This question allows you to demonstrate your ability to carry out calculations such as those introduced in Block 3 Parts 1 and 2 and the Using Numbers (maths) booklet.
In each case you should demonstrate how you worked out your answer, as well as giving the answer. You must show your working to gain full marks. In each case, about 50% of the marks are awarded for a clear explanation of your working.
·a.A sinewave has a period (duration of one cycle) of 35 μs. What is its corresponding frequency, in kHz, expressed to 3 significant figures? (see Study Note 7.1 in the Using Numbers (maths) booklet).
·b.Convert the following dotted decimal IP address into binary (see Block 3, Part 2).
·c.In a high-quality coaxial cable, the power drops by a factor of 10 approximately every 5 km. If the original signal power is 0.25 W (=2.5 x 10-1), how far will a signal be transmitted before the power is attenuated to 25 μW?
As part of your answer, include a Table showing the signal power vs. distance in 5 km intervals (like Table 1.2 in Section 1.4.4).
If optical fibre is used instead of the coaxial cable, briefly explain how you would expect the above calculated distance value to change (see Section 1.4.4). You are not required to include another Table.
Question 2 (30 marks)
As explained in Sections 3.2.2 and 4.4.2 of Block 3, urban environments are more obstructive to radio waves than rural environments, leading to reduced base station (BS) range. This can however be of benefit in urban areas where there is high demand for cellular communication services. Briefly explain, in no more than 100 words, why reduced BS range can be advantageous in this context.
Home automation is an example application of an Internet of Things (IoT) network, in which various mains and battery-operated sensors and devices are controlled from either inside a house or from a remote location. While Wi-Fi is common in domestic settings, it has limitations in effectively supporting IoT devices in the home, which has led to alternative short-range, low-power, low-data networks, like ZigBee, being proposed for home automation purposes.
Based on what you have learnt in Block 3, write a summary, on the requirements for a home automation IoT network (see Section 4.5, P214), discussing whether Wi-Fi is the best network option, by considering radio coverage, power consumption, cost and convenience. You should also outline how, in using ZigBee as a home automation network, some of the Wi-Fi issues you have identified, are addressed.
The maximum word limit is 250 words.
·b.A mobile base station (BS) in an urban environment has a power measurement of 15 µW at 175 m. If the propagation follows an inverse cube-power law (Section 3.2.2), what is a reasonable power value, in µW, to assume at a distance 0.7 km from the BS?
Give your answer in scientific notation to 2 decimal places.
·An analogue signal is sampled every 160 µs to convert it into a digital representation. What is the corresponding sampling rate expressed in kHz?
According to the Sampling Theorem (Section 3.3.1), for this sampling rate, what will approximately be the highest frequency present in the signal, in kHz, assuming the lowest frequency is very close to zero?
If each sample is quantised into 128 levels, what will be the resulting bitrate in bps?
An even parity check bit is now appended to the end of the code so 8 bits are transmitted. What will be the transmitted code for the ASCII character ‘T’?
If even parity check bits are used, which of the following 8-bit received ASCII codes are invalid?
In this part of Question 3 you will contribute a resource to a wiki, and then comment on a resource contributed by another student. Make sure that you contribute your resource at least 5 days before the TMA deadline, so that other students have an opportunity to read and comment on it.
In Block 3 Part 5 Activity 5.12 you found a web resource and added a section about it to a wiki. Now that you have studied Part 6 of Block 3, find a web resource that you think is interesting and relevant specifically to Part 6. Add a section about this resource to the TM111 TMA03 tutor group wiki.
Follow these instructions, which you will also find on the Start page of the wiki.
Follow the link (at the bottom of the Start page), to the ‘page for sharing resources’. You can edit the new page to share resources with other students in your tutor group and comment on their resources. You cannot edit the Start page. On the new page, add a new section (Using the 'Add new section' button near the bottom of the page.)
In your new wiki section you should include a link to your chosen resource, a short explanation of what the resource is about, and an explanation of why it is interesting and how it is relevant to Part 6. You should write no more than 150 words.
As your answer to Part (i) of Question 3:
• paste into your TMA document a copy of the text in your wiki section
• make a screenshot showing your wiki section and paste it into your TMA document.
Choose a section in the wiki that you find interesting and that was contributed by another student. Using the wiki’s ‘Edit section’ facility, add a comment to the wiki section that you chose, explaining why it is of interest to you. You should write no more than 100 words. Precede your comment with ‘A comment from [your name]’ so that your tutor and other students can tell who the comment is from.
• paste a copy of your comment into your TMA document
• take a screenshot showing your comment in the wiki section and paste it into your TMA document.
Write a short piece of text about your experience of the wiki’s usability. You should relate your answer to three of the following concepts that you learnt about in Block 1 Part 6.5.1, ‘What is usability?’:
Carry out web searches to help you understand the terms: ‘artificial intelligence’ and ‘machine learning’. Then write a short explanation of each of these terms in your own words, clarifying the difference between them.
Block 3 Part 6 (Section 6.3.2) discusses electronic triage in medicine, and says that:
“Advanced systems use the techniques of artificial intelligence (AI) in order to replicate (and even, ideally, improve upon) the judgements of a medical expert”.
The 30-minute BBC Radio 4 Analysis programme ‘The NHS, AI and our data’ was broadcast in February 2020. It discusses the use of AI in medicine, with electronic triage, breast cancer and eye disease as examples.
Click the media player below to listen to this programme, making some notes while you listen. You can then use the transcript to help you develop your notes further. Once you have finished making notes, close the transcript (in order to avoid plagiarism) and write a short summary of the ideas in the programme in your own words. Your summary should focus on the following questions:
How is AI being used to address problems in medicine, and what data/datasets are being used?
What are the potential benefits?
What drawbacks or risks are presented?
The maximum word limit for Question 3(b) (ii) is 350 words.
you met the idea of ‘false positive’ and ‘false negative’. In the programme’s discussion of medical triage, give an example of each of the following a false positive a false negative.
Which of these is more serious?