Wireless Networking Fundamentals & Technologies Flashcards

What type of antenna pattern radiates power equally in all directions in the horizontal plane?

Answer: Omni-directional

An omni-directional antenna radiates RF energy equally in all horizontal directions, producing a donut-shaped 3D radiation pattern.

In Wi-Fi, what does RSSI measure?

Answer: The relative received signal strength of a wireless signal

RSSI (Received Signal Strength Indicator) is a relative measurement of the power level of a received radio signal, typically expressed in negative dBm values.

Which Wi-Fi frame type is responsible for negotiating association between a client and an AP?

Answer: Management frame

Management frames handle administrative tasks such as authentication, association, and beacon transmission between clients and APs.

What is the primary purpose of RTS/CTS in 802.11?

Answer: To mitigate the hidden node problem by reserving the medium

RTS/CTS (Request to Send / Clear to Send) reserves the wireless medium before a data transmission, reducing collisions caused by hidden nodes.

When a wireless client moves between APs within the same ESS without losing its IP address, this is called:

Answer: Layer 2 roaming

Layer 2 roaming occurs when a client transitions between APs on the same subnet/VLAN, retaining its IP address without requiring DHCP renewal.

Which modulation scheme is used by 802.11ax that was NOT available in 802.11ac?

Answer: 1024-QAM

802.11ax (Wi-Fi 6) introduced 1024-QAM, encoding 10 bits per symbol and providing approximately 25% higher throughput than 256-QAM when signal conditions allow.

What is the frequency range of the 6 GHz band introduced for Wi-Fi use in the US?

Answer: 5.925–7.125 GHz

The FCC opened 5.925–7.125 GHz (1200 MHz) for unlicensed Wi-Fi use in the US, enabling 802.11ax (Wi-Fi 6E) and 802.11be (Wi-Fi 7) deployments.