航空高度计和5G——最重要的问题

5G and Radio AltimetersCoexistence in 3.3-4.2 GHz October 2025 GSMA The GSMA is a global organisation unifyingthe mobile ecosystem to discover, developand deliver innovation foundational topositive business environments and societalchange. Our vision is to unlock the full powerof connectivity so that people, industryand society thrive. Representing mobileoperators and organisations across themobile ecosystem and adjacent industries,the GSMA delivers for its members acrossthree broad pillars: Connectivity for Good,Industry Services and Solutions andOutreach. This activity includes advancingpolicy, tackling today’s biggest societalchallenges, underpinning the technologyand interoperability that make mobile workand providing the world’s largest platform toconvene the mobile ecosystem at the MWCand M360 series of events. We invite you to find out more atwww.gsma.com Follow the GSMA on Twitter/X: @GSMA Contents Background3 Spectrum aspects5Sharing spectrum65G networks and altimeter spectrum6 Aviation concerns7Background to the debate with aviation8Safe functioning of altimeters8 5G operation and regulation9Tests around the world105G operation and restrictions in the 3.5 GHz range11 Compatibility studies13ECC Report 36214EU roadmap for ensuring safe coexistence between mobile networksand aircraft radio altimeters15Mobile industry considerations15 Today, live 5G networks in over 90 countries are using spectrum in3.3-4.2 GHz (the 3.5 GHz range). More than 60% of 5G networklaunches have used this band so far, adding up to around 260 networksand further auction plans are expected in the years to come.1 The relationship between aircraft altimeters in the 4.2-4.4 GHz band and5G in 3.5 GHz has been closely studied. This has occurred both beforeand after global media reaction to concerns from the aviation industrythat these altimeters could be impacted by 5G networks operatingin the 3.5 GHz range. Since the media storm in late 2021 to early2022, government studies across the world have carried out detailedexamination of the safe operation of the two neighbouring services. Collaboration between the aviation and mobile industries has also beentaking place to reach improvements in radio altimeter equipment tosupport removal of temporary restrictive measures in the limited numberof countries that implemented them. There have been no reported instances of interference from 5G to radioaltimeters. This is further reinforced by the fact that even in high-densityaviation markets such as Europe, Japan, and South Korea, where 5Gbase stations are deployed extremely close to airports, regulators haveconfirmed no harmful interference. The 3.5 GHz range has been under consideration,development and deployment for mobile servicesfor nearly 25 years. It has also been studied at theInternational Telecommunication Union (ITU) and bynational governments during this period and, morerecently, the relationship between altimeters and 5Ghas been intensely scrutinised both nationally and byregional organisations such as CEPT. Coexistence between different radiocommunicationservices is at the foundation of sound radio spectrummanagement to ensure that citizens derive the maximumbenefit from this resource. The 3.5 GHz range is noexception, where the coexistence between 5G networksand aviation in adjacent frequencies is imperative. The 3.5 GHz or ‘5G pioneer band’ was the first used for5G network trials and deployments. The harmonisationof 3.3-3.8 GHz for IMT, carried out over several WorldRadiocommunication Conference (WRC) cycles,was concluded at WRC-23.25G has also been safelyoperating in the upper 3.5 GHz range in spectrumbetween 3.8-4.1 GHz. Spectrum aspects Sharing spectrum 5G is the most spectrum efficient mobile technology todate. It makes use of advanced network technologiessuch as multi-antenna processing, beamforming, activeantenna systems (AAS), massive MIMO, and variousinterference mitigation techniques that in combinationenable very high frequency reuse.4These technologiesdirect signals more precisely, reducing interference intoadjacent areas and bands improving coexistence. 5Gnetworks are engineered with strict out-of-band emissionmasks, helping them operate next to other sensitiveservices like satellite, radio astronomy, broadcast oraircraft altimeters. 5G is an IMT technology and as such the way it usesspectrum is harmonised and coordinated by the ITU.The ITU’s Radio Regulations stipulate how IMT can sharespectrum with other radio systems and define technicaland regulatory conditions for their operation.3 IMT technologies sit adjacent to or near adjacent to,and in some cases share spectrum with, a number ofother services including satellites, Wi-Fi, aeronautical,military, radio astronomy, Earth exploration, deep spaceexploration and other applications and radio services.Ensuring that spectrum is shared in the most efficientmanner helps all users of those services. 5G networks and altimeter spectrum The 3.5 GH