Journey of Communication Technology - Satellite & Digital Communication (1960s–1980s) – The Global Connectivity Era

Journey of Communication Technology - Satellite & Digital Communication (1960s–1980s) – The Global Connectivity Era

This phase introduced real-time, global communication via satellites and began the digital transformation of signals, paving the way for the internet, mobile phones, and globalization.

🛰️ 5.1 Satellite Communication

🔹 Key Milestones

1962: Launch of Telstar 1 – first active communication satellite (USA)

1965: First commercial satellite system (Intelsat I) begins international service

1975: India launches SITE (Satellite Instructional Television Experiment) with NASA

📡 Features

Enabled long-distance TV, phone, and fax

Provided communication access in remote and rural regions

Used geostationary satellites for consistent global coverage

In India:

Year	Satellite Event
1975	SITE – televised education to Indian villages
1976	INSAT program begins planning
1982	INSAT-1A launched (first Indian multipurpose satellite)
1983	First satellite-based telecommunication services in India

💻 5.2 Digital Communication Technologies

🔹 What Changed:

Communication moved from analog signals (waves) to digital signals (bits)

Introduced error correction, encryption, and data compression

Basis for fax, email, digital TV, and eventually the Internet

🔹 Technologies Introduced:

Digital telephone exchanges – replacing analog switches

Modems – allowed computers to send/receive over telephone lines

Packet Switching – foundation of the internet (ARPANET started in 1969)

Early Fax Machines and Pagers

📞 5.3 Mobile Communication Foundations

1973: First mobile phone call made by Martin Cooper (Motorola)

1983: First commercial mobile phone (Motorola DynaTAC 8000X)

India: Introduced mobile phones later, but landline networks expanded during this period

🖥️ 5.4 Computer Networking Begins

1969: ARPANET (precursor to the Internet) launches in the US

1980s: Local Area Networks (LANs) were used in universities, offices

Protocols: TCP/IP developed (foundation for all modern digital communication)

📺 5.5 Cable & TV Expansion

Satellite TV enabled:

Live global news coverage

Olympics, moon landing, and wars broadcast in real time

Growth of Doordarshan in India into a national broadcaster

🧠 Summary of Impact

Domain	Transformation
Global News	Real-time international coverage
Education	Satellite TV for rural literacy
Telecom	Digitized switching, clearer calls
Data Sharing	Foundations of email & the internet
Rural India	Access to TV via satellite (SITE)

🔭 India’s Satellite Pioneering Projects

Project	Purpose	Outcome
SITE (1975)	TV-based rural education	Reached 2,400 villages
INSAT (1982)	Telecommunication, weather, TV	Backbone of Indian digital TV & telecom
NICNET (1980s)	Govt network over satellites	Boosted e-Governance and administration