Analog Transmission , Digital Transmission
Long Questions
Q#1: Write a short note on following:(A): Analog Transmission
(B): Digital TransmissionAns: Analog Transmission:
Analog transmission is a method of conveying voice, data, image, signal, or video information. It uses a continuous signal varying in amplitude, phase, or another property that is in proportion to a specific characteristic of a variable. Analog transmission could mean that the transmission is a transfer of an analog source signal which uses an analog modulation method (or a variance of one or more properties of high frequency periodic waveform, also known as a carrier signal). FM and AM are examples of such a modulation. The transmission could also use no modulation at all. It is most notably an information signal that is constantly varying.
Digital Transmission:
Digital Transmission or Digital communications is the physical transfer of data(a digital bit stream or a digitized analog signal) over a point-to-point or point-to-multipoint communication channel. Digital transmission, in contrast, is concerned with the content of the signl. A gigita signal can be transmitted only a limited distance before attenuation endanger the intergrity of the data; To Achieve greater distances, repeaters are used. A repeater receives the digita signal, recovers the pattern of 1s and 0s, and retransmit a new signal, thereby overcoming the attenuation.
(B): Digital TransmissionAns: Analog Transmission:
Analog transmission is a method of conveying voice, data, image, signal, or video information. It uses a continuous signal varying in amplitude, phase, or another property that is in proportion to a specific characteristic of a variable. Analog transmission could mean that the transmission is a transfer of an analog source signal which uses an analog modulation method (or a variance of one or more properties of high frequency periodic waveform, also known as a carrier signal). FM and AM are examples of such a modulation. The transmission could also use no modulation at all. It is most notably an information signal that is constantly varying.
Digital Transmission:
Digital Transmission or Digital communications is the physical transfer of data(a digital bit stream or a digitized analog signal) over a point-to-point or point-to-multipoint communication channel. Digital transmission, in contrast, is concerned with the content of the signl. A gigita signal can be transmitted only a limited distance before attenuation endanger the intergrity of the data; To Achieve greater distances, repeaters are used. A repeater receives the digita signal, recovers the pattern of 1s and 0s, and retransmit a new signal, thereby overcoming the attenuation.
Q#2: Differentiate Between FDM and TDM?
Ans: Frequency Division Multiplexing:
FDM is an analog technique that can be applied when the bandwidth of a link is greater than the combined bandwidth of the signals to be transmitted. In FDM signal generated by each sending device modulate different carrier frequencies. These modulate signals are then combined into a single composite signal that can be transported by the link. These bandwidth ranges are the channels through which the various signals travel. Channels can be separated by strips of unused bandwidth guard’s band to prevent signals from over lapping. In additions carrier frequencies must not interface with the original data frequencies.
FDM is an analog technique that can combine analog signals.
Time Division Multiplexing:
TDM is a digital multiplexing technique for combining several low rate channels into one high rate channel. Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern. Time Division Multiplexing is a method of putting multiple data streams in a single signal by separating the signal into many segments, each having a very short duration. Each individual data streams are reassembled at the receiving end based on the timing.
The circuit that combines signals at the source (Transmitting) end of a communications link is known as a multiplexer. It accepts the input from each individual end user breaks each signal into segments and assigns the segments to the composite signal in a routing, repeating sequence. The composite signal thus contains data from multiple senders .
TDM is a digital multiplexing technique for combining several low rate channels into one high rate channel. Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern. Time Division Multiplexing is a method of putting multiple data streams in a single signal by separating the signal into many segments, each having a very short duration. Each individual data streams are reassembled at the receiving end based on the timing.
The circuit that combines signals at the source (Transmitting) end of a communications link is known as a multiplexer. It accepts the input from each individual end user breaks each signal into segments and assigns the segments to the composite signal in a routing, repeating sequence. The composite signal thus contains data from multiple senders .
Post a Comment