Recommendation ITU-T G.654 describes the geometrical, mechanical and transmission attributes of a single-mode optical fibre and cable which has the zero-dispersion wavelength around 1300 nm wavelength, and which is loss-minimized and cut-off wavelength shifted at around the 1550 nm wavelength region. This is the latest revision of this Recommendation that was first created in 1988.

Version 9.0 introduced category D ITU-T G.654 fibre in order to improve the optical signal to noise ratio (OSNR) characteristics, e.g., which can be applied to higher bit-rate submarine systems. It is intended to maintain the continuing commercial success of this fibre in the evolving world of high-performance optical transmission systems.