2.2 Data Transmission Media

• Basic transmission concepts: encoding, decoding, modulation, demodulation, multiplexing
• Guided (wired) transmission media: twisted pair, coaxial and fibre optic
• Unguided (wireless) transmission media: radio, microwave, infrared and satellite
• Comparing and choosing transmission media
• Factors that affect communication over a network
• Connecting digital devices to share resources

• define basic concepts used in data transmission
• describe the types of transmission media used in computer networks
• connect digital devices used in data communication
• establish the factors that affect communication over a computer network
• appreciate the role of transmission media in computer networking

“How is data transmitted in a transmission medium?”

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1. How data is transmitted, and guided media
   40 min · 1 practice tasks · quiz
   Encoding, modulation and multiplexing; then the three wired media - twisted pair, coaxial and fibre optic - and what each is for.
2. Wireless media, choosing a medium, and connecting devices
   40 min · 1 practice tasks · quiz
   The unguided media - radio, microwave, infrared and satellite - how to choose between all the media, the factors affecting a network, and connecting devices to share resources.
3. Encoding and decoding a signal
   40 min · 1 practice tasks · quiz
   Data must become a pattern the medium can carry — voltages, light pulses or radio — and become data again at the far end.
4. Modulation, demodulation and the modem
   40 min · 1 practice tasks · quiz
   Impress digital data onto a carrier the line was built for, recover it at the far end, and see why the box is called a modem.
5. Multiplexing: sharing one expensive medium
   40 min · 1 practice tasks · quiz
   Frequency-division and time-division let many signals share one fibre or one radio band; demultiplexing separates them again.
6. Twisted pair and coaxial in practice
   40 min · 1 practice tasks · quiz
   Strip a UTP lead, see the twists, terminate an RJ-45 in principle, and compare coaxial for TV and older networks.
7. Fibre optic: light in glass
   40 min · 1 practice tasks · quiz
   Total internal reflection, why fibre ignores electrical noise, and how undersea and inland fibre shape Kenya’s internet.
8. Factors, choice and connecting devices in Kenya
   40 min · 1 practice tasks · quiz
   Attenuation, latency and the rest as a decision list; then actually share a file on copper or Wi-Fi, with the safety and ethics rules.