scope:

ITU-T has adopted a release-based approach for the production of NGN Recommendations, with the scope of each release clearly defined and target deadlines for completion specified. The objective is to aid project management, and to ensure concentration of effort on a smaller set of deliverables to be achieved in a shorter timescale, thus achieving feasible deliverables in a timely manner.

Considering a priority of a market, the concept of capability set that breaks down the release concept is adopted because necessary functional groups exist prior to a target completion date of the Release. Capability set includes requirements, architecture, and signalling aspects necessary to provide specific services. This means the Release concept determines the scope of standardization in ITU and capability set specifies the related Recommendations necessary for specific services.

This Recommendation gives a description of capability set 1 of NGN release 1 of an anticipated series of releases within ITU-T, in terms of the overall requirements and a high-level overview of the functional features to be addressed. Additionally, this Recommendation only lists Recommendations relevant to capability set 1 of NGN release 1, so a substantial specification is included in each original Recommendation.

To fulfil the general objectives and principles of an NGN identified in [ITU-T Y.2001] and [ITU-T Y.2011], this Recommendation focuses on key initial capabilities whilst ensuring that the general and long-term architectural direction of the NGN is maintained to be as flexible as possible to allow future enhancements and releases.