Today, satellites are used to provide wireless connectivity between different locations. What two prerequisites are needed for two different locations to communicate via satellite links?

A.
They must be connected via a phone line and have access to a modem.

B.
They must be within the satellite’s line of site and footprint.

C.
They must have broadband and a satellite in low Earth orbit.

D.
They must have a transponder and be within the satellite’s footprint.

Explanation:
B: For two different locations to communicate via satellite links, they must be within the satellite’s line of sight and footprint (area covered by the satellite). The sender of
information modulates the data onto a radio signal that is transmitted to the satellite. A transponder on the satellite receives this signal, amplifies it, and relays it to the receiver.
The receiver must have a certain type of antenna, which is one of those circular, dish-like components on top of buildings. The antenna contains one or more microwave
receivers, depending upon how many satellites it is accepting data from. The size of the footprint depends upon the type of satellite being used. It can be as large as a country or
only a few hundred feet in circumference.
A is incorrect because a phone line and a modem are not wireless. However, in most cases satellite broadband is a hybrid system that uses a regular phone line and modemlike
technologies for data and requests sent from the user’s machine, but employs a satellite link to send data to the user.
C is incorrect because the satellite provides broadband transmission. It is commonly used for television channels and PC Internet access. While it is certainly necessary to
have a satellite in orbit, and those in low Earth orbit are commonly used for two-way paging, international cellular communication, TV stations, and Internet use, it is not the best
answer to this question.
D is incorrect because the two locations do not require a transponder. The transponder is on the satellite itself. The transponder receives a signal, amplifies it, and sends it to
the receiver. However, it is necessary for the two locations to be within the satellite’s footprint.