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

Communication Methods

Main article: 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. Handshaking Explain what is handshaking in the context of data transmission. Protocol 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

Main articles: Networks and Wireless Networks

Specification: Networks 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. Inter-networking 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

Main article: 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

Main article: Internet security

Specification: Internet Security Firewalls Packet filtering. Proxy Server. Encryption 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.