All theories, formulation, assumption had a beginning

All our theories of science are formulated on the assumption that space–time is smooth and nearly flat, so they would all break down at

Understanding how Digital broadcasting work

In  digital  television  and  digital  radio  systems,  several  variable  bit-rate data streams are multiplexed together to a fixed bit rate transport stream by means of  statistical  multiplexing. This  makes it possible to transfer several  video  and  audio  channels  simultaneously  over  the  same frequency channel, together with various services. In  the  digital  television  systems,  this  may  involve  several  Standard Definition
 Television  (SDTV)  programmes  (particularly  on  DVB-T, DVB-S2,  ISDB  and  ATSC-C),  or  one  HDTV,  possibly  with  a  single SDTV companion channel over 6 to 8 MHz-wide TV channel. The device
that  accomplishes  this  is  called  a  statistical  multiplexer.  In  several  of  these  systems,  the  multiplexing  results  in  an  MPEG  transport  stream. The  newer  DVB  standards  DVB-S2  and  DVB-T2  has  the  capacity  to carry several  HDTV  channels in one multiplex. Even the original  DVB standards  can  carry  more  HDTV  channels  in  a  multiplex  if  the  most advanced MPEG-4 compressions hardware is used.
On communications satellites  which carry broadcast  television networks and radio networks, this is known as Multiple Channels Per Carrier or MCPC.  Where  multiplexing  is  not  practical  (such  as  where  there  are different sources using a single  transponder),  single channel per carrier mode is used. Signal  multiplexing  of  satellite  TV  and  radio  channels  is  typically carried out in a central signal playout and  uplink  centre, such as  ASTRA Platform  Services  in  Germany,  which  provides  play  out,  digital
archiving,  encryption, and satellite uplinks, as well as multiplexing, for hundreds of digital TV and radio channels.In  digital  radio,  both  the  Eureka  147  system  of  digital  audio broadcasting  and  the  in-band  on-channel  HD  Radio,  FMeXtra,  and digital  radio  mondiale  systems  can  multiplex  channels.  This  is
essentially required with  DAB-type transmissions (where a multiplex is called an ensemble), but is entirely optional with IBOC systems.

Understanding telephony and Video processing

In  telephony,  a  customer's  telephone  line  now  typically  ends  at  the remote concentrator  box down the  street, where it is multiplexed along with other  telephone lines  for that  neighborhood  or other similar area.
The multiplexed signal is then carried to the  central switching office  on significantly  fewer  wires  and  for  much  further  distances  than  a customer's line can practically go. This is likewise also true for  Digital

Subscriber Lines (DSL).Fiber In The Loop  (FITL) is a common method of multiplexing, which uses  optical  fiber  as  the  backbone.  It  not  only  connects  POTS  phone lines  with  the  rest  of  the  PSTN,  but  also  replaces  DSL  by  connecting directly to ethernet wired into the  home.  Asynchronous Transfer Mode
is often the communications protocol used.Since all of the phone (and data) lines have been clumped together, none of them can be accessed except through a demultiplexer. This provides for  more-secured  communications,  though  they  are  not  typically encrypted.The concept is also now used in cable TV, which is increasingly offering the  same  services  as  telephone  companies.  IPTV  also  depends  on
multiplexing. In  video  editing  and  processing  systems,  multiplexing  refers  to  the process  of  interleaving  audio  and  video  into  one  coherent  MPEG transport stream (time-division multiplexing). In  digital  video,  such  a  transport  stream  is  normally  a  feature  of  a container  format  which  may  include  metadata  and  other  information, such  as  subtitles.  The  audio  and  video  streams  may  have  variable  bitrate. Software that produces such a transport stream and/or container is commonly  called  a  statistical  multiplexor  or  muxer.  A  demuxer  is  a software  that  extracts  or,  otherwise,  makes  available  for  separate processing the components of such a stream or container