Why FTTx does not guarantee a fiber connection?

The FTTx acronym includes various fibre optic network topologies. Depending on the last letter at the end of this abbreviation, the physical configuration of a network can be completely different on site and have a direct impact both on the associated costs of the fiber optic roll-out and on maintenance operations or the guaranteed broadband speeds to subscribers.

The FTTx refers to a global network architecture, based on the deployment of fiber optic up to a certain physical point of the network. FTTH, FTTB or FTTP are specific topologies, pointing out the physical location where the optical termination is performed. It is therefore important to distinguish between two terms that are often used interchangeably: network architecture and network topology. The network architecture is the way in which fiber network is designed from a theoretical point of view; a logical sequence of components aiming to ensure the optimal operation of the installation. The network topology is the physical representation of the network: this defines the place where various network equipment such as optical cables, splitters and different distribution boxes are located on site.

 

Customer connection to full fibre ultrafast broadband networks

To get a close look to what really stands behind FTTx, check the following table, summarising the most encountered fiber optic networks:

 

FTTN

Fiber to the Node/Neighborhood

The fiber optic is terminated in a Point of Presence (PoP) or an Access Node which can be either a building, a shelter or a street cabinet. As fiber is available to the neighborhood but far enough to the customer’s premises, this can be an intermediate step towards FTTH.

FTTLA

Fiber to the Last Amplifier

The fiber replaces coaxial cable on the distribution part and is terminated at the last amplifier. This network configuration enables to cut off distribution amplifiers, while also retaining the more expensive part of the access network, the last mile access.

FTTC

Fiber to the Curb

The fiber is installed from the PoP ( Point of Presence) all the way to the curb, near to subscribers’ premises or business. The last part of the network is ensured by coaxial cables or other telecommunications technology.

FTTCab

Fiber to the Cabinet

Fiber terminates in a street cabinet.

FTTS

Fiber to the Street

Fiber termination is located near customer premises, at the street level.

FTTDp

Fiber to the Distribution Point

In this network configuration, fiber is available a little closer to the subscriber than in the case of FTTN or FTTC, generally less than 250m.

FTTB

Fiber to the Building/ Basement

The fiber is deployed up to the building (MDU or business premises). The subscriber connection is made possible thanks to another technological solution such as the existing copper cables, coax, WiFi etc.

FTTP

Fiber to the Premises

In this network configuration, fiber is rolled out from the PoP up to the customer premises. (MDU, SDU or business).

FTTO/FTTE

Fiber to the Office/Enterprise

The fiber terminates in the business premises / server room of the company.

FTTH

Fiber to the Home

Fiber is deployed through the entire network so to reach the subscriber’s premises

FTTD/FTTBD

Fiber to the Desktop

Fiber optic is routed from the main computer room to a switch placed near the user’s desk.

FTTA

Fiber to the Antenna

Fiber is deployed up to cell towers. Connection to very high speed networks is then possible thanks to 4G and 5G technologies.

 

The wall mount OTO, the termination point for FTTH installations

 

The FTTH is by far the access network topology embraced both by telecom players and subscribers at a worldwide scale. About 100 times faster than DSL, FTTH enables the digitalization of companies, enabling thus to reliably meet the actual needs in terms of broadband bandwidth. Unlike other network topologies such as FTTN, FTTLA or FTTB, the FTTH consists of a 100% fiber-based infrastructure. This means that no signal conversion is required between the PoP and the wall mount OTO (optical telecommunications outlet), enabling thus ISPs to ensure very high-speed connections with low latency.

For the roll-out of FTTH networks, several configurations are possible, depending on criteria such as:

  • the area to be covered : high-density or low-density
  • the type of dwelling to be connected: SDU (single dwelling unit) or MDU (multi-dwelling unit)
  • the number of subscribers to be connected to fiber optic access networks
  • to prepare for future connections based on demographic projections

 

In dense and high-density areas such as towns and cities, the fiber optic installation is mainly carried out by using underground infrastructure. To bring optical signal to the subscriber, underground drop cables are then pulled into ducts and conduits so to ensure the horizontal optical distribution between the PoP and the BEP (Building Entry Point). At the ground floor or in the basement, a Building Entry Point is mounted and plays the role of an interface between the operator network and the subscriber network. This optical distribution box also enables the transition between the horizontal optical distribution (the outdoor distribution cable) and the vertical optical distribution (the riser cable). On each floor, a proportionate number of fiber optics are extracted from the riser cable and connected to an indoor optical drop inside a Floor Distribution Box (FDP). The indoor optical drop will be used to enable the optical network termination by linking the FDP to the FTTH outlet.

FTTH outlet for the customer connection to the full fibre ultrafast broadband networks

 

In low-density areas, fiber optics is generally deployed via overhead layouts. Indeed, the FTTH rollout is much more advantageous when using the existing telecommunications and utility poles than when civil engineering works are required to perform trenches for underground installations. In this specific case, but also for performing some of the customer connections to FO access networks in cities, an Optical Distribution Point (ODP) is mounted on a pole or a façade for further routing the optical signal to dwellings and perform subsequently optical network terminations. Depending on the network configuration, a FO transition box can also be installed so to enable reliable transitions between the outdoor drop and the subscriber’s indoor drop. But if there is one optical box that plays an essential role in FTTH rollouts, both for fiber optic deployments in dense or low-dense areas, as well as for connecting MDUs or SDUs to very high speed access networks, it is the FTTH socket. As the last piece of equipment in the FTTH architecture, the subscriber terminal socket must meet strict criteria of performance and reliability.

Which differences between FTTP and FTTB networks?

 

FTTP and FTTB access network architectures are alternative solutions to FTTH deployments. Both of them enable to ensure higher speeds to subscribers than those provided by the ADSL technology. However, depending on the chosen network type, subscribers will benefit from different kinds of advantages. Here are the main differences between these two fiber optic networks:

FTTP

FTTB

  • Optical signal is routed via an optical distribution network from a PoP up to the ONT located at the subscriber’s premises. Thanks to the ONT (Optical Network Termination), the optical signal is converted into an electrical signal and further transmitted to the active equipment of the subscriber. FTTP are thus similar with FTTH networks. It should be noted that in case of FTTP, the optical network termination is not necessary performed inside an optical outlet

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  • Customer connection to ultrafast broadband networks is made by using fiber optics;

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  • Higher installation costs, as the previous generation telecommunications network is completely replaced with fiber optic solutions;
  • Low latency, higher speed rates;

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  • • End-to-end fiber optic network, no additional costs are to be expected afterwards.

  • Optical network termination is performed at the building entry’s level. The last mile access is ensured by using other technology than fiber such as coax cable, copper cable, WiFi or else. The transition between the fiber optic and this other technology has a direct impact on the speed provided to the customer. Thus, FTTB networks generally guarantee lower speed rates than FTTH or FTTP networks.

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  • Network termination at the subscriber’s premises is ensured by using an alternative technology to fiber;

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  • Reduced installation costs as the last mile access is covered by the existing infrastructure;

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  • Higher latency rates, various data speed rates ;

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  • Partial fiber optic network. Depending on future customer needs in terms of bandwidth, additional costs may be incurred for further developing the infrastructure.

 

FTTA networks : why fiber optics is becoming the standard for 5G deployment

 

Fibre optics to be used in replacing telecommunications copper links for 5G and FTTAnetworks

Mostly seen as a replacement solution for wired telecommunications networks, fiber optics is also used as a technological solution for upgrading mobile networks. And that is because wireless networks are not completely wirelless. Indeed, with about 70% of the world’s population using Internet services via mobile phones in 2020, the challenge for telecom operators is to begin deploying today the mobile infrastructures of tomorrow, providing thus for very high speeds to subscribers. In order to ensure 4G and 5G coverage across territories, FTTA networks are being deployed throughout the world.

A FTTA network consists into deploying fiber optics from a PoP or a FDP (Fiber Distribution Point) up to the cell tower. The fiber runs then up along the masts and ends at the antenna’s level, contributing thus to the transmission of high frequency signals.

The constantly increasing demand for bandwidth requires the installation of more and more antennas and cables along the mobile phone masts. The addition of all these equipments may exceed the initial calculated load for these telephone masts. Replacing coaxial cables with fiber optic cables empowers thus telecom operators and their subcontractors to meet today’s challenges, as:

  • Much lighter than coaxial cables, FO cables reduce the load supported by mobile phone masts
  • Deployment costs are lower : one optical cable can replace several coax cables
  • Fiber optic cables offer a better wind resistance
  • Optical cables offer higher performances in terms of attenuation of high -frequency signal compared to coax cables.