TELECOMMUNICATION

Question 1

Outline how a GPS satellite system operates

Answer 1

4 satellites are used to determine the positioning of a user, 3 of the satellites use triangulation to determine 3 intersection points and transmit signals to a receiver to indicate its location and time. The 4th satellite uses its atomic clock to record any inaccuracies of the GPS clock in order to accurately locate the position of the user which is at the centre of the 3 intersection points.

Question 2

Compare and contrast Analogue and Digital signals

Answer 2

Digital signals consist of discrete (discontinuous) values to represenet information, while analogue systems use a continuous range of values to represent information.

Question 3

Outline an advantage and disadvantage of analogue signals for transmission

Answer 3

Advantage: transmision of signals is more accurate and uses less bandwith

Disadvantage: affected by electrical noise, more difficult to multiplex, quality is easily lost

Question 4

Outline an advantage and disadvantage of digital signals for transmission

Answer 4

Advantage: easily compressed, more reliable and secure, easily interfaced with other digital systems

Disadvantage: information can be loss in sampling, requires greater bandwidth

Question 5

Discuss methods for increasing the signal strength of a receiving antenna

Answer 5

Signal Amplification: A weak input signal to an antenna can be boosted by a mast mounted amplifier that increases signal strength to the appliance

Raising and redirecting antenna: repositioning an antenna so that the line of sight to the microwave repeater tower can increase signal strength

directional antenna: specialist directional antenna are designed to more focus signal energy thus increasing signal strength