Virtual Labs

Pathloss with Shadowing

1. In wireless propagation, what does 'shadowing' primarily refer to?

a: Signal loss that increases steadily with distance from the transmitter. Explanation

Explanation

b: Signal strength variations caused by large objects like hills or buildings blocking the path. Explanation

Explanation

c: Rapid signal fluctuations experienced over very short distances or time periods. Explanation

Explanation

d: Noise introduced by other electronic devices operating on the same frequency. Explanation

Explanation

2. The variations in signal strength due to shadowing are most commonly modeled using which statistical distribution?

a: Rayleigh distribution Explanation

Explanation

b: Log-normal distribution Explanation

Explanation

c: Rician distribution Explanation

Explanation

d: Uniform distribution Explanation

Explanation

3. What does the pathloss exponent describe in a propagation model?

a: The fixed amount of power lost at the transmitter. Explanation

Explanation

b: The rate at which the average signal power decreases as distance increases. Explanation

Explanation

c: The degree of signal fluctuation due to multi-path interference. Explanation

Explanation

d: The specific frequency band being used for communication. Explanation

Explanation

4. A high value for the pathloss exponent, such as four or five, typically indicates what type of environment?

a: An open, clear environment with no obstructions, like free space. Explanation

Explanation

b: An environment with a clear line-of-sight path and strong ground reflection. Explanation

Explanation

c: A complex urban environment with many buildings and obstructions. Explanation

Explanation

d: A pure vacuum with no atmosphere. Explanation

Explanation

5. What key characteristic is captured by the 'variance of shadow fading'?

a: The average signal power received from the transmitter. Explanation

Explanation

b: The rate of signal loss as the receiver moves away from the transmitter. Explanation

Explanation

c: The spread of signal strength measurements around the average value at a fixed distance. Explanation

Explanation

d: The time duration for which the signal is completely blocked. Explanation

Explanation

6. A large variance in shadow fading measurements suggests that the propagation environment is...

a: ...very uniform and predictable, like an open field. Explanation

Explanation

b: ...highly varied, with a diverse mix of obstacles and open spaces. Explanation

Explanation

c: ...dominated by a single, strong line-of-sight path. Explanation

Explanation

d: ...experiencing no signal loss from obstructions. Explanation

Explanation

7. Pathloss and shadowing are both considered part of which category of propagation effects?

a: Small-scale fading Explanation

Explanation

b: Doppler shift Explanation

Explanation

c: Large-scale propagation Explanation

Explanation

d: Phase noise Explanation

Explanation

8. What is the primary purpose of determining the pathloss exponent and shadow fading variance from measurements?

a: To determine the exact speed of the mobile device. Explanation

Explanation

b: To build a statistical model that can predict average signal coverage and variability. Explanation

Explanation

c: To eliminate all signal obstructions between the transmitter and receiver. Explanation

Explanation

d: To calculate the precise data transfer rate of the system. Explanation

Explanation

9. How is the effect of shadowing distinguished from the effect of pathloss?

a: Pathloss describes the average signal decrease with distance, while shadowing describes variations around that average. Explanation

Explanation

b: Shadowing describes the average signal decrease with distance, while pathloss describes variations around that average. Explanation

Explanation

c: Pathloss is only caused by buildings, while shadowing is only caused by hills. Explanation

Explanation

d: Pathloss and shadowing are two terms for the exact same physical phenomenon. Explanation

Explanation

10. To accurately determine the statistical characteristics of large-scale propagation, what is required?

a: A single, perfect signal strength reading at one location. Explanation

Explanation

b: The brand and model of the transmitter and receiver. Explanation

Explanation

c: The exact GPS coordinates of every building in the area. Explanation

Explanation

d: Numerous signal strength measurements taken at various locations and distances. Explanation

Explanation