In brief: Internet travel
- 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.
- 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.