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Network Speeds Edexcel

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Exam code:1CP2

Network Speeds

What is network speed?

Network speed is the amount of data that can be transferred across a network in 1 second
The higher the network speed, the more data can be transferred, and in less time
Network speed is measured in bits per second (bps)

Network speed	Written as	Equivalent to
1 kilobit per second	1 Kbps	1000 bps
1 megabit per second	1 Mbps	1000 Kbps OR 1,000,000 bps
1 gigabit per second	1 Gbps	1000 Mbps OR 1,000,000 Kbps OR 1,000,000,000 bps

Network speed

Written as

Equivalent to

1 kilobit per second

1 Kbps

1000 bps

1 megabit per second

1 Mbps

1000 Kbps
OR

1,000,000 bps

1 gigabit per second

1 Gbps

1000 Mbps
OR
1,000,000 Kbps

1,000,000,000 bps

File Size, Transmission Rate & Time

You can calculate the amount of time it would take to transfer data across a network using the file size and transmission rate

What is transmission rate?

Transmission rate is the speed at which data is transferring across a network at that given moment in time
Transmission rate is measured in bits per second (bps)
Transmission rate is closely linked with network speed but with a subtle difference:
- Transmission rate = given moment in time, can fluctuate
- Network speed = fixed value, maximum rate (that you pay for)

Examiner Tips and Tricks

Remember that file size uses the binary (base-2) multiples and network speeds/transmission rates use the denary (base-10) multiples, this means that:

File size
1 KiB = 1024 bytes
1024 x 8 = 8,192 bits

Network speed/transmission rate
1 Kbps = 1000 bps (not 1024!)

File sizes are covered in more detail here (opens in a new tab)

How do you calculate amount of time?

To calculate the amount of time to transfer data across a network, use the formula:
- Time = size of file (bits) / network speed (bits)

Examiner Tips and Tricks

In the exam you are only expected to be able to construct expressions involving file size, transmission rate/network speed and time

You DO NOT have to carry out any calculations!

Example

“Construct an expression to show how many seconds it would take to transfer 750 KiB of data on a network with a speed of 5 Mbps”

Step 1 – convert file size to bits

File size	Expression
750 KiB	750 x 1024 x 8 (KiB > Bytes > Bits)

File size

Expression

750 KiB

750 x 1024 x 8

(KiB > Bytes > Bits)

Step 2 – convert network speed to bits

Network speed	Expression
5 Mbps	5 x 1,000,000 (Mbps > bps)

Step 3 – Construct expression

$fraction numerator b i t s space t o space t r a n s f e r space open parentheses f i l e space s i z e close parentheses over denominator b i t s space p e r space s e c o n d space open parentheses n e t w o r k space s p e e d close parentheses end fraction$ <img alt=”fraction numerator 750 space x space 1024 space x space 8 over denominator 5 space x space 1000000 end fraction” data-mathml=”<math ><semantics><mfrac><mrow><mn>750</mn><mo> </mo><mi>x</mi><mo> </mo><mn>1024</mn><mo> </mo><mi>x</mi><mo> </mo><mn>8</mn></mrow><mrow><mn>5</mn><mo> </mo><mi>x</mi><mo> </mo><mn>1000000</mn></mrow></mfrac><annotation encoding=”application/vnd.wiris.mtweb-params+json”>{“fontFamily”:”Times New Roman”,”fontSize”:”18″,”autoformat”:true,”toolbar”:”<toolbar ref=’general’><tab ref=’general’><removeItem ref=’setColor’/><removeItem ref=’bold’/><removeItem ref=’italic’/><removeItem ref=’autoItalic’/><removeItem ref=’setUnicode’/><removeItem ref=’mtext’ /><removeItem ref=’rtl’/><removeItem ref=’forceLigature’/><removeItem ref=’setFontFamily’ /><removeItem ref=’setFontSize’/></tab></toolbar>”}</annotation></semantics></math>” height=”47″ role=”math” src=”data:image/svg+xml;charset=utf8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20xmlns%3Awrs%3D%22http%3A%2F%2Fwww.wiris.com%2Fxml%2Fmathml-extension%22%20height%3D%2247%22%20width%3D%22117%22%20wrs%3Abaseline%3D%2230%22%3E%3C!–M

Computer Science GCES EDEXCEL

Network Speeds Edexcel

Network Speeds

What is network speed?

File Size, Transmission Rate & Time

What is transmission rate?

Examiner Tips and Tricks

How do you calculate amount of time?

Examiner Tips and Tricks

Example

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