A-level Computing/AQA/Problem Solving, Programming, Operating Systems, Databases and Networking/Communication and Networking

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Communication Methods[edit | edit source]

Main page: Communication Methods
Specification: Communication Methods
  • Define both serial and parallel transmission methods and describe where they are used
  • Consider the effect of distance on the transmission of data.

Baud, bit rate, bandwidth, latency

  • Define these terms.
  • Differentiate between baud and bit rate.
  • Consider the relationship between bit rate and bandwidth.

Asynchronous data transmission

  • Define asynchronous data transmission.

Start and stop bits

  • Describe the purpose of start and stop bits in asynchronous data transmission.

Odd and even parity

  • Explain the use of parity checks.


  • Explain what is handshaking in the context of data transmission.


  • Explain what is meant by a protocol in this context.

Baseband and Broadband

  • Define each mode of network operation and describe where each is appropriate.

Networks[edit | edit source]

Main pages: Networks and Wireless Networks
Specification: Networks

Local Area Networks & Wide Area Networks

  • Contrast wide area and local area networks

Network adapter Topology (Bus & Star)

  • Define the term topology.
  • Differentiate between physical and logical network topologies
  • Describe in general terms the operation of these networks.
  • Compare the advantages and disadvantages of each.
  • Candidates should be able to compare local area networking with standalone operation.

Network Segment

  • Define the term and explain why local-area networks based on a bus topology are segmented.

Peer-to-peer networking & Server-based networking

  • Explain these terms and describe situations where these might be used.

Thin client computing & Web services

  • Compare and contrast thin client computing (software as a service, AJAX, Web 2.0, etc) vs rich client computing (client-server, peer-to-peer), web services as examples of ‘systems architectures’.

Wireless networking (Wi-Fi & Bluetooth)

  • Radio-based LAN protocols for connecting mobile/portable devices.


  • Explain the meaning of the term inter-networking.

Routers particularly, Gateways

  • Define these and consider where and why they are used.
  • Consider how routing is achieved across the Internet and how local area networks are connected to the Internet via gateways.
  • Consider how a subnet mask is used to identify the network identifier part of an IP address.
  • Be familiar with the role of MAC addresses in routing packets/frames.
  • Distinguish between routable and non-routable IP addresses.

Server Side Scripting[edit | edit source]

Main page: Server-side scripting
Specification: Server-side scripting

Common Gateway Interface (CGI)

Server-side scripting – the basis of dynamic web page content.

Practical experience of writing simple server-side scripts.

Accessing data from a DBMS using server-side scripts.

Internet Security[edit | edit source]

Main page: Internet security
Specification: Internet Security


  • Packet filtering.
  • Proxy Server.


  • Private/Public key encryption.

Digital Signatures and Digital Certificates

  • How they are obtained and used.

Virus detection

  • Discuss worms, spam, phishing, pharming as well as viruses, also vulnerabilities that these exploit and how to address them through improved code quality, monitoring, protection.

Computer Security Procedures

  • Authentication
  • Authorisation
  • Accounting.