How the optical fiber network architecture works

How the optical fiber network architecture works

How the optical fiber network worksFrom the FTTN, which is to represent the farthest connection from the user, up to the FTTH, here are all the network architectures existing in the context of the network connection via optical fiber.

Objective 2020. As foreseen by the European legislation and the Broadband strategy and policy , by 2020 100% of the population of the Old Continent (or, better said, of the citizens of the EU Member States) should have access to a domestic Internet connection ultra-broadband band. Translating this statement into figures, it means that no later than 1 January 2020 over 500 million Europeans will have to have a home connection with a speed of 30 megabits per second.

In order for this result to be achieved, both Member States and the various telephone operators and Internet service providers are investing hundreds of millions of euros to modernize the infrastructures and bring the fiber-optic as close as possible to buildings and homes. This led to a new “telephone” technical terminology alongside the more popular ADSL and similar. If terms such as FTTCab and VDSL are already part of the vocabulary used when it comes time to subscribe to new Internet connection offers, you will soon need to know the difference between an FTTC fiber connection from an FTTH or FTTB. Let’s find out together.

The architecture of the optical fiber

FTTXIn the field of telecommunications, the English term Fiber to the x (abbreviated as FTTx term born as generalization of the various possible architectures in this sector) indicates a network architecture that uses optical fiber to carry the signal – whether telephone or Network – as an alternative to the traditional local access network consisting of metal cables (usually, copper twisted pairs ).

The FTTx architectures vary according to the distance between the optical fiber and the end user: the fiber, in fact, can completely or partially replace the previously existing infrastructure, approaching more or less the dwelling (or group of houses) from to reach. The two extremes are represented by the FTTN architecture ( Fiber To The Node, “fiber to the node”) and by the FTTH architecture ( Fiber To The Home , “fiber up to home”).

The acronyms

FTTN :Sometimes called FTT ( Fiber To The Exchange ), the “Fiber up to the node” architecture indicates the connection that goes up to a general control cabin that is several hundred meters away (generally at least 300) if not kilometers from the ‘user. In this case the so-called ” Last Mile ” retains the traditional copper wiring: this results in a progressive degradation of the line performance, in proportion to the length of the copper cable, which leads to very limited connection speed.

FTTC : The Fiber To The Cabinet or Fiber To The Curb architecture (respectively “Fiber to the cabin” or “Fiber to the curb)” identifies the next step in the hierarchy of network architectures related to optical fiber. In this case, the harness for the ultra-broadband approaches up to a few hundred meters from the house to the so-called street closet (usually not more than 300 meters away from the houses), from which the copper connections are then unraveled towards individual houses. Compared to the first case, since the length of the copper cable is more limited, the connection speed is better although not at the levels of a “pure” fiber optic connection.

FTTS: The next step leads from the closet directly to the street. With the “fiber to the street” architecture ( Fiber To The Street , very similar to the FTTC architecture), the fiber line is brought to the mini-distributor present in virtually every block, usually no more than 200 meters away from the houses to be served

FTTB: Acronym of Fiber To The Building or Fiber to the basement (respectively, “fiber up to the building” and “fiber up to the foundation”), with this architecture the fiber reaches the “outer limit” of the building or the basement of the building in the case in the case of a condominium connection. The telephone line – and of network – arrives inside the house always through the copper pairs but, given the very limited length of the same (usually a few tens of meters), the connection speed suffers very little from the signal degradation related to them,

FTTH : The last piece of fiber network architecture is Fiber To The Home , “Fiber Up Home”. In this case the fiber harness arrives up to the house (or to the external telephone box) ensuring high performance connections. Not providing copper pairs in any stretch of the connection path, is the most expensive solution but also that which provides better quality services in the long term

FTTP : The Fiber To The Premises (literally, “fiber to the structure”) is a generic term used to identify fiber optic connections of FTTB or FTTH type for domestic purposes (eg, houses with garden) or to small and medium-sized businesses (e.g. a connection in “fiber up to the company headquarters”)