Mixed Deck — All CWT Topics Flashcards

Which 802.11 amendment introduced MU-MIMO for both uplink and downlink?

Answer: 802.11ax

802.11ax (Wi-Fi 6) introduced uplink and downlink MU-MIMO, whereas 802.11ac supported only downlink MU-MIMO.

How does a PoE Power Sourcing Equipment (PSE) detect a valid Powered Device (PD) before applying full power?

Answer: It applies a low-voltage DC signature detection signal

A PSE applies a low-voltage DC detection signal to identify the characteristic resistive signature (approximately 25kΩ) of a valid PD before committing full power.

In Certified Wireless Technician practice, what is the FIRST step when a safety hazard is identified in the workplace?

Answer: Immediately secure the area and report the hazard

When a safety hazard is identified, the immediate priority is to secure the area to prevent injury and report the hazard through proper channels.

What is the primary function of BSS Coloring introduced in 802.11ax?

Answer: Reduce unnecessary channel contention by identifying overlapping BSS transmissions

BSS Coloring marks frames with a color identifier so devices can distinguish between transmissions from their own BSS and neighboring BSSs, reducing unnecessary backoff.

What is the PRIMARY purpose of obtaining CWT certification in Certified Wireless Technician?

Answer: To demonstrate verified competency and adherence to professional standards

Certification demonstrates verified competency and adherence to professional standards.

A technician performs a packet capture and sees many 802.11 Probe Request frames but few Probe Responses. This suggests:

Answer: The AP is overloaded and dropping management frames

If an AP is heavily loaded or experiencing resource exhaustion, it may fail to respond to client probe requests in a timely manner.

When configuring band steering on a dual-band AP, what is the intended outcome?

Answer: Encourage capable clients to connect on the 5 GHz band

Band steering nudges dual-band capable clients toward the 5 GHz band to reduce congestion on the 2.4 GHz band.

A wireless technician needs to prevent rogue APs from associating with the corporate WLAN. Which feature should be enabled on the WLAN controller?

Answer: Rogue AP containment

Rogue AP containment actively de-authenticates clients that attempt to connect to unauthorized access points.

What is the maximum legal EIRP for a point-to-multipoint (PtMP) 5 GHz outdoor link under FCC rules?

Answer: 4 watts (36 dBm)

The FCC allows up to 4 watts (36 dBm) EIRP for point-to-multipoint 5 GHz outdoor deployments in the UNII-1 and UNII-3 bands.

What is the 802.11v standard and what feature does it add for wireless network management?

Answer: BSS Transition Management, which allows APs to send suggestions to clients recommending they roam to a better AP

802.11v (BSS Transition Management) enables APs to proactively suggest that clients roam to a better AP, helping the network steer clients away from congested or weak APs.

What does RSSI measure in a Wi-Fi network?

Answer: The relative received signal strength at a wireless device

RSSI (Received Signal Strength Indicator) is a relative measure of the power level of a received radio signal, typically expressed as a negative dBm value.

A technician notices that wireless clients in a conference room experience high latency during large meetings. Which likely cause should be investigated first?

Answer: High client density is causing medium contention and channel saturation

High client density causes increased 802.11 medium contention, leading to longer backoff times and elevated latency as all clients compete for airtime on the same channel.

What encryption algorithm does WPA3-Personal use to replace the Pre-Shared Key (PSK) handshake?

Answer: Simultaneous Authentication of Equals (SAE)

WPA3-Personal replaces PSK with SAE (Dragonfly handshake), providing forward secrecy and resistance to offline dictionary attacks.

What best practice should be followed when planning power budgets for a PoE switch in a wireless deployment?

Answer: Sum device power requirements by class and add 20–25% headroom

Summing per-device class power requirements and adding 20–25% headroom prevents power budget exhaustion, accommodating startup surges and future device additions.

During a post-installation walkthrough, you notice dead spots in areas predicted to have coverage. What is the most common cause?

Answer: Obstructions not accounted for in the predictive site survey

Predictive surveys use building blueprints that may not reflect actual RF-attenuating materials like dense walls, metal shelving, or HVAC ducts.

When new equipment is introduced in Certified Wireless Technician, what is REQUIRED before staff use it?

Answer: Formal training, competency verification, and documentation

Formal training, competency verification, and documented training completion are required.

A technician measures 42V at a PoE access point when the PSE outputs 48V. What is the most likely cause?

Answer: Excessive cable length or high cable resistance causing voltage drop

Voltage drop across the cable (V = IR) reduces the voltage at the PD below the PSE output; longer cables or higher-resistance cabling amplifies this effect.

A site survey report shows a persistent -85 dBm noise floor in the 5 GHz band in one area. What does this indicate?

Answer: A significant source of co-channel or adjacent-channel interference

A noise floor of -85 dBm in 5 GHz is elevated and suggests a significant interference source degrading SNR.

BSS Coloring in 802.11ax is designed to improve which aspect of WLAN performance?

Answer: Spatial reuse by allowing concurrent transmissions in overlapping BSSs

BSS Coloring tags frames with a color identifier so stations can differentiate overlapping BSS transmissions and defer only when necessary, improving spatial reuse.

Which foundational principle is MOST important for success in Certified Wireless Technician?

Answer: Commitment to continuous learning, ethical practice, and quality outcomes

Success requires continuous learning, ethical practice, and focus on quality outcomes.