Wireless Fundamentals Flashcards

What does RSSI measure in a wireless network?

Answer: The relative strength of a received wireless signal

RSSI (Received Signal Strength Indicator) is a relative measurement of the power level of a received wireless signal.

Which technology allows multiple antennas to transmit and receive simultaneously in 802.11n and later, improving throughput?

Answer: MIMO

MIMO (Multiple Input Multiple Output) uses multiple antennas to send and receive multiple data streams simultaneously, increasing throughput.

What is the purpose of a Beacon frame in 802.11 wireless networks?

Answer: To periodically advertise the BSS and its capabilities

Beacon frames are periodically broadcast by APs to advertise the SSID, supported rates, and other BSS parameters.

What SNR (Signal-to-Noise Ratio) value in dB is generally considered the minimum for reliable VoIP over Wi-Fi?

Answer: 25 dB

An SNR of at least 25 dB is generally recommended for reliable VoIP traffic over Wi-Fi to ensure acceptable call quality.

Which channel bonding technique doubles the channel width from 20 MHz to 40 MHz in the 5 GHz band?

Answer: Channel bonding

Channel bonding combines two adjacent 20 MHz channels into a 40 MHz channel, nearly doubling maximum throughput.

What is the free-space path loss characteristic — as the distance between transmitter and receiver doubles, signal strength decreases by approximately how much?

Answer: 6 dB

In free space, doubling the distance results in approximately 6 dB of additional path loss, following the inverse square law.

In the context of 802.11 security, what does the 4-way handshake accomplish?

Answer: It derives and confirms the Pairwise Transient Key (PTK) for unicast encryption

The 4-way handshake confirms that both client and AP possess the correct PMK and derives the PTK used for unicast data encryption.