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 1-54 Mbps) is far slower than even the slowest common wired networks (100Mbps up to several Gbps).

What is BluetoothBluetooth 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 searching, online banking, buying movie tickets, hotel reservations and consultation services etc.

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 Shopping.

What is an IntranetAn 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 PowerPoint2.iGCSE ICT website3.Text book – pages 36 - 38

Plenary

• Bluetooth disadvantage??

• http://www.youtube.com/watch?v=ooxTIF98_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.