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Lesson 3: Wired and wireless networks

Year 7 – Networks: from semaphores to the internet

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Wired or wireless?

Starter activity

Look at the image of the living room and the devices within it. Identify if the devices are connected to the network through wires or wirelessly.

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Wired or wireless?

Starter activity

Answers:

Router – Wired
Desktop PC – Wired
Printer – Wired or wireless
TV – Wired or wireless
Games console – Wired or wireless
Tablet – Wireless
Smartphone – Wireless

Some devices can be either wired or wireless. Why might it best for a games console to use a wired connection?

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Lesson 3: Wired and wireless networks

Objectives

In this lesson, you will:

Compare wired to wireless connections and list examples of specific technologies currently used to implement such connections
Define ‘bandwidth’, using the appropriate units for measuring the rate at which data is transmitted, and discuss familiar examples where bandwidth is important

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Wired and wireless data transmission

Activity 1

A computer network can be either wired or wireless.

Wired networks send data along cables.
Wireless networks send data through the air using radio waves.

Do you know any names of wireless technologies? (Think, pair, share)

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Do you know any names of wireless

technologies?

Activity 1

Popular examples of wireless technologies are:

Bluetooth
WiFi
3G (third generation wireless mobile)
4G (fourth generation wireless mobile)

What is the difference between 3G and 4G?

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Popular examples of wireless technologies are Bluetooth, WiFi, 3G, and 4G. Bluetooth is a wireless technology for transferring data over short distances (e.g. Bluetooth headphones paired to a mobile phone to listen to music). WiFi allows computers, smartphones, or other networkable devices to connect to the internet or communicate with each other without wires. 3G and 4G are both wireless mobile phone technologies. There are many others, and learners may have suggested any number of wireless technologies. Other popular examples include infrared, satellite, microwave, and radio.

Learners are asked what the difference is between 3G and 4G. Learners just need to think about their answer at this stage. This question is revisited later on.

WiFi image source: https://pixabay.com/vectors/wlan-signal-black-wireless-network-303722/

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Bandwidth

Activity 2

Bandwidth is the amount of data that can be moved from one point to another in a given time. Higher bandwidth = more data per second

The concept is similar to the volume of water flowing through a pipe. This depends on the size and thickness of the pipe.

More bandwidth DOES NOT increase the speed.

In the analogy of a pipe, the water doesn’t travel any faster as the pipe gets bigger, but you get more water because more can flow through at the given time.

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Bandwidth

Activity 2

Look at the three cables (A, B, and C). Which has the greatest bandwidth?

(Think, pair, share)

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A

B

C

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Answer:

Activity 2

Look at the three cables (A, B, and C). Which has the greatest bandwidth?

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A

B

C

Greatest bandwidth: A

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Measuring bandwidth

Activity 3

Bandwidth is measured in bits per second
A bit is the smallest unit of data
Data transfer rates are now so good that bandwidth is usually measured in Megabits per second (Mbps)
1 Mb = 1 million bits

Which do you think has the highest and the lowest bandwidth? Broadband, 3G, or 4G?

(Think, pair, share)

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Bandwidth compared

Activity 3

The typical download speeds are:

3G: 3 Mbps
4G: 20 Mbps
Broadband: 46 Mbps

Download: Your computer is receiving data (e.g. browsing a web page, watching online videos)

Upload: Your computer is sending data to the internet (e.g. putting a video on YouTube, posting a photo on Instagram)

Upload speeds are usually much slower than download speeds. Why? (Hands up)

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Answer:

Activity 3

Upload speeds are usually much slower than download speeds. Why?

Internet service providers (ISPs) configure our connection based on the most popular activities.

Most users spend much more time downloading than they do uploading.

For this reason, downloading gets allocated much more of the available bandwidth than uploading.

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Performance test

Activity 4

Test the performance of your current connection.

Visit https://www.speedtest.net/

Look at your download speed
Look at your upload speed

Questions:

Are your speeds the same as your neighbours’? If not, why might that be?
If we were all watching YouTube at the same time, would this change the result?

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Note: This is a recommended activity, but if previous activities have overrun, then you could miss out this activity without affecting the learning objectives.

speedtest.net is a website that provides free analysis of internet performance. Learners can test their current connection and view their upload and download rate in Mbps.

When learners have run the test, ask them to pay particular attention to the upload and download speed. Ask them to think about their answers to the following questions:

Are your speeds the same as your neighbours? If not, why might that be?
If we were all watching YouTube at the same time, would this change the result?

Answers:

It is likely that learners have similar speeds, but they could vary. Some might be slower than others due to being further away from the hub connecting all of the machines to the router. An individual PC might have a damaged cable.
If all of the learners were watching videos on YouTube at the same time, all available bandwidth would be used and split across all of the learners’ PCs. As a result, download speeds would be much slower.

Speed test image source: https://commons.wikimedia.org/wiki/File:Jio4G_SpeedTest.jpg

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The future

Activity 4

5G is the next generation of mobile internet connectivity.
It is available now. EE was the first to release it in 6 cities in May 2019.
5G has the potential to reach speeds of 10 Gbps (1 Gb = 1000 Mb).

20 times faster than 4G.
It would take less than 1 second to download an HD film!

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Activity 5

What does this mean and when might you see it? (Think, pair, share)

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Answer: Buffering

Activity 5

Data is arriving at your device at a rate that is slower than it is being processed
Example: when you are watching a film on Netflix and it pauses, and you have to wait for a period of time before it starts again
Indicates that more bandwidth is required

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Bandwidth matters

Activity 6

Some online activities use more data than others.

Those using the most data require higher bandwidth in order to avoid delays, freezing screens, or buffering.

Can you identify which activities use more bandwidth? Complete the activity in your worksheet.

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Bandwidth matters – Answers

Activity 6

Light internet use: reading online news, checking the weather

Medium internet use: checking social media, emailing regularly

High internet use: online gaming, a vlogger uploading videos to YouTube daily

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Wired versus wireless

Activity 7

We know that a network can be wired or wireless.
There are a number of advantages and disadvantages to both wired and wireless networks. Can you think of any?
Hands up

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vs

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Wired versus wireless

Activity 7

There are twelve statements.
You will be given two tables, one for wired networks and one for wireless networks.

Each table contains two columns, one for advantages, and one for disadvantages.

Your challenge:

Identify whether the statement relates to wired or wireless networks.
Next, identify whether it is an advantage or disadvantage.
Next, move the statement into the correct column.

Six statements have been completed for you. Six still need to be sorted.

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Wired networks – Answers

Activity 7

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Advantages	Disadvantages
Faster connection (little to no interference)	Cables can be a trip hazard and look unpleasant
Higher bandwidth	More expensive and time-consuming to add devices, as each device needs cables
Better security	Devices are in fixed positions (no portability)

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Wireless networks – Answers

Activity 7

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Advantages	Disadvantages
No trailing wires/no trip hazard	Lower bandwidth
It is quick and cheap to connect new devices	Wireless connections can be weakened by walls and ceilings
Allows portability	Less secure

Wireless networks

Advantages:

No trailing wires/no trip hazard — networks are unclustered and the connections are invisible, as they occur using radio waves
It is quick and cheap to connect new devices — devices simply have to search for the name of the wireless network and then connect to it (sometimes a password is required)
Allows portability — this is the main advantage; you can move freely with your devices (as long as you remain in range)

Disadvantages:

Lower bandwidth — wireless networks suffer from interference. This could be from neighbouring wireless signals, among others. This lowers the overall bandwidth.
Wireless connections can be weakened by walls and ceilings, causing dropped signals and lower speeds
Less secure — data sent across a wireless network can be intercepted more easily

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Scenarios: wired or wireless?

Activity 8

You have six scenarios to read through.

Identify whether it would be best to use a wired network or a wireless network.

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Wired or wireless? – Answers

Activity 8

Wireless:

The restaurant
The cafe
The family

Wired:

The office
The vlogger
The primary school

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Exit ticket

Plenary

Define bandwidth

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Next lesson

Summary

In this lesson, you…

Learnt about the term ‘bandwidth’ and the difference between wired and wireless connections.

Next lesson, you will…

Learn about the internet and the ways in which data is transmitted between computers across a network.

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