7347Elem Wireless Networks Assessment Answer

Question:

Candidates’ answers to questions can be prepared in a single Word document, using the equation editor as appropriate. The Word document should be converted to a PDF format, prior to final submission in Canvas.

· Candidates may also prepare handwritten answers to examinations if they wish. These must be clear and legible. Illegible answers will not be marked.  must then be scanned and saved as PDF format, prior to final submission in Canvas.

· It is essential that all PDF pages are oriented in the normal upright portrait reading mode. Pages must not be rotated either clockwise nor anticlockwise, nor appear upside down. Pages not in the normal upright reading format, will not be marked.

· Candidates may wish to download the free Adobe Scan app or Scanner for Me app if they do not have access to a desktop scanner.

· If you are not able to submit your answers in the required PDF format, you must urgently contact the module leader to seek further advice.

Discuss what you understand by each of the following:

Authentication, Integrity

Briefly outline the technical process whereby each is implemented. Explain the advantage of using each as part of a network infrastructure.

b. Encryption techniques have several modes of operation. Discuss the operation of ‘Cypher Feedback Mode’ and ‘Counter Mode’. Explain which types of data transfer are they most suited to and why.

c. Security for Internet of Things (IoT) and Cyberphysical Systems (CPS) are important discussion topics.

i. Outline how the operational environments associated with CPS and IoT may affect how security requirements are considered.

ii. The following are some of the concepts which may be considered when examining security within IoT and CPS:

a. Physical Interface

b. Availability

c. Secure routing

You should discuss each concept and include the following A technical explanation.

Outline why the issue is more significant for one of IoT or CPS

Outline why it is LESS significant for the other.

a. Explain the bandwidth delay product in the context of Transmission Control Protocol (TCP) connections.

b. A network connection consists of three links as follows: a 10 Mbps link with Round-Trip Time (RTT) of 5 µs, a 1 Gbps link with RTT of 1 µs, and 100 Mbps link with RTT 2 µs.

i. What are the reasonable TCP window sizes for the individual connections on this link?

ii. Comment on values you have answered in part b.i above, and the implications for TCP traffic.

c.

Outline the significant change introduced by the ‘Binary Increase Congestion’ variant of TCP (BIC) and the impact it had on TCP performance.

d. Multipath TCP (MPTCP) is a development of original TCP.

i. Discuss the justification and aims for the development of MPTCP.

ii. Outline the main elements of MPTCP operation.

iii. Congestion control is a significant feature of TCP. Discuss a scenario where a congested link carries both MPTCP traffic and regular traffic. You should mention how both TCP and MPTCP flows might be affected by congestion, and actions which could be taken to address the situation.

Q3.

a. Compare the operation and application of random and reservation based Multiple Access techniques. You should include a discussion of the suitability of random or reservation based to different communication scenarios.

b. Discuss the effect of delay and data loss in the following situations: Interactive voice traffic (e.g. Skype™ or traditional voice calls) File upload. (e.g. transfer a text file or spreadsheet to a server) What are causes of delay and loss and how might they be alleviated?

c. Explain what is meant by fragmentation in a Wireless Lan environment. Wired Ethernet does not support fragmentation. Discuss why the two protocols have taken a different approach. What are the advantages and disadvantages which might apply in each case?