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Computer Science GCES AQA

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  1. Representing Algorithms Aqa
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  2. Efficiency Of Algorithms Aqa
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  3. Searching Algorithms Aqa
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  4. Sorting Algorithms Aqa
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  5. Data Types Aqa
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  6. Programming Concepts Aqa
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  7. Arithmetic Relational And Boolean Operations Aqa
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  8. Data Structures Aqa
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  9. String Manipulation Aqa
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  10. Random Number Generation Aqa
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  11. Structured Programming Aqa
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  12. Robust And Secure Programming Aqa
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  13. Number Bases Aqa
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  14. Converting Between Number Bases Aqa
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  15. Units Of Information Aqa
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  16. Hardware And Software Aqa
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  17. Boolean Logic Aqa
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  18. Programming Languages And Translators Aqa
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  19. Cpu Architecture Performance And Embedded Systems Aqa
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  20. Memory Aqa
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  21. Secondary Storage Aqa
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  22. Fundamentals Of Computer Networks Aqa
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  23. Fundamentals Of Cyber Security Aqa
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  24. Methods Of Preventing Cyber Security Threats Aqa
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  25. Relational Databases Aqa
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  26. Ethical Legal And Environmental Impacts Aqa
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Exam code:8525

Examiner Tips and Tricks

New syllabus alert – if your exam is in 2027 or later, use the new notes

Wired & Wireless Networks

  • To connect devices to a network, there are two main options:

    • Wired

    • Wireless

  • There are advantages and disadvantages to each option which are explored below

Wired & Wireless Networks

What is a wired network?

  • A wired network is a network where physical cables are used to join devices together and transmit data

  • Computers can be connected to networks using many different types of wires to transmit data

  • The most common types of cables in a wired network are:

    • Ethernet

    • Fibre optic

    • Copper

What is Ethernet?

ethernet-cables
  • Ethernet is a wired networking standard to carry electrical signals between devices on a local area network (LAN)

  • Ethernet is common in most offices and homes to connect devices such a desktop computers & servers

  • Ethernet uses twisted pair cables to allow duplex communication

What is fibre optic?

fibre-optic-cable
  • Fibre optic is a type of cable that uses light to transmit data on a wide area network (WAN)

  • Fibre transmits data at a much higher speed and has a much higher bandwidth compared to copper cables

  • Fibre optic cable does not suffer from interference which makes them the most secure option to send sensitive data

  • Fibre optic cables can cover a long distance without any degradation, they can span cities and countries

What is copper cable?

copper-cable
  • Copper is a type of cable originally used in telecommunication to transmit voice signals, forming the traditional landline phone network

  • The ability to use copper to deliver network traffic on a wide area network (WAN) made the internet possible

  • Copper cables degrade over time which limits their range compared to fibre optic

  • Copper cable suffers from interference which can disrupt data quality

  • Copper transmits data at a much slower rate, and has a much lower bandwidth compared to fibre optic

Advantages & disadvantages of wired networks

Advantages

Disadvantages

Speed – Fast data transfer

Portability – Can’t move easily, location is limited by physical cable

Security – Better physical security 

Cost – Need more cables to add a new device

Range – High (up to 100m), less susceptible to interference

Safety – Cables can be trip hazards, need routing along walls, under floors

What is a wireless network?

  • A wireless network is a network where connections are made using radio waves to transmit data through the air

  • The most common types of wireless connections are:

    • Wi-Fi

    • Bluetooth

    • Near-field Communication (NFC)

    • IrDA/Infrared

    • Zigbee

    • Wireless USB

    • Ultra-wideband (UWB)

What is Wi-Fi?

wifi
  • Wireless fidelity (Wi-Fi) is a common standard for wireless networks

  • Wi-Fi is common in most homes and offices to connect devices such as laptops, tablets & smart phones

  • Using Wi-Fi, devices communicate with a wireless access point (WAP), which can be a standalone device or built into a router or switch 

What is Bluetooth?

bluetooth
  • Bluetooth is another common standard for wireless networks

  • Bluetooth is common in most homes and offices to connect devices such as headphones, controllers, keyboards & mice

  • Bluetooth is used typically for a direct connection between two devices 

Data privacy concerns in wireless networks

  • When setting up a wireless network, organisations must consider how to protect sensitive data from unauthorised access.

  • Common data privacy concerns include:

    • Spoofing / session hijacking – an attacker pretends to be an authorised user to gain access to the network

    • Eavesdropping – because wireless data is broadcast, it can be intercepted by a third party

    • Encrypting data – ensure data is not sent in plain text by enabling encryption on routers

    • Malware infiltration – Wi-Fi is more visible and therefore more exposed to malicious attacks

    • Malicious hotspots – unofficial access points can trick users into connecting, allowing attackers to steal data

Advantages and disadvantages of wireless networks

Advantages

Disadvantages

Portability – Easy to move around, location is only limited by range

Speed – Slower data transfer than wired

Cost – Less expensive to setup and add new devices

Security – Less secure than wired

Compatibility – Most devices are manufactured with a built in wireless adapter

Range – Relies on signal strength to the WAP, signals can be obstructed (up to 90m)

Worked Example

Give three advantages of using a wireless network instead of a wired network [3]

Answer

  • flexibility to expand network/add users/add own devices to the network

  • there is no need to drill holes/install cabling

  • mobility of user/devices (portable)

  • modern devices are more likely to (be designed to) connect wirelessly (built in adapters)

  • guest access (can add temporary connection)

  • no trip hazards

Guidance

  • Cost can be accepted but only If a valid explanation is given

Responses

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