Full-spectrum single-mode fibre in accordance with ITU-T G. D with optimised transmission characteristics. Suitable for the operating wavelengths in all FTTx networks. Superior bending properties allow for easy. This document outlines the specifications for a single-mode optical fiber and cable designed for use around the 1310 nm zero-dispersion wavelength, suitable for both the 1310 nm and 1550 nm regions, and compatible with analogue and digital transmission. Among these, commonly used standards are G. This article intends to provide a clear explanation of G.