Reference no: EM132411292
Assignment - Physical Layer
Review questions -
1. What is the ATIS telecom glossary? How can it be useful to you?
2. What is the primary responsibility of the physical layer in data communication?
3. Define physical medium in the context of computer networking. What are the common physical media used in computer networks?
4. What properties are required for a material to be suitable for use as a physical medium in computer networks?
5. What is UTP? Why is the copper cable commonly used in computer networks called UTP?
6. What are the common categories of copper cable used in networks? Under what conditions would you prefer to use each category of cable?
7. What factors favor the use of optical fiber as a physical medium over copper?
8. What is total internal reflection? How does it help optical fiber transmit light signals efficiently?
9. What are the two categories of optical fiber? Under what conditions is each category preferred?
10. What are the components of optical fiber? What is the role of each component?
11. Define data.
12. Define signal.
13. What is the need to convert data to signals?
14. What are the properties of a good signal?
15. What is modulation? How does modulation help in data transmission?
16. What is amplitude modulation?
17. How does noise affect signals? What happens if the level of noise becomes too high relative to the strength of the signal?
18. Given a communication channel with a bandwidth of 3,000Hz, and a signal to noise ratio of 1,000. Use Shannon's theorem to calculate the maximum data rate that can be supported by this channel. (this is close to the traditional phone line)
19. Why is binary representation preferred in computers over common representations such as decimal?
20. Briefly describe the standard procedure used by the physical layer to send and receive data as a signal.
21. What is the ASCII code? Why is it useful in data communication? What is the ASCII code for the letter a? For the letter A?
22. What is multiplexing?
23. What are some examples of multiplexing in day-to-day life?
24. Describe how the interstate system may be seen as a multiplexed transportation system.
25. What are the two categories of multiplexing?
Critical thinking question -
1. You have been given a truck load of $100 bills, but are not allowed to use them as currency. What are three useful things you can do with the currency bills?
2. You have access to unlimited electricity for a month from your power company, with the condition that this electricity must be used directly, i.e. it cannot be converted to other forms of energy by conventional electrical devices (e.g. bulbs, computers, air-conditioners etc). What are some (say three) useful things you can do with this electricity?
IT infrastructure design exercise -
Using the information about TrendyWidgets provided with the Firm details in the IT infrastructure design exercise, answer the following questions.
1. For each location (Tampa, Amsterdam, Mumbai and Singapore), identify the most suitable physical medium to build the network. Make a rough estimate of the total quantity of the media that will be needed for each location. Use online or other resources to estimate the cost of purchasing enough quantities of the medium for each location.
2. Identify the most suitable physical medium to connect the different locations to each other (the long-distance links).
Example case questions -
1. Visit the website GREATACHIEVEMENTS Which of the top technologies of the 20th century could be categorized as a networking technology, if a network is defined in more general terms as an interconnection of three or more interacting entities?
2. For each of these technologies, briefly describe how networking (interaction) improves the utility of stand-alone components in the network.
3. Why should power be cheap at night and expensive during the day? You may find the Wikipedia article on capacity factors useful.
4. What changes in behaviors will be required of people to exploit the potential of the smart grid?
5. It is expected that smart meters will report the current price of power and smart appliances will be programmable to operate only when power prices fall below values you specify. How might you change your energy usage if smart meters and smart appliances were installed in your house?
6. It is expected that the smart grid will allow you to sell power stored in batteries (charged when power prices are low) or generated using solar, wind, and other means. What changes do you expect to see in your neighborhood if these technologies go mainstream?
7. Broadband over power line (BPL) may allow your local power company to compete as an Internet Service Provider (ISP). What advantages for the power company do you foresee over your current ISP if your power company decides to actually offer ISP service?
8. Using information from the Internet and other sources, write a short report (two to three paragraphs) about the smart-grid initiatives being undertaken by your local power company.