Lesson video

Hello, my name is Mrs. Holbrook.

Welcome to Computing.

I'm so pleased you've decided to join me for the lesson today.

We're going to look at the difference between wired and wireless networks and how bandwidth can affect the performance of a network.

Welcome to today's lesson from the unit Computer Networks and Data Transmission.

This lesson is called Wired and Wireless Networks, and by the end of today's lesson, you'll be able to compare the performance of different network connections.

Shall we make a start? We will be exploring these key words during today's lesson.

Wired.

Wired.

Uses a cable to connect a device to a network.

Wireless.

Wireless.

Uses radio waves to connect a device to a network.

Bandwidth.

Bandwidth.

The maximum amount of data that can be transmitted at a time.

There are three main parts to today's lesson.

We'll start by comparing wired and wireless networks.

We'll then move on to explain what bandwidth is and how it's measured.

And then finally we'll compare bandwidth requirements of different types of network.

Let's make a start by comparing wired and wireless networks.

A computer network can be wired, wireless, or both.

Wired networks send data along cables.

Ethernet and fibre optic are examples of cable types.

Wireless networks send data through the air using radio waves.

Have a look at the picture of this living room.

Jacob is asking, "Can you spot which devices are connected to the network wirelessly? And can you spot which devices are wired to the network?" Pause the video here whilst you have a think.

How did you get on? Did you spot all of the network devices? Andeep has got an answer.

Andeep says, "The router is wired.

The desktop PC could be wired or wireless.

So could the printer, TV, and games console.

The tablet and smartphone are wireless." Did that match your answer? Remember, some devices can be wired or wireless.

Wireless connections are based on radio waves.

Examples of popular wireless technologies are Bluetooth, Wi-Fi, 3G, which stands for third generation wireless mobile, 4G, which is fourth generation, and 5G, which is fifth generation.

Are you familiar with these terms? Have you ever connected to these types of wireless networks? Time to check your understanding.

Which of the following options does not use wireless technology? Is it A, Wi-Fi? Is it B, Bluetooth? Or C, Ethernet? Pause the video here whilst you have a think.

That's right.

C is the correct answer.

Ethernet does not use wireless technology.

There are a number of advantages and disadvantages to both wired and wireless networks.

Can you think of any? Perhaps pause the video here whilst you have a think.

Let's start by looking at the advantages and disadvantages of wired networks.

Wired networks have the advantage of faster connection and there's no interference from other signals.

They often have higher bandwidth than wireless networks.

And they're more secure as data can only be accessed by devices physically attached to the network.

The disadvantage of wireless networks is that cables can be messy and a trip hazard, especially for a larger network.

They're also expensive and time consuming to add devices because each device needs to add a cable.

Devices are in fixed positions and are not portable, which means it's less flexible for the users using the devices on the network.

Let's now have a look at the advantages and disadvantages of wireless networks.

The advantage to a wireless network is that there are no cables, which reduces trip hazards.

It looks neater, and it's faster and cheaper to instal.

It's also easier to add new devices.

People can connect to the network from anywhere within a range, giving them greater flexibility about how and where they work.

Disadvantages to wireless networks include slow connection as there can be interference from other signals.

They offer lower bandwidth than wired networks.

And they're potentially insecure as it can be easier to hack into a wireless system.

Okay, we're now going to move on to the first task for today's lesson, Task A.

Below are some words and phrases that describe different aspects of networks.

Decide whether each one of these applies to a wired network or a wireless network and place it under the correct heading.

Pause the video here whilst you complete the activity.

How did you get on? You're doing a great job so far, so well done.

You were asked to decide whether each word or phrase applied to a wired or wireless network.

Here are the answers.

For wired you should have better security, devices are in fixed positions.

, cables are a trip hazard, and higher bandwidth.

For wireless you should have potentially insecure, portable, no cables needed, and lower bandwidth.

Remember, if you need to make any corrections, you can pause your video here.

Now for part 2A.

For the following scenarios, decide whether the users should have wired or wireless devices and explain why.

The first one has been done for you.

So the scenario is a restaurant where the staff take orders on a tablet device.

The decision here is that wireless would be better and that's because the tablets are portable.

It would be very impractical for wires to be connected from the screen and then to each tablet device.

Complete the rest of the table and pause the video whilst you do the activity.

How did you get on? Let's have a look at some sample answers.

So the first one had already been done for you.

So let's move on to the second scenario.

Office workers with their own desktop PCs.

This is probably a better case for a wired network.

Office workers have desktop computers and their own dedicated area, so they don't need to move about or change location.

So a wired connection is probably better.

The next example was a family of four who have multiple devices that they use in many rooms. This is going to be wireless.

The family members are going to want to move around the house and they're gonna have lots of portable devices like smartphones or tablets.

For part 2B, we have some more scenarios.

Decide whether the users should have wired or wireless devices and remember to explain why.

Pause your video here whilst you complete the activity For Task Two part B, you were given some more scenarios where you have to decide if the users should have wired or wireless devices.

The first one in this table was a vlogger who makes and uploads their own videos.

The decision here is that it should be wired, and that's because uploading videos and online gaming are activities that require greater bandwidth.

The next one was the primary school with PCs in classrooms. Again, this could be wired and that's because the PCs are fixed to desks in the classrooms and they don't need to be portable.

The last one was customers bringing their own devices to a cafe.

This would be most suitable to be wireless, and that's because the devices customers bring into the cafe such as smartphones and tablets are likely to be portable.

It's also simpler to connect devices to a wireless network.

Were your answer similar? Remember to add in your explanations.

If you need a bit of extra time, just pause the video whilst you go and complete the task.

We're now moving on to the second part of today's lesson, where we're going to explain what bandwidth is and how it is measured.

Bandwidth is the amount of data that can be moved from one device to another in a given time.

With a higher bandwidth, more data can be transferred per second.

This is similar to water flowing through a pipe.

The amount of water that can flow will depend on the width of the pipe.

The wider the pipe, the more water can flow through it at any one time.

Increasing the bandwidth does not increase the speed of the data transfer.

Water doesn't travel any faster as the pipe gets wider, but you can get more water because more can flow through the pipe at a given time.

Ah, Sofia here has got a really good comparison.

"It's the same as a school corridor.

If they widened it, more pupils could fit in, but it wouldn't mean that the pupils would travel any faster to their lessons." Bandwidth is measured in bits per second.

A bit is the smallest unit of data.

Data transfer rates are now so fast that bandwidth is typically measured in megabits per second, or MBPS.

One megabit is equal to one million bits.

Time to check your understanding.

What does the unit MBPS stand for when it refers to bandwidth? Is it A, millibits per second? Is it B, megabytes per second? Or is it C, megabits per second? Pause the video here whilst you have A think.

Did you put C? Well done.

Bandwidth is measured in megabits per second.

Okay, we're now going to move on to Task B.

Define the term bandwidth using the example of a water pipe.

Explain why it is not the maximum speed for the network.

Pause your video here whilst you complete the question.

How did you get on? Let's have a look at a sample answer together.

Imagine a water pipe.

The wider the pipe, the more water can flow through it at once.

Bandwidth is like the width of that pipe for your internet connection.

It determines how much data can flow through at once.

A wider pipe, IE more bandwidth, means that more water or data can flow, but the actual speed at which the water or data is moving can change depending many other factors.

Remember to add some detail to your answer if you need to.

For Task B part two, you're going to do a calculation to find the bandwidth and to do this, you need to know that to find the bandwidth, you need to divide the file size by the time it takes to download.

If the file size is 100 million bits and it takes five seconds to download, what is the network bandwidth in megabits per second? Pause your video here whilst you complete the calculation.

How did you get on? You're doing a great job so far, so well done.

Let's have a look at the answer to this question.

You were told to find the bandwidth you needed to divide the file size by the time it takes to download.

So the file size was 100 million bits and the time it took to download was five seconds.

So we've got 100 million divided by 5, which is equal to 20 million bits per second.

And then if we convert that to megabits per second, then we are looking at 20 megabits per second.

Make any corrections you need to before moving on.

Okay, we are now going to move on to the final part of today's lesson where we're going to compare bandwidth requirements of networks.

Ah, Jacob's got a good question.

He's asking, "Why do I see this icon every time I try to stream a film?" Have you ever seen this icon? Do you know what it means? Ah, Sofia's got a great response.

She says, "The movie is buffering because your network has limited bandwidth.

It needs more data to keep playing without stopping." The table below compares the different bandwidths of different network technologies.

So you can see here we've got mobile data and then Wi-Fi.

So mobile data like Bluetooth has a low bandwidth compared to Wi-Fi 5, which has a higher bandwidth.

Remember that bandwidth is measured in megabits per second.

So Bluetooth is around one to three megabits per second, and 5G is around 150 to 200 megabits per second.

If we compare this to Wi-Fi 5, that goes up to 1300 megabits per second.

Time to check your understanding.

Which wireless technology has the highest bandwidth? Is it A, Bluetooth, B, 5G, or C, 3G? Pause the video here whilst you have a think.

That's right.

5G is the wireless technology with the highest bandwidth out of these three.

Some online activities use more data than others.

Those using the most data require higher bandwidths to avoid buffering.

For example, you can see here a video call in HD typically requires 1.

5 megabits per second in terms of bandwidth.

Whereas watching a movie online, a 4K Ultra HD movie, could be 25 megabits per second.

Time to check your understanding.

Which of these activities uses the least amount of bandwidth? Is it A, streaming a movie, B, playing an online multiplayer game, or C checking emails? Pause the video whilst you have a think.

Did you select C? Well done.

Checking emails would require the least amount of bandwidth compared to streaming a movie or playing an online game.

Okay, we are now moving on to the final set of tasks for today's lesson.

So for Task C part one, I'd like you to identify if the activity is a light, medium, or high bandwidth activity.

And you can do this by placing the tick in the correct column in the table.

Pause the video whilst you complete the activity.

How did you get on? You're doing a great job so far, so well done.

So we've got for checking social media, this would be a medium bandwidth activity 'cause there may be some video and image content on there.

Online gaming is high.

Emailing regularly may be medium, especially if you are including lots of attachments.

Reading online news would be low.

Uploading videos would be high.

And checking the weather would be low.

Compare these to your answers and make any corrections if you need to.

Okay, for part two, we have a scenario.

Aisha wants to join an online multiplayer game with her friends.

However, she keeps having problems when playing as the screen keeps freezing.

Suggest why this might happen and the steps that Aisha could take to solve it.

Pause your video here whilst you complete the activity.

How did you do? Let's have a look at a sample answer together.

This problem can be caused by low Wi-Fi bandwidth on the network.

Aisha could consider connecting her console to the router with a wired connection as this would have higher bandwidth than the wireless connection.

We've come to the end of today's lesson and you've done a fantastic job, so well done.

We've covered some fairly tricky concepts here.

Let's summarise what we've learned.

There are advantages and disadvantages to both wired and wireless networks.

Wired networks often have higher bandwidth than wireless ones, but wireless networks offer us greater flexibility.

Bandwidth determines how much data can be sent per second, affecting video streaming and online gaming, for example.

I hope you'll join me again soon.

Bye.