ost completely the electronics in telecommunication equipments. At present this idea has been demonstrated to be completely incorrect. Electronic components have evolved SO fast in terms of cost and functionalities that elec- tronic signal processing plays a fundamental role in the design of modern transmission systems and switching/routing machines are built using electronic switch fabrics and the situation seems not to change in the medium term. As a matter of fact, signal processing CMOS circuits based on 45 and 32 nm technology [25] are SO fast that real-time signal processing is possible also at the very high-speed characteristics of optical transmission. Thus all the equalization and compensation tech- niques that have been developed for other applications can now be applied to optical transmission. As far as switch fabrics are concerned, electronic-based fabrics are convenient both in terms of footprint and of cost, simultaneously offering an unmatched reliability and a great richness of complementary functions. 5.7.1 Development of CMOS Silicon Technology Beyond any architectural property, a baseline element determining the performance of an electronic equalizer or a switch fabric is the technology with which it is realized. In this section we will try to understand achievements and challenges for microelectron- ics when used in telecommunication applications and in particular in electronic equaliza- tion of transmission distortions and in switch fabrics. CMOS circuits are almost the only type of electronic circuits that are used out of analog and special applications. Their diffusion is due to the combination of very large-scale integration, very low cost, and high performances granted by the great miniaturization. CMOS require both n and p metal oxide field effect transistors (MOSFETs); hence the name complementary. The base advantage of CMOS versus other types of transistors is that a CMOS circuit only dissipates power when transistors are switched, not when they stay in a definite state, apart from an