IT2006: Elements of Digital Communications

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Questions and Answers

Which of the following was one of the earliest methods used for long-distance communication?

Wireless Telegraphy

Pigeon Courier (correct)

Electrical Telegraph

Telephone

What significant technological advancement did the 1st Generation (1G) of communication utilize?

Digital signal transmission

Analog wireless technology (correct)

Fiber optic communication

Morse code signaling

Who developed the semaphore flag system for communication?

Guglielmo Marconi

Claude Chappe (correct)

Alexander Graham Bell

Samuel Morse

In which generation did the concept of Code Division Multiple Access (CDMA) become implemented?

2nd Generation (2G) Signup and view all the answers

Which of the following communication methods was specifically designed for voice transmission?

Telephone Signup and view all the answers

What is the primary focus of information theory as described by Claude Shannon?

The fundamental limitations in processing and communicating information Signup and view all the answers

How are words translated into binary code?

By assigning each letter a numeric value in a defined format like ASCII Signup and view all the answers

Which of the following best describes data communication?

The exchange of data between multiple sources and receivers in a network Signup and view all the answers

What distinguishes information theory from communication theory?

Information theory studies processing limitations rather than device operations Signup and view all the answers

Which of the following statements about data bits is correct?

Data bits can be stored in files and can be transmitted in various signal forms Signup and view all the answers

What is the primary range of coverage for personal area networks (PANs)?

Up to 10 meters Signup and view all the answers

Which network type interconnects LANs within a metropolitan area?

Metropolitan Area Network (MAN) Signup and view all the answers

What is an example of a wide area network (WAN)?

Internet Signup and view all the answers

What function does a source encoder perform in a data communication model?

Converts information into an electrical form called message signal Signup and view all the answers

Local area networks (LANs) typically cover what size of geographical area?

A building or campus Signup and view all the answers

Which technology is NOT typically associated with local area networks (LANs)?

Public Switched Telephone Network (PSTN) Signup and view all the answers

Which component is considered the user of the information generated in a data communication network?

Sink Signup and view all the answers

In a Point-to-Multipoint topology, how is the connection structured?

One node is connected to multiple nodes in a Point-to-Point manner Signup and view all the answers

What is the role of a transmitter in the data communication model?

To convert message signals into a format suitable for the channel Signup and view all the answers

Which of the following best describes the channel in a data communication model?

The path or link that connects the transmitter to the receiver Signup and view all the answers

In a star topology, what is the role of the hub?

To serve as the central point of connection for all nodes. Signup and view all the answers

Which topology is characterized by all nodes interconnected without a master-slave relationship?

Bus topology Signup and view all the answers

What defines a ring topology?

Nodes are connected serially to form a loop. Signup and view all the answers

What is the main difference between mesh topology and multidrop topology?

Mesh allows arbitrary interconnection, while multidrop has a single link to a master. Signup and view all the answers

What function does a line terminator serve in bus topology?

It prevents signal reflection that could corrupt data. Signup and view all the answers

Study Notes

Long-Distance Communication History

Long-distance communication began with the transmission of electrical signals over wire communications.
Smoke Signals: Used by American Indians as distress signals, also employed on the Great Wall of China to communicate threats.
Pigeon Courier: Ancient Persians, Romans, and Greeks utilized pigeons for message delivery.
Semaphore Flags: Developed in 1792 by Claude Chappe, using flags for visual communication.
Pony Express: Established in 1860 as a mail service using horse riders to transport messages and newspapers.
Electrical Telegraph: Revolutionized communication by transmitting Morse code signals between stations.
Wireless Telegraphy (Radio): Involves sending electric currents via radio waves into space.
Telephone: Designed for the simultaneous transmission of human voice, marking a significant advancement in personal communication.

Notable Advancements in Digital Communication

1st Generation (1G): Utilized analog wireless technology for communication.
2nd Generation (2G): Transitioned cellphones from analog to digital; introduced Code Division Multiple Access (CDMA) and Global System for Mobiles (GSM). Used binary coding for data transmission through ASCII format.

Information Theory

Founded by Claude Shannon, focusing on the conditions and limitations of information transmission and processing.
Distinct from communication theory as it addresses fundamental limitations rather than specific device operations.

Data Communication Process

Involves the exchange of data between a source and receiver across a network.
Source: Generates information (e.g., computers, smartphones).
Source Encoder: Converts information into electrical signals (e.g., modem).
Transmitter: Converts message signals for channel transmission (e.g., amplifiers, antennas).
Channel: The medium connecting the transmitter and receiver (e.g., wires, radio frequency signals).
Receiver: Recovers message signals through an inverse process (e.g., filters, antennas).
Source Decoder: Converts electrical signals back for user readability (e.g., modem).
Sink: The user of the information received (e.g., computers, smartphones).

Data Communications Network Topology

Point-to-Point (P2P): A direct link between two nodes or devices.
Point-to-Multipoint: One node connected to multiple nodes, each in a P2P manner.
Star Topology: Each node connects to a central hub in P2P configuration.
Tree Topology: Multiple buses form a branching system with no closed loops.
Multidrop Topology: One master node connects to multiple secondary nodes.
Mesh Topology: Nodes interconnected arbitrarily, no need for complete interconnectivity.
Bus Topology: All nodes interconnected with no master-slave relationship.
Ring Topology: Nodes arranged in a loop, each connected to two others.

Data Communications Geographical Coverage

Personal Area Networks (PANs): Connect devices within a 10-meter range, usually personal gadgets.
Local Area Networks (LANs): Cover small geographic areas like buildings or campuses (e.g., Ethernet).
Metropolitan Area Networks (MANs): Interconnect LANs over a larger area like a city (e.g., FDDI).
Wide Area Networks (WANs): Span large geographic areas, such as nations (e.g., PSTN) or globally (e.g., the Internet).

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Description

Explore the evolution of long-distance communication, tracing the journey from ancient smoke signals to modern digital technologies like LTE. This quiz covers key milestones and technological advancements that have shaped how we exchange information over distances. Test your knowledge on this fascinating history!