Telekommunikaatiojärjestelmät

Telecommunication, or telecommunications, refers to the transmission of information over distance by electronic means to enable communication between two or more parties. It covers voice, data, text, images, and video, transported across a range of media, including copper and fiber optic cables, wireless radio links, and satellites. The field combines engineering, computer science, and regulatory policy to provide global connectivity.

Key components include transmission media (copper, fiber, airwaves, satellite channels), signaling and modulation schemes, multiplexing and switching equipment, and user devices such as telephones, modems, routers, and sensors. Networks are organized in layers, from local access networks to wide-area networks and the global backbone, and rely on standardized protocols to ensure interoperability.

Major network types worldwide include public switched telephone networks, broadband internet access, cellular networks (2G through 5G and beyond), wireless LANs (Wi‑Fi), and satellite communications. Services range from traditional voice calls to high-speed internet, video conferencing, streaming, and machine-to-machine communications.

Historically, telecommunications began with telegraphy and telephony and expanded through radio, television, satellite, and the internet era. International regulation and standardization bodies, such as the International Telecommunication Union (ITU), ISO/IEC, and IEEE, coordinate spectrum allocation, interoperability, and safety standards.

The sector underpins modern economies and everyday life but faces challenges such as ensuring universal access, protecting privacy and security, and managing spectrum efficiently. Ongoing trends include the deployment of fiber networks, the rollout of advanced mobile networks, and the integration of wireless, cloud, and edge computing to support diverse applications.