Understanding Signal Types and Communication Systems

Signal Types and Characteristics

• Continuous Signals: Signs that have no breaks in time during measurement. Example: Used temperature.
• Discontinuous Signals: Signals that feature interruptions. Example: A pilot's transition from an airplane.
• Discrete Signals: Signals that possess predetermined values. Example: Buttons in elevators.
• Periodic Signals: Signals that repeat over a set time period.
• Non-Recurrent Signals: Signals that constantly change without order. Example: The flight path of a mosquito.
• Digital Signals: Signals that vary using pulses with discrete values.
• Analog Signals: Signals that normally vary continuously within a defined range and can take infinite values.

Basic Elements of Communication

The basic elements include the sender, message, receiver, and protocol (the process by which the issuer alerts the receiver that a message will be sent).

Electronic Communication Processes

Information in a signal moves from one device to another. During this spread, signals undergo several processes, among which we highlight:

• Noise: The information signal becomes mixed with other unwanted signals produced by diverse sources.
• Attenuation: Energy loss suffered by a signal as it propagates through a medium. This is solved by interposing amplifiers, repeaters, or signal regenerators between the sender and receiver.
• Signal Collision (MCL Violation): A medium can be shared by several signals, but if these coincide, they collide.

Denoising Using Balanced Cables

This method consists of two conductors, where each carries the same signal but with opposite polarity to the other.

The resulting entry calculation is: (Conductor1) - (Conductor2) = (V + N) - (-V + N) = 2V. Thus, the noise (N) is canceled.

Communication Media Types

The media can be of two types:

• Guided or Cabled: Signals are transmitted in a confined environment.
• Unguided or Wireless: Signals travel through the air without being confined.

Guided Media: Electrical Cables

This was the primary means of guided transmission used.

Its electrical characteristics and resistance cause the signal to attenuate quickly. Cable harnesses are bulky and heavy.

Benefits:

• Enable transmission of analog and digital signals.
• They feed easily.

Drawbacks:

• The transmission speed is low to medium.
• They are affected by electromagnetic disturbances.
• The channels become mixed, and they are a heavy medium.