Ever wondered how easily you get online and punch a few keys to visit that website half way around the world or send messages to your loved ones instantly? Ever thought about how you can do live video chatting with people several thousand miles away? If you are thinking about those communication satellites hovering around the globe make this possible then your information is marginally correct.
Underwater communication lines: Before humans even thought about satellites, we knew a better way to send electric signals between two places kilometers apart. Human communication has been relying on cables for decades before first satellite launch. Engineers just took that thought to the extreme by deploying long and huge communication lines on our ocean beds. Fascinating, isn’t it?
Submarine cables have Multi-terabyte bandwidths making them an ideal solution for future of communication. Today our satellites only count for 1% of international communication. Growing network of these submarine cables provides really high reliability incase of a cable break. Engineers can deploy these cables with help of specially designed ships. However, these submarine cables have limitations. Signal through these cables weakens over long distances so manufacturers have to incorporate these cables with repeaters every 6 to 9 km. Another disadvantage is that, in case of a cable break the repair crew has to deep dive to replace whole affected segment and that makes repair work very risky. Advancements in the filed are now allowing robots to do any hazardous underwater work.
Submarine cable vs. Satellite
Why does most of our data still travel via submarine cables instead of satellites?
Data traffic through undersea optical fiber cables offer advantages in terms of reliability, security, capacity and cost.
Microwave satellite signals take about 0.2 seconds to travel roundtrip from the ground to an orbiting satellite, while optical submarine cables can send data across the Atlantic in 1/20th of that time, resulting in lower latency.
The microwave spectrum available to satellites is limited, while the spectrum available for optical communications has more room for increasing IP traffic.
Wavelength division multiplexing technology increases the capacity carried by single fibers and thereby reduces the number of cables required; deploying fewer and smaller cables is then more cost efficient for the amount of capacity versus the high cost of deploying and maintaining satellites. [osa-open.org]
If you are curious, check the map below to get some idea of how the world is connected or click here to view an interactive updated map.