COMMS 3: Data Communication

Data Communication

• Data communication refers to the process of transferring digital information between two or more points.
• Components of data communication:
  • Message
  • Sender
  • Receiver
  • Transmission line
  • Protocol

Data Representation

• Data is represented as a bit pattern, a sequence of bits (0s or 1s).
• Different sets of bit patterns have been designated to represent:
  • Text symbols (e.g., ASCII)
  • Numbers (directly converted to binary)
  • Images (comprise of pixels)
  • Audio (continuous, not discrete)
  • Video (recording or broadcasting of a picture or movie)

Communication Modes

• Simplex: communication is unidirectional.
• Half-duplex: each station can both transmit and receive, but not at the same time.
• Full-duplex: both stations can transmit and receive simultaneously.

Networks

• A network consists of a set of services, often referred to as nodes, connected by communication links.
• Network criteria:
  • Performance
  • Reliability
  • Security
• Performance metrics:
  • Transit time
  • Response time
• Reliability: measured by frequency of failure, time to recover from failure, and network robustness in a catastrophe.
• Security: protecting data from unauthorized access, damage, and development, and implementing policies for recovery.

Network Topologies

• Physical topology: refers to the way in which a network is laid out physically.
• Types of network topology:
  • Bus
  • Ring
  • Star
  • Mesh
  • Tree
  • Hybrid
• Bus topology: all nodes are connected to a single cable.
• Ring topology: each node connects to exactly two other nodes, forming a single continuous pathway.
• Mesh topology: infrastructure nodes connect directly to as many other nodes as possible.
• Hybrid topology: integration of two or more different topologies.
• Tree topology: a hybrid network topology in which star networks are interconnected via bus networks.

Network Categories

• Categories of networks:
  • Local Area Network (LAN)
  • Metropolitan Area Network (MAN)
  • Wide Area Network (WAN)
• Local Area Network (LAN): interconnects computers within a limited area.
• Metropolitan Area Network (MAN): interconnects local area networks in a city into a single larger network.
• Wide Area Network (WAN): exists over a large-scale geographical area and connects different smaller networks.
• Internet: a global computer network providing a variety of information and communication facilities.

This quiz covers the basics of data communication, including data representation, transmission, and recording. Learn about the process of transferring digital information between two or more devices.