Optical Networks: A Practical Perspective - Part 39. This book describes a revolution within a revolution, the opening up of the capacity of the now-familiar optical fiber to carry more messages, handle a wider variety of transmission types, and provide improved reliabilities and ease of use. In many places where fiber has been installed simply as a better form of copper, even the gigabit capacities that result have not proved adequate to keep up with the demand. The inborn human voracity for more and more bandwidth, plus the growing realization that there are other flexibilities to be had by imaginative use of the fiber, have led people. | 350 Transmission System Engineering a You have a transmitter that operates at a wavelength of rm has a spectral width of 1 nm and an output power of mW. The receiver requires 30 dBm of input power in order to achieve the desired bit error rate. What is the length of the longest link that you can build b You have another transmitter that operates at a wavelength of zm has a spectral width of 2 nm and an output power of 1 mW. Assume the same receiver as before. What is the length of the longest link that you can build c You have the same transmitter as before and you must achieve an SNR of 30 dB using an APD receiver with a responsivity of 8 A W a gain of 10 an excess noise factor of 5 dB negligible dark current a load resistance of 50 Q and an amplifier noise figure of 3 dB. Assume that a receiver bandwidth of B 2 Hz is sufficient to support a bit rate of B b s. What is the length of the longest link you can build d Using the same j m transmitter as before you must achieve an SNR of 20 dB using a pin receiver with a responsivity of A W a load resistance of 300 Q and an amplifier noise figure of 5 dB. Assume that a receiver bandwidth of B 2 Hz is sufficient to support a bit rate of B b s. What is the length of the longest link you can build Compute the dispersion-limited transmission distance for links with standard single-mode fiber at 1550 nm as a function of the bit rate 100 Mb s 1 Gb s and 10 Gb s for the following transmitters a a Fabry-Perot laser with a spectral width of 10 nm b a directly modulated DFB laser with a spectral width of nm and c an externally modulated DFB laser with a spectral width of nm. Assume that the modulation bandwidth equals the bit rate and the dispersion penalty is 2 dB. Assume that NRZ modulation is used. Repeat Problem for NZ-DSF assuming a dispersion parameter of 5 ps nm-km. Consider a length L of step-index multimode fiber having a core diameter of 50 gm and a cladding diameter
