The main functions of the HDODF (and mounted subracks) are to provide a managed standard fibre installation, reticulation, interconnection, distribution, re-arrangement and maintenance activities at a common point. It also allows for fibre testing and fault finding activities. The HDODF is usually located at the entrance to an Exchange or CO, where entering external optical fibre cables are terminated. The HDODF’s can also be installed back to back or side by side at a MOF installation, to terminate a large number of fibres (e.g. ~ 15,000) in a compact and organised space.
HDODF’s hold up to 18 x splice/patch subracks, where outdoor/external optical fibre cables are fusion spliced to pigtails that connect to patch cords at a patch panel. The patch cords subsequently connect to transmission equipment, located in a nearby suite of racks.
A major feature of the subrack is the minimum amount of movement that occurs to loose tubes and optical fibre cords, as the subrack opens and closes. This ensures a very high degree of protection for working services. Also, the fusion splices and pigtails are located in a protected position, because there is very little chance of them being disturbed when patch cords are being installed, as the subracks tray only needs to be opened a very small amount