ITT640 Part 1.2

Line-of-sight propagation requires:

• Antennas be visible to each other

• Satellite dishes

• Reflective buildings

• Frequency hopping

Which of the following affects wave propagation?

• Source coding

• Signal modulation

• Material in signal path

• Battery size

What happens to RF signals when they move away from the antenna?

• They stay the same

• They collapse

• They propagate or spread

• They gain amplitude

Propagation time formula is:

• Frequency / Time

• Distance / Propagation speed

• Distance × Frequency

• Amplitude × Phase

In free space, signal propagation speed is:

• 10⁶ m/s

• 3 × 10⁸ m/s

• 1 × 10⁴ m/s

• 9.8 m/s²

What type of propagation is used for long-distance shortwave radio?

• Line-of-sight

• Ground wave

• Sky wave

• Reflected wave

What must WLAN engineers understand to optimize access point location?

• Antenna price

• Device IPs

• RF propagation behavior

• Cable type

Which two main types of RF transmission are used in wireless LAN?

• Laser & LED

• FHSS & DSSS

• PSK & QAM

• TDM & FDM

What is the main advantage of spread spectrum?

• Lower cost

• Reduced jamming & interference

• Simpler setup

• Greater wire length

What does DSSS use to spread the signal?

• Frequency range

• Chips

• Voltage

• Phase