P1g-wireless Signals Flashcards
What is an advantage of radiation being refracted and reflected?
Radio signals can be received a long way from the transmitter
What is a disadvantage of radiation being refracted and reflected?
It can disrupt a signal by bending it away from the receiver dish
What does long distance communication depend on?
The refraction and resulting reflection of waves from the ionosphere
Being received by and re transmitted from satellites
What are the advantages of wireless technology?
No external/direct connection to telephone line needed
Portable
Convenient
Allows access when on the move
What is a disadvantage of wireless technology?
Aerial is needed to pick up signals
What are some common uses of wireless technology?
Tv
Radio
Mobile phones
Laptop
What are the advantages of DAB broadcasts?
More stations available
Less interference with other broadcasts
What are the disadvantages to DAB broadcasts?
May give poorer audio quality compared to FM
Not all areas covered
How does refraction affect communications?
Refraction at the interfaces of different layers of earths atmosphere
How does diffraction affect communications?
Diffraction by transmission dishes results in signal loss
What is the difference in transmitting waves with different frequencies?
Waves with higher frequencies / transmitted at a higher angle of elevation -gradually refracted back to earth
Waves with lower frequency/ transmitted at lower angle of elevation - refracted quickly back to earth
