ater section Nonlinear Optical Transmission and known as "self-phase modulation" (Killey et al., 2006; Agrawal, 2001). The key advantage of EDC over optical techniques is cost, for several reasons: The cost of electronic integrated circuits is commonly lower than that of optical components, especially with volume production. (However, this argument is weakened somewhat if advanced electro-optic modulators, such as in Figure 6.25, are used, because they are expensive in their own right, one is required for each channel, and they may impose the need for additional amplification.) When receiver-end EDC is used, it is possible to integrate the required processors with the receiver circuitry, which leads to space reductions in addition to any possible financial benefits. When some or all of the DCM modules in a system can be eliminated, marked savings result from reducing the additional associated amplification and its electrical power feeds. Belanger and Cavallari (2006) and Jones and colleagues (2006) are techno-economic studies that use these arguments to report potentially significant financial benefits of EDC. EDC confers benefits on the whole system of a more technical nature. Negative- dispersion fiber (especially DCF for use in modules) has a small effective core area and a Polarization Mode Dispersion relatively high GeO2 content. Therefore, it is more susceptible to nonlinear crosstalk and RBS, the details of which were explained earlier and will be considered again in the section on nonlinear optical transmission. Indeed, amplified DCMs can be complicated subsys- items, especially those using many pumps to provide wide bandwidth and spectrally equal- ized Raman gain. Their total launched pump powers can be very high, which requires special precautions to ensure eye and fire safety, and their complexity raises a slight concern regarding long-term reliability. One would also hope for reduced network man- agement complexity through the smaller number of line amplifiers in the transmission path. At the time of 