UPSC Express

In brief: Internet travel

Client-Server Architecture

• Internet is often defined as a network of networks of computers.
• Computer connected to the Internet communicate with each other for data exchange under the Client-Server Architecture.
• Illustration: When you are accessing a mail on Gmail, your computer is a client that wants to access data, information, and other services present on a variety of servers.

Data travel: Internet backbone

• The data exchange often occurs across countries and across continents in the globalised world.
• The physical infrastructure facilitating data transmission is also referred to as the Internet backbone.
  • In simple words, if internet is thought to work like a transportation system, the internet backbone is the highway which carries maximum amount of traffic on the Internet across continents.
• This is made possible through:
  • Wired mediums – made up of twisted-pair cables, coaxial cables and fiber-optic cables.
  • Wireless mediums – like radio transmission through satellite communication.

In focus: Undersea fiber-optic cables

• Undersea fiber-optic cables make up the bulk of internet backbone propelling around 95-99% of data traffic on the internet around the world.
• There are about 300 fiber-optic cable systems covering around 12 lakh km of undersea fiber-optic cables making up the world’s internet.
• In the early days, most of the undersea cable projects were undertaken by telecom companies.
• Today, increasingly the undersea cable projects are being undertaken by content providers like Facebook, Google, and Amazon.
• In India, there are 18 under-sea cable systems situated in Mumbai, Chennai, Cochin, Tuticorin and Trivandrum.

Fiber-optic technology (see figure below)

• The core of a fiber-optic cable consists of hundreds of thin strands of glass called optical fiber.
• Optical fiber basically uses light to transmit data.
• The principle used in transmitting light-propelled data is total internal reflection.
• Each strand of optical fiber is as thin as a human hair.
• Each optical fiber strand has a protective coating (to protect it from water) and an insulating glass cladding.

Undersea optical fiber

• The undersea optical fiber is laid deep below the surface of water.
• They transmit data at the rate of 80 Tbps (terabytes per second)

Advantages of undersea fiber-optics

• Optical fibers are the fastest medium of data transmission.
• As they are undersea, they are less susceptible to noise during transmission
• They are far cheaper than satellite data transmission.

Conclusion

• With new inter-driven technologies like AI, IoT, 5G etc. coming up, undersea cables will remain the mainstay of internet due to faster transmission rates.

Note: Detailed coverage is made keeping in view the importance of fiber-optics technology in prelims (concept-based questions) and mains.