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What medium carries mobile communication
Mobile communication is transmitted using radio waves. Mobile systems use portions of the radio spectrum to carry both data and voice.
Base stations emit radio signals, converting data and voice into electromagnetic waves and transmitting them via antennas. Receivers on user devices such as mobile phones and tablets pick up those waves and decode them into usable information.
Common radio access technologies
- GSM (Global System for Mobile Communications): used for 2G networks.
- CDMA (Code Division Multiple Access): used in some 2G and 3G networks.
- WCDMA (Wideband Code Division Multiple Access): used for 3G networks.
- LTE (Long-Term Evolution): used for 4G networks.
- 5G: the fifth generation mobile communication technology, offering higher throughput and lower latency.
These radio access technologies transmit data and voice through processes such as modulation, coding, and decoding. Radio waves propagate within a limited range and can penetrate some obstacles, enabling widespread mobile communication.
Principles of mobile data transmission
The main aspects of mobile data transmission are:
Radio spectrum allocation
Mobile data uses specific ranges of the radio spectrum. Governments or regulatory bodies allocate and manage spectrum to ensure different technologies and operators have assigned frequency bands for data transmission.
Modulation and demodulation
Data must be converted into signals suitable for wireless channels. Modulation transforms digital data into analog signals that can propagate as radio waves. The receiver demodulates the incoming signals to recover the original digital data.
Multiplexing techniques
To use limited spectrum efficiently and support multiple simultaneous users, mobile systems employ multiplexing. Common techniques include time division multiple access (TDMA), code division multiple access (CDMA), and frequency division multiple access (FDMA). These methods allocate frequency slots, time slots, or code sequences to different users, allowing concurrent transmissions on the same frequency.
Network infrastructure
Mobile data transmission relies on a complete network infrastructure including base stations, transport links, and the core network. Base stations communicate with user devices over radio and forward traffic to the core network. The core network routes, switches, and processes data before delivering it to the destination device or the Internet.
In summary, mobile data transmission converts digital information into signals suited for radio propagation and uses multiplexing and network infrastructure to exchange and route that information, enabling users to access data services via mobile devices.
