Cell phone base stations may use either \"make before break\" or \"break before
ID: 2082908 • Letter: C
Question
Cell phone base stations may use either "make before break" or "break before make" to handle mobile handoff which transfers the mobile device from one base station to another. a. Give one advantages of using "make before break". compared to "break before make" b. a. Give one disadvantage of using "make before break", compared to "break before make" The velocity of waves depends on the density of the atmosphere, this phenomenon is called refraction. As the altitude increases above the surface of the Earth, the density of the atmosphere a._________ Increases b. ________ Decreases c. __________ Remains constant d. _______ Not enough information to determine This causes the electromagnetic wave to: a. __________ Bend away from the surface of the Earth b. __________ Travel in a straight line c. _________ Bend toward the surface of the EarthExplanation / Answer
52.
a)The major advantage of 'make before break' over 'break before make' is that,it maintains channels in multiple cells simultaneously and the call could only fail if all the channels are interfered or fade at the same time.So,chances of call termination due to failed handover is low.
b)The disadvantage of 'make before break' compared to 'break before make' is phone's hardware cost and complexity as 'break before make' uses only one channel for one call at any moment of time.So,it doesn't need to be capable of receiving multiple channels in parallel,which make it cheaper and simple.
53.
a)The density of atmosphere decreases as altitude increases from above suface of Earth.It is because gravity is weaker farther from earth center,So at higher altitudes air molecules can spread out more.
b) The reduced refractive index due to lower densities at the higher altitudes in the Earth's atmosphere bends the Electromagnetic wave towards the surface of Earth.