plan to identify coverage gaps.

In a MU-MIMO downlink transmission, what is the maximum number of simultaneous spatial streams supported by 802.11ac Wave 2?

Answer: 4

802.11ac Wave 2 supports downlink MU-MIMO with up to 4 simultaneous spatial streams transmitted to different clients at the same time.

Which security vulnerability does the KRACK (Key Reinstallation Attack) exploit in WPA2?

Answer: Nonce reuse caused by replaying handshake messages

KRACK exploits the WPA2 4-way handshake by forcing nonce reuse through handshake message replay, allowing decryption of encrypted traffic.