Lesson 1.1A: Elements of Computer Network

• Nodes are the devices that are capable of sending or receiving data generated by other devices.
• Computer Networks contain a set of nodes connected by communication links (wired/wireless) that are responsible for carrying the information - resource sharing.
• NODES

  End Devices - PC, Printer, Server, Tablet, Smartphones

  Intermediary Nodes - Router, Modem, Wireless Router, Cell Tower, Internet Cloud
• The network medium consists of a pathway of communication that allows data to travel to the following:

  • Wired Medium - Ethernet Cables (twisted pair, coaxial, fiber optic)
  • Wireless Medium - Wi-Fi, Bluetooth, Infrared and Radio Waves
• COMMUNICATION CHANNEL

  Unguided Media - transmission mode in which the signals are propagated from one device to another device wirelessly which signals can be a wave through the air, water, or vacuum generally used to transmit signals in all directions.
• a.) Microwave - transmission consists of a transmitter, receiver, and atmosphere. Parabolic Antennas that are mounted on the towers to send a beam to another antenna.
• b.) Radio Wave - radio frequencies offering mobility. It consists of a transmitter and receiver - antennas to radiate and capture the radio signal.
• c.) Infrared - short-distance communication and can pass though any object generally used in TV remotes, wireless mouse etc.