3.4 Protocols and standards

You have already met the idea of protocols in Section 1 – rules to govern how information is sent, transmitted and received. Protocols can be explained using an analogy with the way people talk to each other. When we talk we don't simply string words together in a random fashion: we have a set of rules (grammar) that determines the order of words and the way sentences are constructed. Understand didn't have other us difficult if it would be quite rules each these for to we. We hope t
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3.2 What does a processor look like?

So what do these devices that are manufactured in such vast quantities look like? Processors are manufactured as integrated circuits. Essentially they are circuits, around the size of a fingernail, which contain many millions of electronic components manufactured as one very complex circuit. Figure 4(a) shows how a processor manufactured as an integrated circuit is packaged so it can be used as a component in an electronic circuit. The pins of the package are connected to the integrated circu
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3.1 Processor statistics

In Sections 3.1 and 3.2 you are going to find out a little more about one of the key components of a computer: the processor, which manipulates data according to a list of instructions called a program.

Here is a mini-quiz which explores some facts about processors.

Question 1

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7.1 Worries about security of credit card and personal data

The Internet is intrinsically an insecure medium (for example, sending an unencrypted email is like sending a postcard through the mail – people equipped with the right equipment might be able to monitor communications that flow across the Net and read their content). So naturally people are concerned about whether to entrust their credit card details to an online store. And on the vendor's side, there is always concern about identity theft – i.e. the problem of knowing whether the person
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6.4 Pictures

It used to be thought that a photograph could provide proof of an event – someone could be caught red-handed by a photograph, as proof of their guilt. ‘The camera never lies’, it was said. If you have a digital camera and have been ‘touching up’ photographs on your home computer you will know that this is far from true now. It is easy to lie with a digital photograph.

The idea that the camera never lies has always been a myth, however. As far back as 1917 the photographs of th
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5.2.1 Microwave

You saw the importance of microwave transmission for newsgathering in the Higgins extract. The term ‘microwave’ identifies a particular range of frequencies used for radio communications. The range of frequencies that are referred to as ‘microwave’ is not exactly defined (or, rather, slightly different ranges are used in different contexts), but roughly speaking it is from about 200 MHz to 50 GHz. [Remember that MHz stands for megahertz, which is 1,000,000 Hz (106 Hz) and G
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5.2 Other transmission media

Wires are still used to carry electrical signals over short distances. At the time of writing, for example, most connections between telephones in private houses and the local telephone exchange still use wires. The telephone networks within office buildings are mostly connected with wires, and so are many computer networks (local area networks, LANs) within single buildings. However, all longer-distance communication, between towns, cities or countries, uses either optical fibre or microwave
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4.4.2 Battery parameters

Now that we have covered some background on electricity, I will return to discussing batteries.

Activity 19

What do you think would be the important characteristics of a battery for a portable ICT device such as a camcorder or a
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4.2.5 Emotions

Emotions can be easily misunderstood when you can't see faces or body language. People may not realise you are joking; irony and satire are easily missed. Smileys or emoticons such as :-) and :-( can be used to express your feelings (look at these sideways). Other possibilities are punctuation (?! #@*!), or , , or even using mock HTML tags such as smileys are stupid.

Remember that many discussion systems only support plain text so you can't rel
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4.2 Netiquette

Work through the following material on ‘netiquette’ and then try the quiz at the end of the section.


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References

Pearson, I. (2004) The Future of Everyday Life in 2010, British Telecommunications plc. [online] www.bt.com/sphere/insights/pearson/everyday.htm, accessed 6 September 2006.
Pragnell, M., Spence, L, and Moore R. (November, 2000) The Market Potential for Smart Homes, N40, Joseph Rowntree Foundation [online], York Publishing Services www.jrf.org.uk/knowledge/findings/housing/n40.asp, accessed 6 Septem
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3 The Unified Process

The Unified Process (UP) (Jacobson et al., 1999) has emerged as a popular iterative and incremental development process for building enterprise systems based on an object-oriented approach. It promotes a set of best practices, namely that development should be organised in short time-boxed iterations, and that it should be adaptive to accommodate inevitable change.

Time boxing means that a (usually) short fixed period of time is devoted to each iteration, e.g. three to fo
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2.3 Risk management

No software development is free from risk, and one crucial activity of development is identifying and managing it. Managing risks requires an early identification of any threats to the development or operation of a system, and then monitoring these threats during development. In an iterative and incremental development, risks in the development stage can be tightly monitored and controlled. The emphasis on short cycles that lead to early implementation helps to address technological problems
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Introduction

In this unit I look at a number of different programming and design styles associated with distributed system development. The unit first examines message passing and the role of protocols – both fixed and adaptive protocols. Two styles of message passing are also examined: synchronous and asynchronous message passing. The next part of the unit introduces distributed object technology. Event-based development relies on listener objects listening to events which are propagated along a bus; t
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Acknowledgements

The following material is Proprietary (not subject to Creative Commons) and used under licence (see terms and conditions).

Grateful acknowledgement is made to the following for permission to reproduce material:

Ince, D. Developing Internet Applications, chapters 1 and 4, published by Pearson Education Limited in collaboration with The Open University, © Pearson Education Limited, 2002, 2003. This publication forms part of an Open University course M360 Developing
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3.4 Stage 3: Deciding what to revise

In Stage 2, you will have reminded yourself of the scope of the course, and you will also have a sense of the range and breadth of topics you have covered. Now you need to decide what to revise.

Activity 5

Stages 1 and 2 will have giv
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1 Revision and exams

Most likely, you are reading this unit because you feel unsure about your ability to do yourself justice in exams. You may never have taken an exam and are wondering how to prepare yourself. It may have been a long time since you took an exam, and you feel a need to refresh your technique. You may be looking for reassurance and advice because you may have had a bad exam experience in the past. Whatever your reason, we hope that this unit will help.

This unit is a practical one, and we w
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4.4.7 Realistic

This reminds you to take into account, for example, your current knowledge, skills and qualities; the knowledge skills and qualities you are aiming for; the help and hindrances you are likely to encounter along the way; and the time you have available. Setting realistic goals can help to foster a can-do attitude – success helps to breed success, while failure can breed further failure, as you become more downhearted. So, reach for something that stretches you, but which will not overwhelm y
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2.2 Everyday learning – what’s going on?

This section will start with two examples of the sort of learning that occurs on an everyday basis. The aim here is to start you thinking about the ways in which learning goes on all the time. To illustrate this, read Jim’s story. As you read, you might like to begin to think about whether any aspects of Jim’s story might also be a part of your ‘story’. (In this context, we are using the word ‘story’ to mean what has happened in your life so far. We are not using it to mean someth
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5.1.1 Do you dread deadlines?

Of course, there are lots of different patterns of working: some students can only work to deadlines at the very last minute; while others prefer to work in shorter snatches over longer periods. The main problem with the former is that you may have to skip over some of the points we are now discussing, which could be counter-productive.

Waiting until the last minute may be because you are afraid to begin. If this applies to you – as it will to many others – you might find it helpful
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