Wi-Fi or cable?
In the bedroom your phone loses Wi-Fi. Your friend's gaming PC is on a cable and never drops.
Why? A wireless signal gets weak after walls and distance. A cable gives a steady link. In this lesson you compare three ways to connect: copper cable, fibre cable and wireless.
Key words
| Word | What it means | Example |
|---|---|---|
| Ethernet | A common way to join computers in a building, usually with a copper cable. | The cable behind a desk PC |
| Copper cable | A cable with copper wires that carry electrical signals. | The cable behind a desk PC |
| Fibre-optic cable | A cable of thin glass strands that carries light. | A home broadband line |
| Wireless access point | A device that joins wireless devices to a wired network using radio. | The Wi-Fi box on a ceiling |
| Interference | Other signals that make your signal worse. They cause mistakes or slow speed. | A microwave oven near Wi-Fi |
| Bandwidth | How much data a connection can carry each second. | 100 Mbps |
| Encryption | Scrambling data so that only the right people can read it. | Wi-Fi password protection |
| Network | Computers joined together to share data. | College Wi-Fi |
| Switch | A box that joins the cables of a network and passes data to the right device. | The box in the network room |
The cells students fill in are left blank in this preview.
Three connections compared
| Copper (ethernet) | Fibre-optic | Wireless | |
|---|---|---|---|
| Signal | Electricity | Light | Radio waves |
| Speed | Fast | Fastest | Fast, but it varies |
| Distance | Limited | Very long | Short range indoors |
| Cost | Cheap | Costs the most | Cheap to add devices |
| Interference | Some, from electrical machines | None from electricity | Walls, other Wi-Fi, microwaves |
| Moving devices | No, you must stay near the cable | No | Yes |
| Security | Hard to join without plugging in a cable | Hard for others to read the signal | Needs a strong password and encryption |
The cells students fill in are left blank in this preview.
Quick check
Have a go
Quick check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Copper cable
Most office computers join the network with a copper cable. It carries electrical signals. It is cheap and fast, and easy to install. But a cable run can only be so long.
Drawbacks: you must sit near the cable, and electrical machines can cause interference.
Fibre-optic cable
A fibre-optic cable has thin strands of glass. A light sends pulses along each strand.
It is very fast and can reach a very long distance. Electricity does not affect it. Drawbacks: it costs more, it can break if you bend it too much, and it needs special tools and training to install.
Try it: is the cable too long?
# For this exercise, one copper cable run is at most 100 metres.
cable_length = 120
if cable_length > 100:
print("Too long for one copper cable. Use fibre, or add a switch.")
else:
print("A copper cable is fine.")
# Try 60, then 100, then 101.