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Introducing ICT systems
Introducing ICT systems

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3 Communication systems

3.1 Introduction

Generally, when we talk about communication between humans, we mean one person conveying information to another person. Figure 6 shows a basic model, or representation, of a communication system for getting a message from the sender to the recipient. The diagram shows the sender (User 1), the message, a 'means of conveying a message' and the recipient (User 2).

Figure 6 is an example of a block diagram, which is another graphical way of representing a system. Each block represents something in the real world, and the labels on the blocks tell you what that 'something' is. In this diagram I have chosen to represent people and inanimate objects in different ways. The oval shapes (which are still called 'blocks') represent the users of the communication system. The rectangular blocks represent inanimate objects in the communication system. The lines between the blocks represent the flow of something: here it is the message.

Figure 6
Figure 6 A basic model of a communication system

Activity 3 (exploratory)

Suppose you were planning a birthday party for someone. How could you communicate the message – that is, the details of the date, the time and the venue – to your prospective guests? Jot down four methods of communication. In each case, think of what is needed to convey the message.


The four methods of communication I thought of are as follows. If my guests live in the same house as me, or if I happened to meet the people concerned, I could just tell them the date, time and venue. If not, I could send them an invitation using the postal system. Alternatively, I could telephone them to give them the details, which involves using the telephone network. I could also email the people I wanted to invite, if I knew their email addresses, which would involve using a computer network – probably the internet.

In each of these situations we could say that communication involved a sender, a recipient, some form of message and some means of conveying the message. The various means of conveying the message in my answer include voice communication, the postal system, the telephone network and a computer network.

Activity 4 (self-assessment)

ICTs are the technologies used in the conveying, manipulation and storage of data by electronic means. Which of the four means of conveying the message in Activity 3 involve ICTs?


The first method of communication involves only voice communication. The second, the postal service, does not directly involve ICTs to deliver the message.

The means of conveying a message that directly involve ICTs are the telephone and email. The telephone system involves a telephone network and handsets. An email system involves computers and a computer network.