Field Guide · organization

Also known as: ITU-R, ITU Radiocommunication Sector

The ITU Radiocommunication Sector (ITU-R) is the arm of the International Telecommunication Union responsible for managing the global radio-frequency spectrum and satellite orbits.1 It maintains the international Radio Regulations — the binding treaty that allocates frequency bands to services worldwide — and organises the conferences at which that treaty is revised.2

ITU-R WRC (treaty) Radio Regulations national regulators (FCC, Ofcom, …)
ITU-R runs the WRC and maintains the Radio Regulations that national regulators then implement.

Overview

ITU-R is one of the three sectors of the ITU (the others handle standardisation and development). It was created in 1992 when the ITU reorganised, succeeding the earlier International Radio Consultative Committee (the CCIR). Its core products are the Radio Regulations, the table of frequency allocations that divides the world into three regions and assigns each band to services such as broadcasting, mobile, fixed, maritime, aeronautical, radionavigation, amateur, and space research, and a large library of ITU-R Recommendations giving detailed technical parameters for those services.

Much of ITU-R’s day-to-day work runs through study groups of experts who develop the technical basis for decisions, and through the Radiocommunication Bureau, which records frequency assignments and coordinates satellite filings so that networks in geostationary and other orbits do not interfere. The politically decisive changes, though, happen at the World Radiocommunication Conference — the treaty-making meeting ITU-R convenes, ordinarily every three to four years, to revise the Radio Regulations. Between conferences, ITU-R study groups prepare the technical studies that delegates negotiate over.

Relevance to SDR

Everything you can tune with a software-defined radio sits somewhere in the ITU-R allocation table. When a specific service — ADS-B at 1090 MHz, marine AIS at 162 MHz, a public-safety trunking band — appears in the same place across countries, that consistency traces back to ITU-R allocations that national regulators like the FCC, the UK’s Ofcom, and regional bodies such as CEPT implement domestically. Knowing which service ITU-R has allocated a band to is often the fastest way to guess what an unidentified signal is.

ITU-R does not touch a receiver’s decode chain, so GopherTrunk does not implement any of its regulations directly. But the allocation framework it maintains is the reason a given band plan is worth pointing a scanner at, and its Recommendations are frequently the primary reference for the technical parameters of the systems GopherTrunk decodes.

Sources

  1. ITU-R — Wikipedia, for the sector’s history, structure, and role in global spectrum management. ↩

  2. ITU Radiocommunication Sector — the sector’s official site, for the Radio Regulations, allocation tables, and conference information. ↩

See also