Problem 1
Is an oil pipeline a simplex system, a half-duplex system, a full-duplex system, or none of the above? What about a river or a walkie-talkie-style communication?
Problem 2
What are the advantages of fiber optics over copper as a transmission medium? Is there any downside of using fiber optics over copper?
Problem 3
How much bandwidth is there in \(0.1\) microns of spectrum at a wavelength of 1 micron?
Problem 4
It is desired to send a sequence of computer screen images over an optical fiber. The screen is \(3840 \times 2160\) pixels, each pixel being 24 bits. There are 50 screen images per second. What data rate is needed is needed?
Problem 6
Radio antennas often work best when the diameter of the antenna is equal to the wavelength of the radio wave. Reasonable antennas range from \(1 \mathrm{~cm}\) to 1 meter in diameter. What frequency range does this cover?
Problem 7
Multipath fading is maximized when the two beams arrive 180 degrees out of phase. How much of a path difference is required to maximize the fading for a 100 -km-long 1-GHz microwave link?
Problem 8
A laser beam \(1 \mathrm{~mm}\) wide is aimed at a detector \(1 \mathrm{~mm}\) wide \(100 \mathrm{~m}\) away on the roof of a building. How much of an angular diversion (in degrees) does the laser have to have before it misses the detector?
Problem 10
Identify three physical properties that limit the maximum data rate of digital communication channels used in practice. Explain your answers.
Problem 11
A noiseless \(10-\mathrm{kHz}\) channel is sampled every \(1 \mathrm{msec}\). What is the maximum data rate?
Problem 12
Is the Nyquist theorem true for high-quality single-mode optical fiber or only for copper wire?
