Get connected
Unit Get connected
Year level: 7-8 Topic: Digital Systems Time: 12 hours
A basic computer network consists of a collection of computers, printers and other equipment that is connected together so that they can communicate with each other. The internet is a network of networks connecting devices all around the world, which is based on a set of rules (protocols) governing its use. Choose a familiar network system, such as a transport system, as a way of comparing and contrasting another system with the computer networking system. Computer networks require security measures to protect against threats. Use a practical activity to simulate a basic network. Problem solve a way to send data from program board to program board to represent an image.
Flow of Activities
Network types
Discuss types of networks and simulate a network through role play or by sending data using program boards.Network protocols
Explore network protocols that define rules and processes for communication between network devices.Protect against cybercrime
Explore and use security measures that can protect computer networks against cybercrimes.Send data via a network
Simulate the sending of data that can be used to represent a simple image made up of pixels.Activity Network types
How do computers send data via a network?
Australian Curriculum Alignment
- Digital systems (ACTDIK023)
What's this about?
A basic computer network consists of a collection of computers, printers and other equipment that is connected together so that they can communicate with each other.
The school network provides an opportunity to describe a basic local area network (LAN) connecting computers with each other, the internet, and various servers. The school may also incorporate wireless technology via wireless local area network (WLAN).
Typically, networks are made up of:
- switches – a network switch is a computer networking device that connects devices together on a computer network. Software on the switch manages the packets it receives, then processes the packets and forwards the packets to the destination device
- routers – connect computers from one network to another and to the internet. They dispatch information and ensure that the right packets of information end up at the correct destination (includes firewall functionality)
- hardware devices – such as computers, printers and laptops.
Learning tasks
- Describe familiar networks and the way students interact with their devices at home, at school or at a local library. What does a network allow them to do?
- Find out how the school network fits together, and the various components involved that enable data to be transmitted through the network.
- Network topology refers to the layout of a network. How different nodes in a network are connected to each other and how they communicate is determined by the network's topology. Identify the types of network topology (bus, ring, star etc) and the advantages and disadvantages of each type.
- Collaboratively, discuss the advantages of networking computers, which may include speed, flexible and ready access to files and storage, licensing costs and centralised software management. What would happen if devices were not networked?
- Use a practical activity to simulate a basic network. Simulate a network using a programming board such as a BBC micro:bit or similar that has at least one button, at least two pins and is low voltage (~3V). In pairs, connect two microbits to send a Morse code message and decode it. Show how the microbits can be connected in a linear configuration to represent a bus. Next compare that to a star network with one central microbit connected to other microbits to send messages.
Supporting Resources





Lesson Ideas




Assessment
Distinguish between different types of networks and defined purposes.
Suggested approaches may include
- Labelling diagram
Assessment Resources
Activity Network protocols
How does data travel via the internet?
Australian Curriculum Alignment
- Digital systems (ACTDIK023)
What's this about?
The internet is a network of networks connecting devices all around the world.
Internet Protocol (IP) is a set of rules governing the format of data sent over the internet or other network. It describes how data packets move through a network based on their IP address (a unique address identifying a machine on a network). Transmission control protocol/internet protocol (TCP/IP) is used for controlling file transfers over the internet. TCP/IP makes sure that the packets reach the end destination and are reassembled correctly.
The IP address is similar to the mailing address of a person. It is known as a logical address because it is logically assigned based on the host location.
Data sent across the internet is divided into packets to reduce the file's size. For example, downloading a 3 MB song is likely to be split up into over 20,000 packets of 1,500 bytes each.
Learning tasks
- Pose the question: 'How does information travel via the internet?' For example, you request a song from Spotify, how does that song reach your computer? A misconception is that it travels from the source in one path directly to your computer.
- Ask students to share what they know about IP addresses, IP packets of information, fibre optics and cables, switches and routing that all play a role in information being sent via the internet. Create a flow chart to demonstrate how these work. Compare initial ideas with those developed after referencing relevant videos or other resources.
- Run a traceroute to show students how data travels via the internet divided into packets of information of smaller file size.
- Use an unplugged activity to role-play the sending of information via packets.
- Use the BBC micro:bit to simulate the sending of packets of information, for example, four words, by sending these encoded as Morse code. Set up a network of connected microbits to send the words to a final destination (microbit). Each word represents one packet and each word can be sent on a different route in the network to the final destination. Introduce IP by using a number for each microbit in the network and TCP as a way of ensuring the entire message was received and how to reassemble the message in the correct order.
Supporting Resources







Lesson Ideas



Assessment
Distinguish between different types of networks and defined purposes
Explain how digital systems use whole numbers as a basis for representing a variety of data types.
Suggested approaches may include
- Labelling diagram
Assessment Resources
Activity Protect against cybercrime
In what ways is a computer network similar to other types of networks?
Australian Curriculum Alignment
- Digital systems (ACTDIK023)
What's this about?
The internet provides opportunity for cybercrime. Examples of security measures that can protect computer networks include: passwords, security settings on routers, firewalls, security certificates, and anti-virus and anti-malware tools.

Unauthorised use of our digital devices is an everyday threat and is a key aspect of cybersecurity. We need to ensure measures are in place to protect our personal information and privacy.
There are a range of security measures used, depending on the device. On a smartphone, AI has opened up the way to use biometrics (for example, thumbprint or iris scan) to protect the authorised user of a phone and deny access to unauthorised users.
Learning tasks
- Choose a familiar network system such as a transport system as a way of comparing and contrasting another system with the computer networking system. Like a computer network, the transport system may include security measures to protect users. Create a flow chart to describe how this might work.
- Use the BBC micro:bit to simulate the sending of packets of information. Introduce a 'hacker' (a microbit that connects to the network and reads the messages). Explain the use of encryption to protect information being sent via the internet. A simple encryption can be the letter +1, for example, 'A' is represented by 'B'.

Students can create computer programs to demonstrate a security measure such as using a Personal Identification Number (PIN) – for example, a 4-digit code. Alternatively, students can incorporate a type of image recognition to mimic AI. Another option is to use an AI tool to create a model and incorporate this into their program. Another programming challenge is to create a password generator.
Supporting Resources
Lesson Ideas





Assessment
Distinguish between different types of networks and defined purposes
Explain how digital systems use whole numbers as a basis for representing a variety of data types.
Suggested approaches may include
- Adapted worksheet
Activity Send data via a network
How do you send data (in the form of an image) via a network?
Australian Curriculum Alignment
- Digital systems (ACTDIK023)
What's this about?
In electronic communication, data is represented as 1s and 0s. These separate elements are known as bits (or binary digits). All electronic data is stored in this digital binary format. People interpret words and pictures; however, computers interpret bit patterns.
The advantage of using digital coding is that data can be stored more efficiently and can be transmitted over long distances without the quality becoming degraded.
Learning tasks
- Use the BBC micro:bit to simulate the sending of data that can be used to represent a simple image made up of pixels.
- Building on what students have learnt in previous sessions using the microbit to simulate a network, pose the problem: 'How can we send data to create an image made up of pixels?'
- Students define the width and height of their image, code the image using an agreed representation, such as, B is black, W is white. They then send the message encoded as Morse code to the second microbit to be decoded and drawn. Compare images and discuss any differences and reasons why these might have occurred. Discuss the limitations of Morse code (human error) and reasons why the computer uses binary to encode images.
Lesson Ideas


Assessment
Distinguish between different types of networks and defined purposes
Explain how digital systems use whole numbers as a basis for representing a variety of data types.
Suggested approaches may include
- Presentation or demonstration
- Artefact analysis