Itec 250 Assignment 5

Instructions: This is an individual assignment. Use the blackboard to submit your word file with answers by 11:59 pm on the due date (no hard copies please). Late submissions will receive a zero grade. Start working on this early.

1. a) Distinguish between omnidirectional and dish antennas in terms of operation. b) Under what circumstances would you use an omnidirectional antenna? c) Under what circumstances would you use a dish antenna? d) What type of antenna normally is used in WLANs? Why?

2. a) Which offers more reliable transmission characteristics-UTP or radio transmission? b) What propagation problems become worse as frequency increases?

3. If the signal strength from an omnidirectional radio source is 8 mW at 30 meters, how strong will it be at 120 meters? Show your work.

4. a) Distinguish among the frequency spectrum, service bands, and channels. b) In radio, how can you send multiple signals without the signals interfering with one another?

5. a) What is a channel bandwidth? b) If the lowest frequency in a channel is 1.22MHz and the highest frequency is 1.25 MHz, what is the channel bandwidth? c) Why is a large channel bandwidth desirable?

6. a) Write the Shannon Equation. List what each letter is in the equation. b) What happens to the maximum possible propagation speed in a channel if the bandwidth is tripled while the signal-to-noise ratio remains the same?

7. a) Do WLANs today use licensed or unlicensed bands? b) What is the disadvantage of using unlicensed bands?

8. In unlicensed bands, what type of transmission method is required by regulators?