Data Transmission
Data transmission carries information between devices through a communication medium.
Analog and digital#
- Analog information is represented by continuously varying quantities.
- Digital information is represented by discrete values, typically binary data.
Digital data can also be carried by modulating an analog carrier signal. Wireless systems use modulation to carry information over radio links.
Transmission modes#
| Mode | Direction of communication |
|---|---|
| Simplex | Communication goes in one direction only. |
| Half-duplex | Both sides can transmit, but not simultaneously. |
| Full-duplex | Both sides can transmit and receive simultaneously. |
Modern switched Ethernet connections normally operate in full-duplex mode.
Transmission media#
Wired media include:
- Twisted-pair copper cables.
- Coaxial cables.
- Fiber-optic cables.
Copper cables carry electrical signals, while optical fiber carries light.
Wireless communication uses signals such as radio waves, including those used by Wi-Fi. Infrared is also used for certain short-range applications.
The choice of medium depends on distance, required bandwidth, interference, installation cost, and the environment in which it will operate.