Fiber-to-the-……

Over the past years, one infrastructure media technology in particular has become more and more common in catering to the trends in all types of networks, that of optical fiber. When I say networks, I mean it in widest sense to include Wide Area Networks (WAN), Metropolitan Area Networks (MAN), Local Area Networks (LAN), Cellular and Mobile Networks and Broadband Networks.

As network requirements in both the wired and wireless world fuel the need for high reliability, low delay, high bandwidth, extended distances and the convergence of most networks to IP, fiber optic solutions are reaching deeper and deeper into the network.

You may be thinking that I have stated the obvious, but I have also noticed is that our reference and experience of the use of fiber is often partitioned within the particular type of networks we are working with. So although the media itself is common, how it is used and terminologies around it differ.

Fiber to the x (FTTx) has become a generic term for any network architecture using optical fiber to transmit signals from a central location to various points in the network. This generic term was initially a generalization for several configurations of fiber deployment (FTTN, FTTC, FTTB, FTTH...), all starting with FTT (Fiber-to-the) but differentiated by the last letter, which is substituted by an x in the generalization.

So what versions are being used today? Well, the following are those I can think of:

• FTTA - Fiber-to-the-Antenna - fiber connects the Remote Radio Head to the base station in cellular networks.


• FTTB - Fiber-to-the-building or Fiber-to-the-basement - fiber reaches the boundary of the building, such as the basement in a multi-dwelling unit.


• FTTC - Fiber-to-the-curb / Fiber to the cabinet - this is very similar to FTTN, but the street cabinet or pole is closer to the user's premises; typically within 300m.


• FTTD - Fiber-to-the-desk - fiber connection is installed from the main computer room to an outlet near the user’s desk.


• FTTE – Fiber-to-the-Enclosure is typically used in the enterprise, where fiber is used to link the main computer equipment room to an enclosure close to the desk or workstation


• FTTH - Fiber-to-the-home - fiber reaches the boundary of the living space, such as a box on the outside wall of a home.


• FTTN - Fiber-to-the-node - fiber is terminated in a street cabinet up to several kilometers away from the customer premises.


• FTTP - Fiber-to-the premises - this term is used as a blanket term for both FTTH and FTTB, or where the fiber network includes both homes and small businesses.


• FTTZ – Fiber-to-the-Zone is similar to FTTE where fiber is used to link the main computer equipment room to a zone box that serves an area of a building.

If you have any more FTTx definitions, please feel free to share. It would be a bit of fun to see if we could complete the alphabet!!