Data Communications Essay

Differentiate betwixt an analog and a digital electromagnetic house. What be leash important characteristics of a fortnightly signal. What is the kin between the wavelength and frequency of a sinning wave. Define important frequency.What is the relationship between a signals spectrum and its bandwidth. What is attenuation? Define postise efficacy. What key factors move channel capacity?ProblemsFigure 1 shows the frequency domain function for a single square impulse. The signal pulse could trifle a digital 1 in a communications system. line of business that an infinite number of higher frequencies of decrease magnitudes is needed to represent the single pulse. What importee does that have for a real digital transmission system?Suppose that a digitised TV picture is to be contagious from a microbe that uses a ground substance of 480 x 500 picture elements (pixels), where distributively pixel crowd out take on ace of 32 intensity values. yield that 30 pictures are sent per second. (This digital source is is roughly equivalent to political program TV standards that have been adopted.) produce the source rate R (bps) Assume that the TV picture is to be transmitted oer a channel with 4.5Mhz bandwidth and a 35dB signal-to - dissension ratio. Find the capacity of the channel (bps). Discuss how the parameters wedded in part (a.) could be circumscribed to allow transmission of colour TV signals without increasing the undeniable value for R. What is the channel capacity for a teleprinter channel with a 300Hz bandwidth and a signal-to-noise ratio of 3dB, where the noise is black-and-blue thermal noise? A digital signalling system is needful to operate at 9600bps. If a signal element encodes a 4-bit word, what is the minimum postulate bandwidth of the channel? Repeat part (a.) for the bailiwick of 8-bit words.Given the narrow (usable) audio bandwidth of a teleph ace transmission facility, a nominated SNR of 56dB (400,000), and a certain lev el of distortion, What is the theoretic maximum channel capacity (kbps) of traditional teleph iodin lines? What can we say active the actual maximum channel capacity?Given a channel with an intend capacity of 20Mpbs, the bandwidth of the channel is 3MHz. Assuming white thermal noise, what signal-to-noise ratio is required to achieve this capacity? If an amplifier has a 30dB potential drop gain, what voltage ratio does the gain represent? An amplifier has an output of 20W. What is the output in dBW? Answers concise QuestionsWith manoeuver media, the electromagnetic waves are guided along an enclosed physical room whereas unguided media provide a goernment agency for transmitting electromagnetic waves but do not guide them. A unvarying or analog signal is one in which the signal intensity varies in a smooth fashion everywhere time while a distinguishable or digital signal is one in which the signal intensity maintains one of a finite number of invariable levels for some perio d of time and so changes to another constant level. Amplitude, frequency, and phase are three important characteristics of a bimonthly signal. The relationship is f = v, where is the wavelength, f is the frequency, and v is the speed at which the signal is traveling. The fundamental frequency is the lowest frequency part in the Fourier representation of a periodic quantity. The spectrum of a signal is the frequencies it contains while the bandwidth of a signal is the width of the spectrum. Attenuation is the piecemeal weakening of a signal over distance. The rate at which data can be transmitted over a given communication path, or channel, beneath given conditions, is referred to as the channel capacity. Bandwidth, noise, and fracture rate.