Homework One - Emma Ruth Tiong's

ELHT 553 B11
General Instructions: To be submitted on October 22, 2004. Should be written in Engineering Lettering. Write you name on the top
left hand side of the paper. NO TITLE PAGE. Copy and answer.
1. Why are protocols and standards needed?
2. Give your own example of how the number of users can affect the performance of a network.
3. Define criteria for network reliability other than those defined in the lecture.
4. Suppose you add two new devices to an existing five-device network, if you have a fully connected mesh topology, how many new cable
lines are needed? If, however, the devices are arranged in a ring, how many new cable lines are needed?
5. When a party makes a local telephone call to another party, is this a point to point or multipoint line configuration? Explain.
6. What is the purpose of translation by the presentation layer?
7. How can a composite signal be decomposed into its individual frequencies?
8. What is the phase shift for the following?
a. A sine wave with the maximum amplitude at time zero.
b. A sine wave with the maximum amplitude after ¼ cycle.
c. A sine wave with zero amplitude after ¼ cycle and decreasing
9. A device is sending out data at the rate of 1000 bps, how long does it take to send out 16 bits? 100 characters (assume there are 8 bits
per character).
10. A line has a signal to noise ratio of 1000 and a bandwidth of 4000 kHz. What is the maximum data rate supported by this line?
11. What transmission medium should be used for an environment with many high – voltage devices?