History of Telecommunication – Study Notes
1. Foundations (Pre‑19th Century)
| Period |
Milestone |
Key Figures / Innovations |
| Ancient Times |
Visual signalling (smoke, fire, mirrors) & auditory signalling (drums, horns) |
Early societies (China, Greece, Rome) |
| 16th–18th C |
Optical telegraph (semaphore) – line‑of‑sight towers transmitting coded flags or shutters |
Claude Chappe (France, 1792) |
| Late 18th C |
Electrical experiments with static and voltaic electricity |
Benjamin Franklin, Luigi Galvani, Alessandro Volta |
2. The Birth of Electrical Telecommunication (1800‑1900)
| Year |
Development |
Significance |
| 1837 |
Samuel Morse invents the electric telegraph and Morse code |
First practical long‑distance, near‑instant communication |
| 1844 |
First telegraph line between Washington, D.C. and Baltimore |
Demonstrates commercial viability |
| 1854 |
Cooke & Wheatstone develop the electric telegraph for railways (UK) |
Improves safety and scheduling |
| 1860s‑1870s |
Expansion of national and trans‑continental telegraph networks (e.g., Trans‑Atlantic Cable, 1858, 1866) |
Connects continents; marks true global communication |
| 1876 |
Alexander Graham Bell patents the telephone |
Voice transmission replaces Morse code for many users |
| 1880 |
First telephone exchanges (Boston, New York) |
Enables multiple users to connect via a central switchboard |
| 1890 |
Guglielmo Marconi demonstrates wireless (radio) telegraphy |
Opens the path to broadcast and mobile communication |
3. Early 20th‑Century – Radio, Broadcast & Early Mobile
| Decade |
Highlights |
| 1900s |
Development of AM radio (Reginald Fessenden, 1906) – first voice broadcast |
| 1910s |
World War I accelerates radio tech; introduction of vacuum‑tube amplifiers |
| 1920s |
Commercial radio broadcasting explodes (e.g., KDKA 1920, first US station) |
| 1930s |
Frequency Modulation (FM) invented by Edwin Armstrong – higher fidelity, less static |
| 1940s |
World War II spurs radar, cryptography, and early microwave communication |
| 1947 |
Bell Labs invents the transistor – foundation for miniaturized electronics |
| 1950s |
First telephone satellites (e.g., Telstar, 1962) and microwave relay networks |
4. The Digital Revolution (1960‑1990)
| Year |
Breakthrough |
Impact |
| 1960 |
Introduction of pulse code modulation (PCM) – digitizing voice |
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| 1962 |
Telstar 1 – first active communications satellite (transmits TV, phone, fax) |
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| 1969 |
ARPANET launch – precursor to the Internet |
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| 1971 |
Intel 4004 – first micro |
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