How Fibre Networks are Built
From trenches to light. A look at the engineering and civil works behind South Africa's fibre revolution.
How Fibre Networks are Built: The Engineering of Light
Executive Summary
We often take the "box on the wall" for granted, but the infrastructure behind it is a marvel of modern engineering. Building a fibre network in South Africa involves complex civil works, municipal wayleaves, and precision optics. This guide takes you behind the scenes of a fibre rollout, from the initial planning stages to the "lighting" of the first customer.
The 4 Phases of a Fibre Rollout
Phase 1: Planning and Wayleaves
Before a single spade hits the ground, FNOs must map the suburb and get "Wayleaves" (permissions) from the local municipality to dig under roads and pavements. This can take months or even years.
Phase 2: Civil Works (The Trenches)
This is the part everyone sees. Teams dig narrow trenches (usually 30cm - 50cm deep) along the verges of every street.
- Micro-trenching: A newer, faster method using a circular saw to cut a tiny slit in the road itself.
- Aerial Fibre: In some areas, fibre is strung along existing telephone or power poles to avoid digging.
Phase 3: Hauling and Splicing
Once the protective "ducts" (pipes) are in the ground, the actual glass fibre is "blown" through them using compressed air. Technicians then "splice" the fibres together using a fusion splicer—a machine that uses an electric arc to melt two pieces of glass together with microscopic precision.
Phase 4: The Last Mile
The final step is connecting individual houses to the "Distribution Point" (DP) in the street. This is the cable that eventually plugs into your ONT.
Comparison: Trenching vs. Aerial Fibre
| Feature | Trenched Fibre | Aerial Fibre |
|---|---|---|
| Cost | High | Low |
| Speed of Rollout | Slow | Fast |
| Durability | Very High (Protected underground) | Medium (Exposed to wind/theft) |
| Aesthetics | Invisible | Visible cables on poles |
The Technology: GPON Explained
Most residential fibre in SA uses GPON (Gigabit Passive Optical Network) technology.
- Passive: It doesn't need electricity between the exchange and your house.
- Shared: A single fibre from the exchange is "split" to serve up to 64 or 128 homes. This is why "Peak Congestion" can happen if everyone is downloading at once.
Practical Checklist: Identifying Infrastructure
- Look for the Manholes: FNO-branded manholes are the "access points" for the underground network.
- Check the Poles: Look for small black boxes on telephone poles—these are aerial distribution points.
- Identify the "Pop": The Point of Presence (PoP) is the small, air-conditioned container in your suburb that houses the main network equipment.
Next Steps
See the results of this engineering in your own home.
Related Guides
Frequently Asked Questions
Why do they dig so many holes?
Technicians need 'access pits' every few hundred meters to pull the cables through the ducts and to house the 'splitters' that send fibre to individual houses.
Is fibre made of real glass?
Yes. It is an extremely pure form of silica glass, about the thickness of a human hair, surrounded by protective layers of plastic and Kevlar.
Can fibre be recycled?
The glass itself is difficult to recycle, but the plastic and metal components of the infrastructure are often recyclable.
Next Steps
Ready to put this knowledge into practice? Use our tools to find the best fibre connection for your home or office.