Telecommunications
is a general term for a vast array of technologies that send
information over distances. Mobile phones, land lines, satellite phones and voice over Internet protocol (VoIP) are all telephony
technologies -- just one field of telecommunications. Radio, television
and networks are a few more examples of telecommunication.
While
most people associate telecommunications with modern technologies, the
strict definition of the term encompasses primitive and even ancient
forms of telecommunication. Among these is the use of smoke signals as a
kind of visual telegraph.
Puffs of smoke were time-released by smothering a fire with a blanket,
then quickly removing and replacing the blanket. Widely used by the
American Indians, smoke signals could communicate short messages over
long distances, assuming a clear line of sight.
Other forms of early telecommunications include relay fires or beacons.
Used foremostly in warfare, relay fires required a handful of men
posted along a range of hilltops, with the last man closest to the area
where troop movement was expected. When armies were spotted in the
distance, he would light a bonfire. The fire could be seen from a good
distance away by the next man in the relay, who would in turn light his
own bonfire, and so the fires were lit in succession along the range,
creating an effective telecommunications signal that traveled back over
several miles in a relatively short period of time. Finally, the last
man in the relay would light a beacon to signal his army below that the
opponent was en-route.
The
arrangement of a ship's flags and semaphores were other forms of
telecommunications. A semaphore was a mechanical device atop a tower
with paddle-like blades or flags. The device would be set in a specific
position to communicate information.
Throughout
the 19th century, telecommunications devices became more sophisticated
with the advent of electricity, leading to the telegraph, Morse code,
and signal lamps. A signal lamp, the optical version of the telegraph,
is a powerful lamp with shutters that block the light in long or short
durations to translate to the dots and dashes of Morse code. A heliograph is another optical telegraph -- a mirror used to reflect light to mimic a signal lamp.
In
the 20th century, telecommunications reached beyond our planet. In June
1969, the world watched and listened as astronauts walked on the moon.
Twenty years later, in August 1989, we would see pictures of Neptune
arrive back from the Voyager 2 spacecraft, riding radio waves
that traveled over roughly three billion miles (4.8 billion km) to reach
us in a matter of a few hours.
Strides
in telecommunications have changed the world immeasurably. While
pockets of humankind were once isolated from each other, people now have
multiple ways to see and hear what is occurring on the other side of
the world in real time. Satellite technology, television, the Internet
and telephony
keep the globe connected in a humming buzz of interactive voices and
pictures. In short, telecommunications has come a long way from smoke
signals.