Wireless Fundamentals Flashcards

Which IEEE 802.11 amendment introduced OFDMA as a key feature for improved multi-user efficiency?

Answer: 802.11ax

802.11ax (Wi-Fi 6) introduced OFDMA, which divides channels into resource units to serve multiple clients simultaneously.

What is the primary purpose of a CSMA/CA mechanism in 802.11 wireless networks?

Answer: To avoid collisions before transmitting

CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) listens for channel activity and uses random backoff timers to reduce collisions.

Which wireless band typically provides greater range but lower throughput due to its lower frequency?

Answer: 2.4 GHz

The 2.4 GHz band propagates farther through obstacles but offers fewer non-overlapping channels and lower maximum throughput than 5 GHz.

What does EIRP stand for in the context of wireless networking?

Answer: Effective Isotropic Radiated Power

EIRP is the total radiated power combining transmit power and antenna gain, used by regulators to limit interference.

In 802.11 networks, what is the function of the ACK (Acknowledgment) frame?

Answer: To confirm successful receipt of a unicast data frame

The receiving station sends an ACK frame after successfully receiving a unicast frame to confirm delivery.

Which modulation technique is used by 802.11b to achieve its highest data rate of 11 Mbps?

Answer: CCK

802.11b uses Complementary Code Keying (CCK) to achieve 5.5 and 11 Mbps data rates.

What term describes the phenomenon where a wireless signal bounces off walls, floors, and ceilings, causing multiple copies to arrive at the receiver at different times?

Answer: Multipath

Multipath propagation occurs when signals reflect off surfaces and arrive at the receiver via multiple paths, potentially causing interference.