Fiber optic rollouts in high-density areas

The work required for the installation of fibre optic in a building can be more or less laborious depending on the density of the area. This is why the French Very High Bandwidth plan is divided in two distinct parts: high-density areas and low-density areas. In high-density areas, there are 106 municipalities with more than 6.3 million premises (houses, shops, businesses) to be connected to the ultrafast broadband networks. In these areas, there is one optical fibre network per operator (Orange, Bouygues, SFR, etc.) This is why in high-density areas each telecom operator installs its Central Office (CO also known as the Point of Presence). The CO enables the link between the national network and the local distribution network. In contrast, in low density areas, there is only one Central Office installed by the telecom operator that deploys a shared fibre network. In high-density areas, the underground rollout is preferred as it already exists.

Fibre Optic Street Cabinet

Once that the Central Office is installed, fibre optics must be deployed in the street, as close as possible to the dwellings. This is where the Street Cabinet comes into play, also called splitter node, splitter cabinet or shared access point. This is a metal cabinet installed in the street or at the foot of a building, enabling to link the optical feeder and the fibre addressing: the areas towards which the fibre optics will be distributed and connected. Inside this metal cabinet we will find fibre optic patch cords that will be used to deliver fibre optics to customers. The Street Cabinet or the Fibre Distribution Hub is generally located in the street for buildings with less than 12 dwellings. For buildings with more than 12 dwellings, the Fibre Distribution Hub is located inside the buildings, at the ground floor or in the basement, generally inside technical installations. This is also known as the Building Entry Point. There are two compartments inside a Street Cabinet or a Building Entry Point:


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  • The left one will be used for installing fibre optics coming from the commercial operators
  • The right one will be used for the customer connection
In the compartment foreseen for commercial operators, we can find single mode or multimode optical jumpers. The first case suits for low-density areas as one bidirectional fibre is connected from home to the Street Cabinet/Building Entry Point. In the second case, which concerns high-density areas, up to 4 fibres will be connected so that 4 different operators can offer fibre connections

Fibre optic subscriber terminal socket

The optical outlet is the passive equipment placed at the end of a FTTH (Fibre to the Home) /FTTP (Fibre to the Premises) network. Installed at the subscriber premises, this small box is equipped with a FTTH socket to which the subscriber will connect the ONT (Optica Network Termination) in order to benefit of an access to Very High-Speed Internet thanks to the installed fibre optics. The subscriber terminal socket is available in a multi-fibre or single-fibre version: • Multi-fibre OTO (Optical Telecommunications Outlet): possibility to route 4 fibres from the Street Cabinet/Building Entry Point to the subscriber’s premises so to ease the connection, depending on the ISP. • Single-fibre OTO: a single fibre is run from the Street Cabinet/Building Entry Point to the subscriber’s premises. This optimises its capacity but demands that a field engineer to intervene at the Street Cabinet/Building Entry Point level each time that the subscriber will change the ISP. The optical outlet can also be used as an intermediate distribution point when mounted inside a residential communication gateway, through a simple click action on a DIN rail. This is particularly common in the case of recent buildings, provided with an optical infrastructure.