In this video, we explore the three major transmission windows (850 nm, 1310 nm, and 1550 nm) used in fiber optic communication. By selecting the. In fiber-optic communication, signal integrity and transmission distance are influenced by one core factor: wavelength. Optical transmission windows define the optimal frequency ranges within the fiber where attenuation and dispersion are minimized, enabling high-speed, long-distance, and reliable. So, there is a specific band of wavelength where the signal attenuation is minimum which is known as optical or operating window. We have heard about the O-bands, E-bands, L-bands etc.