Chapter 1 Telecommunication Networks

Chapter 1: Telecommunication Networks

1.1 Evolution of Telecommunications

1.2 Classification of Switching System

The Evolution of Telecommunications

  • Telecommunications technology has transitioned from simple smoke signals to global instant communication capabilities.

Early Signaling and Telegraphy

Semaphore

  • Visual signals, using on/off stages to represent letters or words.

Morse Code

  • Transmission of short and long pulses (dots and dashes) representing characters.

Duplexing

  • Simultaneous transmission of signals in both directions on the same wire.

Multiplexing

  • Simultaneous transmission of multiple signals over a single circuit.

Historical Milestones in Telecommunication

Founding and Growth

  • 1856: Western Union Telegraph Company founded.

  • 1861: Over 2000 telegraph offices in the U.S.

Telephone Technology

Early Devices

  • Figure 3-2: Bell's original liquid-based telephone transmitter.

  • Figure 3-3: A turn-of-the-century wall-mounted telephone.

Definitions

Telecommunication

  • Any transmission of signs, signals, writing, images, or sounds by electromagnetic systems.

Electronic Communications

  • Transmission of sound, text, or images via electromagnetic signals, either wirelessly or through cables.

  • Electronic communications network involves radio equipment and switches for data transmission.

Telephony

  • A form of telecommunication focused primarily on speech exchange, allowing two-way conversations.

Historical Timeline

  • 1837: Samuel Morse patents the telegraph.

  • 1876: Alexander Graham Bell patents the telephone.

  • 1878: First switchboard operational.

  • 1892: The first automatic phone switch.

  • 1895: Marconi transmits a radiotelegram over a short distance.

Telecommunications Progress in the 20th Century

  • 1954: Direct dialing of long-distance calls is introduced.

  • 1966: First mobile phone service introduced in Norway.

  • 1969: US DoD ARPA project ARPANET trials begin.

  • 1983: ARPANET evolves into the Internet.

  • 1989: Tim Berners-Lee proposes the World Wide Web project.

Telecommunication Technology Overview

Components of Telecommunication Networks

  • Main components:

    • Transmission equipment

    • Switching equipment

    • Terminal equipment

    • Support systems

Transmission Technology

  • Networks transmit signals over distances through various transmission media, categorized by signal type and capacity.

Bandwidth

  • Refers to the transmission capacity between two points indicated in bits per second.