Science & Technology in Action

9th Edition

All you need to know about Wi-Fi

Commission for Communications Regulations

This lesson deals with some of the technologies behind the Wi-Fi phenomenon. Various types of network are defined, the various devices in a wireless LAN are described and the term ‘hotspot’ is discussed. Some radio fundamentals are reviewed.
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Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

The importance of technical standards
The various components of a network cannot work together unless they all operate to an agreed standard. If a laptop sends a message to the router, the router must be able to understand it. For example, in computer networks, information is sent in groups of binary digits (bits) called packets or frames. When these packets reach the destination computer it must be able to extract the information from them. The standards, or rules, governing Wi-Fi networks are published by the Institute of Electrical and Electronic Engineers (IEEE). Without such standards there would be no useable Wi-Fi. All equipment manufacturers follow these standards so that if you purchase a Wi-Fi adapter for your computer, either in card form or as a USB device, you know it will work.

What is a hotspot?
A device that allows wireless access to the internet is called a wireless network access point. These points are called hotspots and are often located in places such as cafes, libraries and hotels. These hotspots are often free of charge and are used to attract customers. The range of a hotspot might be around 20 metres. Larger areas can be covered by using a number of overlapping access points.

Radio versus cable
It can be difficult to install cables in buildings, especially in older ones where provision for cabling may not have been made. Wireless removes the need for physical cables and this is an important advantage...

To read the full lesson, download the pdf above.

True or False?

  1. To transmit or receive radio frequencies an aerial or antenna is required. true
  2. The eircom telephone network is a WAN. true
  3. The radio spectrum is not related to the electromagnetic spectrum. false
  4. The component of a WAN that is connected to the Internet is called a router
  5. A wireless network access point and a hotspot are two different things. true
  6. Atmospheric conditions can interfere with radio signals. true
  7. Using someone else’s Wi-Fi service without permission is called piggybacking. true
  8. Changing a carrier wave to embed information is called modulation. true
  9. Data can be protected by encryption. true
  10. ComReg provide licences for Wi-Fi networks. false

Glossary of terms

aerial
antenna
binary digits
bits
card
carrier
decryption key
demodulated
DSL