Which benefits and constraints for FTTH aerial deployments ?
Due to low construction costs and shorter worksite times, the FTTH aerial roll-outs are a profitable solution for CPs and telecom installers. By using the existing telephone poles or utility poles, whenever this is possible, fiber optic network developers can provide customer connections thanks to the use of overhead cables in low density areas.
However, in comparison with underground, buried or in duct installations, aerial optical cables are more exposed to mechanical and climatic risks. In overhead layout, optical cables can be ripped off or crushed as for example in the eventuality of a car accident or a tree fall. Also, in the event of flooding or ice depositing on their sheath, aerial drop cables may register optical signal loss especially if they were not designed to withstand such conditions. Finally, it should be noted that an overhead drop cable installed in a mountainous area is more likely to be subject to climatic risks than an overhead telecommunications line rolled out in an urban area.
Guidelines for choosing the right aerial drop for your network configuration
In case of FTTH deployments in low-density areas and the connection of recent dwellings or premises, generally, cables are rolled out in overhead layout up to a demarcation point. Then the adduction is performed by using underground infrastructures. In this specific case of aerial-underground roll-out and to avoid the straining of the optical budget, telecommunications installers use one single drop, developed as a suitable solution both for aerial and underground installation conditions. Thus, to avoid all network failure, disadvantageous both for communication providers and for end-users, it is essential to choose an aerial cable suitable for your fiber optic deployment project. Here are some indications that will allow you to make an informed choice when selecting your network equipment:
- First of all, analyse the network architecture. Trace the cable route in order to determine which constraints the aerial cable will be exposed to. Beside the risks related to weather and to unintentional mechanical
hazards, tensile strength requirements may vary as for example, depending on the length of the cable span. If possible, at this moment, elaborate a pre-plan of the performance requirements for the cables to be installed overhead.
- Determine where the optical closures will be installed (optical distribution points, splice protection closures, demarcation points or transition points). This will help you not only to establish the length of the
cable needed for the deployment, but also to acknowledge whether you will use an aerial cable developed exclusively for this application between two optical distribution points or a cable engineered as suitable for other applications
such as façade roll-out, underground installation etc. For even simpler fiber rollouts, presenting no risk to the optical budget, installers can use dual sheath aerial cables.
These FTTH drop cables enable the transmission of the optical signal starting from an overhead layout, routing on a facade or in duct up to the room where the subscriber decided to install the optical telecommunications outlet.
- Finally, depending on the preferred technique for enabling FTTH connections ( splicing, preterminated or field mountable connectors), it is important to check if the selected cable meets all the installation needs. For example, when choosing to install connectors on site, only cables identified by manufacturers as “compatible with field-installable connectors” should be used. For enabling subscriber connections by using splicing applications, it is important to foresee a cable slack, whilst for pre-terminated cables it is recommended to carefully estimate the cable’s length in order to avoids issues related to cable slack management at the fiber optical points.During this last step, you may wish to note any other technical constraints as for example the need of respecting a certain bending radius or of using a cable with a reduced diameter in order to ensure installations without interruption between the overhead and the indoor layouts via occupied ducts, etc.
How to choose among the multi-application aerial drop cables ?
To allow telecom installers avoiding complicated product management, aerial optical cabling solutions are developed so to suit several applications with one single part number. Such is the case of Droptic® drop cables. Each fiber optic cable marketed under this brand is engineered as suitable to at least two applications and perfectly compatible with the Telenco® dead-ending and anchor clamps. Here is some information to help you find your way through a complete range of FTTH solutions provided by Telenco networks:
Compatible dead-ending/anchor clamp: Mini-@ | 5/35 FTTH range.
Compatible dead-ending/anchor clamp: @ drop clamp.
Compatible dead-ending/anchor clamp: AC56R | AC560 clamps.The Droptic® LM4 aerial cable is designed with an outer diameter of 5mm for a 25mm bend radius.Thanks to its optimised diameter, this drop cable offers a better wind resistance. Two ripcords enable to remove the HDPE sheath so to access a Droptic® LM1L indoor cable of only 2.8mm.
Compatible dead-ending/anchor clamp: AC560 clamp.
Compatible dead-ending/anchor clamp: @ | 5/35 FTTH R.