RF Principles Flashcards
7 cards from real ACMA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 RF Principles flashcards as text
What is the purpose of Transmit Power Control (TPC) in Aruba wireless networks?
Answer: To dynamically adjust AP transmit power to minimize co-channel interference while maintaining coverage
TPC automatically adjusts AP transmit power levels to reduce interference between APs while ensuring clients maintain sufficient coverage throughout the network.
What RF characteristic determines how much an RF signal is scattered when it strikes a rough or irregular surface?
Answer: Scattering
Scattering occurs when RF signals strike irregular or rough surfaces, causing the energy to disperse in many directions rather than reflecting cleanly.
Which of the following correctly describes the concept of half-power beamwidth for a directional antenna?
Answer: The angular width of the antenna's main lobe measured between the -3 dB points on each side
Half-power beamwidth is the angular width of an antenna's main lobe measured between the two points where power drops to half (-3 dB) of the peak value.
What is diffraction in the context of RF propagation?
Answer: The ability of RF waves to bend around obstacles and edges
RF diffraction allows radio waves to bend around the edges of obstacles such as buildings or hills, enabling signals to reach areas not in the direct line of sight.
In the 5 GHz band, approximately how many non-overlapping 20 MHz channels are available in the U.S. (including UNII-1, UNII-2, UNII-2e, and UNII-3)?
Answer: 24
The 5 GHz band in the U.S. offers approximately 24 non-overlapping 20 MHz channels across the UNII-1, UNII-2, UNII-2e, and UNII-3 sub-bands.
What is the main RF challenge introduced by deploying APs in a high-density environment such as a stadium or conference center?
Answer: Co-channel interference caused by many APs operating on the same or adjacent channels in close proximity
In high-density environments, the close proximity of many APs creates significant co-channel and adjacent channel interference, requiring careful channel planning and reduced transmit power.
What does the term 'link budget' encompass in a wireless network design?
Answer: The total calculation of all gains and losses in an RF link to determine if a connection will be reliable
A link budget accounts for transmit power, antenna gains, cable losses, path loss, and receiver sensitivity to determine whether a wireless link will achieve the required SNR.