What is fiber to the home (FTTH)?
Fiber to the home (FTTH) is the installation and use of optical fiber from a central point to individual buildings to provide high-speed internet access. Compared to other technologies, FTTH dramatically increases connection speeds available to computer users.
FTTH has grown since the 1980s to accommodate increasing network demands. Many fiber cables implemented in the 1980s are still in use today, which is a testament to their flexibility over time. While fiber technology has become cheaper and easier to install, it's costly to implement FTTH on a large scale because it requires installing new cable sets over the last links from existing optical fiber cables to individual users.
Today, FTTH and fiber optic usage continue to increase. FTTH promises connection speeds of up to 1,000 megabits per second (Mbps), or 1 gigabit per second (Gbps), which is much faster than a typical cable modem or DSL connection.
How does FTTH work?
The defining characteristic of FTTH is that it connects optical fiber directly to residences, apartment buildings and businesses. FTTH uses optical fiber for most or all last-mile telecommunications. Optical fiber transmits data using light signals to achieve higher performance.
In FTTH access networks, fiber optic cables run from a central office through a fiber distribution hub. The cables then run through a network access point and finally into the home through a terminal that serves as a junction box.
FTTH architecture and components
Two types of systems enable fiber optic cables to transmit data using light and make FTTH possible: active optical networks (AONs) and passive optical networks (PONs).
AONs use electrically powered switching equipment to direct signals to specific users. PONs, however, use optical splitters to direct signals, but still require electrically powered equipment at the network source and receiving end.
Each type has its benefits, but most FTTH implementations use PONs because they cost less to install and offer high performance. The network topology of PONs consists of the following:
- An optical line terminal (OLT) at the provider's central office.
- Optical network units (ONUs) closer to the end user's premises.
- An optical distribution network between the OLT and ONU to split and distribute the signal traveling along the PON.
Benefits of FTTH
The main benefit of FTTH is increased network performance. FTTH provides higher speeds over longer distances than coaxial cables, twisted-pair cables and DSL can reach.
FTTH also offers significantly higher bandwidth than other connectivity methods. Benefits of FTTH's higher bandwidth capacity include the following:
- Improved performance for high-definition video streaming on applications such as YouTube and Roku.
- Upgrades that don't require fiber replacement. Network professionals can update the infrastructure surrounding the fiber without having to update the fiber itself.
- Better performance than other fiber configurations. Fiber directly connects to residences and can complete remaining network segments with Ethernet or coaxial cables.
Fiber to the x
FTTH is a specific version of the term fiber to the x (FTTx). The x represents the point in the network at which a fiber optic cable connects to provide service to nearby buildings. All versions of FTTx are the driving force behind next-generation access, which means an upgrade to broadband network speed and quality.
FTTH's name comes from the fact that the cable connects directly to the user's home. Network professionals often use the terms fiber to the building (FTTB) and fiber to the premises (FTTP) interchangeably with FTTH. The network structure is the same, and the words home, building and premises all describe dwellings to which fiber networks directly connect.
However, there are small distinctions between FTTH, FTTB and FTTP. While FTTH connects optical fibers directly to residences, one building could have multiple residences. In FTTB, the optical fibers connect to the building and metallic cables connect to the individual units -- such as homes or offices -- inside. FFTP, meanwhile, encompasses both FTTH and FTTB, as they could both be on the same premises.
Some communities currently have fiber to the curb (FTTC) services. FTTC refers to the installation and use of optical fiber cables to the curbs near homes or businesses. A copper medium carries the signals between the curb and the end users.
Many other acronyms exist in the FTTx category, but the only major distinction between them is the point at which the fiber cabling ends and the metallic wiring begins:
- Fiber to the node (FTTN). A setup in which the optical fiber connects to the network cabinet or node and passes the signal to a copper wire.
- Fiber to the terminal (FTTT). Fiber optic cables connect directly to desktop equipment in an office.
- Fiber to the office (FTTO). A fiber optic cable connects to a mini switch at a user's desk in an office. The office usually has several switches throughout the building, managed from one central location. FTTO is similar to FTTT.
- Fiber to the street. FTTS falls between FTTB and FTTC. FTTS transitions to copper wire closer than FTTC but farther away than FTTB.
- Fiber to the distribution point. FTTdp is a mix between FTTC and FTTN. The end of fiber connects to the last possible distribution point before the end user's premises.
Fixed wireless vs. FTTH
Fixed wireless differs slightly from FTTH. Instead of switching from fiber optics to a metallic cable at the endpoint, fixed wireless transmits a wireless signal into the home. This eliminates the need for cabling at the last segment of the network, where most costs are incurred during installation.
