Fibre optic networks can be built using one of two methods – overhead or underground (traditional or using microducts). The choice essentially depends on individual assessment at the investment planning stage.
Overhead networks are used mainly when the distances between the central node and the subscriber are considerable, since this enables the builders to use the existing pole infrastructure (as every building has its own power line) and accordingly reduces investment costs. This also shortens the investment time, both thanks to the use of existing network elements, as well as the ease of installing ADSS (All Dielectric Self Supporting) cables without the need for additional construction equipment. The overhead method is usually used on a given section of the subscriber access network. Another key benefit of this method is easy expansion thanks to the use of fibre optic distribution boxes.
Building an overhead subscriber network requires using existing electrical or telecommunication poles, or building a new infrastructure using composite, concrete or wooden poles. ADSS fibre optic cable with slings (brackets, crossbars, anchor clamps), couplings with frames and accessories also constitute essential elements.
Overhead installation also provides an optimal solution for for the energy sector, which uses OPGW (Optical Ground Wire) – a power line lightning protection system used in the case of power lines with voltages exceeding 110 kV. OPGW cable consists primarily of aluminium and metal tubes, some of which may contain optical fibres.