A-level Computing 2009/CIE/Computer systems, communications and software/Data transmission and networking

Networking (a) describe the characteristics of a local area network (LAN) and a wide area network (WAN) (b) show an understanding of the hardware and software needed for a local area network (LAN) and for accessing a wide area network (WAN) (c) describe basic network topologies (bus, star and ring) explaining the benefits and drawbacks of each topology

• Networking

Data transmission (d) describe the different types of data transmission: serial and parallel; simplex, half duplex and full duplex modes (e) explain the relationship between bit rates and the time sensitivity of the data (f) recognise that errors can occur in data transmission; explain the use of parity checks, echoing and checksums in detecting and correcting these errors, and the use of parity blocks to aid self-checking

• Data transmission

Circuit switching and packet switching (g) explain the difference between packet switching and circuit switching

• Circuit switching and packet switching

Protocols (h) define the term protocol (i) describe the need for communication between devices, and between computers, and explain the need for protocols to establish communication links (j) explain the need for both physical and logical protocols and the need for layering in an interface

• Protocols