Networking Lesson 3

• Computing
• Lower Secondary (Key Stage 3)

Networking Lesson 3

Do Now:
Question 1: Explain the purpose of a network cable.
Question 2: Identify the advantage of using a hub in a network

Lesson 2: Computer networks 

Conquer: Compare wired to wireless connections and list examples of specific technologies.

Aspire: Define ‘bandwidth’, using the appropriate units for measuring the rate at which data is transmitted. 

Wired and wireless data transmission

Wired and wireless data transmission

• Wired networks send data along cables.
  

• Wireless networks send data through the air using radio waves.
  

Do you know any names of wireless technologies?

Wireless technologies

Popular examples of wireless technologies are:

• Bluetooth
  
• WiFi
  
• 3G (third generation wireless mobile)
  
• 4G (fourth generation wireless mobile)
  
• 5G(Fifth generation wireless mobile)

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.

Wireless

Wireless

Wired

Wireless

Bandwidth

• 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 greater your bandwidth the more devices you can have connected at the same time. 

• Netflix would use a high amount of Bandwith while reading the school website would use a small amount. 

How much Bandwith would the following activity use?
Reading a news article.

1. Light
2. Medium
3. High

How much Bandwith would the following use?

A vlogger uploading videos to YouTube daily

1. Light
2. Medium
3. High

How much Bandwith would the following use?

Using social media

1. Light
2. Medium
3. High

Which waves do wireless networks use to send data?

1. Infrared
2. Gamma
3. Radio
4. X-ray

Measuring bandwidth

• Bandwidth is measured in bits per second.

• Data transfer rates are now so good that bandwidth is usually measured in Megabits per second (Mbps)

Which do you think has the highest bandwidth?

1. 4G
2. 3G
3. Bluetooth
4. 5G

Bandwidth compared

The typical download speeds are:

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

• We have 2 kinds of speed, download speed and upload speed. 

Upload speeds are always slower than download speeds.

Why might this be the case?

Answer:

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

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

 

Test the performance of the schools connection.
Look at your download speed
Look at your upload speed

Speed Test

https://www.broadbandspeedchecker.co.uk/?&again

Research the minimum internet speeds required for these activities!
Streaming a film
Playing online games
Reading an email
Downloading an audio Book

What does this symbol mean?

Answer: Buffering

• 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

Wired versus wireless

We know that a network can be wired or wireless

Wired networks 

Advantage 

Disadvantage 

Faster connection (little to no interference)

Higher bandwidth

More expensive. 

time-consuming, each device needs cables

Wireless networks 

Advantage 

Disadvantage 

Can be weakened by walls and ceilings

Allows portability

 

Less secure

It is quick and cheap to connect new devices