RF Safety and Regulatory Spectrum Regulation Informational

How does the ITU allocate frequency bands for different services globally?

The ITU (International Telecommunication Union) is the United Nations agency responsible for the global coordination of radio spectrum. The ITU allocates frequency bands to different radio services through a structured international process: (1) ITU Radio Regulations: the master document that contains the Table of Frequency Allocations (Article 5). This table assigns every frequency from 8.3 kHz to 275 GHz (and increasingly above 275 GHz) to one or more radio services. Radio services include: fixed (point-to-point links), mobile (cellular, PMR), broadcasting (TV, radio), satellite (fixed-satellite, mobile-satellite, broadcasting-satellite), radionavigation (radar, GPS), radio astronomy, ISM, amateur, and many others. (2) Regional structure: the ITU divides the world into three regions: Region 1: Europe, Africa, Middle East, and the CIS states. Region 2: the Americas (North and South). Region 3: Asia-Pacific, Australia. Different regions may have different allocations for the same frequency band. Example: 902-928 MHz: Region 2 (Americas): allocated to ISM and used for unlicensed devices (LoRa, Part 15). Region 1 (Europe): allocated to GSM-R (railway mobile) and not available for unlicensed use. (3) World Radiocommunication Conference (WRC): held every 3-4 years. National delegations negotiate changes to the Table of Frequency Allocations. Recent important WRC decisions: WRC-19 identified 24.25-27.5 GHz, 37-43.5 GHz, and 66-71 GHz for 5G/IMT-2020. WRC-23 addressed 6 GHz coexistence (Wi-Fi vs IMT) and upper mid-band for 5G-Advanced. The WRC process: pre-WRC studies (4 years of technical analysis by ITU-R study groups) → regional preparation → WRC plenary (4 weeks of negotiation) → new Radio Regulations. (4) National implementation: each country implements the ITU allocations through its national regulatory body: US: FCC (Federal Communications Commission) and NTIA (for federal government). EU: individual national administrations guided by CEPT/ECC decisions. China: MIIT (Ministry of Industry and Information Technology). The national implementation may impose additional restrictions or allow additional flexibility within the ITU framework.

Category: RF Safety and Regulatory

Updated: April 2026

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ITU Frequency Allocation

The ITU frequency allocation system is the foundation of global radio spectrum management. Without international coordination, cross-border interference would make many radio services unusable.

Allocation Types

(1) Primary allocation: the service has full protection from interference and cannot be interfered with by secondary services. Example: 2110-2170 MHz is a primary allocation for Mobile Service (used for cellular downlink). (2) Secondary allocation: the service must not cause interference to primary services and cannot claim protection from interference caused by primary services. Example: Amateur Radio has a secondary allocation in many bands shared with primary services. (3) Footnote allocations: individual countries or groups of countries may add additional allocations through footnotes to the Table. Example: a footnote may allow a specific country to use a band for cellular mobile that is allocated differently in the general table. (4) Identified (not allocated): some WRC decisions "identify" bands for a specific use without changing the primary allocation. The identification signals intent and encourages national administrations to make the band available. Example: WRC-19 identified 24.25-27.5 GHz for IMT (5G). Countries are free to implement (or not) based on their national needs.

Key Allocations for RF Engineers

(1) Cellular/IMT: 700 MHz band (694-862 MHz): LTE/5G, available worldwide after the analog TV shutdown (digital dividend). 1.8 GHz (1710-1880 MHz): LTE band 3, the most widely deployed LTE band globally. 2.1 GHz (1920-2170 MHz, FDD): UMTS/LTE band 1. 2.6 GHz (2500-2690 MHz): LTE band 7, wide bandwidth for capacity. 3.5 GHz (3300-4200 MHz): the primary mid-band for 5G NR (n77/n78). 26/28 GHz (24.25-29.5 GHz): mmWave 5G (n257/n258/n261). (2) Satellite: C-band (3.4-4.2 GHz downlink, 5.85-6.425 GHz uplink): traditional satellite TV, now shared with 5G. Ku-band (10.7-12.75 GHz downlink, 13.75-14.5 GHz uplink): VSAT, DTH satellite TV. Ka-band (17.7-21.2 GHz downlink, 27.5-31 GHz uplink): high-throughput satellites, Starlink. V-band (37.5-42.5 GHz downlink, 47.2-51.4 GHz uplink): next-generation LEO constellations. (3) Radar: S-band (2.7-3.1 GHz): weather radar, air traffic control. X-band (8.5-10.68 GHz): maritime radar, military radar. W-band (76-81 GHz): automotive radar (allocated for radiolocation and ISM).

ITU Allocation Framework

ITU Regions: 1 (EMEA), 2 (Americas), 3 (Asia-Pacific)
WRC: every 3-4 years negotiates changes
Primary: full interference protection
Secondary: must not interfere with primary
5G mid-band: 3.3-4.2 GHz (n77/n78)

Common Questions

Frequently Asked Questions

Why do different countries have different frequency bands for the same service?

Historical reasons: spectrum was allocated nationally before the ITU harmonized allocations. Some countries assigned bands to military or government uses that other countries allocated to commercial services. Harmonization is a gradual process (each WRC works toward alignment, but legacy allocations persist). Examples: 700 MHz: the US uses 698-806 MHz (post-TV repack), Europe uses 694-790 MHz (different channel plans). Clearing existing users from the old allocation takes years. 3.5 GHz: the US has CBRS (3.55-3.7 GHz, shared with military radar). Europe has 3.4-3.8 GHz (with some satellite incumbents). China has 3.3-3.6 GHz (different sub-band). Each country must negotiate with its incumbent users (military, satellite, fixed wireless) to clear the band for 5G.

How does a new band get allocated for 5G?

The process takes 6-10 years: (1) ITU-R study (4 years): technical studies assess the feasibility of sharing between the proposed new service (5G) and the existing incumbents (satellite, radar, etc.). The studies determine: the minimum separation distance, required filtering, and interference mitigation techniques. (2) WRC agenda item: the study results are presented to the WRC. National delegations negotiate: which bands to allocate, with what conditions (footnotes, sharing restrictions), and with which regional variations. (3) National implementation (2-4 years): each country conducts its own spectrum auction or assignment process. Incumbent users are relocated or protected. Licenses are issued to mobile operators. (4) Deployment: operators build base stations and networks on the new band. Example timeline for 3.5 GHz 5G: 2015: WRC-15 identified 3.3-3.6 GHz for IMT study. 2019: WRC-19 confirmed identification for IMT. 2020-2023: national auctions (US CBRS, EU 3.5 GHz, China 3.5 GHz). 2023-2025: widespread 5G deployment on 3.5 GHz.

What frequency bands are being studied for 6G?

For the next generation (IMT-2030/6G): WRC-23 agenda item 1.2 studied: 6.425-7.125 GHz (upper 6 GHz): potential for both Wi-Fi and IMT (contentious: Europe favors Wi-Fi, some Asian countries favor IMT). 7.125-8.5 GHz: potential new mid-band for 6G (less congested than current mid-band). 14.8-15.35 GHz: upper mid-band candidate. Sub-THz bands (90-300 GHz): studied for future ultra-high-bandwidth short-range communication. D-band (110-170 GHz) and beyond: potential for 6G backhaul and short-range access. WRC-27 and WRC-31 will likely finalize 6G spectrum allocations. The process continues: each generation requires new spectrum, and the WRC process ensures coordinated global access.

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