3.5.1 Computer Networks
Advantages of computer networks
Disadvantages of computer networks
Types of computer networks
Personal Area Networks (PANs)
Local Area Networks (LANs)
Wide Area Networks (WANs)
Additional information
Data Transmission
Packet Switching
Wireless vs wired networks
Risks of wireless networks
Different types of cable
How do devices/networks connect to other networks?
A computer network is “two or more computer devices linked
together to communicate and share resources and data”.
Advantages of computer networks
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, Share accounts between computers i.e. user profiles and security can be
managed centrally
Software can be distributed across the network (instead of having to be
installed on each individual computer)
All files can be backed up centrally
Files can be shared between computers easily and accessed by authorised
users on the network
Printers, scanners and other peripheral devices can be shared on the network,
allowing all computers on the same network to print using the same printer
See other computers’ screens and control them
Disadvantages of computer networks
If the file server went down, no one would be able to access files or do any
work
Network faults could lead to a loss of data
Increased network traffic would degrade the performance of the network,
slowing it down
Difficult to make the system secure and to protect it from hackers
A virus could be spread through the network to every device
Harder to manage very large networks
Types of computer networks
PAN: Personal Area Network
(W)LAN: (Wireless) Local Area Network
WAN: Wide Area Network
Personal Area Networks (PANs)
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, A Personal Area Network (PAN) is used for data transmission
between devices such as computers, phones and laptops.
A PAN can be used for communication between the devices themselves or for
connecting to the Internet
A common example of a wireless PAN is Bluetooth (which uses short-range
radio waves)
For example, Bluetooth devices such as keyboards and headphones can
connect wirelessly to a mobile phone as long as they are within a few metres of
each other (~10m max)
Local Area Networks (LANs)
A Local Area Network (LAN) usually covers a relatively small
geographical area and consists of a collection of computers and
peripheral devices connected together, often on a single site.
An example is a school campus, where the school’s LAN would connect the
computers in different buildings
A LAN is often owned and managed by a single person or organisation
Wide Area Networks (WANs)
A Wide Area Network (WAN) is a collection of computers and
networks connected together using resources supplied by a ‘third
party carrier’ e.g. BT
The Internet is the biggest example of a WAN.
They usually cover a wide geographic area, with components typically connected
with cables, telephone lines, satellites and radio waves.
They are often under collective or distributed ownership due to their extremely
high costs.
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