Summarize the key terms and causes of attenuation in communication systems.

Here's a summary of your notes on Communication:

Communication is about sharing information, ideas, or feelings between people or groups to create mutual understanding. It involves a sender sending a message through a medium (channel) to a receiver. For it to be effective, the information needs to be encoded (transformed into a signal) by the sender and decoded (extracted from the signal) by the receiver.

Key Terms:

• Encoding: Turning information into a signal (like electrical signals).
• Encoder: The device that does the encoding.
• Decoding: Getting information back from a received signal.
• Decoder: The device that does the decoding.
• Channel/Medium: The path the signal travels through.
• Signal: The encoded information moving through the channel.
• Storage: Keeping information in a medium for later use.
• Retrieval: Getting stored signals back from a channel.
• Attenuation: The weakening of a signal's strength (power) as it travels. This happens because the signal's energy is absorbed, spread out, or diffracted.

Causes of Attenuation:

• Electrical signals in wires: Lose energy as heat due to the wire's resistance. Longer wires mean more loss.
• Radio waves: Weaken as they spread out over a larger area and are absorbed by the transmission medium.
• Light pulses in optical fiber:
  • Scattering (Dispersion): Light spreads out due to tiny imperfections in the fiber, causing the pulse to broaden.
  • Absorption: Light energy is lost due to impurities in the glass material.

Crosstalk:
This is when a signal from one circuit accidentally interferes with another nearby circuit, creating an unwanted effect. For example, when you're tuning a radio to one station but faintly hear another.