Question 1
This question carries 20% of the marks for this assignment
The evolution of optical storage did not stop after the development of High Definition DVD (HD-DVD) and Blu-ray discs. In this question, you are asked to explore the latest technologies of optical media storage. You should select one technology, present how it works (read/write operations) and its main characteristics (size, capacity, R/W speed, etc.)
Your answer should NOT exceed 500 words. You should include the reference(s) of your answer in a standard format (refer to the following link for more information: https://library.open.ac.uk/help/howto/citeref/).
The following mark deduction will be applied:
• Two marks for missing references or outdated references
• Two marks for not listing the references in a standard format
• One mark for exceeding the word count limit
Question 2
This question carries 20% of the marks for this assignment
Consider en error correction encoder that takes as input three-bits message and calculates the codeword as follows:
Codeword = message (3 bits) + one parity check bit (even parity) + message (3 bits)
1- What is the (n, k) representation of this codeword? Calculate its redundancy and code rate. Justify your answer
2- Construct the message/codeword correspondence table (consider all the possible messages and their corresponding codewords)
3- Calculate the Hamming distance of this code. Detail your answer
4- How many error-bits this code can detect? Correct? Justify your answer
5- Provide an example of error that this code cannot correct. Explain your answer
Question 3
This question carries 30% of the marks for this assignment
Microsoft proposed a platform for digital rights management: a content access and protection technology for digital entertainment services, devices and applications called: PlayReady. The development of this technology - according to Microsoft - is "the culmination of 10 years of innovation and more than $1B invested in content protection technology". [1]
In this question, you are asked to:
1- Present the architecture of this platform
2- Explain the role of each element in this architecture.
3- Describe the detailed steps of a content request/download process using this platform (a user that wants to play a media file (audio/video) protected using this platform.
Your answer should NOT exceed 500 words and should mainly rely on reliable Internet sources. You should include the reference(s) of your answer in a standard format (refer to the following link for more information: https://library.open.ac.uk/help/howto/citeref/).
The following mark deduction will be applied:
• Two marks for missing references
• Two marks for not listing the references in a standard format
• One mark for exceeding the word count limit
Question 4
This question carries 30% of the marks for this assignment
The purpose of this question is to compare the cost of a regular international phone call (Mobile telephony network) and the same call but made using VoIP software installed on this phone using Cellular Data Connection.
Consider the case of a user subscribed to a Pay-As-You-Go cellular data service of a Mobile operator where he is charged $0.5 per consumed Megabytes (whether upload or download). This user wants to call a mobile number in France. The rate of the international call to France set by the mobile operator is 0.4$/minute.
1- Taking into consideration that the data rate is 12.2 kbps in each direction of a regular phone call, what is the cost per Megabyte of the regular international call?
2- The user decides to use VoIP software for international call. As you know, the total cost of the phone call is the sum of the VoIP service provider (VSP) rate and the fees that result from data usage (Mobile operator). The second part (data usage) is directly related to the audio codec used in the VoIP software of this VSP. In this question, you are asked to compare this cost for two VoIP service providers.
a. Using Internet search, you are asked to look for two VSPs. For each VSP, you are asked to identify the rate of the international call (to France) and to describe the audio codec used by the VoIP software proposed by the VSP (The description should not be too long you are not asked to go into technical details). A key information to look for is the bit rate of the codec, which will be used in the second part of this question.
b. Using the minute rate and codec bit rate information, calculate the cost of a one-minute call to France for each VSP.
c. What is the cost per Megabyte of the call for each VSP?
d. Compare the numbers you obtained in part 2.c, with the number obtained in 1. What do you conclude?