ITU-T G.984.5 PDF

The purpose of this Recommendation is to define wavelength ranges reserved for additional service signals to be overlaid via wavelength division multiplexing (WDM) in future gigabit-capable passive optical networks (G-PON) for maximizing the value of optical distribution networks (ODNs). Other PON systems, such as B-PON, have wavelength plans based on [ITU-T G.983.3], which includes existing options for enhancement bands. This Recommendation also defines further wavelength ranges reserved for additional service signals to be overlaid via WDM in future PONs whose wavelength allocations are based on [ITU-T G.983.3].

For this purpose, this Recommendation defines and provides:

– wavelength ranges to be reserved; and – X/S tolerance in PON optical network units (ONUs).

Appendices I, II and III provide:

– sample parameters of a discrete WDM filter that combines and isolates the G-PON up/down signals and enhancement bands at the OLT side;

– examples of wavelength allocation for NGA services and video distribution services;

– methods for calculating required isolation for WDM/CE/CEM devices.

The physical media dependent (PMD) layer specification for G-PON in the absence of an enhancement band is defined in [ITU-T G.984.2]. PMD layer specifications for G-PON in the presence of enhancement bands are defined by the combination of [ITU-T G.984.2] and this Recommendation. Whenever a parameter specified in [ITU-T G.984.2] is not explicitly mentioned in this Recommendation, its value given in [ITU-T G.984.2] remains valid. Whenever a parameter is specified in both this Recommendation and [ITU-T G.984.2], the specification in this Recommendation takes precedence