Fiber to the X is a term used to described any broadband network that uses optical fiber to provide all or a part of the local loop used for last mile telecommunications. Fiber optic cables are able to carry much more data than copper cables that are actually used in almost every connection.
Fiber optics work better especially over long distances, copper telephone networks built in the 20th century are now being replaced by fiber optic cables.
FTTX is arranged into two groups: FTTP/FTTH/FTTB (Fiber laid all the way to the premises/home/building) and FTTC/N (fiber laid to the cabinet/node, with copper wires completing the connection).
The telecommunications industry has several types of FTTX, they most used of this types of fiber, in The terms of most widespread use today are:
- FTTP : This term means “fiber to the premises” and is used either as a blanket term for both FTTH and FTTB, or where the fiber network includes both homes and small businesses.
- FTTH : FTTH means “fiber to the home” and this type of fiber reaches the limits of the living space, such as a box on the outside wall of a home. Passive optical networks and point-to-point Ethernet are architectures that deliver triple-play services over FTTH networks directly from an operator's central office.
- FTTB : This term means “fiber to the building”. We call FTTB to the fiber that reaches the building or a place such as the basement in a multi-dwelling unit, with the final connection to the individual living space being made via alternative means, similar to the curb or pole technologies.
- FTTD : This type of fiber means “fiber to the desktop”. This term is used when the fiber optical connection is installed from the main computer room to a terminal or fiber media converter near the user's desk.
- FTTO : FTTO means “fiber to the office”. We use this term when the fiber connection is installed from the main computer room/core switch to a special mini-switch (called FTTO Switch) located at the user´s workplace or service points.
- FTTE / FTTZ: FTTE means “fiber to the telecom enclosure and FTTZ means “fiber to the zone”. This types of fiber are not considered part of the FTTX group of technologies, despite the similarity in name.
- FTTF: This fiber means “fiber to the frontpage” and this type of connection are very similar to FTTB. In a fiber to the front yard scenario, each fiber node serves a single subscriber. This allows for multi-gigabit speeds using XG-fast technology. The fiber node may be reverse-powered by the subscriber modem.
- FTTdp: FTTdp means “fiber to the distribution point” and is very similar to FTTC / FTTN types of fiber but is one-step close again moving the end of the fiber to within meters of the boundary of the customers premises in last junction possible junction box known as the "distribution point" this allows for near-gigabit speeds
- FTTN / FTTLA: This types of fiber are called “fiber to the node, neighborhood or last amplifier”. It’s called FTTN or FTTLA when the fiber optic connection is terminated in a street cabinet, possibly miles away from the customer premises, with the final connections being copper. FTTN is often an interim step toward full FTTH (fiber-to-the-home) and is typically used to deliver 'advanced' triple-play telecommunications services.
- FTTC / FTTK : This fiber means “fiber to the curb, kerb, closet or cabinet” and this connections are very similar to FTTN, but the street cabinet or pole is closer to the user's premises, typically within 1,000 feet (300 m), within range for high-bandwidth copper technologies such as wired ethernet or IEEE 1901 power line networking and wireless Wi-Fi technology.
To promote consistency, especially when comparing FTTH penetration rates between countries, the three FTTH Councils of Europe, North America, and Asia-Pacific agreed upon definitions for FTTH and FTTB in 2006, with an update in 2009, 2011 and another in 2015. The FTTH Councils do not have formal definitions for FTTC and FTTN.
Fiber is often said to be "future-proof" because the data rate of the connection is usually limited by the terminal equipment rather than the fiber, permitting substantial speed improvements by equipment upgrades before the fiber itself must be upgraded.
Still, the type and length of employed fibers chosen, e.g. multimode vs. single-mode, are critical for applicability for future connections of over 1 Gbit/s.
FTTC (where fiber transitions to copper in a street cabinet) is generally too far from the users for standard ethernet configurations over existing copper cabling. They generally use very-high-bit-rate digital subscriber line (VDSL) at downstream rates of 80 Mbit/s, but this falls extremely quickly over a distance of 100 metres.