Principle com Prelim

What is communication?

The exchange of any type of message between a sender and a receiver.

What is an electronic communication message called?

Information or intelligence signal.

What are the three major components of a basic communication system?

Transmitter, communication channel, and receiver.

What does a transmitter do?

Converts a message into an electronic form suitable for transmission.

What does a microphone do?

Converts sound into an electronic audio signal.

What does a camera do?

Converts light information from a scene into a video signal.

What does a keyboard do?

Converts typed information into binary codes.

What is a transducer?

A device that converts physical characteristics such as temperature, pressure, and light intensity into electronic signals.

What is a communication channel?

The medium through which an electronic signal travels from one point to another.

What is an electrical conductor?

A material that conducts electricity and allows the flow of charge.

What are examples of electrical conductors?

Metals, metal alloys, and wires.

What is optical media?

A communication medium that uses light waves to carry information.

What are examples of optical media?

Fiber

What is free space as a communication channel?

A wireless medium that results in a radio communication system.

What medium is commonly used by sonar?

Water.

What is passive sonar?

Sonar that listens for underwater sounds using sensitive hydrophones.

What is active sonar?

Sonar that uses echo

What does a receiver do?

Accepts transmitted messages and translates them into a form humans can understand.

What does an amplifier do?

Produces an increased version of the input signal.

What does an oscillator do?

Produces a continuous repeated alternating waveform without an input.

What does a mixer do?

Combines two or more electronic signals into one or two output signals.

What are tuned circuits also called?

Resonant circuits.

What components are combined in a tuned circuit?

An inductor and a capacitor.

What is the purpose of a tuned circuit?

To make a circuit responsive to a particular frequency.

What does a filter do?

Amplifies specific frequencies and attenuates other frequencies.

What are the five blocks of a communication system?

Information Source, Transmitter, Channel, Receiver, and Destination.

What is the memory sequence for the five communication blocks?

I → T → C → R → D.

What happens at the information source?

The message originates there.

What happens at the transmitter?

The message is converted into an appropriate electronic signal.

What happens at the channel?

The signal is carried from one point to another.

What happens at the receiver?

The signal is received and translated.

What happens at the destination?

The final message is received and processed so the information can be understood.

What happened in 1837?

The telegraph was invented by Samuel Morse.

What happened in 1876?

The telephone was invented by Alexander Graham Bell.

What happened in 1887?

Radio waves were discovered by Heinrich Hertz.

What happened in 1901?

The first transatlantic radio contact occurred through Guglielmo Marconi.

What happened in 1906?

Amplitude modulation was invented by Reginald Fessenden.

What happened in 1920?

The first radio broadcast occurred through KDKA Pittsburgh.

What happened in 1923?

Television was invented or demonstrated by Vladimir Zworykin.

What happened in 1939?

The first use of two

What happened in 1948?

The transistor was invented by Bell Laboratories.

What happened from 1958 to 1969?

The integrated circuit was developed by Jack Kilby and Robert Noyce.

What happened in 1975?

The first personal computers appeared in the United States.

What happened from 1982 to 1990?

Development and first use of the Internet according to the handout.

What happened in 1995?

GPS was deployed in the United States.

What happened from 1996 to 2001?

The first smartphones appeared including BlackBerry, Nokia, and Palm.

What happened in 1997?

The first wireless LANs appeared in the United States.

What happened from 2004 to 2006?

Social media rose in the United States.

What happened in 2007?

The Apple iPhone was introduced.

What happened in 2009?

The first 4G LTE cellular networks appeared worldwide.

What happened in 2019?

5G cellular service began according to the handout.

What year was the telegraph invented?

1837.

What year was the telephone invented?

1876.

What year were radio waves discovered?

1887.

What year was the first transatlantic radio contact?

1901.

What year was amplitude modulation invented?

1906.

What year was the first radio broadcast?

1920.

What year was television demonstrated?

1923.

What year was the transistor invented?

1948.

What year were the first personal computers introduced?

1975.

What year was GPS deployed?

1995.

What year were the first wireless LANs introduced?

1997.

What year was the Apple iPhone introduced?

2007.

What year did 4G LTE cellular networks first appear?

2009.

What year did 5G cellular service begin according to the handout?

2019.

How can electronic communication be categorized?

By one

What is simplex communication?

One

What is the direction of simplex communication?

Sender → Receiver.

Can the receiver send information back in simplex communication?

No.

What are examples of simplex communication?

TV broadcasting and remote control.

What is a simplex downlink?

A one

What is a simplex uplink?

A one

What is duplex communication?

Two

What are the two types of duplex communication?

Full duplex and half duplex.

What is full duplex?

Two

What is an example of full duplex?

A telephone call.

What does FULL mean in full duplex?

Both at the same time.

What is half duplex?

Two

What are examples of half duplex?

Walkie

What does HALF mean in half duplex?

Take turns.

What is the main difference between simplex and duplex?

Simplex is one

What is the main difference between half duplex and full duplex?

Half duplex takes turns while full duplex communicates simultaneously.

What is an analog signal?

A continuously varying voltage or current.

What are examples of analog signals?

Sine wave, voice, and TV signal.

What is the main characteristic of an analog signal?

It changes continuously.

What is a sine wave?

A single

What is a digital signal?

A signal that changes in discrete increments rather than continuously.

What are examples of digital signals?

Morse code, continuous

What is the main difference between analog and digital?

Analog is continuous while digital is discrete.

What does Morse code represent?

Letters and numbers using dots and dashes.

What two symbols are used in Morse code?

Dots and dashes.

How long is a Morse code dot?

1 unit.

How long is a Morse code dash?

3 units.

How long is the space between parts of the same Morse letter?

1 unit.

How long is the space between Morse letters?

3 units.

How long is the space between Morse words?

7 units.