Show Notes
A single video packet travels a remarkable path from your phone to a friend's device. This video breaks down the journey from radio waves to light in fiber and the role of cell towers, handovers, and undersea cables.
From your phone to the air: turning video into radio waves
- Your phone converts digital video data into radio waves using modulation.
- The signal is launched upward to the nearest cell tower.
- The idea of cells: the network divides the world into honeycomb-shaped zones to manage coverage.
The cellular network and towers
- The local cell tower receives your signal and maintains a wireless link with your device.
- As you move, the network performs handovers—passing the connection from one tower to the next so you don’t drop the call or video.
The backbone: fiber optics and landlines
- The cell tower connects to the broader network via fiber optic cables.
- The radio signal is converted to light for transmission through the fiber, making the long-distance hop possible.
Submarine cables and the internet backbone
- Most internet traffic travels underwater through submarine cables, not satellites.
- These cables use glass fibers the width of a human hair to carry enormous amounts of data.
- Each fiber strand can carry a staggering amount of traffic, contributing to global connectivity.
Data path end-to-end
- On the far end, the light signal is converted back to radio waves and delivered to your friend’s device.
- If your friend is moving (e.g., driving), the network keeps the connection alive through continuous handovers across towers.
Takeaways
- Cell networks are built from cells, towers, and a fiber backbone that ties the world together.
- Undersea fiber cables are the main arteries of the internet—satellites play a much smaller role in global traffic.
- Handover is the mechanism that keeps you connected as you move across different cell towers.