: Emerging Developments and New Technologies, Wiley, New York, 2008, ISBN-13: 978-0470986448. 69. Bigos, W., Cousin, B., Gosselin, S., Le Foll, M., Nakajima, H., Survivable MPLS over opti- cal transport networks: Cost and resource usage analysis, IEEE Journal of Selected Areas in Communications, 18(5), 949-962 (2007). 70. Köhn, M., Bodamer, S., Gauger, C.M., Gunreben, S., Hu, G., Sass, D., Comparison of IP/WDM transport network architectures for dynamic data traffic, Proceedings of ECOC 2006, Berlin, Germany, September, 2006. 71. Tornatore, M., Maier, G., Pattavina, A., WDM network optimization by ILP based on source formulation, Proceedings of IEEE INFOCOM, New York, pp. 1813-1821, 2002. 72. Maier, G., Pattavina, A., De Patre, S., Martinelli, M., Optical network survivability: Protection techniques in the WDM layer, Photonic Network Communications, 4(3/4), 251-269 (2002). Technology for Telecommunications: Optical Fibers, Amplifiers, and Passive Devices 4.1 Introduction The ultimate role of the telecommunication network is to deliver services based on the network capability of transmitting the information generated in one place to faraway places. Two basic functionalities are involved in this goal: transmission and switching. Since the introduction of low-loss optical fibers and high-power semiconductor lasers, optics has been the prominent technology for transmission, even if microelectronics have also played a main role in the design of transmission systems. The great success of optical fiber transmission is due to the coincidence of the low-loss wavelength region of optical fibers with the emission wavelength range of Indium Gallium Arsenide Phosphide (InGaAsP) semiconductor lasers. Attenuations as low as .2dB/km can be achieved with standard transmission fibers in the near infrared region (around 1.5 um) where a single-mode semiconductor laser can emit a power as high as 16dBm. Using optical amplifiers to boost the signal power after a fiber propagation of 60-80 km, the signal can reach essentially unaltered