652 fiber is designed to have a zero-dispersion wavelength near 1310 nm, therefore it is optimized for operation in the 1310nm band and can also operate at 1550 nm. B . Recommendation ITU-T G. 652 fiber is the most commonly used. 652 is an international standard that describes the geometrical, mechanical, and transmission attributes of a single-mode optical fibre and cable, developed by the Standardization Sector of the International Telecommunication Union (ITU-T) that specifies the most popular type of single-mode. G. Whether it is a long-distance network, local network, or access network, it is the absolute protagonist, accounting for more than 95% of its overall. ITU-T G. 655 fiber, what are their differences and how to make a wise decision. Standard single-mode fiber (G.