[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["很难理解","hardToUnderstand","thumb-down"],["信息或示例代码不正确","incorrectInformationOrSampleCode","thumb-down"],["没有我需要的信息/示例","missingTheInformationSamplesINeed","thumb-down"],["翻译问题","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC):2025-08-18。"],[],[],null,["# Areas with limited CBRS spectrum\n\nSpectrum Access System (SAS) controls access to the Citizens Broadband Radio Service (CBRS) band\neverywhere in the United States and protects higher-tier users from\ninterference. In certain areas, interference protection requirements might\nlimit the available spectrum. For more information about regions and\nzones, see [Geography and regions](/docs/geography-and-regions).\n\nIn quiet zones\n--------------\n\nSAS rejects registration requests from\nCitizens Broadband Radio Service Devices (CBSDs) located in areas near\n[Federal Communications Commission (FCC)](/spectrum-access-system/docs/key-terms#fcc)\nfield offices and federal government facilities because these locations are\nhighly sensitive to interference. Find a full list of these locations in Section\n8.14 of [WInnForum Document WINNF-TS-0061](https://winnf.memberclicks.net/assets/CBRS/WINNF-TS-0061.pdf).\n\nIf a device is located within the\n[National Radio Quiet Zone (NRQZ)](https://greenbankobservatory.org/about/national-radio-quiet-zone/),\n[confirm the coordination with the NRQZ office](mailto:%20nrqz@gb.nrao.edu) before\nregistration and operation. To confirm successful coordination, a [Certified Professional Installer (CPI)](/spectrum-access-system/docs/key-terms#cpi)\nmust provide the [NRQZ Case ID](/spectrum-access-system/docs/key-terms#nrqz)\nfurnished by the NRQZ office. Learn how to [operate CBSDs in the NRQZ](/spectrum-access-system/docs/cbsd/overview#cbsd-nrqz).\n\nNear the Canadian border\n------------------------\n\n[Arrangement R between the US and Canada](http://transition.fcc.gov/ib/sand/agree/files/can-nb/Arrangement_R.pdf)\nrestricts CBRS operations from 3650 MHz to 3700 MHz.\nWithin 8 km of the border, CBSD power is limited. Between\n8 km and 56 km of the Canadian border, restrictions vary based\non the distance from the border, antenna orientation, and power. For more\ninformation, see paragraph R2-SGN-19 of WInnForum Document\n[WINNF-TS-0112](https://winnf.memberclicks.net/assets/CBRS/WINNF-TS-0112.pdf) and\nSection 8.13.3.2 of WInnForum Document [WINNF-TS-0061](https://winnf.memberclicks.net/assets/CBRS/WINNF-TS-0061.pdf).\n\nOutside the continental US\n--------------------------\n\nDue to their proximity to the ocean, many non-contiguous US locations in Hawaii,\nAlaska, and Guam **except** American Samoa are included in [Dynamic Protection Area (DPA)](/spectrum-access-system/docs/key-terms#dpa)\nneighborhoods. There is no [Environmental Sensing Capability (ESC)](/spectrum-access-system/docs/key-terms#esc)\nnetwork to protect these DPAs, so spectrum availability from 3550 MHz to\n3650 MHz is restricted. American Samoa has access to the full CBRS spectrum\n| **Important:** Google does not have immediate plans to deploy ESC devices outside of the contiguous US. We constantly evaluate ESC deployments based on customer needs.\n\nSpectrum is usually available from 3650 MHz to 3700 MHz in Puerto Rico,\nHawaii, Alaska, and Guam.\n\n**American Samoa, US Virgin Islands, and Northern Mariana Islands.** SAS\nis not authorized to provide CBRS service in American Samoa, the\nUS Virgin Islands, and the Northern Mariana Islands per [PNDA-20-110A1](https://docs.fcc.gov/public/attachments/DA-20-110A1.pdf).\nAs a result, registration requests from CBSDs are rejected.\nOperators with an experimental license (STA) in these areas can contact\n[SAS Support](/spectrum-access-system/docs/getting-support).\n\nNear the Mexican border\n-----------------------\n\nThere are no additional restrictions on CBRS operations near the\nUS border with Mexico."]]