Questions -
1. Explain how an ad hoc wireless area network differs from an infrastructure wireless area network. Maximum word limit is 75 words.
2. What characteristics of ad hoc networks in general, and Zigbee specifically, make this sort of network especially suitable for home automation, particularly where some devices on the network might be battery powered? Maximum word limit is 100 words.
3. At 100 metres from the antenna of a cellular base station in open country, measurements show that the power per square metre is 400µW/m2. What power per square metre could be expected at 200 metres from the base station? Show your working and explain any assumptions you make.
4. A base station is located in an urban environment, and the power per square metre at 100 metres is measured to be 4µW/m2. What would be a reasonable value to expect at 200 metres? (You will have to make an assumption to calculate your answer. State the assumption you make.)
5. Briefly explain the problem that signal attenuation leads to in digital communications and the techniques that can be used to remedy the effects of signal attenuation. Then give a concise outline of how signal attenuation is put to beneficial use in cellular communications. Maximum word limit is 200 words.
6. Read the following article and then answer the preceding questions.
If we don't tame Twitter, we'll face mob rule - In the 1930s radio was the tool of dictators and propagandists. Now social media is fuelling abuse and driving us apart
[...] Social media is polarising our discourse more painfully than before. It amplifies the personal and the extreme, hots up the echo chamber and gives wings to lies. Confirmation bias rules, preaching to the converted dominates, nuance vanishes and moderates stay silent.
I am a bit of a technological determinist about this. I think communications technologies can decide the political temperature. After decades in which they generally helped moderate discourse, outside autocracies, they are now inflaming it. When blogging was all the rage a decade ago, at least there was space for nuance. Now, opinions are boiled down to a single shout.
I use Twitter mainly to find and pass on links to articles and reports on topics that interest me. To do so, though, I have to wade through bitter feuds, walk past vicious ad-homs, jump over blatant embellishments and bump into absurd hyperbole. "I can't even remember what it is like to go to bed not feeling homicidal with rage," read one tweet on Friday, not from a Black Lives Matter activist or a relative of a Dallas policeman, nor from an Islamist or the relative of a victim of Islamist bombing, but from a distinguished journalist upset about Brexit.
I am not the first to make this point. A Pew Research Centre project in America found that "Polarised crowds on Twitter are not arguing. They are ignoring one another while pointing to different web resources and using different hashtags." A group of Italian academics published a paper last year finding that "selective exposure to content ... generates the formation of homogeneous clusters, ie, 'echo chambers'" [...]
(Source: Ridley, 2016)
Matt Ridley says 'I am a bit of a technological determinist about this'.
a) Explain in your own words what is meant by 'technological determinism'. What does Ridley say in the extract above that supports the idea that he is 'a bit of a technological determinist'?
b) Why are explanations based on technological determinism sometimes misleading? Illustrate your answer by presenting counter arguments to those of Ridley about social media.
c) Explain what the 'filter bubble effect' means and how it relates to the ideas in first paragraph of the extract above.
The maximum word limit for (a), (b) and (c) is 300 words.