The Divine Comedy is probably the first book that comes to mind for Italians and not; an epic poem of almost 92,000 pages and about half a million characters. Imagine now putting them all in a simple Word file. Considering that each character would require only 8 bytes (1 bit) of storage, the total file size would amount to approximately 500,000 bytes, equivalent to 0.5 MB.
So, how long would it take to email the Divine Comedy?
Of course, it depends on the available connection speed. The number of bits transmitted per second (bps), with its multiples Mbps, Gbps and Tbps respectively for a million, a billion and a trillion bits per second measures the connection speed.
Thirty years ago, when the data rate stood at a mere 300 bits per second, it would have taken nearly four hours to transmit this file.
However, thanks to remarkable advancements in technology and network protocols, the landscape of data transmission has undergone a dramatic transformation. Today, with lightning-fast speeds, it would only require a mere 0.13 seconds to send the same file!
Over the past few decades, we have witnessed an exponential surge in transmission rates. Gone are the days of the analogue modems from the 1980s, struggling to achieve a data rate of 300 bps. In the late 1980s, the advent of ISDN (Integrated Services Digital Network) saw a significant leap forward, enabling data transmission at 56,000 bps.
But the journey didn’t stop there.
About fifteen years ago, the introduction of DSL (Digital Subscriber Line) revolutionized the game, propelling data transmission capabilities to unprecedented heights. This groundbreaking technology empowered us to transmit data at speeds reaching hundreds of megabits per second, enabling a new era of digital connectivity.
The Fibre Optic Communication
The introduction of new communication channels played a pivotal role in boosting data transmission rates as well. Optical fibres replaced almost everywhere the old telephone cable terminated in our apartments. Optical fibre communication became the building blocks of the new “highways,” spanning continents and oceans, facilitating simultaneous communication among millions of individuals at astonishing transmission rates of tens of millions of Mbps.
Optical fibres carry almost the totality of traffic data today (around 99%), making satellites play a marginal role. In fact, cables can carry far more data at a much lower cost than satellites. To connect Antarctica and some remote areas of the world, satellite links are still used, as it would be too expensive if not impossible to reach them with physical connections.
The First Transatlantic Cables
The history of intercontinental communications is old and complex. The first cable between England and the US was laid down in 1858. The British warship HMS Agamemnon and the American Uss Niagara met halfway in the Atlantic, where the two halves of the transatlantic cable met (for a total cable length of almost 3000 km). After connecting the cable, the two ships turned away laying gradually down the submarine cable on the ocean floor, reaching the shore of Ireland (on the east) and the island of Newfoundland (on the west).
Triumphal celebrations followed that day and on the 16th of August 1858. Queen Victoria sent a telegram to the President of the United States, James Buchanan, to congratulate him on the excellent job. This message, less than 100 words and about 500 bytes took about 17 hours and 40 minutes to get to the destination!
Today, from Buckingham Palace to the White House, the message would have arrived at its destination after a few milliseconds (due to the limited speed of light signal propagating inside the optical fibres).
Unfortunately, the life of the first transatlantic cable was quite short. To improve the SNR of the Morse signal sent over the cable, the operators increased too much the supply voltage and broke irreparably the cable in two parts.
The embarrassing failure of 1858 did not stop the expensive dream of building a transoceanic network though. The push towards progress (and the related business interests) made everyone quickly forget the shock of the first failure and of the many others that come after. In 1866 the two countries successfully pulled a new cable. Due to the improved quality of the cable (i.e. better water insulation of the hose) the cable worked for many years, opening a new era for fibre optic communication.
Only forty years after the first attempt, the world was already equipped with its own “nervous system” (see below figure) with about 200.000 km of cables running along the ocean floor.
Since then, fibre optic communication made significant progress. The advent of fibre optic technology revolutionized the transmission of vast amounts of information, offering improved speed and cost-efficiency. Over time, the data rate has experienced remarkable growth, with cables now capable of transmitting up to 160 terabits per second.
Between 1988 and 2000, optical fibres replaced all copper cables, marking a monumental shift in infrastructure.
The Hibernia Express
In 2013, the installation of the latest submarine fibre optic cable, named Hibernia Express, took place. This groundbreaking cable provided a select group of privileged users with a remarkable improvement in data transmission time. Compared to the previous cable, the Hibernia Express reduced the communication time between London and New York by approximately 5 milliseconds, bringing it down from 65 milliseconds to 60 milliseconds. While this may seem like a marginal improvement, the investment of nearly 300 million dollars is expected to yield substantial returns.
The significance lies in the advantage gained by high-speed computer systems, such as the London Stock Exchange, which can now receive stock prices from Wall Street 5 milliseconds earlier than their competitors.
This seemingly minor time difference holds tremendous value in the world of high-frequency trading, where even a fraction of a second can result in significant financial gains. Therefore, the investment in such advancements may initially appear unwise, but the potential for lucrative returns and competitive advantages makes it a strategic move in the ever-evolving landscape of global finance. In the fast-paced and interconnected world we inhabit, even milliseconds can make a substantial difference.
As technology continues to evolve, these seemingly small improvements can have profound implications for various sectors, unlocking new possibilities and reshaping the dynamics of global communication and commerce.