Summary

Recommendation ITU-T L.209 describes the requirements of a combined housing for a fibre optic network terminal box (FONT) to keep in a single box active elements such as an optical network terminal (ONT), battery and its charge controller (power supply) as well as passive elements such as fibre patch panel, connectors, splitters and fibre splice trays, instead of having multiple boxes for active and passive elements separately. This Recommendation will be especially helpful to service providers for fibre to the x (FTTx) applications in areas where ownership, space, safe custody and availability of power supply source are hurdles to deployment.

The FONT should have two compartments with independent doors. The active elements compartment should have provision for natural ventilation required for active elements in addition to sealing against ingress of dust and liquid which is required for both the compartments. The passive element compartment should have the features of a standard fibre distribution box (FDB).

The FONT is comprised of:

–           a mechanical structure (box housing) for mechanical and environmental protection of active and passive elements with provisions for thermal management/ventilation of active elements and sealing of internal systems;

–           a simple fibre management system for guiding and managing the fibres and fibre connections inside the box;

–           a cable attachment and termination system for attaching and terminating cable ends.

Mechanical and environmental characteristics and evaluation of performance should comply with the provisions of Recommendation ITU-T L.200/L.51 for the passive element compartment and Recommendation ITU-T L.204/L.70 for the active element compartment.