Elements of Digital Communications — Video Notes (LTE, 2016)

Vocabulary flashcards covering key terms from the lecture notes on digital communications.

Long-distance communication

The transmission of electrical signals over wires or other media to relay information across distances.

Smoke signals

An ancient method using smoke as a distress signal; used by American Indians and to relay threats near the Great Wall of China.

Pigeon Courier

Messages carried by pigeons; used by ancient Persians, Romans, and Greeks.

Semaphore Flags

Flag-based signaling system developed by Claude Chappe in 1792 for rapid messaging.

Pony Express

1860 mail service delivering messages, newspapers, and mail via relays of horse-mounted riders.

Electrical Telegraph

Early long-distance communication using electric signals (Morse code) between two stations.

Wireless Telegraphy (Radio)

Transmission of electric current as radio waves projected into space.

Telephone

Instrument designed for the simultaneous transmission of the human voice.

1G

First generation; analog wireless technology used in mobile communications.

2G

Second generation; digital upgrade with CDMA and GSM; introduced SMS, GPRS, and PSN.

3G

Third generation; UMTS enabling multimedia streaming; HSPA+.

4G

Fourth generation; key technologies include MIMO and OFDM; standards WiMAX and LTE.

5G

Fifth generation; speeds up to 10x faster than 4G; supports IoT, autonomous systems, and beamforming.

Analog data

Continuous information; example: human voice.

Digital data

Discrete values; bits (0s and 1s); can be a file, information, or instruction.

Data communication

Exchange of data between a source and a receiver in a network; movement of data between nodes.

Source

Originator of information in a network (e.g., computers, smartphones, tablets).

Source Encoder

Converts information into an electrical form called a message signal (e.g., modem).

Transmitter

Converts the message signal into a form acceptable to the channel (e.g., amplifiers and antennas).

Channel

The path or link that connects the transmitter and receiver; can be a physical medium or RF signals.

Receiver

Performs the inverse function of the transmitter to recover the message signal (e.g., filters and antennas).

Source Decoder

Converts the electrical signal back to a form acceptable to the receiver (e.g., modem).

Sink

The user of the information generated by the source (terminal devices like computers, smartphones, tablets).

Bus topology

A network topology where all nodes are peers; line terminator prevents signal reflections and bouncing.

Wide Area Network (WAN)

A network that covers large geographical areas; examples include PSTN and the Internet.