Fiber optics in Brazil have brought benefits in availability, speed and security-and also the great challenge of reaching all possible locations with speed and availability across the fiber-optic structure deployed for fixed and mobile Internet. The best solution is to use DWDM technology, a variation of WDM (Wavelength division multiplexing, Wavelength split multiplexing). The system optimizes the use of the fiber network through cutting-edge equipment transmitting several light beams with different wavelengths-all composed of information from different networks by the same fiber. There are several advantages of the DWDM system as:-high transmission capacity by higher rates-improvement of modulation systems by introducing the NRZ scheme (Non Return to Zero)-reduction of gaps between channels–more reliability of these Components-less precise spaces for their components and-values more into account. The DWDM system has higher transmission rates with more electro components-and in practice this means smaller and lighter equipment that consumes less electric energy and less heat charge (heat emitted by the equipment that needs to be dissipated via air conditioning). The smaller the number of components in an equipment, the greater the reliability presented by the same with an increase in systemic availability. Cerélix uses the Ciena DWDM system, a market leader in technology, ensuring more security in data transmission.