How Do Fiber Optics and Cable Television Work?

Fiber Optic cable and the old common (coaxial or RF)cable losses are very low.
cable are two different cable system technologies thatDigital Television
can be used to distribute various services to endDigital television in cable networks can be divided into
users--homes. In general, they differ only in technicaltwo totally different ways of distribution. The first one
(electrical/communication) point of view. This is mainlyis an equivalent to digital broadcasting and the other
important for the network operators because endway mainly used in fiber optic networks is IP television.
users or viewers don't care about the technology, theyDigital Cable Broadcasting
are interested in services and TV channels.This is equivalent to analog distribution over (RF) cable
There are few different ways that can be used tobut with digital signal. The same technology
distribute common services like television channels via(modulation) can be used as for terrestrial
cable networks. Each has some advantages andbroadcasting but usually, there are more efficient
disadvantages and needs different topology orsystems that take into account specific properties of
network infrastructure.cable systems. One typical example is DVB-T system
Analog Televisionwhich is used in Europe for digital terrestrial video
The first cable television networks were simply anbroadcasting but cables use similar DVB-C system.
extension of the broadcasts in the air. This wasIP Television
implemented by deploying ordinary antenna cable (butThis is the most popular digital television distribution
with lower losses) from the cable system headend toused with fiber optic cable systems. It means
the homes. Because of the distances there were alsodistributing TV channels with the IP protocol which is
many amplifiers at specific points to ensure requiredthe backbone of internet communications. Each TV
signal levels. The communication was exclusivelychannels is encoded with either MPEG-2 or MPEG-4
one-way, but later most such cable networks weresystem and then distributed over fiber optical cable
extended to allow bidirectional communication needednetwork to the homes. The advantages are
for access to the internet by using systems likeenormous. The capacity for the number of channels is
DocSys.pretty high, all the channels can be encoded and
This approach can be used with RF (coaxial) and fiberdistributed with very high quality, it is very easy to
cables. Fiber optic cables are also used in some casesdistribute HD channels, access to the internet is very
to distribute the old analog cable television. Thesimple because of the IP protocol and native
advantage of optical network is because it can usetechnology.
available fibers in existing fiber optic cables and the