Copper (twisted pair / coaxial): carries electrical signals. Cheap, widely available, susceptible to interference (EMI). Used in Ethernet cables.
Fibre optic: carries light pulses through glass/plastic strands. Very high speed, immune to interference, secure (hard to tap), more expensive. Used for broadband backbones.
Fibre can carry data over much longer distances without signal degradation (attenuation)
Wireless Media
Wi-Fi, Bluetooth & Satellite
Wi-Fi: uses radio waves (2.4 GHz / 5 GHz). Range ~30m indoors. Requires a wireless access point (WAP). Common in homes, schools, offices.
Bluetooth: short-range radio (~10m). Low power. Used for peripherals: headphones, keyboards, mice, smartwatches.
Satellite: global coverage, high latency (~500ms). Used in remote areas and for GPS, TV broadcasting.
Comparing Media
Factors to Consider
Speed: fibre optic > copper > Wi-Fi (in practice); Bluetooth slowest
Security: fibre optic (hardest to tap) > copper > wireless (easiest to intercept)
Cost: copper cheapest to install; fibre optic more expensive; wireless avoids cable costs
Interference: copper affected by EMI; fibre immune; wireless affected by walls and other signals
Exam Practice
Have a go at this question
Cambridge IGCSE 0478 style
Give two advantages of using fibre optic cables instead of copper cables for a broadband network backbone.
2 marks
Any two from: much higher data transfer speeds [1]; immune to electromagnetic interference [1]; data can travel longer distances without degradation [1]; more secure / harder to tap [1].
Key Takeaways
What to Remember
Copper: cheap, electrical signals, prone to interference; Fibre: light, fast, immune to EMI
Wi-Fi: radio waves, ~30m range; Bluetooth: short range (~10m), low power
Satellite: global, but high latency; used in remote areas
Compare media on: speed, cost, security, range, interference susceptibility