FTTH Explained: Fibre to the Home in Plain Language

Key takeaways

• FTTH means fibre to the home: the optical fibre runs all the way into your home or flat.
• FTTB stops at the building and FTTC at a street cabinet, and providers sometimes call all three simply fibre.
• The ONT converts light signals into electrical signals, and the ONT and router both need electricity, so a power cut stops the connection unless they are backed up.
• Fibre brings the connection to your door; WiFi quality still depends on router placement, walls and device age.
• In flats, ask early about housing society permissions and whether the fibre is already inside your building.

What does FTTH stand for?

FTTH stands for fibre to the home. It describes a broadband network in which an optical fibre cable runs all the way from the provider's network to the inside of your home or flat. You may also see related terms such as FTTB, fibre to the building, and FTTC, fibre to the cabinet. These differ in how far the fibre goes before the connection changes to another kind of cable, and that difference can affect how the service behaves. Knowing the term helps you ask the right question when a plan is described simply as fibre.

Why does the last stretch matter?

A broadband network has many parts. There is the core network that connects cities and data centres, a local network that serves a neighbourhood, and the final stretch that reaches your door. Some services use fibre for most of the journey and then switch to copper or coaxial cable for the final stretch to the home. With FTTH, the fibre continues to your home. The practical meaning is that the last part of the path is also made of glass, so there is no switch to older wiring at the end.

• FTTH: fibre reaches the home itself.
• FTTB: fibre reaches the building, and a different cable then runs to each flat.
• FTTC: fibre reaches a street cabinet, and copper covers the rest.

Providers sometimes use the word fibre loosely for any of these. If you want a fibre connection all the way to your home, ask which of the three applies at your address.

How far the fibre goes

What equipment will you see?

An FTTH installation usually involves a few pieces of equipment. The names can vary, but the roles are similar across most services.

• The fibre cable: a thin cable that enters your home, often through a wall or window and ending at a small termination point.
• The ONT or ONU: the optical network terminal, a small box that converts light signals from the fibre into ordinary electrical signals that your devices can use.
• The router: the device that creates your WiFi and shares the connection among your devices. Sometimes the ONT and router are combined in one unit, and sometimes they are two separate boxes.
• Splitters: in many fibre networks, a splitter in the street or building divides one fibre so that several homes share it.

What does a shared fibre mean?

Many home fibre networks use a design where a single fibre from the provider is split to serve several homes. This is a normal and efficient way to build a network, and it does not by itself mean poor service. It does mean that the capacity of that branch is shared among connected homes, which is why a provider may talk about how the network is planned. If you care about steady performance at busy hours, you can ask how many homes share the branch serving your building, though a provider may not always be able to give that detail.

Does fibre guarantee good WiFi?

A common mistake is to assume that a fibre line guarantees fast WiFi everywhere in the house. Fibre brings the connection to your door. WiFi is the wireless link between your router and your devices, and it is affected by walls, distance, other networks nearby and the age of your devices. A good fibre line with a poorly placed router can still feel weak in a far bedroom. When you plan an installation, think about where the fibre will enter the home and where the router will be placed, since you may want them near the middle of the house rather than in a corner.

How should you plan the installation?

Before an installer visits, it helps to prepare. Fibre is delicate and should not be bent sharply, so the route of the cable matters.

• Decide with your family where the router should sit, ideally in an open, central spot.
• Ask where the cable will enter and whether drilling is needed.
• In a rented home, check with the owner or the building society before any drilling or visible cabling.
• Ask who owns the cable and equipment, and what happens to them if you move out.
• Ask if the work includes the cable run inside the home, and whether any extra length is charged.

Do you need building or society permissions?

In apartment buildings, the housing society or building management may have its own rules about laying cables, using shared ducts and accessing common areas. The provider may need permission before work can begin. Asking early about this avoids delay. If you live in a flat, ask the provider whether the fibre is already inside your building, as that is often the main factor in how quickly installation can happen.

How do you care for the equipment?

Fibre cables should not be folded tightly, pulled or crushed under furniture. The ONT should be kept in a ventilated spot, away from direct sun and water. Do not clean or look into the end of a fibre connector with any light source, and let the technician handle connections. If you notice a red or unusual indicator light on the box, the provider's support team can explain what the lights mean for your equipment, since the signals differ between models.

What happens during a power cut?

The ONT and the router both need electricity. During a power cut your home fibre connection will go down unless these devices are on a back-up supply. A small battery unit designed for routers can keep them going for a while. Check the power requirements of your devices before buying one, and ask the provider whether their equipment works with such back-up units.

Which questions should you ask about an FTTH offer?

• Does fibre reach inside my home, or only to the building?
• What equipment will be installed, and who owns it?
• Are installation, cable length and any deposit charged separately?
• How long does installation usually take at my address?
• How do I report faults and what is the usual response time?

Availability, charges and processes differ by provider and city. Verify each detail with the provider and with official sources before you decide.

Frequently asked questions