Communication infrastructure: how messages travel

What carries a message?

Phones, computers and tablets have made communication fast and easy. Behind them is communication infrastructure: cables, wireless devices, mobile towers, satellites and data centres that carry messages, pictures and videos.

Think of Rani, in a village in Madhya Pradesh, who records a voice note for a cousin living in Tamil Nadu. She just taps, records and sends. But electricity first powers the mobile tower near her village. The note then races along fibre-optic cables laid beneath farms and roads, reaches satellites in space and passes through huge servers humming in distant cities, before it pops up on her cousin’s phone. A hidden world works together to carry one little Namaste across India.

Seen and unseen

Some parts are easy to see: the two phones, the mobile tower and the power lines. Others are almost invisible: fibre cables underground, satellites far above us, servers in data centres and the radio signals that carry the message through the air.

How communication changed

For centuries, pigeons, runners and horse riders carried messages. Printing brought newspapers; India’s first printed newspaper, the Bengal Gazette, appeared in 1780. In the 1840s Alexander Bain’s fax machine sent images and Samuel Morse’s telegraph sent messages in dots and dashes. Alexander Graham Bell invented the telephone in 1876. Then came radio, television, personal computers, email and the internet, social media, and today 5G, cloud services and AI-driven chat and voice. In 1947, Shanmukham Chetty broadcast the budget on All India Radio.

J. C. Bose and wireless signals

Jagadish Chandra Bose (1858–1937) pioneered wireless transmission using microwaves. In 1895, in Calcutta, he showed that signals could pass through a wall, ringing a bell and firing a remote-controlled gun. He designed a new kind of coherer, the part of early radio receivers that picked up signals, and a galena crystal detector, an early semiconductor, as well as antennas and waveguides. In 1901 Guglielmo Marconi patented a similar device and sent radio signals across the Atlantic, and in 1909 he received the Nobel Prize in Physics. Bose worked in hard conditions and seldom took patents, so his work won less recognition abroad, though he received many honours. He also studied how plants work and founded the Bose Institute in 1917.

From costly calls to cheap data

The telephone has changed from early sets in the 1880s to dial phones, push-button phones, mobile phones and today’s smartphones. In the 1990s a mobile call in India cost up to ₹17 a minute, and even incoming calls were charged. Now Indian mobile and internet rates are among the lowest in the world. In 2025 India had 1,160 million wireless phone users and close to 900 million internet connections.

What the network makes possible

Students in remote areas can join online classes, use digital libraries and watch educational videos. Quick SMS alerts and apps warn people about natural disasters. Small and large businesses sell across the world through e-commerce, and people pay online in seconds. Through e-governance, citizens apply for documents, file complaints and get information easily, for example keeping documents in the DigiLocker app.

Why it matters

Much of the infrastructure we depend on is invisible, so it is easy to forget how much work goes into a single message. Compare it with roads and railways in transport infrastructure in India, and see the bigger picture in what is infrastructure. Answers to the textbook questions are in the NCERT solutions for Part 2 Chapter 7; see all of Part 2 Chapter 7 notes.