Section 4 – Computer
Networks
Wi-Fi and Bluetooth
Lesson Objectives
• By the end of this lesson you will be able to:
• Describe the use of WIFI and Bluetooth in
networks
• Identify the advantages and disadvantages of
using common network environments such as
the Internet
• Describe the characteristics and purpose of
common network environments, such as
intranets and the internet
Starter
• Name 3 devices that use Bluetooth
• Name 3 devices that rely on a WiFi
connection
Starter Answers
• Bluetooth devices
• WiFi
What is Wi-Fi?
• Wi-Fi is a popular technology that allows an
electronic device to exchange data
wirelessly (using radio waves) over a
computer network, including high-speed
Internet connections.
• A device that can use Wi-Fi can connect to
the Internet via a wireless network access
point. Such an access point (or hotspot)
has a range of about 50 meters indoors and
a greater range outdoors.
Advantages of Wi-Fi
•
Convenience – You can work pretty much anywhere. Most Hotels,
Coffee Shops, Fast Food restaurants now offer free Wi-Fi. You don’t
have to stop working when you are travelling. Wi-Fi is now available
on Buses, Trains and Planes.
•
Deployment – Initial setup of an wireless network requires little more
than a single access point. Wired networks, on the other hand, have
the additional cost of actual physical cables being run to numerous
locations (which can even be impossible for hard-to-reach locations
within a building).
•
Expandability – Wireless networks can serve a suddenly-increased
number of clients with the existing equipment. In a wired network,
additional clients would require additional wiring.
•
Cost – There are no network wires so there are no costs for their
installation.
Disadvantages of Wi-Fi
• Security – The dangers of hackers reading messages.
• Range – Limited signal range. There are areas where you
cannot get a wireless network.
• Speed – The speed on most wireless networks (typically 154 Mbps) is far slower than even the slowest common wired
networks (100Mbps up to several Gbps).
What is Bluetooth
Bluetooth is a way of exchanging data
wirelessly over short distances, and is an
attempt to do away with your computer’s
jungle of wiring.
Using a special radio frequency to transmit
data, it creates a short range network. It is very
secure and can connect up to eight devices
(items of electronic equipment) at the same
time. The chip can be found in items such as
computers, digital cameras, mobile phones and
tablets.
Advantages of Bluetooth
•
Bluetooth is Automatic - Bluetooth doesn't require you to think
about setting up a connection or to push any buttons. When two
or more Bluetooth devices enter a range (Up to 30 feet) of one
another, they automatically begin to communicate without you
having to do anything.
•
Low Energy Consumption - Bluetooth uses low power signals. As a
result, the technology requires little energy and will therefore use
less battery or electrical power. Obviously, this is a great benefit
for mobile devices because Bluetooth won't drain the life of your
device's battery.
The Internet
• The Internet is a worldwide collection of
computer networks, cooperating with each
other to exchange data using a common
software standard. Through telephone wires
and satellite links.
Video
Advantages of the Internet
•
Information The biggest benefit offered by the Internet is information.
•
Communication - The primary goal of the Internet is communication.
Sending an e-mail, we can contact a person who is physically present
thousand miles away within the fraction of a second’s time.
•
Entertainment - Internet functions as a popular medium of entertainment.
A wide variety of entertainment including video games, music, movies,
chat room, news and others can be accessed through the Internet.
•
Shopping - E-commerce has become a fantastic option through which you
can shop anything.
•
Formation of communities Internet helps in formation of communities or
forums. Here a number of people can participate in different types of
debates and discussions, express their views and gather valuable
knowledge.
•
Services A variety of services are offered via Internet, for example job
Disadvantages of the
Internet
• Misinformation – there are bogus or fake
sites so you need to check the information
you obtain carefully or use reliable sites.
• Cyber crime – we have to be much more
careful about revealing personal
information such as bank and credit card
details.
• Increased problems due to hacking and
viruses.
• Empty city centres as shops close down
since they cannot compete with Internet
What is an Intranet
An intranet is a private network, operated by a large company or
other organisation, which uses internet technologies, but is
insulated from the global internet.
Intranets typically start by publishing web pages about
• company events
• health and safety policies
• staff newsletters.
Popular applications follow, such as forms to reclaim expenses or
request holidays. All these help eliminate paperwork and speed up
workflows.
Difference between Intranet and Internet
• The Internet is available to the public (everyone), whereas an
intranet is a private network only available to select users., e.g. a
school may use an intranet so that its pupils can work from home.
• An Intranet provides much high speed than the Internet.
• Intranet-based information is more secure than that of the Internet.
Difference between Internet and WWW
The Internet is a Big Collection of Computers and Cables.
The Internet is named for "interconnection of computer
networks". It is a massive hardware combination of millions of
personal, business, and governmental computers, all
connected like roads and highways.
The Web Is a Big Collection of HTML Pages on the Internet.
The World Wide Web, or "Web" for short, is the way of
accessing the information on all these networked computers.
Task
• Complete worksheet that you have
been provided. You will need to use
the following
1.This PowerPoint
2.iGCSE ICT website
3.Text book – pages 36 - 38
Plenary
• Bluetooth disadvantage??
• http://www.youtube.com/watch?v=o
oxTIF98_lQ
Exam Questions
1. A small office consists of three rooms
each of which has a PC with devices
connected to it using cable. The office
manager thinks the cables are a safety
hazard and wants to remove them. Name
three devices which would be connected
to a PC using Bluetooth.
2. Give two reasons why Bluetooth
technology should not be used to create
an office network.