Watch | Na umra ki seema ho Episode 6 New show

Na umra ki seema ho 

For most of us a mobile phone is a part  of our lives.

  but i'm sure your curious minds have  always been struck by such questions as  how a mobile phone makes a call  and why there are different generations  of mobile communications.  let's explore the technology behind  mobile communications  when you speak on your phone your voice  is picked up by your phone's microphone  the microphone turns your voice into a  digital signal with the help of a mems  sensor and ic  the digital signal contains your voice  in the form of zeros and ones  an antenna inside the phone receives. these zeros and ones and transmits them  in the form of electromagnetic waves  electromagnetic waves transmit the zeros  and ones by altering the wave  characteristics such as the amplitude  frequency phase or combinations of these  for example in the case of frequency 0  and 1 are transmitted by using low and  high frequencies respectively  so if you could find a way to transmit.

  these electromagnetic waves to your  friend's phone you would be able to  establish a call  however electromagnetic waves are  incapable of traveling long distances  they lose their strength due to the  presence of physical objects electrical  equipment and some environmental factors  in fact if there were no such issues  even then electromagnetic waves would  not carry on forever due to the earth's  curved structure  to overcome these issues cell towers  were introduced using the concept of  cellular technology  in cellular technology a geographic area  is divided into hexagonal cells with  each cell having its own tower and  frequency slot generally these cell  towers are connected through wires.

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  more specifically optical fiber cables  these optical fiber cables are laid  under the ground or the ocean to provide  national or international connectivity  the electromagnetic waves produced by  your phone are picked up by the tower in  your cell and convert them into high  frequency light pulses  these light pulses are carried to the  base transceiver box located at the base  of the tower for further signal  processing  after processing your voice signal is  routed towards the destination tower  upon receiving the pulses the  destination tower radiates it outwards  in the form of electromagnetic waves and  your friend's phone then receives the  signal  this signal undergoes a reverse process  and your friend hears your voice  so it's true that mobile communications  are not entirely wireless they do use a  wired medium too  this is how mobile communications are  carried out.

Yo

 however there is a big issue that we  intentionally left unanswered  mobile communication is only successful  when your tower transfers the signal to  your friend's tower but how does your  tower know in which cell tower area your  friend is located  well for this process the cell tower  gets help from something called a mobile  switching center  the mfc is the central point of a group  of cell towers  before moving further let's explain more  information about the msc  when you purchase a sim card all the  subscription information is registered  in a specified msc  this msc will be your home msc  the home msc stores information such as  service plans your current location and  your activity status if you move outside  the range of your home msc the new msc  which serves you instead is known as a  foreign msc  as you enter a foreign msc region it  communicates with your home msc  in short your home msc always knows  which msc area you are in  to understand in which cell location a  subscriber is within the msc area the  msc uses a few techniques  one way is to update the subscriber  location after a certain period.

  when the phone crosses a predefined  number of towers the location update is  again done  the last one of these is when the phone  is turned on  let's try to understand all of these  procedures with an example  suppose emma wants to call john  when emma dials john's number the call  request arrives at emma's home msc  upon receiving john's number the request  will be forwarded to john's home msc  now john's msc checks for his current  mse  if john is in his home mse the call  request will be immediately sent to his  current cell location and it checks  whether john is engaged on another call  or if his mobile is switched off  if everything is positive john's phone  rings and the call will be connected  however if john is not in his home msc  john's home msc simply forwards the call  request to the foreign msc  the foreign msc will follow the  previously explained procedure to locate  john's phone and will then establish the  call  now let's discuss why the frequency  spectrum is quite important in mobile  phone.

 communications to transfer zeros  and ones in digital communication each  subscriber is allocated a frequency  range  however the frequency spectrum available  for cellular communications is quite  limited and there are billions of  subscribers  this issue is solved with the help of  two technologies  one  frequency slot distribution and two  multiple access technique  in the first technique different  frequency slots are carefully allocated  to different cell towers  in the multiple access technique this  frequency slot is efficiently  distributed amongst all the active users  in the cell area  now the big question why are there  different generations of mobile phone  technologies  1g originally allowed users for the  first time to carry a phone without a  cable attached to it but 1g suffered  from two major problems  the first problem was that the wireless  transmission was in an analog format  analog signals are easily altered by  external sources so it provided poor  voice quality and poor security  the second problem was that it used the  frequency division multiple access  technique which used the available  spectrum in an inefficient way  these factors paved the way for the  second generation of mobile  communications 2g used digital multiple  access.

 technologies namely tdma or cdma  technology  the second generation also introduced a  revolutionary data service sms and  internet browsing  3g technology was focused on giving a  higher data transfer speed it used a wcd  multiple access technique along with an  increase in bandwidth to achieve this  the 3g speed of 2 mbps allowed the  transfer of data for uses such as gps  videos voice calls etc  3g was a huge step in the transformation  of the basic phone to a smartphone  next came 4g.

which achieved speeds of 20  to 100 mbps  this was suitable for high resolution  movies and television  this higher speed was made possible due  to the ofd multiple access technology  and mimo technology  mimo uses multiple transmitter receiver  antennas inside both the mobile phone  and the towers  the next generation of mobile  communication 5g to be rolled out soon  will use enhanced mimo technology and  millimeter waves it will provide  seamless connectivity to support the  internet of things such as driverless  cars and smart homes  would you like to learn how a touch  screen works  please check out this video.

 thank you