Transcript
Page 1: Bandwidth What is it? How much do we need? Is it worth it?

BandwidthWhat is it?How much do we need?Is it worth it?

Page 2: Bandwidth What is it? How much do we need? Is it worth it?

Niagara falls567812 litres/sec

Water main5 litres/sec

Tap0.15 litres/sec

Think of water and how it gets to your tap

Think of how much is flowing at each point

Page 3: Bandwidth What is it? How much do we need? Is it worth it?

Now consider the InternetInternet backbone using optical fibre.

13.271 Giga bits per sec

(think Niagara falls of data!)

ISP – somewhere between Niagara falls and a mains water supply!

Average speed in May 2010 - 5.2 Mega bits per sec

Page 4: Bandwidth What is it? How much do we need? Is it worth it?

A measure of how much data can be transferred over time, measured in bits per second (bps).

For example -

What is bandwidth?

Average home broadband speed - 5.2 Mega bits per sec (Mbps)

1 megabit = 1,000,000, 000,000 bits1 gigabit = 1,000,000,000 billion bits

Page 5: Bandwidth What is it? How much do we need? Is it worth it?

What is a bit? A bit is the smallest unit of information

that can be stored or manipulated on a computer; it consists of either zero or one.

Don’t confuse this with bytes. A byte is a collection of bits. For example, “A” is represented as  01000001

Page 6: Bandwidth What is it? How much do we need? Is it worth it?

Bits vs. bytes Bytes are usually used to talk about

data storage. E.g. a 500 gigabyte hard drive.

Bits are usually used when talking about data communications. E.g. a 5 megabit broadband connection.

Page 7: Bandwidth What is it? How much do we need? Is it worth it?

It’s not just the Internet.. Data is transferred between various

parts of the computer and between the computer and peripherals such as hard disks and mobile phones.

USB 2.0 – 480 mbps

100x the average home Internet speed!

Page 8: Bandwidth What is it? How much do we need? Is it worth it?

How much do we need?Is bigger always better?

No, it depends what you want to use it for!