3_5_1 Understand Network Architecture

You should be able to:

Define what a computer network is.
Discuss the benefits and risks of computer networks.
Describe the main types of computer network including:

•• Personal Area Network (PAN)

•• Local Area Network (LAN)

•• Wide Area Network (WAN)

Understand that networks can be wired or wireless.
Discuss the benefits and risks of wireless networks as opposed to wired networks.
Explain the following common network topologies:

•• star

•• bus

REVISE:

What is a network?

A computer network is a number of computers linked together to allow them to share resources. Networked computers can share hardware, software and data.

Most computer networks have at least one server. A server is a powerful computer that provides one or more services to a network and its users. For example, file storage and email.

Advantages and Disadvantages

Advantages:

Data can be shared quickly and easily
Resources can be shared. For example, a printer can be shared amongst a whole classroom
Data can be backed up in a central location (server)
The network can be updated via the server instead of updating each individual machine
Files are stored centrally so that a user can access their files from any location connected to the network

Disadvantages:

Viruses can be spread quickly due to the connectivity of the computers
If the server breaks then all of the computers on the network will stop working
It can be expensive to set up
The set-up and maintenance requires specialist expertise

The Three Main Types of Network

PAN (Personal Area Network)

This is a network that is connected to one individual. Usually as close as 10 meters away from the person. For example, if you are wearing a smart watch and you also have a smart phone then you will have your own PAN because the smart watch will be talking to the smart phone and sharing data.

LAN (Local Area Network)

Covers a small area such as one site or building, eg a school or a college.

WAN (Wide Area Network)

Covers a large geographical area. Most WANs are made from several LANs connected together. An example of a WAN is The Internet.

Wired and Wireless

Networks can be:

Wired (connected only through hard wiring)
Wireless (connected only through wireless technology)
Mixed (a mixture of both wired and wireless)

Wired vs Wireless

Wired:

Negatives

They are expensive to set up
It takes more time to set up
Its harder to expand the network
The workstations must be next to a network connection to work

Positives

The connection is more stable
A wired network is more secure

Wireless:

Negatives

They are less secure
File sharing can be slower without a stable connection
Interference can occur meaning temporary loss of connection

Positives

They are cheaper to set up than a wired connection
It is easier to expand the network
A wireless network doesn't limit the number of users through physical network ports
It allows for mobility, workstations just need to be in range of a wireless connection

Network Topologies

You need to know about Star and Bus

Information on these topologies can be found here: http://www.bbc.co.uk/education/guides/zh4whyc/revision/3

TEST:

Download and print the test paper here: https://drive.google.com/open?id=0B5fLtQ0Xgr2PVVQxdzBHS2h5Rzg
Try the mock test yourself.
Use the 3.5.1 Walking Talking Mock below to guide you through answering the questions.

SOURCE RECOGNITION - PLEASE NOTE: The examination examples used in these walking talking mocks are samples from AQA from their non-confidential section of the public site. They also contain questions designed by TeachIT for AQA as part of the publicly available lesson materials.

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