Fiber Internet
Fiber-optic internet (FTTH)
Internet delivered over glass fibre cables — the fastest, most reliable residential broadband technology.
Fiber internet (FTTH — Fiber to the Home) delivers broadband over thin glass or plastic fibre-optic cables that transmit data as pulses of light. It is the fastest and most reliable residential broadband technology, offering symmetric speeds, minimal latency, and no congestion from neighbours sharing the line.
How fiber internet works
Data is encoded as rapid pulses of laser or LED light and transmitted through a glass core roughly 8–50 microns in diameter — thinner than a human hair. Light travels through the glass at approximately 200,000 km/s (about two-thirds the speed of light in a vacuum). The signal can travel tens of kilometres with minimal loss, and because it is photonic rather than electrical, it is immune to electromagnetic interference, radio frequency noise, and the resistance-induced signal degradation that limits copper cable at longer distances.
Most residential fibre deployments use a passive optical network (PON) architecture. A single fibre from the ISP's central office is split by passive optical splitters — no powered equipment between the headend and the home — serving 32 to 128 premises from a single fibre strand. Common PON standards include GPON (Gigabit PON, 2.5 Gbps downstream / 1.25 Gbps upstream shared across the split), XGS-PON (10 Gbps symmetric, enabling true gigabit+ residential plans), and EPON (Ethernet PON, widely used in Asia).
FTTH vs FTTC vs FTTB
- FTTH (Fiber to the Home) — fibre runs all the way to an ONT inside or on the exterior of your home; the only medium is optical glass from the ISP's headend to your equipment; fastest and most reliable
- FTTC (Fiber to the Cabinet/Curb) — fibre runs to a street-level cabinet, then copper phone wire for the final 50–300 metres; VDSL2 over that copper limits speeds to roughly 40–100 Mbps depending on distance; used by many legacy telco "fibre" plans
- FTTB (Fiber to the Building) — fibre terminates at the building's communications room; copper or Ethernet runs to individual units; common in apartment buildings; speeds depend on the in-building wiring quality
Fiber vs cable vs DSL comparison
| Technology | Download | Upload | Latency | Reliability | Upload symmetry |
|---|---|---|---|---|---|
| Fiber (FTTH) | 300 Mbps–5 Gbps | 300 Mbps–5 Gbps | 3–10 ms | Excellent | Symmetric |
| Cable (DOCSIS 3.1) | Up to 1–2 Gbps | 10–100 Mbps | 10–25 ms | Good (varies by node) | Asymmetric |
| DSL (VDSL2) | Up to 100 Mbps | Up to 20 Mbps | 15–40 ms | Fair (distance-sensitive) | Asymmetric |
Why fiber has lower latency
Fibre's latency advantage over cable comes from two sources. First, light propagates faster than the electrical signals in copper coax — the propagation delay over the same physical distance is lower. Second, and more importantly, fibre runs are dedicated point-to-point paths with no shared node contention. A cable connection's latency degrades during peak hours as the neighbourhood node becomes congested; a fibre connection's latency remains stable regardless of how many neighbours are online simultaneously.
The ONT (Optical Network Terminal)
The ONT is the device installed at your premises that terminates the fibre run and converts the optical signal to Ethernet. It is the fibre equivalent of a cable modem — owned and maintained by the ISP, not replaceable by the customer. The ONT outputs a standard Ethernet port that connects to your router. In some installations the ONT is mounted on an exterior wall or in a utility room; in apartments it may be in a shared communications cabinet with a copper or Ethernet run to your unit.
Availability limitations
Fibre deployment is capital-intensive. Running a new fibre drop to a home requires trenching the street or aerial cable installation, which costs $500–3,000 per home passed depending on terrain and local permitting. ISPs prioritise densely populated areas where the cost per subscriber is lowest. Rural and suburban areas with low housing density often cannot justify the build economics without government subsidy programmes (such as RDOF and BEAD in the US). As of early 2026, approximately 43% of US households had access to FTTH, with coverage expanding by 3–5 percentage points per year.
Fiber installation process
A typical new FTTH installation involves three stages: the drop (a fibre cable run from the nearest distribution point — a utility pole or underground conduit — to your home's exterior); the ONT installation (a technician mounts the ONT, connects the drop, and powers it up); and the router setup (the ONT's Ethernet output connects to your router's WAN port; the ISP provisions the account remotely). The appointment typically takes 2–4 hours. If your home has a pre-existing fibre drop and ONT from a previous occupant, activation can sometimes be completed remotely without a technician visit.
Frequently Asked Questions
Is fiber internet available at my address?
Check each ISP's address-availability tool directly — availability varies street by street. In the US, AT&T Fiber has the widest FTTH coverage, followed by Frontier Fiber and local providers. About 43% of US households had access to fiber as of early 2026.
Can I get fiber without a technician visit?
Most FTTH installations require a technician to run the drop cable from the street cabinet to your home and install an ONT (optical network terminal). If a previous occupant had fiber, the ONT may already be installed and activation can sometimes be done remotely.