Self-paced · Interactive · No prior telecom knowledge required
Understand how the world gets fiber internet — from the laser to the living room.
A ground-up course in fiber-optic access networks (FTTx). We start with light in a glass thread and build, layer by layer, to the full picture: how one laser in a telco building reaches thousands of homes through nothing but glass — and how engineers plan, splice, measure, and map it all.
Who this is for
Anyone who needs to understand fiber networks without being an optical physicist — software engineers, product folks, planners, project managers, new field staff, or the simply curious. If you can picture a tree and a graph, you have everything you need to start. Every acronym is spelled out the first time it appears.
🧭 The one mental model to carry
FTTH is a tree of light: one laser in a telco building fans out — through nothing but glass and passive splitters — to thousands of homes. Almost everything in this course is a consequence of that one picture. Hold onto the word tree.
The whole domain on one page
Every module below is one branch of this single picture. Skim it now — it'll fill in, piece by piece, as you go.
The FTTx access network at a glance: the laser, the glass, the homes — and everything that keeps the light strong enough to arrive.
The learning path
Designed to be taken in order — each module assumes the one before it. But every page stands alone if you need to jump.
How Light Travels: The Physics Floor
The core facts about light in glass that quietly govern every later decision.
PON Architecture: OLT, ODN, ONT
The tree of light: one shared fiber, passive splitters, and how 64 homes take turns.
PON Standards & Generations
GPON to XGS-PON to 50G — speeds, wavelengths, and how generations coexist on one glass.
Optical Splitters
The passive heart of the PON — ratios, levels, and why every split costs you light.
The Outside Plant: CO to Couch
Walk the cable end to end: feeder → cabinet → distribution → drop terminal → home.
Cable Anatomy & Color Coding
Strands, tubes, and the universal 12-color code that finds one hair among 144.
Splicing & Termination
Joining glass to glass — fusion vs. mechanical, connectors, and the all-important splice plan.
The Optical Loss Budget
The master constraint. Distance vs. split ratio, worked end to end — with a live calculator.
Test & Measurement: OTDR & Friends
Radar for fiber — read a trace, find a fault, and prove a link passes.
Network Inventory, GIS & the Digital Twin
Two maps of one network — spatial vs. logical — plus tracing, feasibility, and the KPIs that decide if a build made money.
Vocabulary, Glossary & Capstone Quiz
The words you'll hear daily, in one place — and a final quiz across the whole course.
How to use this course
Read top to bottom
Modules build on each other. The sidebar tracks where you are and checks off what you've visited.
Play with the widgets
Drag sliders, build a splice, read a trace. The interactive bits are where intuition actually forms.
Take the quizzes
Each module ends with a quick self-check. Active recall is how this sticks — don't skip them.
Expand the deep-dives
Optional “go deeper” panels hold the extra detail for when you want it — and stay folded when you don't.
💡 Progress is saved locally
Your visited-module checkmarks live in this browser only (no account, no server). Open index.html any time to pick up where you left off.