Optical transport systems of xWDM wave multiplication constitute the basis for the construction of any larger optical network, enabling its more effective use, both in terms of increasing the bit capacity and extending the transmission range. Thanks to the multiplication of individual transmissions at different wavelengths and advanced control of the flow of streams, both at the level of the optical channel and the electrical channel (OTN), the fibre network becomes much more capacious, flexible and versatile. In today’s world, CWDM / DWDM class technologies are no longer only needed by telecom operators, but also by many enterprises with distributed data centres. xWDM optical transport systems stand for reliability, high performance, long transmission distances and security. The evolution of xWDM systems has led to SDON (Software Defined Optical Networks), which are the latest manifestation of this technology. The xWDM technology is also at the heart of the fastest networks currently available or under design, such as Terabit Ethernet, where bit rates exceed 100Gbps and even go beyond 1Tbps, thanks to the new generation of IPT multicore fibre. We have extensive expertise in the design, implementation and maintenance of xWDM optical transport networks, backed by many years of experience and a large number of deployed systems.