Wi-Fi Standards · Frequencies · Security · Advantages and Disadvantages
CSZoneAQA GCSE Computer Science 8525
How Wi-Fi Works
Wireless Transmission Basics
Wi-Fi uses radio waves to transmit data wirelessly. A Wireless Access Point (WAP) sends and receives radio signals. Devices need a wireless NIC to connect. Data is split into packets and transmitted on agreed frequencies.
2.4 GHz — longer range, more penetration through walls, but more congested (many devices use this band). Slower max speed.
5 GHz — shorter range, faster speeds, less congestion. Better for video streaming in close proximity.
Advantages and Disadvantages of Wi-Fi
Wireless vs Wired
ADVANTAGES
Mobile — devices can move freely
No cables — easier to set up, less clutter
Easy to add new devices
DISADVANTAGES
Generally slower than wired connections
Signal weakens with distance and walls
Less secure — signals can be intercepted
Interference from other devices
Wireless Security
Protecting Wi-Fi Networks
WPA2/WPA3 — encrypts data transmitted over Wi-Fi. Required password to connect. Much more secure than old WEP.
SSID hiding — hides the network name from casual searches (not truly secure — tools can still find it)
MAC address filtering — only devices with approved MAC addresses can connect
Strong password — prevents brute-force attacks on the Wi-Fi key
Exam Practice
Have a go at this question
AQA-style question
Give two reasons why a wired connection might be chosen over Wi-Fi for a school network.
2 marks
Wired connections are faster and more reliable, with consistent bandwidth unaffected by distance or interference [1]. Wired connections are more secure as data cannot be easily intercepted — unlike Wi-Fi signals which can be captured by anyone in range [1].
Key Takeaways
What to Remember
Wi-Fi uses radio waves. 2.4 GHz = longer range. 5 GHz = faster but shorter range.
Wi-Fi: mobile, convenient but slower, less secure, interference-prone