You are placing PTP fiber between two locations 55 km (34 miles) apart. You are told that DWDM equipment will be installed within the next 5 years. Which of the following optical fiber types should…

ITU-T G.652 standard single-mode fiber has high chromatic dispersion at 1550 nm, requiring heavy dispersion compensation and making it non-ideal for planned DWDM deployments at this distance.

ITU-T G.653 dispersion shifted fiber moves the zero-dispersion point to 1550 nm, making it highly vulnerable to four-wave mixing crosstalk between DWDM channels and explicitly unsuitable for DWDM use.

ITU-T G.654 cut-off shifted fiber is optimized for ultra-low attenuation in long-haul submarine applications and is not designed for terrestrial DWDM multi-channel deployments.

ITU-T G.655 (non-zero dispersion shifted fiber) maintains a small but intentionally non-zero chromatic dispersion value at the 1550 nm DWDM operating window. This non-zero dispersion suppresses four-wave mixing - a nonlinear crosstalk effect that degrades closely spaced DWDM channels - while dispersion compensation modules can handle the residual dispersion over the 55 km span.

ITU-T G.657 bending loss insensitive fiber is engineered for FTTH and indoor installations requiring tight bend radii, not for long-haul point-to-point DWDM links.