1 T215A: Communication and information technologies (I) ______________________________________________________________________________ Tutor-Marked Assignment Fall 2015 ______________________________________

1
T215A: Communication and information technologies (I)
______________________________________________________________________________ Tutor-Marked Assignment Fall 2015 _____________________________________________________________________________ Cut-off date: To be assigned by deanship _____________________________________________________________________________ Total Marks: 100
TMA Contents Question 1 (30 marks)…………………………………………………… Question 2 (40 marks)…………………………………………………… Question 3 (30 marks)……………………………………………………
Plagiarism Warning:
As per AOU rules and regulations, all students are required to submit their own TMA work and avoid plagiarism. The AOU has implemented sophisticated techniques for plagiarism detection. You must provide all references in case you use and quote another person's work in your TMA. You will be penalized for any act of plagiarism as per the AOU's rules and regulations.
Declaration of No Plagiarism by Student (to be signed and submitted by student with TMA work):
I hereby declare that this submitted TMA work is a result of my own efforts and I have not plagiarized any other person's work. I have provided all references of information that I have used and quoted in my TMA work.
Name of Student:………………………………..
Signature:…………………………………………...
Date:……………………………………………………
2

Question 1:
This question carries 30% of the marks for this assignment.
Internet security systems are becoming increasing important since the threats to internet security are becoming ever more sophisticated. Also, more and more businesses are being conducted suing the internet and hence to safeguard the internet resources against malicious attacks is extremely important. Using the internet and other resources (e.g., books and AOU e-library), write a short report explaining the following factors:
 Describe a computer virus in the context of internet security. Discuss the damage that a computer virus can cause to a computer system. Also discuss the security measures that are commonly implemented to safeguard against computer viruses. (6 marks)  Describe a computer worm in the context of internet security. Discuss the damage that a computer worm can cause. (6 marks)  Discuss the term computer hacking. Discuss the ethical issues concerning computer hacking. (6 marks)  Describe briefly, a firewall in the context of internet security. Discuss the Application Layer Firewall and the Network Layer Firewall in your report. (6 marks) Short Report Writing:
Please adhere to the following guidelines for writing your report:
Your report should be between 500 and 600 words in length. Under-length and over-length reports will be penalized. Your report should include at least two figures and/or tables. Do not forget to include a caption for each figure/table and to use cross-referencing. (2 Marks) Ensure that your report meets the objectives, has an appropriate structure and style, and that its technical level is appropriate for the audience, purpose and medium. For more details, you can refer to the T215 textbooks (Block 1 – Part 7; Block 2 – Part 7 and Block 3). (2 marks) You must cite all the references i.e. any internet web site, book, journal, article etc. that you have used as a source of information for your report (2 marks) You are advised to remind yourself of the issues concerning plagiarism.
3
Question 2:
This question carries 40% of the marks for this assignment.
WLAN “Wireless local area network” enables devices to communicate with each other without the constraints of connecting cables. Wireless LANs use radio signals as the communication medium instead of wires. WLAN standards are specified by the Institute of Electrical and Electronics Engineers (IEEE) and known as the IEEE 802.11 family of standards for wireless LANs. Using the internet and other resources (e.g., books and AOU e-library), write a report explaining the following factors:
 What standards are contained in the IEEE 802.11 wireless family? (6 marks)  Describe briefly, at least three common and frequent attacks made on WLAN networks? (6 marks)  In the context of network security what do we mean by “tunneling”? How it works? Provide your explanation with a diagram. (9 marks)  Explain briefly, at least, three common protocols and methods used to secure WLAN transmissions? (9 marks)
Report Writing:
Please adhere to the following guidelines for writing your report:
Your report should be between 800 and 1000 words in length. Under-length and over-length reports will be penalized. Your report should include at least two figures and/or tables. Do not forget to include a caption for each figure/table and to use cross-referencing. (3 Marks) Ensure that your report meets the objectives, has an appropriate structure and style, and that its technical level is appropriate for the audience, purpose and medium. For more details, you can refer to the T215 textbooks (Block 1 – Part 7; Block 2 – Part 7 and Block 3). (4 marks) You must cite all the references i.e. any internet web site, book, journal, article etc. that you have used as a source of information for your report (3 marks) You are advised to remind yourself of the issues concerning plagiarism.
4
Question 3:
This question carries 30% of the marks for this assignment. Answer all of the following parts:
1. WEP is part of the original 802.11 standard for wireless LAN and provides an optional encryption procedure. What is the main aim of WEP? Explain how WEP works and how its encryption scheme works. (8 marks)
2. Suppose a memory card is used that can store 16 GB. What is the smallest compression ratio that a user can set the camera to if he wants to store 4000 photos on the card and the raw photo size is 16 MB? (Assume 1 GB=1000 MB) (6 marks)
3. If eight users are connected to a wireless network that offers a maximum data rate of 200 Mbit/s and a throughput of 40%, what is the typical average practical message data rate available for each user? (8 marks)
4. From your study of GSM mobile telephony system, state four essential features of this digital mobile system? (8 marks)
***************************
End of TMA questions