radiospectrum

The radio spectrum is the portion of the electromagnetic spectrum that is used for radio communication. It extends roughly from 3 kilohertz to 300 gigahertz, though some services operate outside this range. The spectrum is subdivided into bands allocated to different services and regulatory regimes to avoid interference and to organize use.

Management of the radio spectrum is coordinated internationally by the International Telecommunication Union (ITU), with national regulators issuing licenses and coordinating usage within their jurisdictions. Spectrum is a scarce public resource, and allocation processes include auctions, licensing, and enforcement. Many devices also operate in unlicensed bands, such as the 2.4 GHz and 5 GHz ranges, which support consumer wireless technologies.

Allocation and bands are designed to match different propagation characteristics and service needs. Common ranges include VHF (roughly 30–300 MHz) and UHF (roughly 300 MHz–3 GHz), SHF (roughly 3–30 GHz), and higher millimeter-wave bands beyond 30 GHz. Specific bands are reserved for services such as broadcasting, mobile cellular networks, satellite communications, radio navigation, aviation, maritime, radar, and amateur radio. Lower frequencies typically travel farther and penetrate obstacles better, while higher frequencies offer higher data rates but shorter range and greater sensitivity to obstacles.

Technically, improvements in modulation, digital transmission, multiplexing, and antenna techniques have increased spectrum efficiency. Concepts such as dynamic spectrum access and cognitive radio explore sensing and sharing unused spectrum to reduce waste and accommodate growing demand.

Trends in the radio spectrum include the expansion of mobile networks (5G and beyond), satellite broadband, the Internet of Things, and efforts toward spectrum sharing and harmonization to support global connectivity and innovation. The radio spectrum remains essential for communications, broadcasting, navigation, and safety services.