December
1998 QUESTION 3 Total Marks: 20 Marks |
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| (a) | Give two advantages of using fibre optics over
coaxial cable.
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[2] |
| (b) | Briefly describe any two types of
noise that can occur during transmission.
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[4] |
| (c) | In addition to noise, there are two other
impairments which can result in faults occurring during transmission. What are these two
faults?
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[2] |
| (d) | RS232-C is a physical layer standard
with four components. One is the procedural specification. Explain this feature of RS232-C
in detail, referring where necessary to the other parts of the specification.
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[8] |
| (e) | A modem is running at 9600 baud. It modulates signals using both amplitude modulation and frequency modulation. It uses two different amplitudes and four different frequencies. How many bits per second can it transmit? Show all working and assumptions that you make. | [4] |