ITU-T G.987.1 PDF

This Recommendation addresses the general requirements of 10-Gigabit-capable passive optical networks (XG-PON) systems, in order to guide and motivate the physical layer and the transmission convergence layer specifications. The general requirements include examples of services, user network interfaces (UNIs) and service node interfaces (SNIs), as well as the principal deployment configurations that are requested by network operators. This Recommendation also includes the system and operational requirements to meet the needs of supporting various business and residential applications.

As much as possible, this Recommendation maintains characteristics from [ITU-T G.982], and the ITU-T G.983.x, and ITU-T G.984.x series of Recommendations. This is to promote backward compatibility with existing optical distribution networks (ODNs) that comply with those Recommendations. Furthermore, this Recommendation provides a mechanism that enables seamless subscriber migration from Gigabit PON (generic term to represent both G-PON and GE-PON) to XGPON using the wavelength division multiplexing (WDM) defined in the ITU-T G.984.x series of Recommendations.

There are two types of XG-PONs based on the upstream line rate: XG-PON1, featuring a 2.5 Gbit/s upstream path, and XG-PON2, featuring a 10 Gbit/s one, XG-PON2 being symmetrical it can be referred to as XGS-PON. The initial phase of this Recommendation only addresses XG-PON1. XG-PON2 will be addressed at a later phase, when the technology becomes more mature.