Frequency :-

    Frequency means occurrence of anything in particular given time period, for  example if someone is throwing one by
    one ten balls towards you in one minute then you can say the frequency of balls in a minute are ten balls per
    minute.

    In electronic terms the occurrence of electrical cycles/waves in a second is called Frequency of that cycle/wave. If
    one wave/cycle takes a time period of 'T' to occure then the frequency of that wave will be 
                                                        
    Frequency  =  1 / T

    where 1 is the one second and T is the time taken by one wave. So as per above equation definition of Frequency is
    the occurrence of No. of consecutive cycles in a second.

    As we measure water in Liter and weight in Grams, like that the unit of Frequency is "Hertz". So that we can
    measure frequency in Hertz (Hz), Kilo Hertz (KHz), Mega Hertz (MHz), Giga Hertz (GHz) and so on.

    Cycle/wave:-                                                              Frequency:-

                                                                    

 

   

   dB :-

    dB (deci Bell ) is the logarithmic value and it is used to measure communication signals.Basically the dB is the
    logarithmic ratio of any two values. These values may be signals, pressure, power, voltage etc.

    In DTH dB is used to measure signal intensity of transmitted/received signals from uplink centre to satellite and from
    satellite to mini dish respectively.

    formula :-

    dB = 10 log (P2/P1)

    Symbol rate :- 
 
    Symbol rate is basically refers to the rate of bits transmitted. It indicates how fast the data are being transmitted
    from broadcaster to satellite or from satellite to dish.Each symbol contains a No. of  data bits to transmit.

    FEC :-

    FEC means Forward Error Correction. FEC is the error correction method used in telecommunication to correct the
    error occur during the transmission. In this system the broadcaster adds a bit to recognize the error by the receiver.
    This additional bit which is called parity bit allows receiver to detect and correct the error in the received data.

    MPEG :-

    MPEG is the Motion Picture Experts Group. It is the group for the development of audio and video encoding. MPEG 2
    format is widely used for the compression of audio and video signals by the many DTH broadcasters. This format
    compresses the digital data so that maximum No. of channels can be transmitted without any loss of data.

    Normal audio CD can store maximum of 10-15 songs whereas MP3 Disk can store more than 150 songs by
    compressing the digital data.

 

   

   

    

 

 

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