Multiplexing - PowerPoint PPT Presentation

1 / 14
About This Presentation
Title:

Multiplexing

Description:

Multiplexing Group members * Harpreet kaur * Amandeep kaur * Sunnia kataria What is Multiplexing It is the process of sending signals from two or more different ... – PowerPoint PPT presentation

Number of Views:439
Avg rating:3.0/5.0
Slides: 15
Provided by: w3profess
Category:

less

Transcript and Presenter's Notes

Title: Multiplexing


1
Multiplexing

Group members
Harpreet kaur
Amandeep kaur
Sunnia kataria
2
What is Multiplexing It is the process of
sending signals from two or more different
sources simultaneously over a single
communication channel. Multiplexing is
done by using a device called multiplexer(MUX)
that combines n input lines to gernate one output
line i.e (many to one).Therefore multiplexer
(MUX) has serval inputs one output.
At the receiving end , a device demultiplexer
(DEMUX) is used that separtes signal into its
components.so DEMUX has one input ans seval
outputs.
3
  • Types of Multiplexing
  • Frequency Division Multiplexing (FDM)
  • Wave Division Multiplexing (WDM)
  • Time Division Multiplexing (TDM)

4
  • Frequency Division Multiplexing
  • It is analog technique.
  • In FDM, signals of different frequencies are
    combined into a single composite signal and is
    transmitted on single link.
  • FDM requires that the bandwidth of a link should
    be greater than the combined bandwidths of
    various signals to be transmitted.
  • Thus each signal having different frequency from
    a particular logical channel on the link and
    follow this channel only.
  • These channels are then separeted by the strips
    of unused bandwidth called gurad band.These gurad
    bands band prevent the signals from overlapping.

5
  • Frequency Division Multiplexing
  • In FDM signals to be transmitted must be analog
    signals. Thus digital signals need to be
    converted to analog form, if they are to use FDM.

6
  • Applications of FDM
  • FDM is used for FM AM radio broadcasting. Each
    AM FM radio stations uses a different carries
    frequency .
  • FDM is used in television broadcasting.
  • First generation cellular telephone also uses
    FDM.

7
  • Wave Division Multiplexing
  • WDM is the analog multiplexing technique.WDM is
    conceptually similar to FDM, in sense that it
    combines different signals of different signals
    of different frequencies into single composite
    signal and transmit it on a single link.
  • In WDM the different signals are optical or
    light signals that are transmitted through
    optical fiber.Wavelength goes up down and
    vice-verse.
  • In WDM various waves from different sources are
    combined to form composite light signal that is
    transmitted across the channels to the different
    receiver.

8
  • Wave Division Multiplexing
  • At the receiver side, this composite light
    signal is broken into different light waves by
    demultiplexer.
  • This combines and splitting of light waves is
    not by using a prism.
  • One prism is used at the sender side to perform
    multiplexing and another prism is used at
    receiver side that perform demultiplexing.
  • The basic principal behind the usage of prism is
    that,the prism bends a beam of light based on the
    angle of incidence and the frequency of light
    wave.

9
  • Applications of WDM
  • WDM is used in SONET(Synchronous Optical
    Network).It makes use of multiple optical fiber
    lines which are multiplexed demultiplexed.

10
  • Time Division Multiplexing
  • TDM is a digital multiplexing technique.
  • In TDM, the channels is not divided on the basis
    of frequency but on the basic of time.
  • Total time available in the channel is divided
    between serveral users.
  • Each time is allotted a particular a time
    interval called time slot during which the data
    is transmitted by that user.
  • Each sending device takes control of entire
    bandwidth .

11
  • Time Division Multiplexing
  • There are two types of TDM
  • Synchronous TDM Asynchronous TDM

12
  • Synchronous TDM
  • Multiplexer allots the same time slot to each
    device at all time either device having data or
    not.
  • If there are n input lines then there are n
    slots in one frame. Number of slots No of input
    lines.
  • Synchronous TDM does not give guarantee that
    full capacity of link is used .
  • The no of time slot in a frame is always based
    on no of input devices .
  • The time slots are fixed and predefined.

13
  • Asynchronous TDM
  • It is also known as STATISTICAL TDM.
  • Multiplexer does not allots same time slot to
    each device at all time . Time slots are flexible
    and not fixed.
  • If there are n input lines then there are m
    slots perform. m is less than n.
  • Asynchronous TDM give guarantee that full
    capacity of link is used .
  • The no of time slot in a frame is always based
    on statistical analysis of no of input devices.
  • The time slots are not fixed and predefined.

14
ThanksHOUSE IS OPEN FOR QUERY
  • Reference
  • Charanjeet singh

  • (kalyani Publisher)
Write a Comment
User Comments (0)
About PowerShow.com